| /* |
| * linux/fs/ext4/inode.c |
| * |
| * Copyright (C) 1992, 1993, 1994, 1995 |
| * Remy Card (card@masi.ibp.fr) |
| * Laboratoire MASI - Institut Blaise Pascal |
| * Universite Pierre et Marie Curie (Paris VI) |
| * |
| * from |
| * |
| * linux/fs/minix/inode.c |
| * |
| * Copyright (C) 1991, 1992 Linus Torvalds |
| * |
| * Goal-directed block allocation by Stephen Tweedie |
| * (sct@redhat.com), 1993, 1998 |
| * Big-endian to little-endian byte-swapping/bitmaps by |
| * David S. Miller (davem@caip.rutgers.edu), 1995 |
| * 64-bit file support on 64-bit platforms by Jakub Jelinek |
| * (jj@sunsite.ms.mff.cuni.cz) |
| * |
| * Assorted race fixes, rewrite of ext4_get_block() by Al Viro, 2000 |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/fs.h> |
| #include <linux/time.h> |
| #include <linux/jbd2.h> |
| #include <linux/highuid.h> |
| #include <linux/pagemap.h> |
| #include <linux/quotaops.h> |
| #include <linux/string.h> |
| #include <linux/buffer_head.h> |
| #include <linux/writeback.h> |
| #include <linux/pagevec.h> |
| #include <linux/mpage.h> |
| #include <linux/namei.h> |
| #include <linux/uio.h> |
| #include <linux/bio.h> |
| #include "ext4_jbd2.h" |
| #include "xattr.h" |
| #include "acl.h" |
| #include "ext4_extents.h" |
| |
| #define MPAGE_DA_EXTENT_TAIL 0x01 |
| |
| static inline int ext4_begin_ordered_truncate(struct inode *inode, |
| loff_t new_size) |
| { |
| return jbd2_journal_begin_ordered_truncate( |
| EXT4_SB(inode->i_sb)->s_journal, |
| &EXT4_I(inode)->jinode, |
| new_size); |
| } |
| |
| static void ext4_invalidatepage(struct page *page, unsigned long offset); |
| |
| /* |
| * Test whether an inode is a fast symlink. |
| */ |
| static int ext4_inode_is_fast_symlink(struct inode *inode) |
| { |
| int ea_blocks = EXT4_I(inode)->i_file_acl ? |
| (inode->i_sb->s_blocksize >> 9) : 0; |
| |
| return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0); |
| } |
| |
| /* |
| * The ext4 forget function must perform a revoke if we are freeing data |
| * which has been journaled. Metadata (eg. indirect blocks) must be |
| * revoked in all cases. |
| * |
| * "bh" may be NULL: a metadata block may have been freed from memory |
| * but there may still be a record of it in the journal, and that record |
| * still needs to be revoked. |
| * |
| * If the handle isn't valid we're not journaling so there's nothing to do. |
| */ |
| int ext4_forget(handle_t *handle, int is_metadata, struct inode *inode, |
| struct buffer_head *bh, ext4_fsblk_t blocknr) |
| { |
| int err; |
| |
| if (!ext4_handle_valid(handle)) |
| return 0; |
| |
| might_sleep(); |
| |
| BUFFER_TRACE(bh, "enter"); |
| |
| jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, " |
| "data mode %lx\n", |
| bh, is_metadata, inode->i_mode, |
| test_opt(inode->i_sb, DATA_FLAGS)); |
| |
| /* Never use the revoke function if we are doing full data |
| * journaling: there is no need to, and a V1 superblock won't |
| * support it. Otherwise, only skip the revoke on un-journaled |
| * data blocks. */ |
| |
| if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA || |
| (!is_metadata && !ext4_should_journal_data(inode))) { |
| if (bh) { |
| BUFFER_TRACE(bh, "call jbd2_journal_forget"); |
| return ext4_journal_forget(handle, bh); |
| } |
| return 0; |
| } |
| |
| /* |
| * data!=journal && (is_metadata || should_journal_data(inode)) |
| */ |
| BUFFER_TRACE(bh, "call ext4_journal_revoke"); |
| err = ext4_journal_revoke(handle, blocknr, bh); |
| if (err) |
| ext4_abort(inode->i_sb, __func__, |
| "error %d when attempting revoke", err); |
| BUFFER_TRACE(bh, "exit"); |
| return err; |
| } |
| |
| /* |
| * Work out how many blocks we need to proceed with the next chunk of a |
| * truncate transaction. |
| */ |
| static unsigned long blocks_for_truncate(struct inode *inode) |
| { |
| ext4_lblk_t needed; |
| |
| needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9); |
| |
| /* Give ourselves just enough room to cope with inodes in which |
| * i_blocks is corrupt: we've seen disk corruptions in the past |
| * which resulted in random data in an inode which looked enough |
| * like a regular file for ext4 to try to delete it. Things |
| * will go a bit crazy if that happens, but at least we should |
| * try not to panic the whole kernel. */ |
| if (needed < 2) |
| needed = 2; |
| |
| /* But we need to bound the transaction so we don't overflow the |
| * journal. */ |
| if (needed > EXT4_MAX_TRANS_DATA) |
| needed = EXT4_MAX_TRANS_DATA; |
| |
| return EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + needed; |
| } |
| |
| /* |
| * Truncate transactions can be complex and absolutely huge. So we need to |
| * be able to restart the transaction at a conventient checkpoint to make |
| * sure we don't overflow the journal. |
| * |
| * start_transaction gets us a new handle for a truncate transaction, |
| * and extend_transaction tries to extend the existing one a bit. If |
| * extend fails, we need to propagate the failure up and restart the |
| * transaction in the top-level truncate loop. --sct |
| */ |
| static handle_t *start_transaction(struct inode *inode) |
| { |
| handle_t *result; |
| |
| result = ext4_journal_start(inode, blocks_for_truncate(inode)); |
| if (!IS_ERR(result)) |
| return result; |
| |
| ext4_std_error(inode->i_sb, PTR_ERR(result)); |
| return result; |
| } |
| |
| /* |
| * Try to extend this transaction for the purposes of truncation. |
| * |
| * Returns 0 if we managed to create more room. If we can't create more |
| * room, and the transaction must be restarted we return 1. |
| */ |
| static int try_to_extend_transaction(handle_t *handle, struct inode *inode) |
| { |
| if (!ext4_handle_valid(handle)) |
| return 0; |
| if (ext4_handle_has_enough_credits(handle, EXT4_RESERVE_TRANS_BLOCKS+1)) |
| return 0; |
| if (!ext4_journal_extend(handle, blocks_for_truncate(inode))) |
| return 0; |
| return 1; |
| } |
| |
| /* |
| * Restart the transaction associated with *handle. This does a commit, |
| * so before we call here everything must be consistently dirtied against |
| * this transaction. |
| */ |
| static int ext4_journal_test_restart(handle_t *handle, struct inode *inode) |
| { |
| BUG_ON(EXT4_JOURNAL(inode) == NULL); |
| jbd_debug(2, "restarting handle %p\n", handle); |
| return ext4_journal_restart(handle, blocks_for_truncate(inode)); |
| } |
| |
| /* |
| * Called at the last iput() if i_nlink is zero. |
| */ |
| void ext4_delete_inode(struct inode *inode) |
| { |
| handle_t *handle; |
| int err; |
| |
| if (ext4_should_order_data(inode)) |
| ext4_begin_ordered_truncate(inode, 0); |
| truncate_inode_pages(&inode->i_data, 0); |
| |
| if (is_bad_inode(inode)) |
| goto no_delete; |
| |
| handle = ext4_journal_start(inode, blocks_for_truncate(inode)+3); |
| if (IS_ERR(handle)) { |
| ext4_std_error(inode->i_sb, PTR_ERR(handle)); |
| /* |
| * If we're going to skip the normal cleanup, we still need to |
| * make sure that the in-core orphan linked list is properly |
| * cleaned up. |
| */ |
| ext4_orphan_del(NULL, inode); |
| goto no_delete; |
| } |
| |
| if (IS_SYNC(inode)) |
| ext4_handle_sync(handle); |
| inode->i_size = 0; |
| err = ext4_mark_inode_dirty(handle, inode); |
| if (err) { |
| ext4_warning(inode->i_sb, __func__, |
| "couldn't mark inode dirty (err %d)", err); |
| goto stop_handle; |
| } |
| if (inode->i_blocks) |
| ext4_truncate(inode); |
| |
| /* |
| * ext4_ext_truncate() doesn't reserve any slop when it |
| * restarts journal transactions; therefore there may not be |
| * enough credits left in the handle to remove the inode from |
| * the orphan list and set the dtime field. |
| */ |
| if (!ext4_handle_has_enough_credits(handle, 3)) { |
| err = ext4_journal_extend(handle, 3); |
| if (err > 0) |
| err = ext4_journal_restart(handle, 3); |
| if (err != 0) { |
| ext4_warning(inode->i_sb, __func__, |
| "couldn't extend journal (err %d)", err); |
| stop_handle: |
| ext4_journal_stop(handle); |
| goto no_delete; |
| } |
| } |
| |
| /* |
| * Kill off the orphan record which ext4_truncate created. |
| * AKPM: I think this can be inside the above `if'. |
| * Note that ext4_orphan_del() has to be able to cope with the |
| * deletion of a non-existent orphan - this is because we don't |
| * know if ext4_truncate() actually created an orphan record. |
| * (Well, we could do this if we need to, but heck - it works) |
| */ |
| ext4_orphan_del(handle, inode); |
| EXT4_I(inode)->i_dtime = get_seconds(); |
| |
| /* |
| * One subtle ordering requirement: if anything has gone wrong |
| * (transaction abort, IO errors, whatever), then we can still |
| * do these next steps (the fs will already have been marked as |
| * having errors), but we can't free the inode if the mark_dirty |
| * fails. |
| */ |
| if (ext4_mark_inode_dirty(handle, inode)) |
| /* If that failed, just do the required in-core inode clear. */ |
| clear_inode(inode); |
| else |
| ext4_free_inode(handle, inode); |
| ext4_journal_stop(handle); |
| return; |
| no_delete: |
| clear_inode(inode); /* We must guarantee clearing of inode... */ |
| } |
| |
| typedef struct { |
| __le32 *p; |
| __le32 key; |
| struct buffer_head *bh; |
| } Indirect; |
| |
| static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) |
| { |
| p->key = *(p->p = v); |
| p->bh = bh; |
| } |
| |
| /** |
| * ext4_block_to_path - parse the block number into array of offsets |
| * @inode: inode in question (we are only interested in its superblock) |
| * @i_block: block number to be parsed |
| * @offsets: array to store the offsets in |
| * @boundary: set this non-zero if the referred-to block is likely to be |
| * followed (on disk) by an indirect block. |
| * |
| * To store the locations of file's data ext4 uses a data structure common |
| * for UNIX filesystems - tree of pointers anchored in the inode, with |
| * data blocks at leaves and indirect blocks in intermediate nodes. |
| * This function translates the block number into path in that tree - |
| * return value is the path length and @offsets[n] is the offset of |
| * pointer to (n+1)th node in the nth one. If @block is out of range |
| * (negative or too large) warning is printed and zero returned. |
| * |
| * Note: function doesn't find node addresses, so no IO is needed. All |
| * we need to know is the capacity of indirect blocks (taken from the |
| * inode->i_sb). |
| */ |
| |
| /* |
| * Portability note: the last comparison (check that we fit into triple |
| * indirect block) is spelled differently, because otherwise on an |
| * architecture with 32-bit longs and 8Kb pages we might get into trouble |
| * if our filesystem had 8Kb blocks. We might use long long, but that would |
| * kill us on x86. Oh, well, at least the sign propagation does not matter - |
| * i_block would have to be negative in the very beginning, so we would not |
| * get there at all. |
| */ |
| |
| static int ext4_block_to_path(struct inode *inode, |
| ext4_lblk_t i_block, |
| ext4_lblk_t offsets[4], int *boundary) |
| { |
| int ptrs = EXT4_ADDR_PER_BLOCK(inode->i_sb); |
| int ptrs_bits = EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb); |
| const long direct_blocks = EXT4_NDIR_BLOCKS, |
| indirect_blocks = ptrs, |
| double_blocks = (1 << (ptrs_bits * 2)); |
| int n = 0; |
| int final = 0; |
| |
| if (i_block < 0) { |
| ext4_warning(inode->i_sb, "ext4_block_to_path", "block < 0"); |
| } else if (i_block < direct_blocks) { |
| offsets[n++] = i_block; |
| final = direct_blocks; |
| } else if ((i_block -= direct_blocks) < indirect_blocks) { |
| offsets[n++] = EXT4_IND_BLOCK; |
| offsets[n++] = i_block; |
| final = ptrs; |
| } else if ((i_block -= indirect_blocks) < double_blocks) { |
| offsets[n++] = EXT4_DIND_BLOCK; |
| offsets[n++] = i_block >> ptrs_bits; |
| offsets[n++] = i_block & (ptrs - 1); |
| final = ptrs; |
| } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { |
| offsets[n++] = EXT4_TIND_BLOCK; |
| offsets[n++] = i_block >> (ptrs_bits * 2); |
| offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); |
| offsets[n++] = i_block & (ptrs - 1); |
| final = ptrs; |
| } else { |
| ext4_warning(inode->i_sb, "ext4_block_to_path", |
| "block %lu > max in inode %lu", |
| i_block + direct_blocks + |
| indirect_blocks + double_blocks, inode->i_ino); |
| } |
| if (boundary) |
| *boundary = final - 1 - (i_block & (ptrs - 1)); |
| return n; |
| } |
| |
| /** |
| * ext4_get_branch - read the chain of indirect blocks leading to data |
| * @inode: inode in question |
| * @depth: depth of the chain (1 - direct pointer, etc.) |
| * @offsets: offsets of pointers in inode/indirect blocks |
| * @chain: place to store the result |
| * @err: here we store the error value |
| * |
| * Function fills the array of triples <key, p, bh> and returns %NULL |
| * if everything went OK or the pointer to the last filled triple |
| * (incomplete one) otherwise. Upon the return chain[i].key contains |
| * the number of (i+1)-th block in the chain (as it is stored in memory, |
| * i.e. little-endian 32-bit), chain[i].p contains the address of that |
| * number (it points into struct inode for i==0 and into the bh->b_data |
| * for i>0) and chain[i].bh points to the buffer_head of i-th indirect |
| * block for i>0 and NULL for i==0. In other words, it holds the block |
| * numbers of the chain, addresses they were taken from (and where we can |
| * verify that chain did not change) and buffer_heads hosting these |
| * numbers. |
| * |
| * Function stops when it stumbles upon zero pointer (absent block) |
| * (pointer to last triple returned, *@err == 0) |
| * or when it gets an IO error reading an indirect block |
| * (ditto, *@err == -EIO) |
| * or when it reads all @depth-1 indirect blocks successfully and finds |
| * the whole chain, all way to the data (returns %NULL, *err == 0). |
| * |
| * Need to be called with |
| * down_read(&EXT4_I(inode)->i_data_sem) |
| */ |
| static Indirect *ext4_get_branch(struct inode *inode, int depth, |
| ext4_lblk_t *offsets, |
| Indirect chain[4], int *err) |
| { |
| struct super_block *sb = inode->i_sb; |
| Indirect *p = chain; |
| struct buffer_head *bh; |
| |
| *err = 0; |
| /* i_data is not going away, no lock needed */ |
| add_chain(chain, NULL, EXT4_I(inode)->i_data + *offsets); |
| if (!p->key) |
| goto no_block; |
| while (--depth) { |
| bh = sb_bread(sb, le32_to_cpu(p->key)); |
| if (!bh) |
| goto failure; |
| add_chain(++p, bh, (__le32 *)bh->b_data + *++offsets); |
| /* Reader: end */ |
| if (!p->key) |
| goto no_block; |
| } |
| return NULL; |
| |
| failure: |
| *err = -EIO; |
| no_block: |
| return p; |
| } |
| |
| /** |
| * ext4_find_near - find a place for allocation with sufficient locality |
| * @inode: owner |
| * @ind: descriptor of indirect block. |
| * |
| * This function returns the preferred place for block allocation. |
| * It is used when heuristic for sequential allocation fails. |
| * Rules are: |
| * + if there is a block to the left of our position - allocate near it. |
| * + if pointer will live in indirect block - allocate near that block. |
| * + if pointer will live in inode - allocate in the same |
| * cylinder group. |
| * |
| * In the latter case we colour the starting block by the callers PID to |
| * prevent it from clashing with concurrent allocations for a different inode |
| * in the same block group. The PID is used here so that functionally related |
| * files will be close-by on-disk. |
| * |
| * Caller must make sure that @ind is valid and will stay that way. |
| */ |
| static ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind) |
| { |
| struct ext4_inode_info *ei = EXT4_I(inode); |
| __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data; |
| __le32 *p; |
| ext4_fsblk_t bg_start; |
| ext4_fsblk_t last_block; |
| ext4_grpblk_t colour; |
| |
| /* Try to find previous block */ |
| for (p = ind->p - 1; p >= start; p--) { |
| if (*p) |
| return le32_to_cpu(*p); |
| } |
| |
| /* No such thing, so let's try location of indirect block */ |
| if (ind->bh) |
| return ind->bh->b_blocknr; |
| |
| /* |
| * It is going to be referred to from the inode itself? OK, just put it |
| * into the same cylinder group then. |
| */ |
| bg_start = ext4_group_first_block_no(inode->i_sb, ei->i_block_group); |
| last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1; |
| |
| if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block) |
| colour = (current->pid % 16) * |
| (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16); |
| else |
| colour = (current->pid % 16) * ((last_block - bg_start) / 16); |
| return bg_start + colour; |
| } |
| |
| /** |
| * ext4_find_goal - find a preferred place for allocation. |
| * @inode: owner |
| * @block: block we want |
| * @partial: pointer to the last triple within a chain |
| * |
| * Normally this function find the preferred place for block allocation, |
| * returns it. |
| */ |
| static ext4_fsblk_t ext4_find_goal(struct inode *inode, ext4_lblk_t block, |
| Indirect *partial) |
| { |
| /* |
| * XXX need to get goal block from mballoc's data structures |
| */ |
| |
| return ext4_find_near(inode, partial); |
| } |
| |
| /** |
| * ext4_blks_to_allocate: Look up the block map and count the number |
| * of direct blocks need to be allocated for the given branch. |
| * |
| * @branch: chain of indirect blocks |
| * @k: number of blocks need for indirect blocks |
| * @blks: number of data blocks to be mapped. |
| * @blocks_to_boundary: the offset in the indirect block |
| * |
| * return the total number of blocks to be allocate, including the |
| * direct and indirect blocks. |
| */ |
| static int ext4_blks_to_allocate(Indirect *branch, int k, unsigned int blks, |
| int blocks_to_boundary) |
| { |
| unsigned int count = 0; |
| |
| /* |
| * Simple case, [t,d]Indirect block(s) has not allocated yet |
| * then it's clear blocks on that path have not allocated |
| */ |
| if (k > 0) { |
| /* right now we don't handle cross boundary allocation */ |
| if (blks < blocks_to_boundary + 1) |
| count += blks; |
| else |
| count += blocks_to_boundary + 1; |
| return count; |
| } |
| |
| count++; |
| while (count < blks && count <= blocks_to_boundary && |
| le32_to_cpu(*(branch[0].p + count)) == 0) { |
| count++; |
| } |
| return count; |
| } |
| |
| /** |
| * ext4_alloc_blocks: multiple allocate blocks needed for a branch |
| * @indirect_blks: the number of blocks need to allocate for indirect |
| * blocks |
| * |
| * @new_blocks: on return it will store the new block numbers for |
| * the indirect blocks(if needed) and the first direct block, |
| * @blks: on return it will store the total number of allocated |
| * direct blocks |
| */ |
| static int ext4_alloc_blocks(handle_t *handle, struct inode *inode, |
| ext4_lblk_t iblock, ext4_fsblk_t goal, |
| int indirect_blks, int blks, |
| ext4_fsblk_t new_blocks[4], int *err) |
| { |
| struct ext4_allocation_request ar; |
| int target, i; |
| unsigned long count = 0, blk_allocated = 0; |
| int index = 0; |
| ext4_fsblk_t current_block = 0; |
| int ret = 0; |
| |
| /* |
| * Here we try to allocate the requested multiple blocks at once, |
| * on a best-effort basis. |
| * To build a branch, we should allocate blocks for |
| * the indirect blocks(if not allocated yet), and at least |
| * the first direct block of this branch. That's the |
| * minimum number of blocks need to allocate(required) |
| */ |
| /* first we try to allocate the indirect blocks */ |
| target = indirect_blks; |
| while (target > 0) { |
| count = target; |
| /* allocating blocks for indirect blocks and direct blocks */ |
| current_block = ext4_new_meta_blocks(handle, inode, |
| goal, &count, err); |
| if (*err) |
| goto failed_out; |
| |
| target -= count; |
| /* allocate blocks for indirect blocks */ |
| while (index < indirect_blks && count) { |
| new_blocks[index++] = current_block++; |
| count--; |
| } |
| if (count > 0) { |
| /* |
| * save the new block number |
| * for the first direct block |
| */ |
| new_blocks[index] = current_block; |
| printk(KERN_INFO "%s returned more blocks than " |
| "requested\n", __func__); |
| WARN_ON(1); |
| break; |
| } |
| } |
| |
| target = blks - count ; |
| blk_allocated = count; |
| if (!target) |
| goto allocated; |
| /* Now allocate data blocks */ |
| memset(&ar, 0, sizeof(ar)); |
| ar.inode = inode; |
| ar.goal = goal; |
| ar.len = target; |
| ar.logical = iblock; |
| if (S_ISREG(inode->i_mode)) |
| /* enable in-core preallocation only for regular files */ |
| ar.flags = EXT4_MB_HINT_DATA; |
| |
| current_block = ext4_mb_new_blocks(handle, &ar, err); |
| |
| if (*err && (target == blks)) { |
| /* |
| * if the allocation failed and we didn't allocate |
| * any blocks before |
| */ |
| goto failed_out; |
| } |
| if (!*err) { |
| if (target == blks) { |
| /* |
| * save the new block number |
| * for the first direct block |
| */ |
| new_blocks[index] = current_block; |
| } |
| blk_allocated += ar.len; |
| } |
| allocated: |
| /* total number of blocks allocated for direct blocks */ |
| ret = blk_allocated; |
| *err = 0; |
| return ret; |
| failed_out: |
| for (i = 0; i < index; i++) |
| ext4_free_blocks(handle, inode, new_blocks[i], 1, 0); |
| return ret; |
| } |
| |
| /** |
| * ext4_alloc_branch - allocate and set up a chain of blocks. |
| * @inode: owner |
| * @indirect_blks: number of allocated indirect blocks |
| * @blks: number of allocated direct blocks |
| * @offsets: offsets (in the blocks) to store the pointers to next. |
| * @branch: place to store the chain in. |
| * |
| * This function allocates blocks, zeroes out all but the last one, |
| * links them into chain and (if we are synchronous) writes them to disk. |
| * In other words, it prepares a branch that can be spliced onto the |
| * inode. It stores the information about that chain in the branch[], in |
| * the same format as ext4_get_branch() would do. We are calling it after |
| * we had read the existing part of chain and partial points to the last |
| * triple of that (one with zero ->key). Upon the exit we have the same |
| * picture as after the successful ext4_get_block(), except that in one |
| * place chain is disconnected - *branch->p is still zero (we did not |
| * set the last link), but branch->key contains the number that should |
| * be placed into *branch->p to fill that gap. |
| * |
| * If allocation fails we free all blocks we've allocated (and forget |
| * their buffer_heads) and return the error value the from failed |
| * ext4_alloc_block() (normally -ENOSPC). Otherwise we set the chain |
| * as described above and return 0. |
| */ |
| static int ext4_alloc_branch(handle_t *handle, struct inode *inode, |
| ext4_lblk_t iblock, int indirect_blks, |
| int *blks, ext4_fsblk_t goal, |
| ext4_lblk_t *offsets, Indirect *branch) |
| { |
| int blocksize = inode->i_sb->s_blocksize; |
| int i, n = 0; |
| int err = 0; |
| struct buffer_head *bh; |
| int num; |
| ext4_fsblk_t new_blocks[4]; |
| ext4_fsblk_t current_block; |
| |
| num = ext4_alloc_blocks(handle, inode, iblock, goal, indirect_blks, |
| *blks, new_blocks, &err); |
| if (err) |
| return err; |
| |
| branch[0].key = cpu_to_le32(new_blocks[0]); |
| /* |
| * metadata blocks and data blocks are allocated. |
| */ |
| for (n = 1; n <= indirect_blks; n++) { |
| /* |
| * Get buffer_head for parent block, zero it out |
| * and set the pointer to new one, then send |
| * parent to disk. |
| */ |
| bh = sb_getblk(inode->i_sb, new_blocks[n-1]); |
| branch[n].bh = bh; |
| lock_buffer(bh); |
| BUFFER_TRACE(bh, "call get_create_access"); |
| err = ext4_journal_get_create_access(handle, bh); |
| if (err) { |
| unlock_buffer(bh); |
| brelse(bh); |
| goto failed; |
| } |
| |
| memset(bh->b_data, 0, blocksize); |
| branch[n].p = (__le32 *) bh->b_data + offsets[n]; |
| branch[n].key = cpu_to_le32(new_blocks[n]); |
| *branch[n].p = branch[n].key; |
| if (n == indirect_blks) { |
| current_block = new_blocks[n]; |
| /* |
| * End of chain, update the last new metablock of |
| * the chain to point to the new allocated |
| * data blocks numbers |
| */ |
| for (i=1; i < num; i++) |
| *(branch[n].p + i) = cpu_to_le32(++current_block); |
| } |
| BUFFER_TRACE(bh, "marking uptodate"); |
| set_buffer_uptodate(bh); |
| unlock_buffer(bh); |
| |
| BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); |
| err = ext4_handle_dirty_metadata(handle, inode, bh); |
| if (err) |
| goto failed; |
| } |
| *blks = num; |
| return err; |
| failed: |
| /* Allocation failed, free what we already allocated */ |
| for (i = 1; i <= n ; i++) { |
| BUFFER_TRACE(branch[i].bh, "call jbd2_journal_forget"); |
| ext4_journal_forget(handle, branch[i].bh); |
| } |
| for (i = 0; i < indirect_blks; i++) |
| ext4_free_blocks(handle, inode, new_blocks[i], 1, 0); |
| |
| ext4_free_blocks(handle, inode, new_blocks[i], num, 0); |
| |
| return err; |
| } |
| |
| /** |
| * ext4_splice_branch - splice the allocated branch onto inode. |
| * @inode: owner |
| * @block: (logical) number of block we are adding |
| * @chain: chain of indirect blocks (with a missing link - see |
| * ext4_alloc_branch) |
| * @where: location of missing link |
| * @num: number of indirect blocks we are adding |
| * @blks: number of direct blocks we are adding |
| * |
| * This function fills the missing link and does all housekeeping needed in |
| * inode (->i_blocks, etc.). In case of success we end up with the full |
| * chain to new block and return 0. |
| */ |
| static int ext4_splice_branch(handle_t *handle, struct inode *inode, |
| ext4_lblk_t block, Indirect *where, int num, int blks) |
| { |
| int i; |
| int err = 0; |
| ext4_fsblk_t current_block; |
| |
| /* |
| * If we're splicing into a [td]indirect block (as opposed to the |
| * inode) then we need to get write access to the [td]indirect block |
| * before the splice. |
| */ |
| if (where->bh) { |
| BUFFER_TRACE(where->bh, "get_write_access"); |
| err = ext4_journal_get_write_access(handle, where->bh); |
| if (err) |
| goto err_out; |
| } |
| /* That's it */ |
| |
| *where->p = where->key; |
| |
| /* |
| * Update the host buffer_head or inode to point to more just allocated |
| * direct blocks blocks |
| */ |
| if (num == 0 && blks > 1) { |
| current_block = le32_to_cpu(where->key) + 1; |
| for (i = 1; i < blks; i++) |
| *(where->p + i) = cpu_to_le32(current_block++); |
| } |
| |
| /* We are done with atomic stuff, now do the rest of housekeeping */ |
| |
| inode->i_ctime = ext4_current_time(inode); |
| ext4_mark_inode_dirty(handle, inode); |
| |
| /* had we spliced it onto indirect block? */ |
| if (where->bh) { |
| /* |
| * If we spliced it onto an indirect block, we haven't |
| * altered the inode. Note however that if it is being spliced |
| * onto an indirect block at the very end of the file (the |
| * file is growing) then we *will* alter the inode to reflect |
| * the new i_size. But that is not done here - it is done in |
| * generic_commit_write->__mark_inode_dirty->ext4_dirty_inode. |
| */ |
| jbd_debug(5, "splicing indirect only\n"); |
| BUFFER_TRACE(where->bh, "call ext4_handle_dirty_metadata"); |
| err = ext4_handle_dirty_metadata(handle, inode, where->bh); |
| if (err) |
| goto err_out; |
| } else { |
| /* |
| * OK, we spliced it into the inode itself on a direct block. |
| * Inode was dirtied above. |
| */ |
| jbd_debug(5, "splicing direct\n"); |
| } |
| return err; |
| |
| err_out: |
| for (i = 1; i <= num; i++) { |
| BUFFER_TRACE(where[i].bh, "call jbd2_journal_forget"); |
| ext4_journal_forget(handle, where[i].bh); |
| ext4_free_blocks(handle, inode, |
| le32_to_cpu(where[i-1].key), 1, 0); |
| } |
| ext4_free_blocks(handle, inode, le32_to_cpu(where[num].key), blks, 0); |
| |
| return err; |
| } |
| |
| /* |
| * Allocation strategy is simple: if we have to allocate something, we will |
| * have to go the whole way to leaf. So let's do it before attaching anything |
| * to tree, set linkage between the newborn blocks, write them if sync is |
| * required, recheck the path, free and repeat if check fails, otherwise |
| * set the last missing link (that will protect us from any truncate-generated |
| * removals - all blocks on the path are immune now) and possibly force the |
| * write on the parent block. |
| * That has a nice additional property: no special recovery from the failed |
| * allocations is needed - we simply release blocks and do not touch anything |
| * reachable from inode. |
| * |
| * `handle' can be NULL if create == 0. |
| * |
| * return > 0, # of blocks mapped or allocated. |
| * return = 0, if plain lookup failed. |
| * return < 0, error case. |
| * |
| * |
| * Need to be called with |
| * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block |
| * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem) |
| */ |
| static int ext4_get_blocks_handle(handle_t *handle, struct inode *inode, |
| ext4_lblk_t iblock, unsigned int maxblocks, |
| struct buffer_head *bh_result, |
| int create, int extend_disksize) |
| { |
| int err = -EIO; |
| ext4_lblk_t offsets[4]; |
| Indirect chain[4]; |
| Indirect *partial; |
| ext4_fsblk_t goal; |
| int indirect_blks; |
| int blocks_to_boundary = 0; |
| int depth; |
| struct ext4_inode_info *ei = EXT4_I(inode); |
| int count = 0; |
| ext4_fsblk_t first_block = 0; |
| loff_t disksize; |
| |
| |
| J_ASSERT(!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)); |
| J_ASSERT(handle != NULL || create == 0); |
| depth = ext4_block_to_path(inode, iblock, offsets, |
| &blocks_to_boundary); |
| |
| if (depth == 0) |
| goto out; |
| |
| partial = ext4_get_branch(inode, depth, offsets, chain, &err); |
| |
| /* Simplest case - block found, no allocation needed */ |
| if (!partial) { |
| first_block = le32_to_cpu(chain[depth - 1].key); |
| clear_buffer_new(bh_result); |
| count++; |
| /*map more blocks*/ |
| while (count < maxblocks && count <= blocks_to_boundary) { |
| ext4_fsblk_t blk; |
| |
| blk = le32_to_cpu(*(chain[depth-1].p + count)); |
| |
| if (blk == first_block + count) |
| count++; |
| else |
| break; |
| } |
| goto got_it; |
| } |
| |
| /* Next simple case - plain lookup or failed read of indirect block */ |
| if (!create || err == -EIO) |
| goto cleanup; |
| |
| /* |
| * Okay, we need to do block allocation. |
| */ |
| goal = ext4_find_goal(inode, iblock, partial); |
| |
| /* the number of blocks need to allocate for [d,t]indirect blocks */ |
| indirect_blks = (chain + depth) - partial - 1; |
| |
| /* |
| * Next look up the indirect map to count the totoal number of |
| * direct blocks to allocate for this branch. |
| */ |
| count = ext4_blks_to_allocate(partial, indirect_blks, |
| maxblocks, blocks_to_boundary); |
| /* |
| * Block out ext4_truncate while we alter the tree |
| */ |
| err = ext4_alloc_branch(handle, inode, iblock, indirect_blks, |
| &count, goal, |
| offsets + (partial - chain), partial); |
| |
| /* |
| * The ext4_splice_branch call will free and forget any buffers |
| * on the new chain if there is a failure, but that risks using |
| * up transaction credits, especially for bitmaps where the |
| * credits cannot be returned. Can we handle this somehow? We |
| * may need to return -EAGAIN upwards in the worst case. --sct |
| */ |
| if (!err) |
| err = ext4_splice_branch(handle, inode, iblock, |
| partial, indirect_blks, count); |
| /* |
| * i_disksize growing is protected by i_data_sem. Don't forget to |
| * protect it if you're about to implement concurrent |
| * ext4_get_block() -bzzz |
| */ |
| if (!err && extend_disksize) { |
| disksize = ((loff_t) iblock + count) << inode->i_blkbits; |
| if (disksize > i_size_read(inode)) |
| disksize = i_size_read(inode); |
| if (disksize > ei->i_disksize) |
| ei->i_disksize = disksize; |
| } |
| if (err) |
| goto cleanup; |
| |
| set_buffer_new(bh_result); |
| got_it: |
| map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); |
| if (count > blocks_to_boundary) |
| set_buffer_boundary(bh_result); |
| err = count; |
| /* Clean up and exit */ |
| partial = chain + depth - 1; /* the whole chain */ |
| cleanup: |
| while (partial > chain) { |
| BUFFER_TRACE(partial->bh, "call brelse"); |
| brelse(partial->bh); |
| partial--; |
| } |
| BUFFER_TRACE(bh_result, "returned"); |
| out: |
| return err; |
| } |
| |
| /* |
| * Calculate the number of metadata blocks need to reserve |
| * to allocate @blocks for non extent file based file |
| */ |
| static int ext4_indirect_calc_metadata_amount(struct inode *inode, int blocks) |
| { |
| int icap = EXT4_ADDR_PER_BLOCK(inode->i_sb); |
| int ind_blks, dind_blks, tind_blks; |
| |
| /* number of new indirect blocks needed */ |
| ind_blks = (blocks + icap - 1) / icap; |
| |
| dind_blks = (ind_blks + icap - 1) / icap; |
| |
| tind_blks = 1; |
| |
| return ind_blks + dind_blks + tind_blks; |
| } |
| |
| /* |
| * Calculate the number of metadata blocks need to reserve |
| * to allocate given number of blocks |
| */ |
| static int ext4_calc_metadata_amount(struct inode *inode, int blocks) |
| { |
| if (!blocks) |
| return 0; |
| |
| if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) |
| return ext4_ext_calc_metadata_amount(inode, blocks); |
| |
| return ext4_indirect_calc_metadata_amount(inode, blocks); |
| } |
| |
| static void ext4_da_update_reserve_space(struct inode *inode, int used) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| int total, mdb, mdb_free; |
| |
| spin_lock(&EXT4_I(inode)->i_block_reservation_lock); |
| /* recalculate the number of metablocks still need to be reserved */ |
| total = EXT4_I(inode)->i_reserved_data_blocks - used; |
| mdb = ext4_calc_metadata_amount(inode, total); |
| |
| /* figure out how many metablocks to release */ |
| BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks); |
| mdb_free = EXT4_I(inode)->i_reserved_meta_blocks - mdb; |
| |
| if (mdb_free) { |
| /* Account for allocated meta_blocks */ |
| mdb_free -= EXT4_I(inode)->i_allocated_meta_blocks; |
| |
| /* update fs dirty blocks counter */ |
| percpu_counter_sub(&sbi->s_dirtyblocks_counter, mdb_free); |
| EXT4_I(inode)->i_allocated_meta_blocks = 0; |
| EXT4_I(inode)->i_reserved_meta_blocks = mdb; |
| } |
| |
| /* update per-inode reservations */ |
| BUG_ON(used > EXT4_I(inode)->i_reserved_data_blocks); |
| EXT4_I(inode)->i_reserved_data_blocks -= used; |
| |
| spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); |
| } |
| |
| /* |
| * The ext4_get_blocks_wrap() function try to look up the requested blocks, |
| * and returns if the blocks are already mapped. |
| * |
| * Otherwise it takes the write lock of the i_data_sem and allocate blocks |
| * and store the allocated blocks in the result buffer head and mark it |
| * mapped. |
| * |
| * If file type is extents based, it will call ext4_ext_get_blocks(), |
| * Otherwise, call with ext4_get_blocks_handle() to handle indirect mapping |
| * based files |
| * |
| * On success, it returns the number of blocks being mapped or allocate. |
| * if create==0 and the blocks are pre-allocated and uninitialized block, |
| * the result buffer head is unmapped. If the create ==1, it will make sure |
| * the buffer head is mapped. |
| * |
| * It returns 0 if plain look up failed (blocks have not been allocated), in |
| * that casem, buffer head is unmapped |
| * |
| * It returns the error in case of allocation failure. |
| */ |
| int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block, |
| unsigned int max_blocks, struct buffer_head *bh, |
| int create, int extend_disksize, int flag) |
| { |
| int retval; |
| |
| clear_buffer_mapped(bh); |
| |
| /* |
| * Try to see if we can get the block without requesting |
| * for new file system block. |
| */ |
| down_read((&EXT4_I(inode)->i_data_sem)); |
| if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) { |
| retval = ext4_ext_get_blocks(handle, inode, block, max_blocks, |
| bh, 0, 0); |
| } else { |
| retval = ext4_get_blocks_handle(handle, |
| inode, block, max_blocks, bh, 0, 0); |
| } |
| up_read((&EXT4_I(inode)->i_data_sem)); |
| |
| /* If it is only a block(s) look up */ |
| if (!create) |
| return retval; |
| |
| /* |
| * Returns if the blocks have already allocated |
| * |
| * Note that if blocks have been preallocated |
| * ext4_ext_get_block() returns th create = 0 |
| * with buffer head unmapped. |
| */ |
| if (retval > 0 && buffer_mapped(bh)) |
| return retval; |
| |
| /* |
| * New blocks allocate and/or writing to uninitialized extent |
| * will possibly result in updating i_data, so we take |
| * the write lock of i_data_sem, and call get_blocks() |
| * with create == 1 flag. |
| */ |
| down_write((&EXT4_I(inode)->i_data_sem)); |
| |
| /* |
| * if the caller is from delayed allocation writeout path |
| * we have already reserved fs blocks for allocation |
| * let the underlying get_block() function know to |
| * avoid double accounting |
| */ |
| if (flag) |
| EXT4_I(inode)->i_delalloc_reserved_flag = 1; |
| /* |
| * We need to check for EXT4 here because migrate |
| * could have changed the inode type in between |
| */ |
| if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) { |
| retval = ext4_ext_get_blocks(handle, inode, block, max_blocks, |
| bh, create, extend_disksize); |
| } else { |
| retval = ext4_get_blocks_handle(handle, inode, block, |
| max_blocks, bh, create, extend_disksize); |
| |
| if (retval > 0 && buffer_new(bh)) { |
| /* |
| * We allocated new blocks which will result in |
| * i_data's format changing. Force the migrate |
| * to fail by clearing migrate flags |
| */ |
| EXT4_I(inode)->i_flags = EXT4_I(inode)->i_flags & |
| ~EXT4_EXT_MIGRATE; |
| } |
| } |
| |
| if (flag) { |
| EXT4_I(inode)->i_delalloc_reserved_flag = 0; |
| /* |
| * Update reserved blocks/metadata blocks |
| * after successful block allocation |
| * which were deferred till now |
| */ |
| if ((retval > 0) && buffer_delay(bh)) |
| ext4_da_update_reserve_space(inode, retval); |
| } |
| |
| up_write((&EXT4_I(inode)->i_data_sem)); |
| return retval; |
| } |
| |
| /* Maximum number of blocks we map for direct IO at once. */ |
| #define DIO_MAX_BLOCKS 4096 |
| |
| int ext4_get_block(struct inode *inode, sector_t iblock, |
| struct buffer_head *bh_result, int create) |
| { |
| handle_t *handle = ext4_journal_current_handle(); |
| int ret = 0, started = 0; |
| unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; |
| int dio_credits; |
| |
| if (create && !handle) { |
| /* Direct IO write... */ |
| if (max_blocks > DIO_MAX_BLOCKS) |
| max_blocks = DIO_MAX_BLOCKS; |
| dio_credits = ext4_chunk_trans_blocks(inode, max_blocks); |
| handle = ext4_journal_start(inode, dio_credits); |
| if (IS_ERR(handle)) { |
| ret = PTR_ERR(handle); |
| goto out; |
| } |
| started = 1; |
| } |
| |
| ret = ext4_get_blocks_wrap(handle, inode, iblock, |
| max_blocks, bh_result, create, 0, 0); |
| if (ret > 0) { |
| bh_result->b_size = (ret << inode->i_blkbits); |
| ret = 0; |
| } |
| if (started) |
| ext4_journal_stop(handle); |
| out: |
| return ret; |
| } |
| |
| /* |
| * `handle' can be NULL if create is zero |
| */ |
| struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode, |
| ext4_lblk_t block, int create, int *errp) |
| { |
| struct buffer_head dummy; |
| int fatal = 0, err; |
| |
| J_ASSERT(handle != NULL || create == 0); |
| |
| dummy.b_state = 0; |
| dummy.b_blocknr = -1000; |
| buffer_trace_init(&dummy.b_history); |
| err = ext4_get_blocks_wrap(handle, inode, block, 1, |
| &dummy, create, 1, 0); |
| /* |
| * ext4_get_blocks_handle() returns number of blocks |
| * mapped. 0 in case of a HOLE. |
| */ |
| if (err > 0) { |
| if (err > 1) |
| WARN_ON(1); |
| err = 0; |
| } |
| *errp = err; |
| if (!err && buffer_mapped(&dummy)) { |
| struct buffer_head *bh; |
| bh = sb_getblk(inode->i_sb, dummy.b_blocknr); |
| if (!bh) { |
| *errp = -EIO; |
| goto err; |
| } |
| if (buffer_new(&dummy)) { |
| J_ASSERT(create != 0); |
| J_ASSERT(handle != NULL); |
| |
| /* |
| * Now that we do not always journal data, we should |
| * keep in mind whether this should always journal the |
| * new buffer as metadata. For now, regular file |
| * writes use ext4_get_block instead, so it's not a |
| * problem. |
| */ |
| lock_buffer(bh); |
| BUFFER_TRACE(bh, "call get_create_access"); |
| fatal = ext4_journal_get_create_access(handle, bh); |
| if (!fatal && !buffer_uptodate(bh)) { |
| memset(bh->b_data, 0, inode->i_sb->s_blocksize); |
| set_buffer_uptodate(bh); |
| } |
| unlock_buffer(bh); |
| BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); |
| err = ext4_handle_dirty_metadata(handle, inode, bh); |
| if (!fatal) |
| fatal = err; |
| } else { |
| BUFFER_TRACE(bh, "not a new buffer"); |
| } |
| if (fatal) { |
| *errp = fatal; |
| brelse(bh); |
| bh = NULL; |
| } |
| return bh; |
| } |
| err: |
| return NULL; |
| } |
| |
| struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode, |
| ext4_lblk_t block, int create, int *err) |
| { |
| struct buffer_head *bh; |
| |
| bh = ext4_getblk(handle, inode, block, create, err); |
| if (!bh) |
| return bh; |
| if (buffer_uptodate(bh)) |
| return bh; |
| ll_rw_block(READ_META, 1, &bh); |
| wait_on_buffer(bh); |
| if (buffer_uptodate(bh)) |
| return bh; |
| put_bh(bh); |
| *err = -EIO; |
| return NULL; |
| } |
| |
| static int walk_page_buffers(handle_t *handle, |
| struct buffer_head *head, |
| unsigned from, |
| unsigned to, |
| int *partial, |
| int (*fn)(handle_t *handle, |
| struct buffer_head *bh)) |
| { |
| struct buffer_head *bh; |
| unsigned block_start, block_end; |
| unsigned blocksize = head->b_size; |
| int err, ret = 0; |
| struct buffer_head *next; |
| |
| for (bh = head, block_start = 0; |
| ret == 0 && (bh != head || !block_start); |
| block_start = block_end, bh = next) |
| { |
| next = bh->b_this_page; |
| block_end = block_start + blocksize; |
| if (block_end <= from || block_start >= to) { |
| if (partial && !buffer_uptodate(bh)) |
| *partial = 1; |
| continue; |
| } |
| err = (*fn)(handle, bh); |
| if (!ret) |
| ret = err; |
| } |
| return ret; |
| } |
| |
| /* |
| * To preserve ordering, it is essential that the hole instantiation and |
| * the data write be encapsulated in a single transaction. We cannot |
| * close off a transaction and start a new one between the ext4_get_block() |
| * and the commit_write(). So doing the jbd2_journal_start at the start of |
| * prepare_write() is the right place. |
| * |
| * Also, this function can nest inside ext4_writepage() -> |
| * block_write_full_page(). In that case, we *know* that ext4_writepage() |
| * has generated enough buffer credits to do the whole page. So we won't |
| * block on the journal in that case, which is good, because the caller may |
| * be PF_MEMALLOC. |
| * |
| * By accident, ext4 can be reentered when a transaction is open via |
| * quota file writes. If we were to commit the transaction while thus |
| * reentered, there can be a deadlock - we would be holding a quota |
| * lock, and the commit would never complete if another thread had a |
| * transaction open and was blocking on the quota lock - a ranking |
| * violation. |
| * |
| * So what we do is to rely on the fact that jbd2_journal_stop/journal_start |
| * will _not_ run commit under these circumstances because handle->h_ref |
| * is elevated. We'll still have enough credits for the tiny quotafile |
| * write. |
| */ |
| static int do_journal_get_write_access(handle_t *handle, |
| struct buffer_head *bh) |
| { |
| if (!buffer_mapped(bh) || buffer_freed(bh)) |
| return 0; |
| return ext4_journal_get_write_access(handle, bh); |
| } |
| |
| static int ext4_write_begin(struct file *file, struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned flags, |
| struct page **pagep, void **fsdata) |
| { |
| struct inode *inode = mapping->host; |
| int ret, needed_blocks = ext4_writepage_trans_blocks(inode); |
| handle_t *handle; |
| int retries = 0; |
| struct page *page; |
| pgoff_t index; |
| unsigned from, to; |
| |
| trace_mark(ext4_write_begin, |
| "dev %s ino %lu pos %llu len %u flags %u", |
| inode->i_sb->s_id, inode->i_ino, |
| (unsigned long long) pos, len, flags); |
| index = pos >> PAGE_CACHE_SHIFT; |
| from = pos & (PAGE_CACHE_SIZE - 1); |
| to = from + len; |
| |
| retry: |
| handle = ext4_journal_start(inode, needed_blocks); |
| if (IS_ERR(handle)) { |
| ret = PTR_ERR(handle); |
| goto out; |
| } |
| |
| /* We cannot recurse into the filesystem as the transaction is already |
| * started */ |
| flags |= AOP_FLAG_NOFS; |
| |
| page = grab_cache_page_write_begin(mapping, index, flags); |
| if (!page) { |
| ext4_journal_stop(handle); |
| ret = -ENOMEM; |
| goto out; |
| } |
| *pagep = page; |
| |
| ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata, |
| ext4_get_block); |
| |
| if (!ret && ext4_should_journal_data(inode)) { |
| ret = walk_page_buffers(handle, page_buffers(page), |
| from, to, NULL, do_journal_get_write_access); |
| } |
| |
| if (ret) { |
| unlock_page(page); |
| ext4_journal_stop(handle); |
| page_cache_release(page); |
| /* |
| * block_write_begin may have instantiated a few blocks |
| * outside i_size. Trim these off again. Don't need |
| * i_size_read because we hold i_mutex. |
| */ |
| if (pos + len > inode->i_size) |
| vmtruncate(inode, inode->i_size); |
| } |
| |
| if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) |
| goto retry; |
| out: |
| return ret; |
| } |
| |
| /* For write_end() in data=journal mode */ |
| static int write_end_fn(handle_t *handle, struct buffer_head *bh) |
| { |
| if (!buffer_mapped(bh) || buffer_freed(bh)) |
| return 0; |
| set_buffer_uptodate(bh); |
| return ext4_handle_dirty_metadata(handle, NULL, bh); |
| } |
| |
| /* |
| * We need to pick up the new inode size which generic_commit_write gave us |
| * `file' can be NULL - eg, when called from page_symlink(). |
| * |
| * ext4 never places buffers on inode->i_mapping->private_list. metadata |
| * buffers are managed internally. |
| */ |
| static int ext4_ordered_write_end(struct file *file, |
| struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned copied, |
| struct page *page, void *fsdata) |
| { |
| handle_t *handle = ext4_journal_current_handle(); |
| struct inode *inode = mapping->host; |
| int ret = 0, ret2; |
| |
| trace_mark(ext4_ordered_write_end, |
| "dev %s ino %lu pos %llu len %u copied %u", |
| inode->i_sb->s_id, inode->i_ino, |
| (unsigned long long) pos, len, copied); |
| ret = ext4_jbd2_file_inode(handle, inode); |
| |
| if (ret == 0) { |
| loff_t new_i_size; |
| |
| new_i_size = pos + copied; |
| if (new_i_size > EXT4_I(inode)->i_disksize) { |
| ext4_update_i_disksize(inode, new_i_size); |
| /* We need to mark inode dirty even if |
| * new_i_size is less that inode->i_size |
| * bu greater than i_disksize.(hint delalloc) |
| */ |
| ext4_mark_inode_dirty(handle, inode); |
| } |
| |
| ret2 = generic_write_end(file, mapping, pos, len, copied, |
| page, fsdata); |
| copied = ret2; |
| if (ret2 < 0) |
| ret = ret2; |
| } |
| ret2 = ext4_journal_stop(handle); |
| if (!ret) |
| ret = ret2; |
| |
| return ret ? ret : copied; |
| } |
| |
| static int ext4_writeback_write_end(struct file *file, |
| struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned copied, |
| struct page *page, void *fsdata) |
| { |
| handle_t *handle = ext4_journal_current_handle(); |
| struct inode *inode = mapping->host; |
| int ret = 0, ret2; |
| loff_t new_i_size; |
| |
| trace_mark(ext4_writeback_write_end, |
| "dev %s ino %lu pos %llu len %u copied %u", |
| inode->i_sb->s_id, inode->i_ino, |
| (unsigned long long) pos, len, copied); |
| new_i_size = pos + copied; |
| if (new_i_size > EXT4_I(inode)->i_disksize) { |
| ext4_update_i_disksize(inode, new_i_size); |
| /* We need to mark inode dirty even if |
| * new_i_size is less that inode->i_size |
| * bu greater than i_disksize.(hint delalloc) |
| */ |
| ext4_mark_inode_dirty(handle, inode); |
| } |
| |
| ret2 = generic_write_end(file, mapping, pos, len, copied, |
| page, fsdata); |
| copied = ret2; |
| if (ret2 < 0) |
| ret = ret2; |
| |
| ret2 = ext4_journal_stop(handle); |
| if (!ret) |
| ret = ret2; |
| |
| return ret ? ret : copied; |
| } |
| |
| static int ext4_journalled_write_end(struct file *file, |
| struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned copied, |
| struct page *page, void *fsdata) |
| { |
| handle_t *handle = ext4_journal_current_handle(); |
| struct inode *inode = mapping->host; |
| int ret = 0, ret2; |
| int partial = 0; |
| unsigned from, to; |
| loff_t new_i_size; |
| |
| trace_mark(ext4_journalled_write_end, |
| "dev %s ino %lu pos %llu len %u copied %u", |
| inode->i_sb->s_id, inode->i_ino, |
| (unsigned long long) pos, len, copied); |
| from = pos & (PAGE_CACHE_SIZE - 1); |
| to = from + len; |
| |
| if (copied < len) { |
| if (!PageUptodate(page)) |
| copied = 0; |
| page_zero_new_buffers(page, from+copied, to); |
| } |
| |
| ret = walk_page_buffers(handle, page_buffers(page), from, |
| to, &partial, write_end_fn); |
| if (!partial) |
| SetPageUptodate(page); |
| new_i_size = pos + copied; |
| if (new_i_size > inode->i_size) |
| i_size_write(inode, pos+copied); |
| EXT4_I(inode)->i_state |= EXT4_STATE_JDATA; |
| if (new_i_size > EXT4_I(inode)->i_disksize) { |
| ext4_update_i_disksize(inode, new_i_size); |
| ret2 = ext4_mark_inode_dirty(handle, inode); |
| if (!ret) |
| ret = ret2; |
| } |
| |
| unlock_page(page); |
| ret2 = ext4_journal_stop(handle); |
| if (!ret) |
| ret = ret2; |
| page_cache_release(page); |
| |
| return ret ? ret : copied; |
| } |
| |
| static int ext4_da_reserve_space(struct inode *inode, int nrblocks) |
| { |
| int retries = 0; |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| unsigned long md_needed, mdblocks, total = 0; |
| |
| /* |
| * recalculate the amount of metadata blocks to reserve |
| * in order to allocate nrblocks |
| * worse case is one extent per block |
| */ |
| repeat: |
| spin_lock(&EXT4_I(inode)->i_block_reservation_lock); |
| total = EXT4_I(inode)->i_reserved_data_blocks + nrblocks; |
| mdblocks = ext4_calc_metadata_amount(inode, total); |
| BUG_ON(mdblocks < EXT4_I(inode)->i_reserved_meta_blocks); |
| |
| md_needed = mdblocks - EXT4_I(inode)->i_reserved_meta_blocks; |
| total = md_needed + nrblocks; |
| |
| if (ext4_claim_free_blocks(sbi, total)) { |
| spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); |
| if (ext4_should_retry_alloc(inode->i_sb, &retries)) { |
| yield(); |
| goto repeat; |
| } |
| return -ENOSPC; |
| } |
| EXT4_I(inode)->i_reserved_data_blocks += nrblocks; |
| EXT4_I(inode)->i_reserved_meta_blocks = mdblocks; |
| |
| spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); |
| return 0; /* success */ |
| } |
| |
| static void ext4_da_release_space(struct inode *inode, int to_free) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| int total, mdb, mdb_free, release; |
| |
| if (!to_free) |
| return; /* Nothing to release, exit */ |
| |
| spin_lock(&EXT4_I(inode)->i_block_reservation_lock); |
| |
| if (!EXT4_I(inode)->i_reserved_data_blocks) { |
| /* |
| * if there is no reserved blocks, but we try to free some |
| * then the counter is messed up somewhere. |
| * but since this function is called from invalidate |
| * page, it's harmless to return without any action |
| */ |
| printk(KERN_INFO "ext4 delalloc try to release %d reserved " |
| "blocks for inode %lu, but there is no reserved " |
| "data blocks\n", to_free, inode->i_ino); |
| spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); |
| return; |
| } |
| |
| /* recalculate the number of metablocks still need to be reserved */ |
| total = EXT4_I(inode)->i_reserved_data_blocks - to_free; |
| mdb = ext4_calc_metadata_amount(inode, total); |
| |
| /* figure out how many metablocks to release */ |
| BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks); |
| mdb_free = EXT4_I(inode)->i_reserved_meta_blocks - mdb; |
| |
| release = to_free + mdb_free; |
| |
| /* update fs dirty blocks counter for truncate case */ |
| percpu_counter_sub(&sbi->s_dirtyblocks_counter, release); |
| |
| /* update per-inode reservations */ |
| BUG_ON(to_free > EXT4_I(inode)->i_reserved_data_blocks); |
| EXT4_I(inode)->i_reserved_data_blocks -= to_free; |
| |
| BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks); |
| EXT4_I(inode)->i_reserved_meta_blocks = mdb; |
| spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); |
| } |
| |
| static void ext4_da_page_release_reservation(struct page *page, |
| unsigned long offset) |
| { |
| int to_release = 0; |
| struct buffer_head *head, *bh; |
| unsigned int curr_off = 0; |
| |
| head = page_buffers(page); |
| bh = head; |
| do { |
| unsigned int next_off = curr_off + bh->b_size; |
| |
| if ((offset <= curr_off) && (buffer_delay(bh))) { |
| to_release++; |
| clear_buffer_delay(bh); |
| } |
| curr_off = next_off; |
| } while ((bh = bh->b_this_page) != head); |
| ext4_da_release_space(page->mapping->host, to_release); |
| } |
| |
| /* |
| * Delayed allocation stuff |
| */ |
| |
| struct mpage_da_data { |
| struct inode *inode; |
| struct buffer_head lbh; /* extent of blocks */ |
| unsigned long first_page, next_page; /* extent of pages */ |
| get_block_t *get_block; |
| struct writeback_control *wbc; |
| int io_done; |
| int pages_written; |
| int retval; |
| }; |
| |
| /* |
| * mpage_da_submit_io - walks through extent of pages and try to write |
| * them with writepage() call back |
| * |
| * @mpd->inode: inode |
| * @mpd->first_page: first page of the extent |
| * @mpd->next_page: page after the last page of the extent |
| * @mpd->get_block: the filesystem's block mapper function |
| * |
| * By the time mpage_da_submit_io() is called we expect all blocks |
| * to be allocated. this may be wrong if allocation failed. |
| * |
| * As pages are already locked by write_cache_pages(), we can't use it |
| */ |
| static int mpage_da_submit_io(struct mpage_da_data *mpd) |
| { |
| long pages_skipped; |
| struct pagevec pvec; |
| unsigned long index, end; |
| int ret = 0, err, nr_pages, i; |
| struct inode *inode = mpd->inode; |
| struct address_space *mapping = inode->i_mapping; |
| |
| BUG_ON(mpd->next_page <= mpd->first_page); |
| /* |
| * We need to start from the first_page to the next_page - 1 |
| * to make sure we also write the mapped dirty buffer_heads. |
| * If we look at mpd->lbh.b_blocknr we would only be looking |
| * at the currently mapped buffer_heads. |
| */ |
| index = mpd->first_page; |
| end = mpd->next_page - 1; |
| |
| pagevec_init(&pvec, 0); |
| while (index <= end) { |
| nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE); |
| if (nr_pages == 0) |
| break; |
| for (i = 0; i < nr_pages; i++) { |
| struct page *page = pvec.pages[i]; |
| |
| index = page->index; |
| if (index > end) |
| break; |
| index++; |
| |
| BUG_ON(!PageLocked(page)); |
| BUG_ON(PageWriteback(page)); |
| |
| pages_skipped = mpd->wbc->pages_skipped; |
| err = mapping->a_ops->writepage(page, mpd->wbc); |
| if (!err && (pages_skipped == mpd->wbc->pages_skipped)) |
| /* |
| * have successfully written the page |
| * without skipping the same |
| */ |
| mpd->pages_written++; |
| /* |
| * In error case, we have to continue because |
| * remaining pages are still locked |
| * XXX: unlock and re-dirty them? |
| */ |
| if (ret == 0) |
| ret = err; |
| } |
| pagevec_release(&pvec); |
| } |
| return ret; |
| } |
| |
| /* |
| * mpage_put_bnr_to_bhs - walk blocks and assign them actual numbers |
| * |
| * @mpd->inode - inode to walk through |
| * @exbh->b_blocknr - first block on a disk |
| * @exbh->b_size - amount of space in bytes |
| * @logical - first logical block to start assignment with |
| * |
| * the function goes through all passed space and put actual disk |
| * block numbers into buffer heads, dropping BH_Delay |
| */ |
| static void mpage_put_bnr_to_bhs(struct mpage_da_data *mpd, sector_t logical, |
| struct buffer_head *exbh) |
| { |
| struct inode *inode = mpd->inode; |
| struct address_space *mapping = inode->i_mapping; |
| int blocks = exbh->b_size >> inode->i_blkbits; |
| sector_t pblock = exbh->b_blocknr, cur_logical; |
| struct buffer_head *head, *bh; |
| pgoff_t index, end; |
| struct pagevec pvec; |
| int nr_pages, i; |
| |
| index = logical >> (PAGE_CACHE_SHIFT - inode->i_blkbits); |
| end = (logical + blocks - 1) >> (PAGE_CACHE_SHIFT - inode->i_blkbits); |
| cur_logical = index << (PAGE_CACHE_SHIFT - inode->i_blkbits); |
| |
| pagevec_init(&pvec, 0); |
| |
| while (index <= end) { |
| /* XXX: optimize tail */ |
| nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE); |
| if (nr_pages == 0) |
| break; |
| for (i = 0; i < nr_pages; i++) { |
| struct page *page = pvec.pages[i]; |
| |
| index = page->index; |
| if (index > end) |
| break; |
| index++; |
| |
| BUG_ON(!PageLocked(page)); |
| BUG_ON(PageWriteback(page)); |
| BUG_ON(!page_has_buffers(page)); |
| |
| bh = page_buffers(page); |
| head = bh; |
| |
| /* skip blocks out of the range */ |
| do { |
| if (cur_logical >= logical) |
| break; |
| cur_logical++; |
| } while ((bh = bh->b_this_page) != head); |
| |
| do { |
| if (cur_logical >= logical + blocks) |
| break; |
| if (buffer_delay(bh)) { |
| bh->b_blocknr = pblock; |
| clear_buffer_delay(bh); |
| bh->b_bdev = inode->i_sb->s_bdev; |
| } else if (buffer_unwritten(bh)) { |
| bh->b_blocknr = pblock; |
| clear_buffer_unwritten(bh); |
| set_buffer_mapped(bh); |
| set_buffer_new(bh); |
| bh->b_bdev = inode->i_sb->s_bdev; |
| } else if (buffer_mapped(bh)) |
| BUG_ON(bh->b_blocknr != pblock); |
| |
| cur_logical++; |
| pblock++; |
| } while ((bh = bh->b_this_page) != head); |
| } |
| pagevec_release(&pvec); |
| } |
| } |
| |
| |
| /* |
| * __unmap_underlying_blocks - just a helper function to unmap |
| * set of blocks described by @bh |
| */ |
| static inline void __unmap_underlying_blocks(struct inode *inode, |
| struct buffer_head *bh) |
| { |
| struct block_device *bdev = inode->i_sb->s_bdev; |
| int blocks, i; |
| |
| blocks = bh->b_size >> inode->i_blkbits; |
| for (i = 0; i < blocks; i++) |
| unmap_underlying_metadata(bdev, bh->b_blocknr + i); |
| } |
| |
| static void ext4_da_block_invalidatepages(struct mpage_da_data *mpd, |
| sector_t logical, long blk_cnt) |
| { |
| int nr_pages, i; |
| pgoff_t index, end; |
| struct pagevec pvec; |
| struct inode *inode = mpd->inode; |
| struct address_space *mapping = inode->i_mapping; |
| |
| index = logical >> (PAGE_CACHE_SHIFT - inode->i_blkbits); |
| end = (logical + blk_cnt - 1) >> |
| (PAGE_CACHE_SHIFT - inode->i_blkbits); |
| while (index <= end) { |
| nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE); |
| if (nr_pages == 0) |
| break; |
| for (i = 0; i < nr_pages; i++) { |
| struct page *page = pvec.pages[i]; |
| index = page->index; |
| if (index > end) |
| break; |
| index++; |
| |
| BUG_ON(!PageLocked(page)); |
| BUG_ON(PageWriteback(page)); |
| block_invalidatepage(page, 0); |
| ClearPageUptodate(page); |
| unlock_page(page); |
| } |
| } |
| return; |
| } |
| |
| static void ext4_print_free_blocks(struct inode *inode) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| printk(KERN_EMERG "Total free blocks count %lld\n", |
| ext4_count_free_blocks(inode->i_sb)); |
| printk(KERN_EMERG "Free/Dirty block details\n"); |
| printk(KERN_EMERG "free_blocks=%lld\n", |
| (long long)percpu_counter_sum(&sbi->s_freeblocks_counter)); |
| printk(KERN_EMERG "dirty_blocks=%lld\n", |
| (long long)percpu_counter_sum(&sbi->s_dirtyblocks_counter)); |
| printk(KERN_EMERG "Block reservation details\n"); |
| printk(KERN_EMERG "i_reserved_data_blocks=%u\n", |
| EXT4_I(inode)->i_reserved_data_blocks); |
| printk(KERN_EMERG "i_reserved_meta_blocks=%u\n", |
| EXT4_I(inode)->i_reserved_meta_blocks); |
| return; |
| } |
| |
| /* |
| * mpage_da_map_blocks - go through given space |
| * |
| * @mpd->lbh - bh describing space |
| * @mpd->get_block - the filesystem's block mapper function |
| * |
| * The function skips space we know is already mapped to disk blocks. |
| * |
| */ |
| static int mpage_da_map_blocks(struct mpage_da_data *mpd) |
| { |
| int err = 0; |
| struct buffer_head new; |
| struct buffer_head *lbh = &mpd->lbh; |
| sector_t next; |
| |
| /* |
| * We consider only non-mapped and non-allocated blocks |
| */ |
| if (buffer_mapped(lbh) && !buffer_delay(lbh)) |
| return 0; |
| new.b_state = lbh->b_state; |
| new.b_blocknr = 0; |
| new.b_size = lbh->b_size; |
| next = lbh->b_blocknr; |
| /* |
| * If we didn't accumulate anything |
| * to write simply return |
| */ |
| if (!new.b_size) |
| return 0; |
| err = mpd->get_block(mpd->inode, next, &new, 1); |
| if (err) { |
| |
| /* If get block returns with error |
| * we simply return. Later writepage |
| * will redirty the page and writepages |
| * will find the dirty page again |
| */ |
| if (err == -EAGAIN) |
| return 0; |
| |
| if (err == -ENOSPC && |
| ext4_count_free_blocks(mpd->inode->i_sb)) { |
| mpd->retval = err; |
| return 0; |
| } |
| |
| /* |
| * get block failure will cause us |
| * to loop in writepages. Because |
| * a_ops->writepage won't be able to |
| * make progress. The page will be redirtied |
| * by writepage and writepages will again |
| * try to write the same. |
| */ |
| printk(KERN_EMERG "%s block allocation failed for inode %lu " |
| "at logical offset %llu with max blocks " |
| "%zd with error %d\n", |
| __func__, mpd->inode->i_ino, |
| (unsigned long long)next, |
| lbh->b_size >> mpd->inode->i_blkbits, err); |
| printk(KERN_EMERG "This should not happen.!! " |
| "Data will be lost\n"); |
| if (err == -ENOSPC) { |
| ext4_print_free_blocks(mpd->inode); |
| } |
| /* invlaidate all the pages */ |
| ext4_da_block_invalidatepages(mpd, next, |
| lbh->b_size >> mpd->inode->i_blkbits); |
| return err; |
| } |
| BUG_ON(new.b_size == 0); |
| |
| if (buffer_new(&new)) |
| __unmap_underlying_blocks(mpd->inode, &new); |
| |
| /* |
| * If blocks are delayed marked, we need to |
| * put actual blocknr and drop delayed bit |
| */ |
| if (buffer_delay(lbh) || buffer_unwritten(lbh)) |
| mpage_put_bnr_to_bhs(mpd, next, &new); |
| |
| return 0; |
| } |
| |
| #define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \ |
| (1 << BH_Delay) | (1 << BH_Unwritten)) |
| |
| /* |
| * mpage_add_bh_to_extent - try to add one more block to extent of blocks |
| * |
| * @mpd->lbh - extent of blocks |
| * @logical - logical number of the block in the file |
| * @bh - bh of the block (used to access block's state) |
| * |
| * the function is used to collect contig. blocks in same state |
| */ |
| static void mpage_add_bh_to_extent(struct mpage_da_data *mpd, |
| sector_t logical, struct buffer_head *bh) |
| { |
| sector_t next; |
| size_t b_size = bh->b_size; |
| struct buffer_head *lbh = &mpd->lbh; |
| int nrblocks = lbh->b_size >> mpd->inode->i_blkbits; |
| |
| /* check if thereserved journal credits might overflow */ |
| if (!(EXT4_I(mpd->inode)->i_flags & EXT4_EXTENTS_FL)) { |
| if (nrblocks >= EXT4_MAX_TRANS_DATA) { |
| /* |
| * With non-extent format we are limited by the journal |
| * credit available. Total credit needed to insert |
| * nrblocks contiguous blocks is dependent on the |
| * nrblocks. So limit nrblocks. |
| */ |
| goto flush_it; |
| } else if ((nrblocks + (b_size >> mpd->inode->i_blkbits)) > |
| EXT4_MAX_TRANS_DATA) { |
| /* |
| * Adding the new buffer_head would make it cross the |
| * allowed limit for which we have journal credit |
| * reserved. So limit the new bh->b_size |
| */ |
| b_size = (EXT4_MAX_TRANS_DATA - nrblocks) << |
| mpd->inode->i_blkbits; |
| /* we will do mpage_da_submit_io in the next loop */ |
| } |
| } |
| /* |
| * First block in the extent |
| */ |
| if (lbh->b_size == 0) { |
| lbh->b_blocknr = logical; |
| lbh->b_size = b_size; |
| lbh->b_state = bh->b_state & BH_FLAGS; |
| return; |
| } |
| |
| next = lbh->b_blocknr + nrblocks; |
| /* |
| * Can we merge the block to our big extent? |
| */ |
| if (logical == next && (bh->b_state & BH_FLAGS) == lbh->b_state) { |
| lbh->b_size += b_size; |
| return; |
| } |
| |
| flush_it: |
| /* |
| * We couldn't merge the block to our extent, so we |
| * need to flush current extent and start new one |
| */ |
| if (mpage_da_map_blocks(mpd) == 0) |
| mpage_da_submit_io(mpd); |
| mpd->io_done = 1; |
| return; |
| } |
| |
| /* |
| * __mpage_da_writepage - finds extent of pages and blocks |
| * |
| * @page: page to consider |
| * @wbc: not used, we just follow rules |
| * @data: context |
| * |
| * The function finds extents of pages and scan them for all blocks. |
| */ |
| static int __mpage_da_writepage(struct page *page, |
| struct writeback_control *wbc, void *data) |
| { |
| struct mpage_da_data *mpd = data; |
| struct inode *inode = mpd->inode; |
| struct buffer_head *bh, *head, fake; |
| sector_t logical; |
| |
| if (mpd->io_done) { |
| /* |
| * Rest of the page in the page_vec |
| * redirty then and skip then. We will |
| * try to to write them again after |
| * starting a new transaction |
| */ |
| redirty_page_for_writepage(wbc, page); |
| unlock_page(page); |
| return MPAGE_DA_EXTENT_TAIL; |
| } |
| /* |
| * Can we merge this page to current extent? |
| */ |
| if (mpd->next_page != page->index) { |
| /* |
| * Nope, we can't. So, we map non-allocated blocks |
| * and start IO on them using writepage() |
| */ |
| if (mpd->next_page != mpd->first_page) { |
| if (mpage_da_map_blocks(mpd) == 0) |
| mpage_da_submit_io(mpd); |
| /* |
| * skip rest of the page in the page_vec |
| */ |
| mpd->io_done = 1; |
| redirty_page_for_writepage(wbc, page); |
| unlock_page(page); |
| return MPAGE_DA_EXTENT_TAIL; |
| } |
| |
| /* |
| * Start next extent of pages ... |
| */ |
| mpd->first_page = page->index; |
| |
| /* |
| * ... and blocks |
| */ |
| mpd->lbh.b_size = 0; |
| mpd->lbh.b_state = 0; |
| mpd->lbh.b_blocknr = 0; |
| } |
| |
| mpd->next_page = page->index + 1; |
| logical = (sector_t) page->index << |
| (PAGE_CACHE_SHIFT - inode->i_blkbits); |
| |
| if (!page_has_buffers(page)) { |
| /* |
| * There is no attached buffer heads yet (mmap?) |
| * we treat the page asfull of dirty blocks |
| */ |
| bh = &fake; |
| bh->b_size = PAGE_CACHE_SIZE; |
| bh->b_state = 0; |
| set_buffer_dirty(bh); |
| set_buffer_uptodate(bh); |
| mpage_add_bh_to_extent(mpd, logical, bh); |
| if (mpd->io_done) |
| return MPAGE_DA_EXTENT_TAIL; |
| } else { |
| /* |
| * Page with regular buffer heads, just add all dirty ones |
| */ |
| head = page_buffers(page); |
| bh = head; |
| do { |
| BUG_ON(buffer_locked(bh)); |
| /* |
| * We need to try to allocate |
| * unmapped blocks in the same page. |
| * Otherwise we won't make progress |
| * with the page in ext4_da_writepage |
| */ |
| if (buffer_dirty(bh) && |
| (!buffer_mapped(bh) || buffer_delay(bh))) { |
| mpage_add_bh_to_extent(mpd, logical, bh); |
| if (mpd->io_done) |
| return MPAGE_DA_EXTENT_TAIL; |
| } else if (buffer_dirty(bh) && (buffer_mapped(bh))) { |
| /* |
| * mapped dirty buffer. We need to update |
| * the b_state because we look at |
| * b_state in mpage_da_map_blocks. We don't |
| * update b_size because if we find an |
| * unmapped buffer_head later we need to |
| * use the b_state flag of that buffer_head. |
| */ |
| if (mpd->lbh.b_size == 0) |
| mpd->lbh.b_state = |
| bh->b_state & BH_FLAGS; |
| } |
| logical++; |
| } while ((bh = bh->b_this_page) != head); |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * mpage_da_writepages - walk the list of dirty pages of the given |
| * address space, allocates non-allocated blocks, maps newly-allocated |
| * blocks to existing bhs and issue IO them |
| * |
| * @mapping: address space structure to write |
| * @wbc: subtract the number of written pages from *@wbc->nr_to_write |
| * @get_block: the filesystem's block mapper function. |
| * |
| * This is a library function, which implements the writepages() |
| * address_space_operation. |
| */ |
| static int mpage_da_writepages(struct address_space *mapping, |
| struct writeback_control *wbc, |
| struct mpage_da_data *mpd) |
| { |
| int ret; |
| |
| if (!mpd->get_block) |
| return generic_writepages(mapping, wbc); |
| |
| mpd->lbh.b_size = 0; |
| mpd->lbh.b_state = 0; |
| mpd->lbh.b_blocknr = 0; |
| mpd->first_page = 0; |
| mpd->next_page = 0; |
| mpd->io_done = 0; |
| mpd->pages_written = 0; |
| mpd->retval = 0; |
| |
| ret = write_cache_pages(mapping, wbc, __mpage_da_writepage, mpd); |
| /* |
| * Handle last extent of pages |
| */ |
| if (!mpd->io_done && mpd->next_page != mpd->first_page) { |
| if (mpage_da_map_blocks(mpd) == 0) |
| mpage_da_submit_io(mpd); |
| |
| mpd->io_done = 1; |
| ret = MPAGE_DA_EXTENT_TAIL; |
| } |
| wbc->nr_to_write -= mpd->pages_written; |
| return ret; |
| } |
| |
| /* |
| * this is a special callback for ->write_begin() only |
| * it's intention is to return mapped block or reserve space |
| */ |
| static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock, |
| struct buffer_head *bh_result, int create) |
| { |
| int ret = 0; |
| |
| BUG_ON(create == 0); |
| BUG_ON(bh_result->b_size != inode->i_sb->s_blocksize); |
| |
| /* |
| * first, we need to know whether the block is allocated already |
| * preallocated blocks are unmapped but should treated |
| * the same as allocated blocks. |
| */ |
| ret = ext4_get_blocks_wrap(NULL, inode, iblock, 1, bh_result, 0, 0, 0); |
| if ((ret == 0) && !buffer_delay(bh_result)) { |
| /* the block isn't (pre)allocated yet, let's reserve space */ |
| /* |
| * XXX: __block_prepare_write() unmaps passed block, |
| * is it OK? |
| */ |
| ret = ext4_da_reserve_space(inode, 1); |
| if (ret) |
| /* not enough space to reserve */ |
| return ret; |
| |
| map_bh(bh_result, inode->i_sb, 0); |
| set_buffer_new(bh_result); |
| set_buffer_delay(bh_result); |
| } else if (ret > 0) { |
| bh_result->b_size = (ret << inode->i_blkbits); |
| ret = 0; |
| } |
| |
| return ret; |
| } |
| #define EXT4_DELALLOC_RSVED 1 |
| static int ext4_da_get_block_write(struct inode *inode, sector_t iblock, |
| struct buffer_head *bh_result, int create) |
| { |
| int ret; |
| unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; |
| loff_t disksize = EXT4_I(inode)->i_disksize; |
| handle_t *handle = NULL; |
| |
| handle = ext4_journal_current_handle(); |
| BUG_ON(!handle); |
| ret = ext4_get_blocks_wrap(handle, inode, iblock, max_blocks, |
| bh_result, create, 0, EXT4_DELALLOC_RSVED); |
| if (ret > 0) { |
| |
| bh_result->b_size = (ret << inode->i_blkbits); |
| |
| if (ext4_should_order_data(inode)) { |
| int retval; |
| retval = ext4_jbd2_file_inode(handle, inode); |
| if (retval) |
| /* |
| * Failed to add inode for ordered |
| * mode. Don't update file size |
| */ |
| return retval; |
| } |
| |
| /* |
| * Update on-disk size along with block allocation |
| * we don't use 'extend_disksize' as size may change |
| * within already allocated block -bzzz |
| */ |
| disksize = ((loff_t) iblock + ret) << inode->i_blkbits; |
| if (disksize > i_size_read(inode)) |
| disksize = i_size_read(inode); |
| if (disksize > EXT4_I(inode)->i_disksize) { |
| ext4_update_i_disksize(inode, disksize); |
| ret = ext4_mark_inode_dirty(handle, inode); |
| return ret; |
| } |
| ret = 0; |
| } |
| return ret; |
| } |
| |
| static int ext4_bh_unmapped_or_delay(handle_t *handle, struct buffer_head *bh) |
| { |
| /* |
| * unmapped buffer is possible for holes. |
| * delay buffer is possible with delayed allocation |
| */ |
| return ((!buffer_mapped(bh) || buffer_delay(bh)) && buffer_dirty(bh)); |
| } |
| |
| static int ext4_normal_get_block_write(struct inode *inode, sector_t iblock, |
| struct buffer_head *bh_result, int create) |
| { |
| int ret = 0; |
| unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; |
| |
| /* |
| * we don't want to do block allocation in writepage |
| * so call get_block_wrap with create = 0 |
| */ |
| ret = ext4_get_blocks_wrap(NULL, inode, iblock, max_blocks, |
| bh_result, 0, 0, 0); |
| if (ret > 0) { |
| bh_result->b_size = (ret << inode->i_blkbits); |
| ret = 0; |
| } |
| return ret; |
| } |
| |
| /* |
| * get called vi ext4_da_writepages after taking page lock (have journal handle) |
| * get called via journal_submit_inode_data_buffers (no journal handle) |
| * get called via shrink_page_list via pdflush (no journal handle) |
| * or grab_page_cache when doing write_begin (have journal handle) |
| */ |
| static int ext4_da_writepage(struct page *page, |
| struct writeback_control *wbc) |
| { |
| int ret = 0; |
| loff_t size; |
| unsigned int len; |
| struct buffer_head *page_bufs; |
| struct inode *inode = page->mapping->host; |
| |
| trace_mark(ext4_da_writepage, |
| "dev %s ino %lu page_index %lu", |
| inode->i_sb->s_id, inode->i_ino, page->index); |
| size = i_size_read(inode); |
| if (page->index == size >> PAGE_CACHE_SHIFT) |
| len = size & ~PAGE_CACHE_MASK; |
| else |
| len = PAGE_CACHE_SIZE; |
| |
| if (page_has_buffers(page)) { |
| page_bufs = page_buffers(page); |
| if (walk_page_buffers(NULL, page_bufs, 0, len, NULL, |
| ext4_bh_unmapped_or_delay)) { |
| /* |
| * We don't want to do block allocation |
| * So redirty the page and return |
| * We may reach here when we do a journal commit |
| * via journal_submit_inode_data_buffers. |
| * If we don't have mapping block we just ignore |
| * them. We can also reach here via shrink_page_list |
| */ |
| redirty_page_for_writepage(wbc, page); |
| unlock_page(page); |
| return 0; |
| } |
| } else { |
| /* |
| * The test for page_has_buffers() is subtle: |
| * We know the page is dirty but it lost buffers. That means |
| * that at some moment in time after write_begin()/write_end() |
| * has been called all buffers have been clean and thus they |
| * must have been written at least once. So they are all |
| * mapped and we can happily proceed with mapping them |
| * and writing the page. |
| * |
| * Try to initialize the buffer_heads and check whether |
| * all are mapped and non delay. We don't want to |
| * do block allocation here. |
| */ |
| ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE, |
| ext4_normal_get_block_write); |
| if (!ret) { |
| page_bufs = page_buffers(page); |
| /* check whether all are mapped and non delay */ |
| if (walk_page_buffers(NULL, page_bufs, 0, len, NULL, |
| ext4_bh_unmapped_or_delay)) { |
| redirty_page_for_writepage(wbc, page); |
| unlock_page(page); |
| return 0; |
| } |
| } else { |
| /* |
| * We can't do block allocation here |
| * so just redity the page and unlock |
| * and return |
| */ |
| redirty_page_for_writepage(wbc, page); |
| unlock_page(page); |
| return 0; |
| } |
| /* now mark the buffer_heads as dirty and uptodate */ |
| block_commit_write(page, 0, PAGE_CACHE_SIZE); |
| } |
| |
| if (test_opt(inode->i_sb, NOBH) && ext4_should_writeback_data(inode)) |
| ret = nobh_writepage(page, ext4_normal_get_block_write, wbc); |
| else |
| ret = block_write_full_page(page, |
| ext4_normal_get_block_write, |
| wbc); |
| |
| return ret; |
| } |
| |
| /* |
| * This is called via ext4_da_writepages() to |
| * calulate the total number of credits to reserve to fit |
| * a single extent allocation into a single transaction, |
| * ext4_da_writpeages() will loop calling this before |
| * the block allocation. |
| */ |
| |
| static int ext4_da_writepages_trans_blocks(struct inode *inode) |
| { |
| int max_blocks = EXT4_I(inode)->i_reserved_data_blocks; |
| |
| /* |
| * With non-extent format the journal credit needed to |
| * insert nrblocks contiguous block is dependent on |
| * number of contiguous block. So we will limit |
| * number of contiguous block to a sane value |
| */ |
| if (!(inode->i_flags & EXT4_EXTENTS_FL) && |
| (max_blocks > EXT4_MAX_TRANS_DATA)) |
| max_blocks = EXT4_MAX_TRANS_DATA; |
| |
| return ext4_chunk_trans_blocks(inode, max_blocks); |
| } |
| |
| static int ext4_da_writepages(struct address_space *mapping, |
| struct writeback_control *wbc) |
| { |
| pgoff_t index; |
| int range_whole = 0; |
| handle_t *handle = NULL; |
| struct mpage_da_data mpd; |
| struct inode *inode = mapping->host; |
| int no_nrwrite_index_update; |
| int pages_written = 0; |
| long pages_skipped; |
| int range_cyclic, cycled = 1, io_done = 0; |
| int needed_blocks, ret = 0, nr_to_writebump = 0; |
| struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb); |
| |
| trace_mark(ext4_da_writepages, |
| "dev %s ino %lu nr_t_write %ld " |
| "pages_skipped %ld range_start %llu " |
| "range_end %llu nonblocking %d " |
| "for_kupdate %d for_reclaim %d " |
| "for_writepages %d range_cyclic %d", |
| inode->i_sb->s_id, inode->i_ino, |
| wbc->nr_to_write, wbc->pages_skipped, |
| (unsigned long long) wbc->range_start, |
| (unsigned long long) wbc->range_end, |
| wbc->nonblocking, wbc->for_kupdate, |
| wbc->for_reclaim, wbc->for_writepages, |
| wbc->range_cyclic); |
| |
| /* |
| * No pages to write? This is mainly a kludge to avoid starting |
| * a transaction for special inodes like journal inode on last iput() |
| * because that could violate lock ordering on umount |
| */ |
| if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) |
| return 0; |
| |
| /* |
| * If the filesystem has aborted, it is read-only, so return |
| * right away instead of dumping stack traces later on that |
| * will obscure the real source of the problem. We test |
| * EXT4_MOUNT_ABORT instead of sb->s_flag's MS_RDONLY because |
| * the latter could be true if the filesystem is mounted |
| * read-only, and in that case, ext4_da_writepages should |
| * *never* be called, so if that ever happens, we would want |
| * the stack trace. |
| */ |
| if (unlikely(sbi->s_mount_opt & EXT4_MOUNT_ABORT)) |
| return -EROFS; |
| |
| /* |
| * Make sure nr_to_write is >= sbi->s_mb_stream_request |
| * This make sure small files blocks are allocated in |
| * single attempt. This ensure that small files |
| * get less fragmented. |
| */ |
| if (wbc->nr_to_write < sbi->s_mb_stream_request) { |
| nr_to_writebump = sbi->s_mb_stream_request - wbc->nr_to_write; |
| wbc->nr_to_write = sbi->s_mb_stream_request; |
| } |
| if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) |
| range_whole = 1; |
| |
| range_cyclic = wbc->range_cyclic; |
| if (wbc->range_cyclic) { |
| index = mapping->writeback_index; |
| if (index) |
| cycled = 0; |
| wbc->range_start = index << PAGE_CACHE_SHIFT; |
| wbc->range_end = LLONG_MAX; |
| wbc->range_cyclic = 0; |
| } else |
| index = wbc->range_start >> PAGE_CACHE_SHIFT; |
| |
| mpd.wbc = wbc; |
| mpd.inode = mapping->host; |
| |
| /* |
| * we don't want write_cache_pages to update |
| * nr_to_write and writeback_index |
| */ |
| no_nrwrite_index_update = wbc->no_nrwrite_index_update; |
| wbc->no_nrwrite_index_update = 1; |
| pages_skipped = wbc->pages_skipped; |
| |
| retry: |
| while (!ret && wbc->nr_to_write > 0) { |
| |
| /* |
| * we insert one extent at a time. So we need |
| * credit needed for single extent allocation. |
| * journalled mode is currently not supported |
| * by delalloc |
| */ |
| BUG_ON(ext4_should_journal_data(inode)); |
| needed_blocks = ext4_da_writepages_trans_blocks(inode); |
| |
| /* start a new transaction*/ |
| handle = ext4_journal_start(inode, needed_blocks); |
| if (IS_ERR(handle)) { |
| ret = PTR_ERR(handle); |
| printk(KERN_CRIT "%s: jbd2_start: " |
| "%ld pages, ino %lu; err %d\n", __func__, |
| wbc->nr_to_write, inode->i_ino, ret); |
| dump_stack(); |
| goto out_writepages; |
| } |
| mpd.get_block = ext4_da_get_block_write; |
| ret = mpage_da_writepages(mapping, wbc, &mpd); |
| |
| ext4_journal_stop(handle); |
| |
| if ((mpd.retval == -ENOSPC) && sbi->s_journal) { |
| /* commit the transaction which would |
| * free blocks released in the transaction |
| * and try again |
| */ |
| jbd2_journal_force_commit_nested(sbi->s_journal); |
| wbc->pages_skipped = pages_skipped; |
| ret = 0; |
| } else if (ret == MPAGE_DA_EXTENT_TAIL) { |
| /* |
| * got one extent now try with |
| * rest of the pages |
| */ |
| pages_written += mpd.pages_written; |
| wbc->pages_skipped = pages_skipped; |
| ret = 0; |
| io_done = 1; |
| } else if (wbc->nr_to_write) |
| /* |
| * There is no more writeout needed |
| * or we requested for a noblocking writeout |
| * and we found the device congested |
| */ |
| break; |
| } |
| if (!io_done && !cycled) { |
| cycled = 1; |
| index = 0; |
| wbc->range_start = index << PAGE_CACHE_SHIFT; |
| wbc->range_end = mapping->writeback_index - 1; |
| goto retry; |
| } |
| if (pages_skipped != wbc->pages_skipped) |
| printk(KERN_EMERG "This should not happen leaving %s " |
| "with nr_to_write = %ld ret = %d\n", |
| __func__, wbc->nr_to_write, ret); |
| |
| /* Update index */ |
| index += pages_written; |
| wbc->range_cyclic = range_cyclic; |
| if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) |
| /* |
| * set the writeback_index so that range_cyclic |
| * mode will write it back later |
| */ |
| mapping->writeback_index = index; |
| |
| out_writepages: |
| if (!no_nrwrite_index_update) |
| wbc->no_nrwrite_index_update = 0; |
| wbc->nr_to_write -= nr_to_writebump; |
| trace_mark(ext4_da_writepage_result, |
| "dev %s ino %lu ret %d pages_written %d " |
| "pages_skipped %ld congestion %d " |
| "more_io %d no_nrwrite_index_update %d", |
| inode->i_sb->s_id, inode->i_ino, ret, |
| pages_written, wbc->pages_skipped, |
| wbc->encountered_congestion, wbc->more_io, |
| wbc->no_nrwrite_index_update); |
| return ret; |
| } |
| |
| #define FALL_BACK_TO_NONDELALLOC 1 |
| static int ext4_nonda_switch(struct super_block *sb) |
| { |
| s64 free_blocks, dirty_blocks; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| |
| /* |
| * switch to non delalloc mode if we are running low |
| * on free block. The free block accounting via percpu |
| * counters can get slightly wrong with percpu_counter_batch getting |
| * accumulated on each CPU without updating global counters |
| * Delalloc need an accurate free block accounting. So switch |
| * to non delalloc when we are near to error range. |
| */ |
| free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter); |
| dirty_blocks = percpu_counter_read_positive(&sbi->s_dirtyblocks_counter); |
| if (2 * free_blocks < 3 * dirty_blocks || |
| free_blocks < (dirty_blocks + EXT4_FREEBLOCKS_WATERMARK)) { |
| /* |
| * free block count is less that 150% of dirty blocks |
| * or free blocks is less that watermark |
| */ |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int ext4_da_write_begin(struct file *file, struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned flags, |
| struct page **pagep, void **fsdata) |
| { |
| int ret, retries = 0; |
| struct page *page; |
| pgoff_t index; |
| unsigned from, to; |
| struct inode *inode = mapping->host; |
| handle_t *handle; |
| |
| index = pos >> PAGE_CACHE_SHIFT; |
| from = pos & (PAGE_CACHE_SIZE - 1); |
| to = from + len; |
| |
| if (ext4_nonda_switch(inode->i_sb)) { |
| *fsdata = (void *)FALL_BACK_TO_NONDELALLOC; |
| return ext4_write_begin(file, mapping, pos, |
| len, flags, pagep, fsdata); |
| } |
| *fsdata = (void *)0; |
| |
| trace_mark(ext4_da_write_begin, |
| "dev %s ino %lu pos %llu len %u flags %u", |
| inode->i_sb->s_id, inode->i_ino, |
| (unsigned long long) pos, len, flags); |
| retry: |
| /* |
| * With delayed allocation, we don't log the i_disksize update |
| * if there is delayed block allocation. But we still need |
| * to journalling the i_disksize update if writes to the end |
| * of file which has an already mapped buffer. |
| */ |
| handle = ext4_journal_start(inode, 1); |
| if (IS_ERR(handle)) { |
| ret = PTR_ERR(handle); |
| goto out; |
| } |
| /* We cannot recurse into the filesystem as the transaction is already |
| * started */ |
| flags |= AOP_FLAG_NOFS; |
| |
| page = grab_cache_page_write_begin(mapping, index, flags); |
| if (!page) { |
| ext4_journal_stop(handle); |
| ret = -ENOMEM; |
| goto out; |
| } |
| *pagep = page; |
| |
| ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata, |
| ext4_da_get_block_prep); |
| if (ret < 0) { |
| unlock_page(page); |
| ext4_journal_stop(handle); |
| page_cache_release(page); |
| /* |
| * block_write_begin may have instantiated a few blocks |
| * outside i_size. Trim these off again. Don't need |
| * i_size_read because we hold i_mutex. |
| */ |
| if (pos + len > inode->i_size) |
| vmtruncate(inode, inode->i_size); |
| } |
| |
| if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) |
| goto retry; |
| out: |
| return ret; |
| } |
| |
| /* |
| * Check if we should update i_disksize |
| * when write to the end of file but not require block allocation |
| */ |
| static int ext4_da_should_update_i_disksize(struct page *page, |
| unsigned long offset) |
| { |
| struct buffer_head *bh; |
| struct inode *inode = page->mapping->host; |
| unsigned int idx; |
| int i; |
| |
| bh = page_buffers(page); |
| idx = offset >> inode->i_blkbits; |
| |
| for (i = 0; i < idx; i++) |
| bh = bh->b_this_page; |
| |
| if (!buffer_mapped(bh) || (buffer_delay(bh))) |
| return 0; |
| return 1; |
| } |
| |
| static int ext4_da_write_end(struct file *file, |
| struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned copied, |
| struct page *page, void *fsdata) |
| { |
| struct inode *inode = mapping->host; |
| int ret = 0, ret2; |
| handle_t *handle = ext4_journal_current_handle(); |
| loff_t new_i_size; |
| unsigned long start, end; |
| int write_mode = (int)(unsigned long)fsdata; |
| |
| if (write_mode == FALL_BACK_TO_NONDELALLOC) { |
| if (ext4_should_order_data(inode)) { |
| return ext4_ordered_write_end(file, mapping, pos, |
| len, copied, page, fsdata); |
| } else if (ext4_should_writeback_data(inode)) { |
| return ext4_writeback_write_end(file, mapping, pos, |
| len, copied, page, fsdata); |
| } else { |
| BUG(); |
| } |
| } |
| |
| trace_mark(ext4_da_write_end, |
| "dev %s ino %lu pos %llu len %u copied %u", |
| inode->i_sb->s_id, inode->i_ino, |
| (unsigned long long) pos, len, copied); |
| start = pos & (PAGE_CACHE_SIZE - 1); |
| end = start + copied - 1; |
| |
| /* |
| * generic_write_end() will run mark_inode_dirty() if i_size |
| * changes. So let's piggyback the i_disksize mark_inode_dirty |
| * into that. |
| */ |
| |
| new_i_size = pos + copied; |
| if (new_i_size > EXT4_I(inode)->i_disksize) { |
| if (ext4_da_should_update_i_disksize(page, end)) { |
| down_write(&EXT4_I(inode)->i_data_sem); |
| if (new_i_size > EXT4_I(inode)->i_disksize) { |
| /* |
| * Updating i_disksize when extending file |
| * without needing block allocation |
| */ |
| if (ext4_should_order_data(inode)) |
| ret = ext4_jbd2_file_inode(handle, |
| inode); |
| |
| EXT4_I(inode)->i_disksize = new_i_size; |
| } |
| up_write(&EXT4_I(inode)->i_data_sem); |
| /* We need to mark inode dirty even if |
| * new_i_size is less that inode->i_size |
| * bu greater than i_disksize.(hint delalloc) |
| */ |
| ext4_mark_inode_dirty(handle, inode); |
| } |
| } |
| ret2 = generic_write_end(file, mapping, pos, len, copied, |
| page, fsdata); |
| copied = ret2; |
| if (ret2 < 0) |
| ret = ret2; |
| ret2 = ext4_journal_stop(handle); |
| if (!ret) |
| ret = ret2; |
| |
| return ret ? ret : copied; |
| } |
| |
| static void ext4_da_invalidatepage(struct page *page, unsigned long offset) |
| { |
| /* |
| * Drop reserved blocks |
| */ |
| BUG_ON(!PageLocked(page)); |
| if (!page_has_buffers(page)) |
| goto out; |
| |
| ext4_da_page_release_reservation(page, offset); |
| |
| out: |
| ext4_invalidatepage(page, offset); |
| |
| return; |
| } |
| |
| |
| /* |
| * bmap() is special. It gets used by applications such as lilo and by |
| * the swapper to find the on-disk block of a specific piece of data. |
| * |
| * Naturally, this is dangerous if the block concerned is still in the |
| * journal. If somebody makes a swapfile on an ext4 data-journaling |
| * filesystem and enables swap, then they may get a nasty shock when the |
| * data getting swapped to that swapfile suddenly gets overwritten by |
| * the original zero's written out previously to the journal and |
| * awaiting writeback in the kernel's buffer cache. |
| * |
| * So, if we see any bmap calls here on a modified, data-journaled file, |
| * take extra steps to flush any blocks which might be in the cache. |
| */ |
| static sector_t ext4_bmap(struct address_space *mapping, sector_t block) |
| { |
| struct inode *inode = mapping->host; |
| journal_t *journal; |
| int err; |
| |
| if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) && |
| test_opt(inode->i_sb, DELALLOC)) { |
| /* |
| * With delalloc we want to sync the file |
| * so that we can make sure we allocate |
| * blocks for file |
| */ |
| filemap_write_and_wait(mapping); |
| } |
| |
| if (EXT4_JOURNAL(inode) && EXT4_I(inode)->i_state & EXT4_STATE_JDATA) { |
| /* |
| * This is a REALLY heavyweight approach, but the use of |
| * bmap on dirty files is expected to be extremely rare: |
| * only if we run lilo or swapon on a freshly made file |
| * do we expect this to happen. |
| * |
| * (bmap requires CAP_SYS_RAWIO so this does not |
| * represent an unprivileged user DOS attack --- we'd be |
| * in trouble if mortal users could trigger this path at |
| * will.) |
| * |
| * NB. EXT4_STATE_JDATA is not set on files other than |
| * regular files. If somebody wants to bmap a directory |
| * or symlink and gets confused because the buffer |
| * hasn't yet been flushed to disk, they deserve |
| * everything they get. |
| */ |
| |
| EXT4_I(inode)->i_state &= ~EXT4_STATE_JDATA; |
| journal = EXT4_JOURNAL(inode); |
| jbd2_journal_lock_updates(journal); |
| err = jbd2_journal_flush(journal); |
| jbd2_journal_unlock_updates(journal); |
| |
| if (err) |
| return 0; |
| } |
| |
| return generic_block_bmap(mapping, block, ext4_get_block); |
| } |
| |
| static int bget_one(handle_t *handle, struct buffer_head *bh) |
| { |
| get_bh(bh); |
| return 0; |
| } |
| |
| static int bput_one(handle_t *handle, struct buffer_head *bh) |
| { |
| put_bh(bh); |
| return 0; |
| } |
| |
| /* |
| * Note that we don't need to start a transaction unless we're journaling data |
| * because we should have holes filled from ext4_page_mkwrite(). We even don't |
| * need to file the inode to the transaction's list in ordered mode because if |
| * we are writing back data added by write(), the inode is already there and if |
| * we are writing back data modified via mmap(), noone guarantees in which |
| * transaction the data will hit the disk. In case we are journaling data, we |
| * cannot start transaction directly because transaction start ranks above page |
| * lock so we have to do some magic. |
| * |
| * In all journaling modes block_write_full_page() will start the I/O. |
| * |
| * Problem: |
| * |
| * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() -> |
| * ext4_writepage() |
| * |
| * Similar for: |
| * |
| * ext4_file_write() -> generic_file_write() -> __alloc_pages() -> ... |
| * |
| * Same applies to ext4_get_block(). We will deadlock on various things like |
| * lock_journal and i_data_sem |
| * |
| * Setting PF_MEMALLOC here doesn't work - too many internal memory |
| * allocations fail. |
| * |
| * 16May01: If we're reentered then journal_current_handle() will be |
| * non-zero. We simply *return*. |
| * |
| * 1 July 2001: @@@ FIXME: |
| * In journalled data mode, a data buffer may be metadata against the |
| * current transaction. But the same file is part of a shared mapping |
| * and someone does a writepage() on it. |
| * |
| * We will move the buffer onto the async_data list, but *after* it has |
| * been dirtied. So there's a small window where we have dirty data on |
| * BJ_Metadata. |
| * |
| * Note that this only applies to the last partial page in the file. The |
| * bit which block_write_full_page() uses prepare/commit for. (That's |
| * broken code anyway: it's wrong for msync()). |
| * |
| * It's a rare case: affects the final partial page, for journalled data |
| * where the file is subject to bith write() and writepage() in the same |
| * transction. To fix it we'll need a custom block_write_full_page(). |
| * We'll probably need that anyway for journalling writepage() output. |
| * |
| * We don't honour synchronous mounts for writepage(). That would be |
| * disastrous. Any write() or metadata operation will sync the fs for |
| * us. |
| * |
| */ |
| static int __ext4_normal_writepage(struct page *page, |
| struct writeback_control *wbc) |
| { |
| struct inode *inode = page->mapping->host; |
| |
| if (test_opt(inode->i_sb, NOBH)) |
| return nobh_writepage(page, |
| ext4_normal_get_block_write, wbc); |
| else |
| return block_write_full_page(page, |
| ext4_normal_get_block_write, |
| wbc); |
| } |
| |
| static int ext4_normal_writepage(struct page *page, |
| struct writeback_control *wbc) |
| { |
| struct inode *inode = page->mapping->host; |
| loff_t size = i_size_read(inode); |
| loff_t len; |
| |
| trace_mark(ext4_normal_writepage, |
| "dev %s ino %lu page_index %lu", |
| inode->i_sb->s_id, inode->i_ino, page->index); |
| J_ASSERT(PageLocked(page)); |
| if (page->index == size >> PAGE_CACHE_SHIFT) |
| len = size & ~PAGE_CACHE_MASK; |
| else |
| len = PAGE_CACHE_SIZE; |
| |
| if (page_has_buffers(page)) { |
| /* if page has buffers it should all be mapped |
| * and allocated. If there are not buffers attached |
| * to the page we know the page is dirty but it lost |
| * buffers. That means that at some moment in time |
| * after write_begin() / write_end() has been called |
| * all buffers have been clean and thus they must have been |
| * written at least once. So they are all mapped and we can |
| * happily proceed with mapping them and writing the page. |
| */ |
| BUG_ON(walk_page_buffers(NULL, page_buffers(page), 0, len, NULL, |
| ext4_bh_unmapped_or_delay)); |
| } |
| |
| if (!ext4_journal_current_handle()) |
| return __ext4_normal_writepage(page, wbc); |
| |
| redirty_page_for_writepage(wbc, page); |
| unlock_page(page); |
| return 0; |
| } |
| |
| static int __ext4_journalled_writepage(struct page *page, |
| struct writeback_control *wbc) |
| { |
| struct address_space *mapping = page->mapping; |
| struct inode *inode = mapping->host; |
| struct buffer_head *page_bufs; |
| handle_t *handle = NULL; |
| int ret = 0; |
| int err; |
| |
| ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE, |
| ext4_normal_get_block_write); |
| if (ret != 0) |
| goto out_unlock; |
| |
| page_bufs = page_buffers(page); |
| walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE, NULL, |
| bget_one); |
| /* As soon as we unlock the page, it can go away, but we have |
| * references to buffers so we are safe */ |
| unlock_page(page); |
| |
| handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode)); |
| if (IS_ERR(handle)) { |
| ret = PTR_ERR(handle); |
| goto out; |
| } |
| |
| ret = walk_page_buffers(handle, page_bufs, 0, |
| PAGE_CACHE_SIZE, NULL, do_journal_get_write_access); |
| |
| err = walk_page_buffers(handle, page_bufs, 0, |
| PAGE_CACHE_SIZE, NULL, write_end_fn); |
| if (ret == 0) |
| ret = err; |
| err = ext4_journal_stop(handle); |
| if (!ret) |
| ret = err; |
| |
| walk_page_buffers(handle, page_bufs, 0, |
| PAGE_CACHE_SIZE, NULL, bput_one); |
| EXT4_I(inode)->i_state |= EXT4_STATE_JDATA; |
| goto out; |
| |
| out_unlock: |
| unlock_page(page); |
| out: |
| return ret; |
| } |
| |
| static int ext4_journalled_writepage(struct page *page, |
| struct writeback_control *wbc) |
| { |
| struct inode *inode = page->mapping->host; |
| loff_t size = i_size_read(inode); |
| loff_t len; |
| |
| trace_mark(ext4_journalled_writepage, |
| "dev %s ino %lu page_index %lu", |
| inode->i_sb->s_id, inode->i_ino, page->index); |
| J_ASSERT(PageLocked(page)); |
| if (page->index == size >> PAGE_CACHE_SHIFT) |
| len = size & ~PAGE_CACHE_MASK; |
| else |
| len = PAGE_CACHE_SIZE; |
| |
| if (page_has_buffers(page)) { |
| /* if page has buffers it should all be mapped |
| * and allocated. If there are not buffers attached |
| * to the page we know the page is dirty but it lost |
| * buffers. That means that at some moment in time |
| * after write_begin() / write_end() has been called |
| * all buffers have been clean and thus they must have been |
| * written at least once. So they are all mapped and we can |
| * happily proceed with mapping them and writing the page. |
| */ |
| BUG_ON(walk_page_buffers(NULL, page_buffers(page), 0, len, NULL, |
| ext4_bh_unmapped_or_delay)); |
| } |
| |
| if (ext4_journal_current_handle()) |
| goto no_write; |
| |
| if (PageChecked(page)) { |
| /* |
| * It's mmapped pagecache. Add buffers and journal it. There |
| * doesn't seem much point in redirtying the page here. |
| */ |
| ClearPageChecked(page); |
| return __ext4_journalled_writepage(page, wbc); |
| } else { |
| /* |
| * It may be a page full of checkpoint-mode buffers. We don't |
| * really know unless we go poke around in the buffer_heads. |
| * But block_write_full_page will do the right thing. |
| */ |
| return block_write_full_page(page, |
| ext4_normal_get_block_write, |
| wbc); |
| } |
| no_write: |
| redirty_page_for_writepage(wbc, page); |
| unlock_page(page); |
| return 0; |
| } |
| |
| static int ext4_readpage(struct file *file, struct page *page) |
| { |
| return mpage_readpage(page, ext4_get_block); |
| } |
| |
| static int |
| ext4_readpages(struct file *file, struct address_space *mapping, |
| struct list_head *pages, unsigned nr_pages) |
| { |
| return mpage_readpages(mapping, pages, nr_pages, ext4_get_block); |
| } |
| |
| static void ext4_invalidatepage(struct page *page, unsigned long offset) |
| { |
| journal_t *journal = EXT4_JOURNAL(page->mapping->host); |
| |
| /* |
| * If it's a full truncate we just forget about the pending dirtying |
| */ |
| if (offset == 0) |
| ClearPageChecked(page); |
| |
| if (journal) |
| jbd2_journal_invalidatepage(journal, page, offset); |
| else |
| block_invalidatepage(page, offset); |
| } |
| |
| static int ext4_releasepage(struct page *page, gfp_t wait) |
| { |
| journal_t *journal = EXT4_JOURNAL(page->mapping->host); |
| |
| WARN_ON(PageChecked(page)); |
| if (!page_has_buffers(page)) |
| return 0; |
| if (journal) |
| return jbd2_journal_try_to_free_buffers(journal, page, wait); |
| else |
| return try_to_free_buffers(page); |
| } |
| |
| /* |
| * If the O_DIRECT write will extend the file then add this inode to the |
| * orphan list. So recovery will truncate it back to the original size |
| * if the machine crashes during the write. |
| * |
| * If the O_DIRECT write is intantiating holes inside i_size and the machine |
| * crashes then stale disk data _may_ be exposed inside the file. But current |
| * VFS code falls back into buffered path in that case so we are safe. |
| */ |
| static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb, |
| const struct iovec *iov, loff_t offset, |
| unsigned long nr_segs) |
| { |
| struct file *file = iocb->ki_filp; |
| struct inode *inode = file->f_mapping->host; |
| struct ext4_inode_info *ei = EXT4_I(inode); |
| handle_t *handle; |
| ssize_t ret; |
| int orphan = 0; |
| size_t count = iov_length(iov, nr_segs); |
| |
| if (rw == WRITE) { |
| loff_t final_size = offset + count; |
| |
| if (final_size > inode->i_size) { |
| /* Credits for sb + inode write */ |
| handle = ext4_journal_start(inode, 2); |
| if (IS_ERR(handle)) { |
| ret = PTR_ERR(handle); |
| goto out; |
| } |
| ret = ext4_orphan_add(handle, inode); |
| if (ret) { |
| ext4_journal_stop(handle); |
| goto out; |
| } |
| orphan = 1; |
| ei->i_disksize = inode->i_size; |
| ext4_journal_stop(handle); |
| } |
| } |
| |
| ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov, |
| offset, nr_segs, |
| ext4_get_block, NULL); |
| |
| if (orphan) { |
| int err; |
| |
| /* Credits for sb + inode write */ |
| handle = ext4_journal_start(inode, 2); |
| if (IS_ERR(handle)) { |
| /* This is really bad luck. We've written the data |
| * but cannot extend i_size. Bail out and pretend |
| * the write failed... */ |
| ret = PTR_ERR(handle); |
| goto out; |
| } |
| if (inode->i_nlink) |
| ext4_orphan_del(handle, inode); |
| if (ret > 0) { |
| loff_t end = offset + ret; |
| if (end > inode->i_size) { |
| ei->i_disksize = end; |
| i_size_write(inode, end); |
| /* |
| * We're going to return a positive `ret' |
| * here due to non-zero-length I/O, so there's |
| * no way of reporting error returns from |
| * ext4_mark_inode_dirty() to userspace. So |
| * ignore it. |
| */ |
| ext4_mark_inode_dirty(handle, inode); |
| } |
| } |
| err = ext4_journal_stop(handle); |
| if (ret == 0) |
| ret = err; |
| } |
| out: |
| return ret; |
| } |
| |
| /* |
| * Pages can be marked dirty completely asynchronously from ext4's journalling |
| * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do |
| * much here because ->set_page_dirty is called under VFS locks. The page is |
| * not necessarily locked. |
| * |
| * We cannot just dirty the page and leave attached buffers clean, because the |
| * buffers' dirty state is "definitive". We cannot just set the buffers dirty |
| * or jbddirty because all the journalling code will explode. |
| * |
| * So what we do is to mark the page "pending dirty" and next time writepage |
| * is called, propagate that into the buffers appropriately. |
| */ |
| static int ext4_journalled_set_page_dirty(struct page *page) |
| { |
| SetPageChecked(page); |
| return __set_page_dirty_nobuffers(page); |
| } |
| |
| static const struct address_space_operations ext4_ordered_aops = { |
| .readpage = ext4_readpage, |
| .readpages = ext4_readpages, |
| .writepage = ext4_normal_writepage, |
| .sync_page = block_sync_page, |
| .write_begin = ext4_write_begin, |
| .write_end = ext4_ordered_write_end, |
| .bmap = ext4_bmap, |
| .invalidatepage = ext4_invalidatepage, |
| .releasepage = ext4_releasepage, |
| .direct_IO = ext4_direct_IO, |
| .migratepage = buffer_migrate_page, |
| .is_partially_uptodate = block_is_partially_uptodate, |
| }; |
| |
| static const struct address_space_operations ext4_writeback_aops = { |
| .readpage = ext4_readpage, |
| .readpages = ext4_readpages, |
| .writepage = ext4_normal_writepage, |
| .sync_page = block_sync_page, |
| .write_begin = ext4_write_begin, |
| .write_end = ext4_writeback_write_end, |
| .bmap = ext4_bmap, |
| .invalidatepage = ext4_invalidatepage, |
| .releasepage = ext4_releasepage, |
| .direct_IO = ext4_direct_IO, |
| .migratepage = buffer_migrate_page, |
| .is_partially_uptodate = block_is_partially_uptodate, |
| }; |
| |
| static const struct address_space_operations ext4_journalled_aops = { |
| .readpage = ext4_readpage, |
| .readpages = ext4_readpages, |
| .writepage = ext4_journalled_writepage, |
| .sync_page = block_sync_page, |
| .write_begin = ext4_write_begin, |
| .write_end = ext4_journalled_write_end, |
| .set_page_dirty = ext4_journalled_set_page_dirty, |
| .bmap = ext4_bmap, |
| .invalidatepage = ext4_invalidatepage, |
| .releasepage = ext4_releasepage, |
| .is_partially_uptodate = block_is_partially_uptodate, |
| }; |
| |
| static const struct address_space_operations ext4_da_aops = { |
| .readpage = ext4_readpage, |
| .readpages = ext4_readpages, |
| .writepage = ext4_da_writepage, |
| .writepages = ext4_da_writepages, |
| .sync_page = block_sync_page, |
| .write_begin = ext4_da_write_begin, |
| .write_end = ext4_da_write_end, |
| .bmap = ext4_bmap, |
| .invalidatepage = ext4_da_invalidatepage, |
| .releasepage = ext4_releasepage, |
| .direct_IO = ext4_direct_IO, |
| .migratepage = buffer_migrate_page, |
| .is_partially_uptodate = block_is_partially_uptodate, |
| }; |
| |
| void ext4_set_aops(struct inode *inode) |
| { |
| if (ext4_should_order_data(inode) && |
| test_opt(inode->i_sb, DELALLOC)) |
| inode->i_mapping->a_ops = &ext4_da_aops; |
| else if (ext4_should_order_data(inode)) |
| inode->i_mapping->a_ops = &ext4_ordered_aops; |
| else if (ext4_should_writeback_data(inode) && |
| test_opt(inode->i_sb, DELALLOC)) |
| inode->i_mapping->a_ops = &ext4_da_aops; |
| else if (ext4_should_writeback_data(inode)) |
| inode->i_mapping->a_ops = &ext4_writeback_aops; |
| else |
| inode->i_mapping->a_ops = &ext4_journalled_aops; |
| } |
| |
| /* |
| * ext4_block_truncate_page() zeroes out a mapping from file offset `from' |
| * up to the end of the block which corresponds to `from'. |
| * This required during truncate. We need to physically zero the tail end |
| * of that block so it doesn't yield old data if the file is later grown. |
| */ |
| int ext4_block_truncate_page(handle_t *handle, |
| struct address_space *mapping, loff_t from) |
| { |
| ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT; |
| unsigned offset = from & (PAGE_CACHE_SIZE-1); |
| unsigned blocksize, length, pos; |
| ext4_lblk_t iblock; |
| struct inode *inode = mapping->host; |
| struct buffer_head *bh; |
| struct page *page; |
| int err = 0; |
| |
| page = grab_cache_page(mapping, from >> PAGE_CACHE_SHIFT); |
| if (!page) |
| return -EINVAL; |
| |
| blocksize = inode->i_sb->s_blocksize; |
| length = blocksize - (offset & (blocksize - 1)); |
| iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits); |
| |
| /* |
| * For "nobh" option, we can only work if we don't need to |
| * read-in the page - otherwise we create buffers to do the IO. |
| */ |
| if (!page_has_buffers(page) && test_opt(inode->i_sb, NOBH) && |
| ext4_should_writeback_data(inode) && PageUptodate(page)) { |
| zero_user(page, offset, length); |
| set_page_dirty(page); |
| goto unlock; |
| } |
| |
| if (!page_has_buffers(page)) |
| create_empty_buffers(page, blocksize, 0); |
| |
| /* Find the buffer that contains "offset" */ |
| bh = page_buffers(page); |
| pos = blocksize; |
| while (offset >= pos) { |
| bh = bh->b_this_page; |
| iblock++; |
| pos += blocksize; |
| } |
| |
| err = 0; |
| if (buffer_freed(bh)) { |
| BUFFER_TRACE(bh, "freed: skip"); |
| goto unlock; |
| } |
| |
| if (!buffer_mapped(bh)) { |
| BUFFER_TRACE(bh, "unmapped"); |
| ext4_get_block(inode, iblock, bh, 0); |
| /* unmapped? It's a hole - nothing to do */ |
| if (!buffer_mapped(bh)) { |
| BUFFER_TRACE(bh, "still unmapped"); |
| goto unlock; |
| } |
| } |
| |
| /* Ok, it's mapped. Make sure it's up-to-date */ |
| if (PageUptodate(page)) |
| set_buffer_uptodate(bh); |
| |
| if (!buffer_uptodate(bh)) { |
| err = -EIO; |
| ll_rw_block(READ, 1, &bh); |
| wait_on_buffer(bh); |
| /* Uhhuh. Read error. Complain and punt. */ |
| if (!buffer_uptodate(bh)) |
| goto unlock; |
| } |
| |
| if (ext4_should_journal_data(inode)) { |
| BUFFER_TRACE(bh, "get write access"); |
| err = ext4_journal_get_write_access(handle, bh); |
| if (err) |
| goto unlock; |
| } |
| |
| zero_user(page, offset, length); |
| |
| BUFFER_TRACE(bh, "zeroed end of block"); |
| |
| err = 0; |
| if (ext4_should_journal_data(inode)) { |
| err = ext4_handle_dirty_metadata(handle, inode, bh); |
| } else { |
| if (ext4_should_order_data(inode)) |
| err = ext4_jbd2_file_inode(handle, inode); |
| mark_buffer_dirty(bh); |
| } |
| |
| unlock: |
| unlock_page(page); |
| page_cache_release(page); |
| return err; |
| } |
| |
| /* |
| * Probably it should be a library function... search for first non-zero word |
| * or memcmp with zero_page, whatever is better for particular architecture. |
| * Linus? |
| */ |
| static inline int all_zeroes(__le32 *p, __le32 *q) |
| { |
| while (p < q) |
| if (*p++) |
| return 0; |
| return 1; |
| } |
| |
| /** |
| * ext4_find_shared - find the indirect blocks for partial truncation. |
| * @inode: inode in question |
| * @depth: depth of the affected branch |
| * @offsets: offsets of pointers in that branch (see ext4_block_to_path) |
| * @chain: place to store the pointers to partial indirect blocks |
| * @top: place to the (detached) top of branch |
| * |
| * This is a helper function used by ext4_truncate(). |
| * |
| * When we do truncate() we may have to clean the ends of several |
| * indirect blocks but leave the blocks themselves alive. Block is |
| * partially truncated if some data below the new i_size is refered |
| * from it (and it is on the path to the first completely truncated |
| * data block, indeed). We have to free the top of that path along |
| * with everything to the right of the path. Since no allocation |
| * past the truncation point is possible until ext4_truncate() |
| * finishes, we may safely do the latter, but top of branch may |
| * require special attention - pageout below the truncation point |
| * might try to populate it. |
| * |
| * We atomically detach the top of branch from the tree, store the |
| * block number of its root in *@top, pointers to buffer_heads of |
| * partially truncated blocks - in @chain[].bh and pointers to |
| * their last elements that should not be removed - in |
| * @chain[].p. Return value is the pointer to last filled element |
| * of @chain. |
| * |
| * The work left to caller to do the actual freeing of subtrees: |
| * a) free the subtree starting from *@top |
| * b) free the subtrees whose roots are stored in |
| * (@chain[i].p+1 .. end of @chain[i].bh->b_data) |
| * c) free the subtrees growing from the inode past the @chain[0]. |
| * (no partially truncated stuff there). */ |
| |
| static Indirect *ext4_find_shared(struct inode *inode, int depth, |
| ext4_lblk_t offsets[4], Indirect chain[4], __le32 *top) |
| { |
| Indirect *partial, *p; |
| int k, err; |
| |
| *top = 0; |
| /* Make k index the deepest non-null offest + 1 */ |
| for (k = depth; k > 1 && !offsets[k-1]; k--) |
| ; |
| partial = ext4_get_branch(inode, k, offsets, chain, &err); |
| /* Writer: pointers */ |
| if (!partial) |
| partial = chain + k-1; |
| /* |
| * If the branch acquired continuation since we've looked at it - |
| * fine, it should all survive and (new) top doesn't belong to us. |
| */ |
| if (!partial->key && *partial->p) |
| /* Writer: end */ |
| goto no_top; |
| for (p = partial; (p > chain) && all_zeroes((__le32 *) p->bh->b_data, p->p); p--) |
| ; |
| /* |
| * OK, we've found the last block that must survive. The rest of our |
| * branch should be detached before unlocking. However, if that rest |
| * of branch is all ours and does not grow immediately from the inode |
| * it's easier to cheat and just decrement partial->p. |
| */ |
| if (p == chain + k - 1 && p > chain) { |
| p->p--; |
| } else { |
| *top = *p->p; |
| /* Nope, don't do this in ext4. Must leave the tree intact */ |
| #if 0 |
| *p->p = 0; |
| #endif |
| } |
| /* Writer: end */ |
| |
| while (partial > p) { |
| brelse(partial->bh); |
| partial--; |
| } |
| no_top: |
| return partial; |
| } |
| |
| /* |
| * Zero a number of block pointers in either an inode or an indirect block. |
| * If we restart the transaction we must again get write access to the |
| * indirect block for further modification. |
| * |
| * We release `count' blocks on disk, but (last - first) may be greater |
| * than `count' because there can be holes in there. |
| */ |
| static void ext4_clear_blocks(handle_t *handle, struct inode *inode, |
| struct buffer_head *bh, ext4_fsblk_t block_to_free, |
| unsigned long count, __le32 *first, __le32 *last) |
| { |
| __le32 *p; |
| if (try_to_extend_transaction(handle, inode)) { |
| if (bh) { |
| BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); |
| ext4_handle_dirty_metadata(handle, inode, bh); |
| } |
| ext4_mark_inode_dirty(handle, inode); |
| ext4_journal_test_restart(handle, inode); |
| if (bh) { |
| BUFFER_TRACE(bh, "retaking write access"); |
| ext4_journal_get_write_access(handle, bh); |
| } |
| } |
| |
| /* |
| * Any buffers which are on the journal will be in memory. We find |
| * them on the hash table so jbd2_journal_revoke() will run jbd2_journal_forget() |
| * on them. We've already detached each block from the file, so |
| * bforget() in jbd2_journal_forget() should be safe. |
| * |
| * AKPM: turn on bforget in jbd2_journal_forget()!!! |
| */ |
| for (p = first; p < last; p++) { |
| u32 nr = le32_to_cpu(*p); |
| if (nr) { |
| struct buffer_head *tbh; |
| |
| *p = 0; |
| tbh = sb_find_get_block(inode->i_sb, nr); |
| ext4_forget(handle, 0, inode, tbh, nr); |
| } |
| } |
| |
| ext4_free_blocks(handle, inode, block_to_free, count, 0); |
| } |
| |
| /** |
| * ext4_free_data - free a list of data blocks |
| * @handle: handle for this transaction |
| * @inode: inode we are dealing with |
| * @this_bh: indirect buffer_head which contains *@first and *@last |
| * @first: array of block numbers |
| * @last: points immediately past the end of array |
| * |
| * We are freeing all blocks refered from that array (numbers are stored as |
| * little-endian 32-bit) and updating @inode->i_blocks appropriately. |
| * |
| * We accumulate contiguous runs of blocks to free. Conveniently, if these |
| * blocks are contiguous then releasing them at one time will only affect one |
| * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't |
| * actually use a lot of journal space. |
| * |
| * @this_bh will be %NULL if @first and @last point into the inode's direct |
| * block pointers. |
| */ |
| static void ext4_free_data(handle_t *handle, struct inode *inode, |
| struct buffer_head *this_bh, |
| __le32 *first, __le32 *last) |
| { |
| ext4_fsblk_t block_to_free = 0; /* Starting block # of a run */ |
| unsigned long count = 0; /* Number of blocks in the run */ |
| __le32 *block_to_free_p = NULL; /* Pointer into inode/ind |
| corresponding to |
| block_to_free */ |
| ext4_fsblk_t nr; /* Current block # */ |
| __le32 *p; /* Pointer into inode/ind |
| for current block */ |
| int err; |
| |
| if (this_bh) { /* For indirect block */ |
| BUFFER_TRACE(this_bh, "get_write_access"); |
| err = ext4_journal_get_write_access(handle, this_bh); |
| /* Important: if we can't update the indirect pointers |
| * to the blocks, we can't free them. */ |
| if (err) |
| return; |
| } |
| |
| for (p = first; p < last; p++) { |
| nr = le32_to_cpu(*p); |
| if (nr) { |
| /* accumulate blocks to free if they're contiguous */ |
| if (count == 0) { |
| block_to_free = nr; |
| block_to_free_p = p; |
| count = 1; |
| } else if (nr == block_to_free + count) { |
| count++; |
| } else { |
| ext4_clear_blocks(handle, inode, this_bh, |
| block_to_free, |
| count, block_to_free_p, p); |
| block_to_free = nr; |
| block_to_free_p = p; |
| count = 1; |
| } |
| } |
| } |
| |
| if (count > 0) |
| ext4_clear_blocks(handle, inode, this_bh, block_to_free, |
| count, block_to_free_p, p); |
| |
| if (this_bh) { |
| BUFFER_TRACE(this_bh, "call ext4_handle_dirty_metadata"); |
| |
| /* |
| * The buffer head should have an attached journal head at this |
| * point. However, if the data is corrupted and an indirect |
| * block pointed to itself, it would have been detached when |
| * the block was cleared. Check for this instead of OOPSing. |
| */ |
| if ((EXT4_JOURNAL(inode) == NULL) || bh2jh(this_bh)) |
| ext4_handle_dirty_metadata(handle, inode, this_bh); |
| else |
| ext4_error(inode->i_sb, __func__, |
| "circular indirect block detected, " |
| "inode=%lu, block=%llu", |
| inode->i_ino, |
| (unsigned long long) this_bh->b_blocknr); |
| } |
| } |
| |
| /** |
| * ext4_free_branches - free an array of branches |
| * @handle: JBD handle for this transaction |
| * @inode: inode we are dealing with |
| * @parent_bh: the buffer_head which contains *@first and *@last |
| * @first: array of block numbers |
| * @last: pointer immediately past the end of array |
| * @depth: depth of the branches to free |
| * |
| * We are freeing all blocks refered from these branches (numbers are |
| * stored as little-endian 32-bit) and updating @inode->i_blocks |
| * appropriately. |
| */ |
| static void ext4_free_branches(handle_t *handle, struct inode *inode, |
| struct buffer_head *parent_bh, |
| __le32 *first, __le32 *last, int depth) |
| { |
| ext4_fsblk_t nr; |
| __le32 *p; |
| |
| if (ext4_handle_is_aborted(handle)) |
| return; |
| |
| if (depth--) { |
| struct buffer_head *bh; |
| int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb); |
| p = last; |
| while (--p >= first) { |
| nr = le32_to_cpu(*p); |
| if (!nr) |
| continue; /* A hole */ |
| |
| /* Go read the buffer for the next level down */ |
| bh = sb_bread(inode->i_sb, nr); |
| |
| /* |
| * A read failure? Report error and clear slot |
| * (should be rare). |
| */ |
| if (!bh) { |
| ext4_error(inode->i_sb, "ext4_free_branches", |
| "Read failure, inode=%lu, block=%llu", |
| inode->i_ino, nr); |
| continue; |
| } |
| |
| /* This zaps the entire block. Bottom up. */ |
| BUFFER_TRACE(bh, "free child branches"); |
| ext4_free_branches(handle, inode, bh, |
| (__le32 *) bh->b_data, |
| (__le32 *) bh->b_data + addr_per_block, |
| depth); |
| |
| /* |
| * We've probably journalled the indirect block several |
| * times during the truncate. But it's no longer |
| * needed and we now drop it from the transaction via |
| * jbd2_journal_revoke(). |
| * |
| * That's easy if it's exclusively part of this |
| * transaction. But if it's part of the committing |
| * transaction then jbd2_journal_forget() will simply |
| * brelse() it. That means that if the underlying |
| * block is reallocated in ext4_get_block(), |
| * unmap_underlying_metadata() will find this block |
| * and will try to get rid of it. damn, damn. |
| * |
| * If this block has already been committed to the |
| * journal, a revoke record will be written. And |
| * revoke records must be emitted *before* clearing |
| * this block's bit in the bitmaps. |
| */ |
| ext4_forget(handle, 1, inode, bh, bh->b_blocknr); |
| |
| /* |
| * Everything below this this pointer has been |
| * released. Now let this top-of-subtree go. |
| * |
| * We want the freeing of this indirect block to be |
| * atomic in the journal with the updating of the |
| * bitmap block which owns it. So make some room in |
| * the journal. |
| * |
| * We zero the parent pointer *after* freeing its |
| * pointee in the bitmaps, so if extend_transaction() |
| * for some reason fails to put the bitmap changes and |
| * the release into the same transaction, recovery |
| * will merely complain about releasing a free block, |
| * rather than leaking blocks. |
| */ |
| if (ext4_handle_is_aborted(handle)) |
| return; |
| if (try_to_extend_transaction(handle, inode)) { |
| ext4_mark_inode_dirty(handle, inode); |
| ext4_journal_test_restart(handle, inode); |
| } |
| |
| ext4_free_blocks(handle, inode, nr, 1, 1); |
| |
| if (parent_bh) { |
| /* |
| * The block which we have just freed is |
| * pointed to by an indirect block: journal it |
| */ |
| BUFFER_TRACE(parent_bh, "get_write_access"); |
| if (!ext4_journal_get_write_access(handle, |
| parent_bh)){ |
| *p = 0; |
| BUFFER_TRACE(parent_bh, |
| "call ext4_handle_dirty_metadata"); |
| ext4_handle_dirty_metadata(handle, |
| inode, |
| parent_bh); |
| } |
| } |
| } |
| } else { |
| /* We have reached the bottom of the tree. */ |
| BUFFER_TRACE(parent_bh, "free data blocks"); |
| ext4_free_data(handle, inode, parent_bh, first, last); |
| } |
| } |
| |
| int ext4_can_truncate(struct inode *inode) |
| { |
| if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) |
| return 0; |
| if (S_ISREG(inode->i_mode)) |
| return 1; |
| if (S_ISDIR(inode->i_mode)) |
| return 1; |
| if (S_ISLNK(inode->i_mode)) |
| return !ext4_inode_is_fast_symlink(inode); |
| return 0; |
| } |
| |
| /* |
| * ext4_truncate() |
| * |
| * We block out ext4_get_block() block instantiations across the entire |
| * transaction, and VFS/VM ensures that ext4_truncate() cannot run |
| * simultaneously on behalf of the same inode. |
| * |
| * As we work through the truncate and commmit bits of it to the journal there |
| * is one core, guiding principle: the file's tree must always be consistent on |
| * disk. We must be able to restart the truncate after a crash. |
| * |
| * The file's tree may be transiently inconsistent in memory (although it |
| * probably isn't), but whenever we close off and commit a journal transaction, |
| * the contents of (the filesystem + the journal) must be consistent and |
| * restartable. It's pretty simple, really: bottom up, right to left (although |
| * left-to-right works OK too). |
| * |
| * Note that at recovery time, journal replay occurs *before* the restart of |
| * truncate against the orphan inode list. |
| * |
| * The committed inode has the new, desired i_size (which is the same as |
| * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see |
| * that this inode's truncate did not complete and it will again call |
| * ext4_truncate() to have another go. So there will be instantiated blocks |
| * to the right of the truncation point in a crashed ext4 filesystem. But |
| * that's fine - as long as they are linked from the inode, the post-crash |
| * ext4_truncate() run will find them and release them. |
| */ |
| void ext4_truncate(struct inode *inode) |
| { |
| handle_t *handle; |
| struct ext4_inode_info *ei = EXT4_I(inode); |
| __le32 *i_data = ei->i_data; |
| int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb); |
| struct address_space *mapping = inode->i_mapping; |
| ext4_lblk_t offsets[4]; |
| Indirect chain[4]; |
| Indirect *partial; |
| __le32 nr = 0; |
| int n; |
| ext4_lblk_t last_block; |
| unsigned blocksize = inode->i_sb->s_blocksize; |
| |
| if (!ext4_can_truncate(inode)) |
| return; |
| |
| if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) { |
| ext4_ext_truncate(inode); |
| return; |
| } |
| |
| handle = start_transaction(inode); |
| if (IS_ERR(handle)) |
| return; /* AKPM: return what? */ |
| |
| last_block = (inode->i_size + blocksize-1) |
| >> EXT4_BLOCK_SIZE_BITS(inode->i_sb); |
| |
| if (inode->i_size & (blocksize - 1)) |
| if (ext4_block_truncate_page(handle, mapping, inode->i_size)) |
| goto out_stop; |
| |
| n = ext4_block_to_path(inode, last_block, offsets, NULL); |
| if (n == 0) |
| goto out_stop; /* error */ |
| |
| /* |
| * OK. This truncate is going to happen. We add the inode to the |
| * orphan list, so that if this truncate spans multiple transactions, |
| * and we crash, we will resume the truncate when the filesystem |
| * recovers. It also marks the inode dirty, to catch the new size. |
| * |
| * Implication: the file must always be in a sane, consistent |
| * truncatable state while each transaction commits. |
| */ |
| if (ext4_orphan_add(handle, inode)) |
| goto out_stop; |
| |
| /* |
| * From here we block out all ext4_get_block() callers who want to |
| * modify the block allocation tree. |
| */ |
| down_write(&ei->i_data_sem); |
| |
| ext4_discard_preallocations(inode); |
| |
| /* |
| * The orphan list entry will now protect us from any crash which |
| * occurs before the truncate completes, so it is now safe to propagate |
| * the new, shorter inode size (held for now in i_size) into the |
| * on-disk inode. We do this via i_disksize, which is the value which |
| * ext4 *really* writes onto the disk inode. |
| */ |
| ei->i_disksize = inode->i_size; |
| |
| if (n == 1) { /* direct blocks */ |
| ext4_free_data(handle, inode, NULL, i_data+offsets[0], |
| i_data + EXT4_NDIR_BLOCKS); |
| goto do_indirects; |
| } |
| |
| partial = ext4_find_shared(inode, n, offsets, chain, &nr); |
| /* Kill the top of shared branch (not detached) */ |
| if (nr) { |
| if (partial == chain) { |
| /* Shared branch grows from the inode */ |
| ext4_free_branches(handle, inode, NULL, |
| &nr, &nr+1, (chain+n-1) - partial); |
| *partial->p = 0; |
| /* |
| * We mark the inode dirty prior to restart, |
| * and prior to stop. No need for it here. |
| */ |
| } else { |
| /* Shared branch grows from an indirect block */ |
| BUFFER_TRACE(partial->bh, "get_write_access"); |
| ext4_free_branches(handle, inode, partial->bh, |
| partial->p, |
| partial->p+1, (chain+n-1) - partial); |
| } |
| } |
| /* Clear the ends of indirect blocks on the shared branch */ |
| while (partial > chain) { |
| ext4_free_branches(handle, inode, partial->bh, partial->p + 1, |
| (__le32*)partial->bh->b_data+addr_per_block, |
| (chain+n-1) - partial); |
| BUFFER_TRACE(partial->bh, "call brelse"); |
| brelse (partial->bh); |
| partial--; |
| } |
| do_indirects: |
| /* Kill the remaining (whole) subtrees */ |
| switch (offsets[0]) { |
| default: |
| nr = i_data[EXT4_IND_BLOCK]; |
| if (nr) { |
| ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 1); |
| i_data[EXT4_IND_BLOCK] = 0; |
| } |
| case EXT4_IND_BLOCK: |
| nr = i_data[EXT4_DIND_BLOCK]; |
| if (nr) { |
| ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 2); |
| i_data[EXT4_DIND_BLOCK] = 0; |
| } |
| case EXT4_DIND_BLOCK: |
| nr = i_data[EXT4_TIND_BLOCK]; |
| if (nr) { |
| ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 3); |
| i_data[EXT4_TIND_BLOCK] = 0; |
| } |
| case EXT4_TIND_BLOCK: |
| ; |
| } |
| |
| up_write(&ei->i_data_sem); |
| inode->i_mtime = inode->i_ctime = ext4_current_time(inode); |
| ext4_mark_inode_dirty(handle, inode); |
| |
| /* |
| * In a multi-transaction truncate, we only make the final transaction |
| * synchronous |
| */ |
| if (IS_SYNC(inode)) |
| ext4_handle_sync(handle); |
| out_stop: |
| /* |
| * If this was a simple ftruncate(), and the file will remain alive |
| * then we need to clear up the orphan record which we created above. |
| * However, if this was a real unlink then we were called by |
| * ext4_delete_inode(), and we allow that function to clean up the |
| * orphan info for us. |
| */ |
| if (inode->i_nlink) |
| ext4_orphan_del(handle, inode); |
| |
| ext4_journal_stop(handle); |
| } |
| |
| /* |
| * ext4_get_inode_loc returns with an extra refcount against the inode's |
| * underlying buffer_head on success. If 'in_mem' is true, we have all |
| * data in memory that is needed to recreate the on-disk version of this |
| * inode. |
| */ |
| static int __ext4_get_inode_loc(struct inode *inode, |
| struct ext4_iloc *iloc, int in_mem) |
| { |
| struct ext4_group_desc *gdp; |
| struct buffer_head *bh; |
| struct super_block *sb = inode->i_sb; |
| ext4_fsblk_t block; |
| int inodes_per_block, inode_offset; |
| |
| iloc->bh = NULL; |
| if (!ext4_valid_inum(sb, inode->i_ino)) |
| return -EIO; |
| |
| iloc->block_group = (inode->i_ino - 1) / EXT4_INODES_PER_GROUP(sb); |
| gdp = ext4_get_group_desc(sb, iloc->block_group, NULL); |
| if (!gdp) |
| return -EIO; |
| |
| /* |
| * Figure out the offset within the block group inode table |
| */ |
| inodes_per_block = (EXT4_BLOCK_SIZE(sb) / EXT4_INODE_SIZE(sb)); |
| inode_offset = ((inode->i_ino - 1) % |
| EXT4_INODES_PER_GROUP(sb)); |
| block = ext4_inode_table(sb, gdp) + (inode_offset / inodes_per_block); |
| iloc->offset = (inode_offset % inodes_per_block) * EXT4_INODE_SIZE(sb); |
| |
| bh = sb_getblk(sb, block); |
| if (!bh) { |
| ext4_error(sb, "ext4_get_inode_loc", "unable to read " |
| "inode block - inode=%lu, block=%llu", |
| inode->i_ino, block); |
| return -EIO; |
| } |
| if (!buffer_uptodate(bh)) { |
| lock_buffer(bh); |
| |
| /* |
| * If the buffer has the write error flag, we have failed |
| * to write out another inode in the same block. In this |
| * case, we don't have to read the block because we may |
| * read the old inode data successfully. |
| */ |
| if (buffer_write_io_error(bh) && !buffer_uptodate(bh)) |
| set_buffer_uptodate(bh); |
| |
| if (buffer_uptodate(bh)) { |
| /* someone brought it uptodate while we waited */ |
| unlock_buffer(bh); |
| goto has_buffer; |
| } |
| |
| /* |
| * If we have all information of the inode in memory and this |
| * is the only valid inode in the block, we need not read the |
| * block. |
| */ |
| if (in_mem) { |
| struct buffer_head *bitmap_bh; |
| int i, start; |
| |
| start = inode_offset & ~(inodes_per_block - 1); |
| |
| /* Is the inode bitmap in cache? */ |
| bitmap_bh = sb_getblk(sb, ext4_inode_bitmap(sb, gdp)); |
| if (!bitmap_bh) |
| goto make_io; |
| |
| /* |
| * If the inode bitmap isn't in cache then the |
| * optimisation may end up performing two reads instead |
| * of one, so skip it. |
| */ |
| if (!buffer_uptodate(bitmap_bh)) { |
| brelse(bitmap_bh); |
| goto make_io; |
| } |
| for (i = start; i < start + inodes_per_block; i++) { |
| if (i == inode_offset) |
| continue; |
| if (ext4_test_bit(i, bitmap_bh->b_data)) |
| break; |
| } |
| brelse(bitmap_bh); |
| if (i == start + inodes_per_block) { |
| /* all other inodes are free, so skip I/O */ |
| memset(bh->b_data, 0, bh->b_size); |
| set_buffer_uptodate(bh); |
| unlock_buffer(bh); |
| goto has_buffer; |
| } |
| } |
| |
| make_io: |
| /* |
| * If we need to do any I/O, try to pre-readahead extra |
| * blocks from the inode table. |
| */ |
| if (EXT4_SB(sb)->s_inode_readahead_blks) { |
| ext4_fsblk_t b, end, table; |
| unsigned num; |
| |
| table = ext4_inode_table(sb, gdp); |
| /* Make sure s_inode_readahead_blks is a power of 2 */ |
| while (EXT4_SB(sb)->s_inode_readahead_blks & |
| (EXT4_SB(sb)->s_inode_readahead_blks-1)) |
| EXT4_SB(sb)->s_inode_readahead_blks = |
| (EXT4_SB(sb)->s_inode_readahead_blks & |
| (EXT4_SB(sb)->s_inode_readahead_blks-1)); |
| b = block & ~(EXT4_SB(sb)->s_inode_readahead_blks-1); |
| if (table > b) |
| b = table; |
| end = b + EXT4_SB(sb)->s_inode_readahead_blks; |
| num = EXT4_INODES_PER_GROUP(sb); |
| if (EXT4_HAS_RO_COMPAT_FEATURE(sb, |
| EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) |
| num -= ext4_itable_unused_count(sb, gdp); |
| table += num / inodes_per_block; |
| if (end > table) |
| end = table; |
| while (b <= end) |
| sb_breadahead(sb, b++); |
| } |
| |
| /* |
| * There are other valid inodes in the buffer, this inode |
| * has in-inode xattrs, or we don't have this inode in memory. |
| * Read the block from disk. |
| */ |
| get_bh(bh); |
| bh->b_end_io = end_buffer_read_sync; |
| submit_bh(READ_META, bh); |
| wait_on_buffer(bh); |
| if (!buffer_uptodate(bh)) { |
| ext4_error(sb, __func__, |
| "unable to read inode block - inode=%lu, " |
| "block=%llu", inode->i_ino, block); |
| brelse(bh); |
| return -EIO; |
| } |
| } |
| has_buffer: |
| iloc->bh = bh; |
| return 0; |
| } |
| |
| int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc) |
| { |
| /* We have all inode data except xattrs in memory here. */ |
| return __ext4_get_inode_loc(inode, iloc, |
| !(EXT4_I(inode)->i_state & EXT4_STATE_XATTR)); |
| } |
| |
| void ext4_set_inode_flags(struct inode *inode) |
| { |
| unsigned int flags = EXT4_I(inode)->i_flags; |
| |
| inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); |
| if (flags & EXT4_SYNC_FL) |
| inode->i_flags |= S_SYNC; |
| if (flags & EXT4_APPEND_FL) |
| inode->i_flags |= S_APPEND; |
| if (flags & EXT4_IMMUTABLE_FL) |
| inode->i_flags |= S_IMMUTABLE; |
| if (flags & EXT4_NOATIME_FL) |
| inode->i_flags |= S_NOATIME; |
| if (flags & EXT4_DIRSYNC_FL) |
| inode->i_flags |= S_DIRSYNC; |
| } |
| |
| /* Propagate flags from i_flags to EXT4_I(inode)->i_flags */ |
| void ext4_get_inode_flags(struct ext4_inode_info *ei) |
| { |
| unsigned int flags = ei->vfs_inode.i_flags; |
| |
| ei->i_flags &= ~(EXT4_SYNC_FL|EXT4_APPEND_FL| |
| EXT4_IMMUTABLE_FL|EXT4_NOATIME_FL|EXT4_DIRSYNC_FL); |
| if (flags & S_SYNC) |
| ei->i_flags |= EXT4_SYNC_FL; |
| if (flags & S_APPEND) |
| ei->i_flags |= EXT4_APPEND_FL; |
| if (flags & S_IMMUTABLE) |
| ei->i_flags |= EXT4_IMMUTABLE_FL; |
| if (flags & S_NOATIME) |
| ei->i_flags |= EXT4_NOATIME_FL; |
| if (flags & S_DIRSYNC) |
| ei->i_flags |= EXT4_DIRSYNC_FL; |
| } |
| static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode, |
| struct ext4_inode_info *ei) |
| { |
| blkcnt_t i_blocks ; |
| struct inode *inode = &(ei->vfs_inode); |
| struct super_block *sb = inode->i_sb; |
| |
| if (EXT4_HAS_RO_COMPAT_FEATURE(sb, |
| EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) { |
| /* we are using combined 48 bit field */ |
| i_blocks = ((u64)le16_to_cpu(raw_inode->i_blocks_high)) << 32 | |
| le32_to_cpu(raw_inode->i_blocks_lo); |
| if (ei->i_flags & EXT4_HUGE_FILE_FL) { |
| /* i_blocks represent file system block size */ |
| return i_blocks << (inode->i_blkbits - 9); |
| } else { |
| return i_blocks; |
| } |
| } else { |
| return le32_to_cpu(raw_inode->i_blocks_lo); |
| } |
| } |
| |
| struct inode *ext4_iget(struct super_block *sb, unsigned long ino) |
| { |
| struct ext4_iloc iloc; |
| struct ext4_inode *raw_inode; |
| struct ext4_inode_info *ei; |
| struct buffer_head *bh; |
| struct inode *inode; |
| long ret; |
| int block; |
| |
| inode = iget_locked(sb, ino); |
| if (!inode) |
| return ERR_PTR(-ENOMEM); |
| if (!(inode->i_state & I_NEW)) |
| return inode; |
| |
| ei = EXT4_I(inode); |
| #ifdef CONFIG_EXT4_FS_POSIX_ACL |
| ei->i_acl = EXT4_ACL_NOT_CACHED; |
| ei->i_default_acl = EXT4_ACL_NOT_CACHED; |
| #endif |
| |
| ret = __ext4_get_inode_loc(inode, &iloc, 0); |
| if (ret < 0) |
| goto bad_inode; |
| bh = iloc.bh; |
| raw_inode = ext4_raw_inode(&iloc); |
| inode->i_mode = le16_to_cpu(raw_inode->i_mode); |
| inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); |
| inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); |
| if (!(test_opt(inode->i_sb, NO_UID32))) { |
| inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; |
| inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; |
| } |
| inode->i_nlink = le16_to_cpu(raw_inode->i_links_count); |
| |
| ei->i_state = 0; |
| ei->i_dir_start_lookup = 0; |
| ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); |
| /* We now have enough fields to check if the inode was active or not. |
| * This is needed because nfsd might try to access dead inodes |
| * the test is that same one that e2fsck uses |
| * NeilBrown 1999oct15 |
| */ |
| if (inode->i_nlink == 0) { |
| if (inode->i_mode == 0 || |
| !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) { |
| /* this inode is deleted */ |
| brelse(bh); |
| ret = -ESTALE; |
| goto bad_inode; |
| } |
| /* The only unlinked inodes we let through here have |
| * valid i_mode and are being read by the orphan |
| * recovery code: that's fine, we're about to complete |
| * the process of deleting those. */ |
| } |
| ei->i_flags = le32_to_cpu(raw_inode->i_flags); |
| inode->i_blocks = ext4_inode_blocks(raw_inode, ei); |
| ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo); |
| if (EXT4_SB(inode->i_sb)->s_es->s_creator_os != |
| cpu_to_le32(EXT4_OS_HURD)) { |
| ei->i_file_acl |= |
| ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32; |
| } |
| inode->i_size = ext4_isize(raw_inode); |
| ei->i_disksize = inode->i_size; |
| inode->i_generation = le32_to_cpu(raw_inode->i_generation); |
| ei->i_block_group = iloc.block_group; |
| /* |
| * NOTE! The in-memory inode i_data array is in little-endian order |
| * even on big-endian machines: we do NOT byteswap the block numbers! |
| */ |
| for (block = 0; block < EXT4_N_BLOCKS; block++) |
| ei->i_data[block] = raw_inode->i_block[block]; |
| INIT_LIST_HEAD(&ei->i_orphan); |
| |
| if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) { |
| ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize); |
| if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize > |
| EXT4_INODE_SIZE(inode->i_sb)) { |
| brelse(bh); |
| ret = -EIO; |
| goto bad_inode; |
| } |
| if (ei->i_extra_isize == 0) { |
| /* The extra space is currently unused. Use it. */ |
| ei->i_extra_isize = sizeof(struct ext4_inode) - |
| EXT4_GOOD_OLD_INODE_SIZE; |
| } else { |
| __le32 *magic = (void *)raw_inode + |
| EXT4_GOOD_OLD_INODE_SIZE + |
| ei->i_extra_isize; |
| if (*magic == cpu_to_le32(EXT4_XATTR_MAGIC)) |
| ei->i_state |= EXT4_STATE_XATTR; |
| } |
| } else |
| ei->i_extra_isize = 0; |
| |
| EXT4_INODE_GET_XTIME(i_ctime, inode, raw_inode); |
| EXT4_INODE_GET_XTIME(i_mtime, inode, raw_inode); |
| EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode); |
| EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode); |
| |
| inode->i_version = le32_to_cpu(raw_inode->i_disk_version); |
| if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) { |
| if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi)) |
| inode->i_version |= |
| (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32; |
| } |
| |
| if (S_ISREG(inode->i_mode)) { |
| inode->i_op = &ext4_file_inode_operations; |
| inode->i_fop = &ext4_file_operations; |
| ext4_set_aops(inode); |
| } else if (S_ISDIR(inode->i_mode)) { |
| inode->i_op = &ext4_dir_inode_operations; |
| inode->i_fop = &ext4_dir_operations; |
| } else if (S_ISLNK(inode->i_mode)) { |
| if (ext4_inode_is_fast_symlink(inode)) { |
| inode->i_op = &ext4_fast_symlink_inode_operations; |
| nd_terminate_link(ei->i_data, inode->i_size, |
| sizeof(ei->i_data) - 1); |
| } else { |
| inode->i_op = &ext4_symlink_inode_operations; |
| ext4_set_aops(inode); |
| } |
| } else { |
| inode->i_op = &ext4_special_inode_operations; |
| if (raw_inode->i_block[0]) |
| init_special_inode(inode, inode->i_mode, |
| old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); |
| else |
| init_special_inode(inode, inode->i_mode, |
| new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); |
| } |
| brelse(iloc.bh); |
| ext4_set_inode_flags(inode); |
| unlock_new_inode(inode); |
| return inode; |
| |
| bad_inode: |
| iget_failed(inode); |
| return ERR_PTR(ret); |
| } |
| |
| static int ext4_inode_blocks_set(handle_t *handle, |
| struct ext4_inode *raw_inode, |
| struct ext4_inode_info *ei) |
| { |
| struct inode *inode = &(ei->vfs_inode); |
| u64 i_blocks = inode->i_blocks; |
| struct super_block *sb = inode->i_sb; |
| |
| if (i_blocks <= ~0U) { |
| /* |
| * i_blocks can be represnted in a 32 bit variable |
| * as multiple of 512 bytes |
| */ |
| raw_inode->i_blocks_lo = cpu_to_le32(i_blocks); |
| raw_inode->i_blocks_high = 0; |
| ei->i_flags &= ~EXT4_HUGE_FILE_FL; |
| return 0; |
| } |
| if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) |
| return -EFBIG; |
| |
| if (i_blocks <= 0xffffffffffffULL) { |
| /* |
| * i_blocks can be represented in a 48 bit variable |
| * as multiple of 512 bytes |
| */ |
| raw_inode->i_blocks_lo = cpu_to_le32(i_blocks); |
| raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32); |
| ei->i_flags &= ~EXT4_HUGE_FILE_FL; |
| } else { |
| ei->i_flags |= EXT4_HUGE_FILE_FL; |
| /* i_block is stored in file system block size */ |
| i_blocks = i_blocks >> (inode->i_blkbits - 9); |
| raw_inode->i_blocks_lo = cpu_to_le32(i_blocks); |
| raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32); |
| } |
| return 0; |
| } |
| |
| /* |
| * Post the struct inode info into an on-disk inode location in the |
| * buffer-cache. This gobbles the caller's reference to the |
| * buffer_head in the inode location struct. |
| * |
| * The caller must have write access to iloc->bh. |
| */ |
| static int ext4_do_update_inode(handle_t *handle, |
| struct inode *inode, |
| struct ext4_iloc *iloc) |
| { |
| struct ext4_inode *raw_inode = ext4_raw_inode(iloc); |
| struct ext4_inode_info *ei = EXT4_I(inode); |
| struct buffer_head *bh = iloc->bh; |
| int err = 0, rc, block; |
| |
| /* For fields not not tracking in the in-memory inode, |
| * initialise them to zero for new inodes. */ |
| if (ei->i_state & EXT4_STATE_NEW) |
| memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size); |
| |
| ext4_get_inode_flags(ei); |
| raw_inode->i_mode = cpu_to_le16(inode->i_mode); |
| if (!(test_opt(inode->i_sb, NO_UID32))) { |
| raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid)); |
| raw_inode->i_gid_low = cpu_to_le16(low_16_bits(inode->i_gid)); |
| /* |
| * Fix up interoperability with old kernels. Otherwise, old inodes get |
| * re-used with the upper 16 bits of the uid/gid intact |
| */ |
| if (!ei->i_dtime) { |
| raw_inode->i_uid_high = |
| cpu_to_le16(high_16_bits(inode->i_uid)); |
| raw_inode->i_gid_high = |
| cpu_to_le16(high_16_bits(inode->i_gid)); |
| } else { |
| raw_inode->i_uid_high = 0; |
| raw_inode->i_gid_high = 0; |
| } |
| } else { |
| raw_inode->i_uid_low = |
| cpu_to_le16(fs_high2lowuid(inode->i_uid)); |
| raw_inode->i_gid_low = |
| cpu_to_le16(fs_high2lowgid(inode->i_gid)); |
| raw_inode->i_uid_high = 0; |
| raw_inode->i_gid_high = 0; |
| } |
| raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); |
| |
| EXT4_INODE_SET_XTIME(i_ctime, inode, raw_inode); |
| EXT4_INODE_SET_XTIME(i_mtime, inode, raw_inode); |
| EXT4_INODE_SET_XTIME(i_atime, inode, raw_inode); |
| EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode); |
| |
| if (ext4_inode_blocks_set(handle, raw_inode, ei)) |
| goto out_brelse; |
| raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); |
| /* clear the migrate flag in the raw_inode */ |
| raw_inode->i_flags = cpu_to_le32(ei->i_flags & ~EXT4_EXT_MIGRATE); |
| if (EXT4_SB(inode->i_sb)->s_es->s_creator_os != |
| cpu_to_le32(EXT4_OS_HURD)) |
| raw_inode->i_file_acl_high = |
| cpu_to_le16(ei->i_file_acl >> 32); |
| raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl); |
| ext4_isize_set(raw_inode, ei->i_disksize); |
| if (ei->i_disksize > 0x7fffffffULL) { |
| struct super_block *sb = inode->i_sb; |
| if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, |
| EXT4_FEATURE_RO_COMPAT_LARGE_FILE) || |
| EXT4_SB(sb)->s_es->s_rev_level == |
| cpu_to_le32(EXT4_GOOD_OLD_REV)) { |
| /* If this is the first large file |
| * created, add a flag to the superblock. |
| */ |
| err = ext4_journal_get_write_access(handle, |
| EXT4_SB(sb)->s_sbh); |
| if (err) |
| goto out_brelse; |
| ext4_update_dynamic_rev(sb); |
| EXT4_SET_RO_COMPAT_FEATURE(sb, |
| EXT4_FEATURE_RO_COMPAT_LARGE_FILE); |
| sb->s_dirt = 1; |
| ext4_handle_sync(handle); |
| err = ext4_handle_dirty_metadata(handle, inode, |
| EXT4_SB(sb)->s_sbh); |
| } |
| } |
| raw_inode->i_generation = cpu_to_le32(inode->i_generation); |
| if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { |
| if (old_valid_dev(inode->i_rdev)) { |
| raw_inode->i_block[0] = |
| cpu_to_le32(old_encode_dev(inode->i_rdev)); |
| raw_inode->i_block[1] = 0; |
| } else { |
| raw_inode->i_block[0] = 0; |
| raw_inode->i_block[1] = |
| cpu_to_le32(new_encode_dev(inode->i_rdev)); |
| raw_inode->i_block[2] = 0; |
| } |
| } else for (block = 0; block < EXT4_N_BLOCKS; block++) |
| raw_inode->i_block[block] = ei->i_data[block]; |
| |
| raw_inode->i_disk_version = cpu_to_le32(inode->i_version); |
| if (ei->i_extra_isize) { |
| if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi)) |
| raw_inode->i_version_hi = |
| cpu_to_le32(inode->i_version >> 32); |
| raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize); |
| } |
| |
| BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); |
| rc = ext4_handle_dirty_metadata(handle, inode, bh); |
| if (!err) |
| err = rc; |
| ei->i_state &= ~EXT4_STATE_NEW; |
| |
| out_brelse: |
| brelse(bh); |
| ext4_std_error(inode->i_sb, err); |
| return err; |
| } |
| |
| /* |
| * ext4_write_inode() |
| * |
| * We are called from a few places: |
| * |
| * - Within generic_file_write() for O_SYNC files. |
| * Here, there will be no transaction running. We wait for any running |
| * trasnaction to commit. |
| * |
| * - Within sys_sync(), kupdate and such. |
| * We wait on commit, if tol to. |
| * |
| * - Within prune_icache() (PF_MEMALLOC == true) |
| * Here we simply return. We can't afford to block kswapd on the |
| * journal commit. |
| * |
| * In all cases it is actually safe for us to return without doing anything, |
| * because the inode has been copied into a raw inode buffer in |
| * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for |
| * knfsd. |
| * |
| * Note that we are absolutely dependent upon all inode dirtiers doing the |
| * right thing: they *must* call mark_inode_dirty() after dirtying info in |
| * which we are interested. |
| * |
| * It would be a bug for them to not do this. The code: |
| * |
| * mark_inode_dirty(inode) |
| * stuff(); |
| * inode->i_size = expr; |
| * |
| * is in error because a kswapd-driven write_inode() could occur while |
| * `stuff()' is running, and the new i_size will be lost. Plus the inode |
| * will no longer be on the superblock's dirty inode list. |
| */ |
| int ext4_write_inode(struct inode *inode, int wait) |
| { |
| if (current->flags & PF_MEMALLOC) |
| return 0; |
| |
| if (ext4_journal_current_handle()) { |
| jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n"); |
| dump_stack(); |
| return -EIO; |
| } |
| |
| if (!wait) |
| return 0; |
| |
| return ext4_force_commit(inode->i_sb); |
| } |
| |
| int __ext4_write_dirty_metadata(struct inode *inode, struct buffer_head *bh) |
| { |
| int err = 0; |
| |
| mark_buffer_dirty(bh); |
| if (inode && inode_needs_sync(inode)) { |
| sync_dirty_buffer(bh); |
| if (buffer_req(bh) && !buffer_uptodate(bh)) { |
| ext4_error(inode->i_sb, __func__, |
| "IO error syncing inode, " |
| "inode=%lu, block=%llu", |
| inode->i_ino, |
| (unsigned long long)bh->b_blocknr); |
| err = -EIO; |
| } |
| } |
| return err; |
| } |
| |
| /* |
| * ext4_setattr() |
| * |
| * Called from notify_change. |
| * |
| * We want to trap VFS attempts to truncate the file as soon as |
| * possible. In particular, we want to make sure that when the VFS |
| * shrinks i_size, we put the inode on the orphan list and modify |
| * i_disksize immediately, so that during the subsequent flushing of |
| * dirty pages and freeing of disk blocks, we can guarantee that any |
| * commit will leave the blocks being flushed in an unused state on |
| * disk. (On recovery, the inode will get truncated and the blocks will |
| * be freed, so we have a strong guarantee that no future commit will |
| * leave these blocks visible to the user.) |
| * |
| * Another thing we have to assure is that if we are in ordered mode |
| * and inode is still attached to the committing transaction, we must |
| * we start writeout of all the dirty pages which are being truncated. |
| * This way we are sure that all the data written in the previous |
| * transaction are already on disk (truncate waits for pages under |
| * writeback). |
| * |
| * Called with inode->i_mutex down. |
| */ |
| int ext4_setattr(struct dentry *dentry, struct iattr *attr) |
| { |
| struct inode *inode = dentry->d_inode; |
| int error, rc = 0; |
| const unsigned int ia_valid = attr->ia_valid; |
| |
| error = inode_change_ok(inode, attr); |
| if (error) |
| return error; |
| |
| if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) || |
| (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) { |
| handle_t *handle; |
| |
| /* (user+group)*(old+new) structure, inode write (sb, |
| * inode block, ? - but truncate inode update has it) */ |
| handle = ext4_journal_start(inode, 2*(EXT4_QUOTA_INIT_BLOCKS(inode->i_sb)+ |
| EXT4_QUOTA_DEL_BLOCKS(inode->i_sb))+3); |
| if (IS_ERR(handle)) { |
| error = PTR_ERR(handle); |
| goto err_out; |
| } |
| error = DQUOT_TRANSFER(inode, attr) ? -EDQUOT : 0; |
| if (error) { |
| ext4_journal_stop(handle); |
| return error; |
| } |
| /* Update corresponding info in inode so that everything is in |
| * one transaction */ |
| if (attr->ia_valid & ATTR_UID) |
| inode->i_uid = attr->ia_uid; |
| if (attr->ia_valid & ATTR_GID) |
| inode->i_gid = attr->ia_gid; |
| error = ext4_mark_inode_dirty(handle, inode); |
| ext4_journal_stop(handle); |
| } |
| |
| if (attr->ia_valid & ATTR_SIZE) { |
| if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)) { |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| |
| if (attr->ia_size > sbi->s_bitmap_maxbytes) { |
| error = -EFBIG; |
| goto err_out; |
| } |
| } |
| } |
| |
| if (S_ISREG(inode->i_mode) && |
| attr->ia_valid & ATTR_SIZE && attr->ia_size < inode->i_size) { |
| handle_t *handle; |
| |
| handle = ext4_journal_start(inode, 3); |
| if (IS_ERR(handle)) { |
| error = PTR_ERR(handle); |
| goto err_out; |
| } |
| |
| error = ext4_orphan_add(handle, inode); |
| EXT4_I(inode)->i_disksize = attr->ia_size; |
| rc = ext4_mark_inode_dirty(handle, inode); |
| if (!error) |
| error = rc; |
| ext4_journal_stop(handle); |
| |
| if (ext4_should_order_data(inode)) { |
| error = ext4_begin_ordered_truncate(inode, |
| attr->ia_size); |
| if (error) { |
| /* Do as much error cleanup as possible */ |
| handle = ext4_journal_start(inode, 3); |
| if (IS_ERR(handle)) { |
| ext4_orphan_del(NULL, inode); |
| goto err_out; |
| } |
| ext4_orphan_del(handle, inode); |
| ext4_journal_stop(handle); |
| goto err_out; |
| } |
| } |
| } |
| |
| rc = inode_setattr(inode, attr); |
| |
| /* If inode_setattr's call to ext4_truncate failed to get a |
| * transaction handle at all, we need to clean up the in-core |
| * orphan list manually. */ |
| if (inode->i_nlink) |
| ext4_orphan_del(NULL, inode); |
| |
| if (!rc && (ia_valid & ATTR_MODE)) |
| rc = ext4_acl_chmod(inode); |
| |
| err_out: |
| ext4_std_error(inode->i_sb, error); |
| if (!error) |
| error = rc; |
| return error; |
| } |
| |
| int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry, |
| struct kstat *stat) |
| { |
| struct inode *inode; |
| unsigned long delalloc_blocks; |
| |
| inode = dentry->d_inode; |
| generic_fillattr(inode, stat); |
| |
| /* |
| * We can't update i_blocks if the block allocation is delayed |
| * otherwise in the case of system crash before the real block |
| * allocation is done, we will have i_blocks inconsistent with |
| * on-disk file blocks. |
| * We always keep i_blocks updated together with real |
| * allocation. But to not confuse with user, stat |
| * will return the blocks that include the delayed allocation |
| * blocks for this file. |
| */ |
| spin_lock(&EXT4_I(inode)->i_block_reservation_lock); |
| delalloc_blocks = EXT4_I(inode)->i_reserved_data_blocks; |
| spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); |
| |
| stat->blocks += (delalloc_blocks << inode->i_sb->s_blocksize_bits)>>9; |
| return 0; |
| } |
| |
| static int ext4_indirect_trans_blocks(struct inode *inode, int nrblocks, |
| int chunk) |
| { |
| int indirects; |
| |
| /* if nrblocks are contiguous */ |
| if (chunk) { |
| /* |
| * With N contiguous data blocks, it need at most |
| * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) indirect blocks |
| * 2 dindirect blocks |
| * 1 tindirect block |
| */ |
| indirects = nrblocks / EXT4_ADDR_PER_BLOCK(inode->i_sb); |
| return indirects + 3; |
| } |
| /* |
| * if nrblocks are not contiguous, worse case, each block touch |
| * a indirect block, and each indirect block touch a double indirect |
| * block, plus a triple indirect block |
| */ |
| indirects = nrblocks * 2 + 1; |
| return indirects; |
| } |
| |
| static int ext4_index_trans_blocks(struct inode *inode, int nrblocks, int chunk) |
| { |
| if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)) |
| return ext4_indirect_trans_blocks(inode, nrblocks, chunk); |
| return ext4_ext_index_trans_blocks(inode, nrblocks, chunk); |
| } |
| |
| /* |
| * Account for index blocks, block groups bitmaps and block group |
| * descriptor blocks if modify datablocks and index blocks |
| * worse case, the indexs blocks spread over different block groups |
| * |
| * If datablocks are discontiguous, they are possible to spread over |
| * different block groups too. If they are contiugous, with flexbg, |
| * they could still across block group boundary. |
| * |
| * Also account for superblock, inode, quota and xattr blocks |
| */ |
| int ext4_meta_trans_blocks(struct inode *inode, int nrblocks, int chunk) |
| { |
| int groups, gdpblocks; |
| int idxblocks; |
| int ret = 0; |
| |
| /* |
| * How many index blocks need to touch to modify nrblocks? |
| * The "Chunk" flag indicating whether the nrblocks is |
| * physically contiguous on disk |
| * |
| * For Direct IO and fallocate, they calls get_block to allocate |
| * one single extent at a time, so they could set the "Chunk" flag |
| */ |
| idxblocks = ext4_index_trans_blocks(inode, nrblocks, chunk); |
| |
| ret = idxblocks; |
| |
| /* |
| * Now let's see how many group bitmaps and group descriptors need |
| * to account |
| */ |
| groups = idxblocks; |
| if (chunk) |
| groups += 1; |
| else |
| groups += nrblocks; |
| |
| gdpblocks = groups; |
| if (groups > EXT4_SB(inode->i_sb)->s_groups_count) |
| groups = EXT4_SB(inode->i_sb)->s_groups_count; |
| if (groups > EXT4_SB(inode->i_sb)->s_gdb_count) |
| gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count; |
| |
| /* bitmaps and block group descriptor blocks */ |
| ret += groups + gdpblocks; |
| |
| /* Blocks for super block, inode, quota and xattr blocks */ |
| ret += EXT4_META_TRANS_BLOCKS(inode->i_sb); |
| |
| return ret; |
| } |
| |
| /* |
| * Calulate the total number of credits to reserve to fit |
| * the modification of a single pages into a single transaction, |
| * which may include multiple chunks of block allocations. |
| * |
| * This could be called via ext4_write_begin() |
| * |
| * We need to consider the worse case, when |
| * one new block per extent. |
| */ |
| int ext4_writepage_trans_blocks(struct inode *inode) |
| { |
| int bpp = ext4_journal_blocks_per_page(inode); |
| int ret; |
| |
| ret = ext4_meta_trans_blocks(inode, bpp, 0); |
| |
| /* Account for data blocks for journalled mode */ |
| if (ext4_should_journal_data(inode)) |
| ret += bpp; |
| return ret; |
| } |
| |
| /* |
| * Calculate the journal credits for a chunk of data modification. |
| * |
| * This is called from DIO, fallocate or whoever calling |
| * ext4_get_blocks_wrap() to map/allocate a chunk of contigous disk blocks. |
| * |
| * journal buffers for data blocks are not included here, as DIO |
| * and fallocate do no need to journal data buffers. |
| */ |
| int ext4_chunk_trans_blocks(struct inode *inode, int nrblocks) |
| { |
| return ext4_meta_trans_blocks(inode, nrblocks, 1); |
| } |
| |
| /* |
| * The caller must have previously called ext4_reserve_inode_write(). |
| * Give this, we know that the caller already has write access to iloc->bh. |
| */ |
| int ext4_mark_iloc_dirty(handle_t *handle, |
| struct inode *inode, struct ext4_iloc *iloc) |
| { |
| int err = 0; |
| |
| if (test_opt(inode->i_sb, I_VERSION)) |
| inode_inc_iversion(inode); |
| |
| /* the do_update_inode consumes one bh->b_count */ |
| get_bh(iloc->bh); |
| |
| /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */ |
| err = ext4_do_update_inode(handle, inode, iloc); |
| put_bh(iloc->bh); |
| return err; |
| } |
| |
| /* |
| * On success, We end up with an outstanding reference count against |
| * iloc->bh. This _must_ be cleaned up later. |
| */ |
| |
| int |
| ext4_reserve_inode_write(handle_t *handle, struct inode *inode, |
| struct ext4_iloc *iloc) |
| { |
| int err; |
| |
| err = ext4_get_inode_loc(inode, iloc); |
| if (!err) { |
| BUFFER_TRACE(iloc->bh, "get_write_access"); |
| err = ext4_journal_get_write_access(handle, iloc->bh); |
| if (err) { |
| brelse(iloc->bh); |
| iloc->bh = NULL; |
| } |
| } |
| ext4_std_error(inode->i_sb, err); |
| return err; |
| } |
| |
| /* |
| * Expand an inode by new_extra_isize bytes. |
| * Returns 0 on success or negative error number on failure. |
| */ |
| static int ext4_expand_extra_isize(struct inode *inode, |
| unsigned int new_extra_isize, |
| struct ext4_iloc iloc, |
| handle_t *handle) |
| { |
| struct ext4_inode *raw_inode; |
| struct ext4_xattr_ibody_header *header; |
| struct ext4_xattr_entry *entry; |
| |
| if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) |
| return 0; |
| |
| raw_inode = ext4_raw_inode(&iloc); |
| |
| header = IHDR(inode, raw_inode); |
| entry = IFIRST(header); |
| |
| /* No extended attributes present */ |
| if (!(EXT4_I(inode)->i_state & EXT4_STATE_XATTR) || |
| header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) { |
| memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE, 0, |
| new_extra_isize); |
| EXT4_I(inode)->i_extra_isize = new_extra_isize; |
| return 0; |
| } |
| |
| /* try to expand with EAs present */ |
| return ext4_expand_extra_isize_ea(inode, new_extra_isize, |
| raw_inode, handle); |
| } |
| |
| /* |
| * What we do here is to mark the in-core inode as clean with respect to inode |
| * dirtiness (it may still be data-dirty). |
| * This means that the in-core inode may be reaped by prune_icache |
| * without having to perform any I/O. This is a very good thing, |
| * because *any* task may call prune_icache - even ones which |
| * have a transaction open against a different journal. |
| * |
| * Is this cheating? Not really. Sure, we haven't written the |
| * inode out, but prune_icache isn't a user-visible syncing function. |
| * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync) |
| * we start and wait on commits. |
| * |
| * Is this efficient/effective? Well, we're being nice to the system |
| * by cleaning up our inodes proactively so they can be reaped |
| * without I/O. But we are potentially leaving up to five seconds' |
| * worth of inodes floating about which prune_icache wants us to |
| * write out. One way to fix that would be to get prune_icache() |
| * to do a write_super() to free up some memory. It has the desired |
| * effect. |
| */ |
| int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode) |
| { |
| struct ext4_iloc iloc; |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| static unsigned int mnt_count; |
| int err, ret; |
| |
| might_sleep(); |
| err = ext4_reserve_inode_write(handle, inode, &iloc); |
| if (ext4_handle_valid(handle) && |
| EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize && |
| !(EXT4_I(inode)->i_state & EXT4_STATE_NO_EXPAND)) { |
| /* |
| * We need extra buffer credits since we may write into EA block |
| * with this same handle. If journal_extend fails, then it will |
| * only result in a minor loss of functionality for that inode. |
| * If this is felt to be critical, then e2fsck should be run to |
| * force a large enough s_min_extra_isize. |
| */ |
| if ((jbd2_journal_extend(handle, |
| EXT4_DATA_TRANS_BLOCKS(inode->i_sb))) == 0) { |
| ret = ext4_expand_extra_isize(inode, |
| sbi->s_want_extra_isize, |
| iloc, handle); |
| if (ret) { |
| EXT4_I(inode)->i_state |= EXT4_STATE_NO_EXPAND; |
| if (mnt_count != |
| le16_to_cpu(sbi->s_es->s_mnt_count)) { |
| ext4_warning(inode->i_sb, __func__, |
| "Unable to expand inode %lu. Delete" |
| " some EAs or run e2fsck.", |
| inode->i_ino); |
| mnt_count = |
| le16_to_cpu(sbi->s_es->s_mnt_count); |
| } |
| } |
| } |
| } |
| if (!err) |
| err = ext4_mark_iloc_dirty(handle, inode, &iloc); |
| return err; |
| } |
| |
| /* |
| * ext4_dirty_inode() is called from __mark_inode_dirty() |
| * |
| * We're really interested in the case where a file is being extended. |
| * i_size has been changed by generic_commit_write() and we thus need |
| * to include the updated inode in the current transaction. |
| * |
| * Also, DQUOT_ALLOC_SPACE() will always dirty the inode when blocks |
| * are allocated to the file. |
| * |
| * If the inode is marked synchronous, we don't honour that here - doing |
| * so would cause a commit on atime updates, which we don't bother doing. |
| * We handle synchronous inodes at the highest possible level. |
| */ |
| void ext4_dirty_inode(struct inode *inode) |
| { |
| handle_t *current_handle = ext4_journal_current_handle(); |
| handle_t *handle; |
| |
| if (!ext4_handle_valid(current_handle)) { |
| ext4_mark_inode_dirty(current_handle, inode); |
| return; |
| } |
| |
| handle = ext4_journal_start(inode, 2); |
| if (IS_ERR(handle)) |
| goto out; |
| if (current_handle && |
| current_handle->h_transaction != handle->h_transaction) { |
| /* This task has a transaction open against a different fs */ |
| printk(KERN_EMERG "%s: transactions do not match!\n", |
| __func__); |
| } else { |
| jbd_debug(5, "marking dirty. outer handle=%p\n", |
| current_handle); |
| ext4_mark_inode_dirty(handle, inode); |
| } |
| ext4_journal_stop(handle); |
| out: |
| return; |
| } |
| |
| #if 0 |
| /* |
| * Bind an inode's backing buffer_head into this transaction, to prevent |
| * it from being flushed to disk early. Unlike |
| * ext4_reserve_inode_write, this leaves behind no bh reference and |
| * returns no iloc structure, so the caller needs to repeat the iloc |
| * lookup to mark the inode dirty later. |
| */ |
| static int ext4_pin_inode(handle_t *handle, struct inode *inode) |
| { |
| struct ext4_iloc iloc; |
| |
| int err = 0; |
| if (handle) { |
| err = ext4_get_inode_loc(inode, &iloc); |
| if (!err) { |
| BUFFER_TRACE(iloc.bh, "get_write_access"); |
| err = jbd2_journal_get_write_access(handle, iloc.bh); |
| if (!err) |
| err = ext4_handle_dirty_metadata(handle, |
| inode, |
| iloc.bh); |
| brelse(iloc.bh); |
| } |
| } |
| ext4_std_error(inode->i_sb, err); |
| return err; |
| } |
| #endif |
| |
| int ext4_change_inode_journal_flag(struct inode *inode, int val) |
| { |
| journal_t *journal; |
| handle_t *handle; |
| int err; |
| |
| /* |
| * We have to be very careful here: changing a data block's |
| * journaling status dynamically is dangerous. If we write a |
| * data block to the journal, change the status and then delete |
| * that block, we risk forgetting to revoke the old log record |
| * from the journal and so a subsequent replay can corrupt data. |
| * So, first we make sure that the journal is empty and that |
| * nobody is changing anything. |
| */ |
| |
| journal = EXT4_JOURNAL(inode); |
| if (!journal) |
| return 0; |
| if (is_journal_aborted(journal)) |
| return -EROFS; |
| |
| jbd2_journal_lock_updates(journal); |
| jbd2_journal_flush(journal); |
| |
| /* |
| * OK, there are no updates running now, and all cached data is |
| * synced to disk. We are now in a completely consistent state |
| * which doesn't have anything in the journal, and we know that |
| * no filesystem updates are running, so it is safe to modify |
| * the inode's in-core data-journaling state flag now. |
| */ |
| |
| if (val) |
| EXT4_I(inode)->i_flags |= EXT4_JOURNAL_DATA_FL; |
| else |
| EXT4_I(inode)->i_flags &= ~EXT4_JOURNAL_DATA_FL; |
| ext4_set_aops(inode); |
| |
| jbd2_journal_unlock_updates(journal); |
| |
| /* Finally we can mark the inode as dirty. */ |
| |
| handle = ext4_journal_start(inode, 1); |
| if (IS_ERR(handle)) |
| return PTR_ERR(handle); |
| |
| err = ext4_mark_inode_dirty(handle, inode); |
| ext4_handle_sync(handle); |
| ext4_journal_stop(handle); |
| ext4_std_error(inode->i_sb, err); |
| |
| return err; |
| } |
| |
| static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh) |
| { |
| return !buffer_mapped(bh); |
| } |
| |
| int ext4_page_mkwrite(struct vm_area_struct *vma, struct page *page) |
| { |
| loff_t size; |
| unsigned long len; |
| int ret = -EINVAL; |
| void *fsdata; |
| struct file *file = vma->vm_file; |
| struct inode *inode = file->f_path.dentry->d_inode; |
| struct address_space *mapping = inode->i_mapping; |
| |
| /* |
| * Get i_alloc_sem to stop truncates messing with the inode. We cannot |
| * get i_mutex because we are already holding mmap_sem. |
| */ |
| down_read(&inode->i_alloc_sem); |
| size = i_size_read(inode); |
| if (page->mapping != mapping || size <= page_offset(page) |
| || !PageUptodate(page)) { |
| /* page got truncated from under us? */ |
| goto out_unlock; |
| } |
| ret = 0; |
| if (PageMappedToDisk(page)) |
| goto out_unlock; |
| |
| if (page->index == size >> PAGE_CACHE_SHIFT) |
| len = size & ~PAGE_CACHE_MASK; |
| else |
| len = PAGE_CACHE_SIZE; |
| |
| if (page_has_buffers(page)) { |
| /* return if we have all the buffers mapped */ |
| if (!walk_page_buffers(NULL, page_buffers(page), 0, len, NULL, |
| ext4_bh_unmapped)) |
| goto out_unlock; |
| } |
| /* |
| * OK, we need to fill the hole... Do write_begin write_end |
| * to do block allocation/reservation.We are not holding |
| * inode.i__mutex here. That allow * parallel write_begin, |
| * write_end call. lock_page prevent this from happening |
| * on the same page though |
| */ |
| ret = mapping->a_ops->write_begin(file, mapping, page_offset(page), |
| len, AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata); |
| if (ret < 0) |
| goto out_unlock; |
| ret = mapping->a_ops->write_end(file, mapping, page_offset(page), |
| len, len, page, fsdata); |
| if (ret < 0) |
| goto out_unlock; |
| ret = 0; |
| out_unlock: |
| up_read(&inode->i_alloc_sem); |
| return ret; |
| } |