Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
new file mode 100644
index 0000000..b890be0
--- /dev/null
+++ b/fs/ext2/inode.c
@@ -0,0 +1,1276 @@
+/*
+ * linux/fs/ext2/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@dcs.ed.ac.uk), 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 ext2_get_block() by Al Viro, 2000
+ */
+
+#include <linux/smp_lock.h>
+#include <linux/time.h>
+#include <linux/highuid.h>
+#include <linux/pagemap.h>
+#include <linux/quotaops.h>
+#include <linux/module.h>
+#include <linux/writeback.h>
+#include <linux/buffer_head.h>
+#include <linux/mpage.h>
+#include "ext2.h"
+#include "acl.h"
+
+MODULE_AUTHOR("Remy Card and others");
+MODULE_DESCRIPTION("Second Extended Filesystem");
+MODULE_LICENSE("GPL");
+
+static int ext2_update_inode(struct inode * inode, int do_sync);
+
+/*
+ * Test whether an inode is a fast symlink.
+ */
+static inline int ext2_inode_is_fast_symlink(struct inode *inode)
+{
+ int ea_blocks = EXT2_I(inode)->i_file_acl ?
+ (inode->i_sb->s_blocksize >> 9) : 0;
+
+ return (S_ISLNK(inode->i_mode) &&
+ inode->i_blocks - ea_blocks == 0);
+}
+
+/*
+ * Called at the last iput() if i_nlink is zero.
+ */
+void ext2_delete_inode (struct inode * inode)
+{
+ if (is_bad_inode(inode))
+ goto no_delete;
+ EXT2_I(inode)->i_dtime = get_seconds();
+ mark_inode_dirty(inode);
+ ext2_update_inode(inode, inode_needs_sync(inode));
+
+ inode->i_size = 0;
+ if (inode->i_blocks)
+ ext2_truncate (inode);
+ ext2_free_inode (inode);
+
+ return;
+no_delete:
+ clear_inode(inode); /* We must guarantee clearing of inode... */
+}
+
+void ext2_discard_prealloc (struct inode * inode)
+{
+#ifdef EXT2_PREALLOCATE
+ struct ext2_inode_info *ei = EXT2_I(inode);
+ write_lock(&ei->i_meta_lock);
+ if (ei->i_prealloc_count) {
+ unsigned short total = ei->i_prealloc_count;
+ unsigned long block = ei->i_prealloc_block;
+ ei->i_prealloc_count = 0;
+ ei->i_prealloc_block = 0;
+ write_unlock(&ei->i_meta_lock);
+ ext2_free_blocks (inode, block, total);
+ return;
+ } else
+ write_unlock(&ei->i_meta_lock);
+#endif
+}
+
+static int ext2_alloc_block (struct inode * inode, unsigned long goal, int *err)
+{
+#ifdef EXT2FS_DEBUG
+ static unsigned long alloc_hits, alloc_attempts;
+#endif
+ unsigned long result;
+
+
+#ifdef EXT2_PREALLOCATE
+ struct ext2_inode_info *ei = EXT2_I(inode);
+ write_lock(&ei->i_meta_lock);
+ if (ei->i_prealloc_count &&
+ (goal == ei->i_prealloc_block || goal + 1 == ei->i_prealloc_block))
+ {
+ result = ei->i_prealloc_block++;
+ ei->i_prealloc_count--;
+ write_unlock(&ei->i_meta_lock);
+ ext2_debug ("preallocation hit (%lu/%lu).\n",
+ ++alloc_hits, ++alloc_attempts);
+ } else {
+ write_unlock(&ei->i_meta_lock);
+ ext2_discard_prealloc (inode);
+ ext2_debug ("preallocation miss (%lu/%lu).\n",
+ alloc_hits, ++alloc_attempts);
+ if (S_ISREG(inode->i_mode))
+ result = ext2_new_block (inode, goal,
+ &ei->i_prealloc_count,
+ &ei->i_prealloc_block, err);
+ else
+ result = ext2_new_block(inode, goal, NULL, NULL, err);
+ }
+#else
+ result = ext2_new_block (inode, goal, 0, 0, err);
+#endif
+ return result;
+}
+
+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;
+}
+
+static inline int verify_chain(Indirect *from, Indirect *to)
+{
+ while (from <= to && from->key == *from->p)
+ from++;
+ return (from > to);
+}
+
+/**
+ * ext2_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 ext2 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 ext2_block_to_path(struct inode *inode,
+ long i_block, int offsets[4], int *boundary)
+{
+ int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb);
+ int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb);
+ const long direct_blocks = EXT2_NDIR_BLOCKS,
+ indirect_blocks = ptrs,
+ double_blocks = (1 << (ptrs_bits * 2));
+ int n = 0;
+ int final = 0;
+
+ if (i_block < 0) {
+ ext2_warning (inode->i_sb, "ext2_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++] = EXT2_IND_BLOCK;
+ offsets[n++] = i_block;
+ final = ptrs;
+ } else if ((i_block -= indirect_blocks) < double_blocks) {
+ offsets[n++] = EXT2_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++] = EXT2_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 {
+ ext2_warning (inode->i_sb, "ext2_block_to_path", "block > big");
+ }
+ if (boundary)
+ *boundary = (i_block & (ptrs - 1)) == (final - 1);
+ return n;
+}
+
+/**
+ * ext2_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 notices that chain had been changed while it was reading
+ * (ditto, *@err == -EAGAIN)
+ * or when it reads all @depth-1 indirect blocks successfully and finds
+ * the whole chain, all way to the data (returns %NULL, *err == 0).
+ */
+static Indirect *ext2_get_branch(struct inode *inode,
+ int depth,
+ int *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, EXT2_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;
+ read_lock(&EXT2_I(inode)->i_meta_lock);
+ if (!verify_chain(chain, p))
+ goto changed;
+ add_chain(++p, bh, (__le32*)bh->b_data + *++offsets);
+ read_unlock(&EXT2_I(inode)->i_meta_lock);
+ if (!p->key)
+ goto no_block;
+ }
+ return NULL;
+
+changed:
+ read_unlock(&EXT2_I(inode)->i_meta_lock);
+ brelse(bh);
+ *err = -EAGAIN;
+ goto no_block;
+failure:
+ *err = -EIO;
+no_block:
+ return p;
+}
+
+/**
+ * ext2_find_near - find a place for allocation with sufficient locality
+ * @inode: owner
+ * @ind: descriptor of indirect block.
+ *
+ * This function returns the prefered 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 unsigned long ext2_find_near(struct inode *inode, Indirect *ind)
+{
+ struct ext2_inode_info *ei = EXT2_I(inode);
+ __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;
+ __le32 *p;
+ unsigned long bg_start;
+ unsigned long 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 refered from inode itself? OK, just put it into
+ * the same cylinder group then.
+ */
+ bg_start = (ei->i_block_group * EXT2_BLOCKS_PER_GROUP(inode->i_sb)) +
+ le32_to_cpu(EXT2_SB(inode->i_sb)->s_es->s_first_data_block);
+ colour = (current->pid % 16) *
+ (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16);
+ return bg_start + colour;
+}
+
+/**
+ * ext2_find_goal - find a prefered place for allocation.
+ * @inode: owner
+ * @block: block we want
+ * @chain: chain of indirect blocks
+ * @partial: pointer to the last triple within a chain
+ * @goal: place to store the result.
+ *
+ * Normally this function find the prefered place for block allocation,
+ * stores it in *@goal and returns zero. If the branch had been changed
+ * under us we return -EAGAIN.
+ */
+
+static inline int ext2_find_goal(struct inode *inode,
+ long block,
+ Indirect chain[4],
+ Indirect *partial,
+ unsigned long *goal)
+{
+ struct ext2_inode_info *ei = EXT2_I(inode);
+ write_lock(&ei->i_meta_lock);
+ if ((block == ei->i_next_alloc_block + 1) && ei->i_next_alloc_goal) {
+ ei->i_next_alloc_block++;
+ ei->i_next_alloc_goal++;
+ }
+ if (verify_chain(chain, partial)) {
+ /*
+ * try the heuristic for sequential allocation,
+ * failing that at least try to get decent locality.
+ */
+ if (block == ei->i_next_alloc_block)
+ *goal = ei->i_next_alloc_goal;
+ if (!*goal)
+ *goal = ext2_find_near(inode, partial);
+ write_unlock(&ei->i_meta_lock);
+ return 0;
+ }
+ write_unlock(&ei->i_meta_lock);
+ return -EAGAIN;
+}
+
+/**
+ * ext2_alloc_branch - allocate and set up a chain of blocks.
+ * @inode: owner
+ * @num: depth of the chain (number of blocks to allocate)
+ * @offsets: offsets (in the blocks) to store the pointers to next.
+ * @branch: place to store the chain in.
+ *
+ * This function allocates @num 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 ext2_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 ext2_get_block(), excpet 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
+ * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain
+ * as described above and return 0.
+ */
+
+static int ext2_alloc_branch(struct inode *inode,
+ int num,
+ unsigned long goal,
+ int *offsets,
+ Indirect *branch)
+{
+ int blocksize = inode->i_sb->s_blocksize;
+ int n = 0;
+ int err;
+ int i;
+ int parent = ext2_alloc_block(inode, goal, &err);
+
+ branch[0].key = cpu_to_le32(parent);
+ if (parent) for (n = 1; n < num; n++) {
+ struct buffer_head *bh;
+ /* Allocate the next block */
+ int nr = ext2_alloc_block(inode, parent, &err);
+ if (!nr)
+ break;
+ branch[n].key = cpu_to_le32(nr);
+ /*
+ * 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, parent);
+ lock_buffer(bh);
+ memset(bh->b_data, 0, blocksize);
+ branch[n].bh = bh;
+ branch[n].p = (__le32 *) bh->b_data + offsets[n];
+ *branch[n].p = branch[n].key;
+ set_buffer_uptodate(bh);
+ unlock_buffer(bh);
+ mark_buffer_dirty_inode(bh, inode);
+ /* We used to sync bh here if IS_SYNC(inode).
+ * But we now rely upon generic_osync_inode()
+ * and b_inode_buffers. But not for directories.
+ */
+ if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode))
+ sync_dirty_buffer(bh);
+ parent = nr;
+ }
+ if (n == num)
+ return 0;
+
+ /* Allocation failed, free what we already allocated */
+ for (i = 1; i < n; i++)
+ bforget(branch[i].bh);
+ for (i = 0; i < n; i++)
+ ext2_free_blocks(inode, le32_to_cpu(branch[i].key), 1);
+ return err;
+}
+
+/**
+ * ext2_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
+ * ext2_alloc_branch)
+ * @where: location of missing link
+ * @num: number of blocks we are adding
+ *
+ * This function verifies that chain (up to the missing link) had not
+ * changed, 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. Otherwise (== chain had been changed)
+ * we free the new blocks (forgetting their buffer_heads, indeed) and
+ * return -EAGAIN.
+ */
+
+static inline int ext2_splice_branch(struct inode *inode,
+ long block,
+ Indirect chain[4],
+ Indirect *where,
+ int num)
+{
+ struct ext2_inode_info *ei = EXT2_I(inode);
+ int i;
+
+ /* Verify that place we are splicing to is still there and vacant */
+
+ write_lock(&ei->i_meta_lock);
+ if (!verify_chain(chain, where-1) || *where->p)
+ goto changed;
+
+ /* That's it */
+
+ *where->p = where->key;
+ ei->i_next_alloc_block = block;
+ ei->i_next_alloc_goal = le32_to_cpu(where[num-1].key);
+
+ write_unlock(&ei->i_meta_lock);
+
+ /* We are done with atomic stuff, now do the rest of housekeeping */
+
+ inode->i_ctime = CURRENT_TIME_SEC;
+
+ /* had we spliced it onto indirect block? */
+ if (where->bh)
+ mark_buffer_dirty_inode(where->bh, inode);
+
+ mark_inode_dirty(inode);
+ return 0;
+
+changed:
+ write_unlock(&ei->i_meta_lock);
+ for (i = 1; i < num; i++)
+ bforget(where[i].bh);
+ for (i = 0; i < num; i++)
+ ext2_free_blocks(inode, le32_to_cpu(where[i].key), 1);
+ return -EAGAIN;
+}
+
+/*
+ * 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.
+ */
+
+int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
+{
+ int err = -EIO;
+ int offsets[4];
+ Indirect chain[4];
+ Indirect *partial;
+ unsigned long goal;
+ int left;
+ int boundary = 0;
+ int depth = ext2_block_to_path(inode, iblock, offsets, &boundary);
+
+ if (depth == 0)
+ goto out;
+
+reread:
+ partial = ext2_get_branch(inode, depth, offsets, chain, &err);
+
+ /* Simplest case - block found, no allocation needed */
+ if (!partial) {
+got_it:
+ map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
+ if (boundary)
+ set_buffer_boundary(bh_result);
+ /* Clean up and exit */
+ partial = chain+depth-1; /* the whole chain */
+ goto cleanup;
+ }
+
+ /* Next simple case - plain lookup or failed read of indirect block */
+ if (!create || err == -EIO) {
+cleanup:
+ while (partial > chain) {
+ brelse(partial->bh);
+ partial--;
+ }
+out:
+ return err;
+ }
+
+ /*
+ * Indirect block might be removed by truncate while we were
+ * reading it. Handling of that case (forget what we've got and
+ * reread) is taken out of the main path.
+ */
+ if (err == -EAGAIN)
+ goto changed;
+
+ goal = 0;
+ if (ext2_find_goal(inode, iblock, chain, partial, &goal) < 0)
+ goto changed;
+
+ left = (chain + depth) - partial;
+ err = ext2_alloc_branch(inode, left, goal,
+ offsets+(partial-chain), partial);
+ if (err)
+ goto cleanup;
+
+ if (ext2_splice_branch(inode, iblock, chain, partial, left) < 0)
+ goto changed;
+
+ set_buffer_new(bh_result);
+ goto got_it;
+
+changed:
+ while (partial > chain) {
+ brelse(partial->bh);
+ partial--;
+ }
+ goto reread;
+}
+
+static int ext2_writepage(struct page *page, struct writeback_control *wbc)
+{
+ return block_write_full_page(page, ext2_get_block, wbc);
+}
+
+static int ext2_readpage(struct file *file, struct page *page)
+{
+ return mpage_readpage(page, ext2_get_block);
+}
+
+static int
+ext2_readpages(struct file *file, struct address_space *mapping,
+ struct list_head *pages, unsigned nr_pages)
+{
+ return mpage_readpages(mapping, pages, nr_pages, ext2_get_block);
+}
+
+static int
+ext2_prepare_write(struct file *file, struct page *page,
+ unsigned from, unsigned to)
+{
+ return block_prepare_write(page,from,to,ext2_get_block);
+}
+
+static int
+ext2_nobh_prepare_write(struct file *file, struct page *page,
+ unsigned from, unsigned to)
+{
+ return nobh_prepare_write(page,from,to,ext2_get_block);
+}
+
+static int ext2_nobh_writepage(struct page *page,
+ struct writeback_control *wbc)
+{
+ return nobh_writepage(page, ext2_get_block, wbc);
+}
+
+static sector_t ext2_bmap(struct address_space *mapping, sector_t block)
+{
+ return generic_block_bmap(mapping,block,ext2_get_block);
+}
+
+static int
+ext2_get_blocks(struct inode *inode, sector_t iblock, unsigned long max_blocks,
+ struct buffer_head *bh_result, int create)
+{
+ int ret;
+
+ ret = ext2_get_block(inode, iblock, bh_result, create);
+ if (ret == 0)
+ bh_result->b_size = (1 << inode->i_blkbits);
+ return ret;
+}
+
+static ssize_t
+ext2_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;
+
+ return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
+ offset, nr_segs, ext2_get_blocks, NULL);
+}
+
+static int
+ext2_writepages(struct address_space *mapping, struct writeback_control *wbc)
+{
+ return mpage_writepages(mapping, wbc, ext2_get_block);
+}
+
+struct address_space_operations ext2_aops = {
+ .readpage = ext2_readpage,
+ .readpages = ext2_readpages,
+ .writepage = ext2_writepage,
+ .sync_page = block_sync_page,
+ .prepare_write = ext2_prepare_write,
+ .commit_write = generic_commit_write,
+ .bmap = ext2_bmap,
+ .direct_IO = ext2_direct_IO,
+ .writepages = ext2_writepages,
+};
+
+struct address_space_operations ext2_nobh_aops = {
+ .readpage = ext2_readpage,
+ .readpages = ext2_readpages,
+ .writepage = ext2_nobh_writepage,
+ .sync_page = block_sync_page,
+ .prepare_write = ext2_nobh_prepare_write,
+ .commit_write = nobh_commit_write,
+ .bmap = ext2_bmap,
+ .direct_IO = ext2_direct_IO,
+ .writepages = ext2_writepages,
+};
+
+/*
+ * 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;
+}
+
+/**
+ * ext2_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 ext2_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 ext2_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 ext2_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].p
+ * (no partially truncated stuff there).
+ */
+
+static Indirect *ext2_find_shared(struct inode *inode,
+ int depth,
+ int offsets[4],
+ Indirect chain[4],
+ __le32 *top)
+{
+ Indirect *partial, *p;
+ int k, err;
+
+ *top = 0;
+ for (k = depth; k > 1 && !offsets[k-1]; k--)
+ ;
+ partial = ext2_get_branch(inode, k, offsets, chain, &err);
+ 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.
+ */
+ write_lock(&EXT2_I(inode)->i_meta_lock);
+ if (!partial->key && *partial->p) {
+ write_unlock(&EXT2_I(inode)->i_meta_lock);
+ 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;
+ *p->p = 0;
+ }
+ write_unlock(&EXT2_I(inode)->i_meta_lock);
+
+ while(partial > p)
+ {
+ brelse(partial->bh);
+ partial--;
+ }
+no_top:
+ return partial;
+}
+
+/**
+ * ext2_free_data - free a list of data blocks
+ * @inode: inode we are dealing with
+ * @p: array of block numbers
+ * @q: 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.
+ */
+static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q)
+{
+ unsigned long block_to_free = 0, count = 0;
+ unsigned long nr;
+
+ for ( ; p < q ; p++) {
+ nr = le32_to_cpu(*p);
+ if (nr) {
+ *p = 0;
+ /* accumulate blocks to free if they're contiguous */
+ if (count == 0)
+ goto free_this;
+ else if (block_to_free == nr - count)
+ count++;
+ else {
+ mark_inode_dirty(inode);
+ ext2_free_blocks (inode, block_to_free, count);
+ free_this:
+ block_to_free = nr;
+ count = 1;
+ }
+ }
+ }
+ if (count > 0) {
+ mark_inode_dirty(inode);
+ ext2_free_blocks (inode, block_to_free, count);
+ }
+}
+
+/**
+ * ext2_free_branches - free an array of branches
+ * @inode: inode we are dealing with
+ * @p: array of block numbers
+ * @q: 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 ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth)
+{
+ struct buffer_head * bh;
+ unsigned long nr;
+
+ if (depth--) {
+ int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
+ for ( ; p < q ; p++) {
+ nr = le32_to_cpu(*p);
+ if (!nr)
+ continue;
+ *p = 0;
+ bh = sb_bread(inode->i_sb, nr);
+ /*
+ * A read failure? Report error and clear slot
+ * (should be rare).
+ */
+ if (!bh) {
+ ext2_error(inode->i_sb, "ext2_free_branches",
+ "Read failure, inode=%ld, block=%ld",
+ inode->i_ino, nr);
+ continue;
+ }
+ ext2_free_branches(inode,
+ (__le32*)bh->b_data,
+ (__le32*)bh->b_data + addr_per_block,
+ depth);
+ bforget(bh);
+ ext2_free_blocks(inode, nr, 1);
+ mark_inode_dirty(inode);
+ }
+ } else
+ ext2_free_data(inode, p, q);
+}
+
+void ext2_truncate (struct inode * inode)
+{
+ __le32 *i_data = EXT2_I(inode)->i_data;
+ int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
+ int offsets[4];
+ Indirect chain[4];
+ Indirect *partial;
+ __le32 nr = 0;
+ int n;
+ long iblock;
+ unsigned blocksize;
+
+ if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+ S_ISLNK(inode->i_mode)))
+ return;
+ if (ext2_inode_is_fast_symlink(inode))
+ return;
+ if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+ return;
+
+ ext2_discard_prealloc(inode);
+
+ blocksize = inode->i_sb->s_blocksize;
+ iblock = (inode->i_size + blocksize-1)
+ >> EXT2_BLOCK_SIZE_BITS(inode->i_sb);
+
+ if (test_opt(inode->i_sb, NOBH))
+ nobh_truncate_page(inode->i_mapping, inode->i_size);
+ else
+ block_truncate_page(inode->i_mapping,
+ inode->i_size, ext2_get_block);
+
+ n = ext2_block_to_path(inode, iblock, offsets, NULL);
+ if (n == 0)
+ return;
+
+ if (n == 1) {
+ ext2_free_data(inode, i_data+offsets[0],
+ i_data + EXT2_NDIR_BLOCKS);
+ goto do_indirects;
+ }
+
+ partial = ext2_find_shared(inode, n, offsets, chain, &nr);
+ /* Kill the top of shared branch (already detached) */
+ if (nr) {
+ if (partial == chain)
+ mark_inode_dirty(inode);
+ else
+ mark_buffer_dirty_inode(partial->bh, inode);
+ ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial);
+ }
+ /* Clear the ends of indirect blocks on the shared branch */
+ while (partial > chain) {
+ ext2_free_branches(inode,
+ partial->p + 1,
+ (__le32*)partial->bh->b_data+addr_per_block,
+ (chain+n-1) - partial);
+ mark_buffer_dirty_inode(partial->bh, inode);
+ brelse (partial->bh);
+ partial--;
+ }
+do_indirects:
+ /* Kill the remaining (whole) subtrees */
+ switch (offsets[0]) {
+ default:
+ nr = i_data[EXT2_IND_BLOCK];
+ if (nr) {
+ i_data[EXT2_IND_BLOCK] = 0;
+ mark_inode_dirty(inode);
+ ext2_free_branches(inode, &nr, &nr+1, 1);
+ }
+ case EXT2_IND_BLOCK:
+ nr = i_data[EXT2_DIND_BLOCK];
+ if (nr) {
+ i_data[EXT2_DIND_BLOCK] = 0;
+ mark_inode_dirty(inode);
+ ext2_free_branches(inode, &nr, &nr+1, 2);
+ }
+ case EXT2_DIND_BLOCK:
+ nr = i_data[EXT2_TIND_BLOCK];
+ if (nr) {
+ i_data[EXT2_TIND_BLOCK] = 0;
+ mark_inode_dirty(inode);
+ ext2_free_branches(inode, &nr, &nr+1, 3);
+ }
+ case EXT2_TIND_BLOCK:
+ ;
+ }
+ inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
+ if (inode_needs_sync(inode)) {
+ sync_mapping_buffers(inode->i_mapping);
+ ext2_sync_inode (inode);
+ } else {
+ mark_inode_dirty(inode);
+ }
+}
+
+static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino,
+ struct buffer_head **p)
+{
+ struct buffer_head * bh;
+ unsigned long block_group;
+ unsigned long block;
+ unsigned long offset;
+ struct ext2_group_desc * gdp;
+
+ *p = NULL;
+ if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) ||
+ ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
+ goto Einval;
+
+ block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb);
+ gdp = ext2_get_group_desc(sb, block_group, &bh);
+ if (!gdp)
+ goto Egdp;
+ /*
+ * Figure out the offset within the block group inode table
+ */
+ offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb);
+ block = le32_to_cpu(gdp->bg_inode_table) +
+ (offset >> EXT2_BLOCK_SIZE_BITS(sb));
+ if (!(bh = sb_bread(sb, block)))
+ goto Eio;
+
+ *p = bh;
+ offset &= (EXT2_BLOCK_SIZE(sb) - 1);
+ return (struct ext2_inode *) (bh->b_data + offset);
+
+Einval:
+ ext2_error(sb, "ext2_get_inode", "bad inode number: %lu",
+ (unsigned long) ino);
+ return ERR_PTR(-EINVAL);
+Eio:
+ ext2_error(sb, "ext2_get_inode",
+ "unable to read inode block - inode=%lu, block=%lu",
+ (unsigned long) ino, block);
+Egdp:
+ return ERR_PTR(-EIO);
+}
+
+void ext2_set_inode_flags(struct inode *inode)
+{
+ unsigned int flags = EXT2_I(inode)->i_flags;
+
+ inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
+ if (flags & EXT2_SYNC_FL)
+ inode->i_flags |= S_SYNC;
+ if (flags & EXT2_APPEND_FL)
+ inode->i_flags |= S_APPEND;
+ if (flags & EXT2_IMMUTABLE_FL)
+ inode->i_flags |= S_IMMUTABLE;
+ if (flags & EXT2_NOATIME_FL)
+ inode->i_flags |= S_NOATIME;
+ if (flags & EXT2_DIRSYNC_FL)
+ inode->i_flags |= S_DIRSYNC;
+}
+
+void ext2_read_inode (struct inode * inode)
+{
+ struct ext2_inode_info *ei = EXT2_I(inode);
+ ino_t ino = inode->i_ino;
+ struct buffer_head * bh;
+ struct ext2_inode * raw_inode = ext2_get_inode(inode->i_sb, ino, &bh);
+ int n;
+
+#ifdef CONFIG_EXT2_FS_POSIX_ACL
+ ei->i_acl = EXT2_ACL_NOT_CACHED;
+ ei->i_default_acl = EXT2_ACL_NOT_CACHED;
+#endif
+ if (IS_ERR(raw_inode))
+ goto bad_inode;
+
+ 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);
+ inode->i_size = le32_to_cpu(raw_inode->i_size);
+ inode->i_atime.tv_sec = le32_to_cpu(raw_inode->i_atime);
+ inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->i_ctime);
+ inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->i_mtime);
+ inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 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 && (inode->i_mode == 0 || ei->i_dtime)) {
+ /* this inode is deleted */
+ brelse (bh);
+ goto bad_inode;
+ }
+ inode->i_blksize = PAGE_SIZE; /* This is the optimal IO size (for stat), not the fs block size */
+ inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
+ ei->i_flags = le32_to_cpu(raw_inode->i_flags);
+ ei->i_faddr = le32_to_cpu(raw_inode->i_faddr);
+ ei->i_frag_no = raw_inode->i_frag;
+ ei->i_frag_size = raw_inode->i_fsize;
+ ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
+ ei->i_dir_acl = 0;
+ if (S_ISREG(inode->i_mode))
+ inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
+ else
+ ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
+ ei->i_dtime = 0;
+ inode->i_generation = le32_to_cpu(raw_inode->i_generation);
+ ei->i_state = 0;
+ ei->i_next_alloc_block = 0;
+ ei->i_next_alloc_goal = 0;
+ ei->i_prealloc_count = 0;
+ ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
+ ei->i_dir_start_lookup = 0;
+
+ /*
+ * 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 (n = 0; n < EXT2_N_BLOCKS; n++)
+ ei->i_data[n] = raw_inode->i_block[n];
+
+ if (S_ISREG(inode->i_mode)) {
+ inode->i_op = &ext2_file_inode_operations;
+ inode->i_fop = &ext2_file_operations;
+ if (test_opt(inode->i_sb, NOBH))
+ inode->i_mapping->a_ops = &ext2_nobh_aops;
+ else
+ inode->i_mapping->a_ops = &ext2_aops;
+ } else if (S_ISDIR(inode->i_mode)) {
+ inode->i_op = &ext2_dir_inode_operations;
+ inode->i_fop = &ext2_dir_operations;
+ if (test_opt(inode->i_sb, NOBH))
+ inode->i_mapping->a_ops = &ext2_nobh_aops;
+ else
+ inode->i_mapping->a_ops = &ext2_aops;
+ } else if (S_ISLNK(inode->i_mode)) {
+ if (ext2_inode_is_fast_symlink(inode))
+ inode->i_op = &ext2_fast_symlink_inode_operations;
+ else {
+ inode->i_op = &ext2_symlink_inode_operations;
+ if (test_opt(inode->i_sb, NOBH))
+ inode->i_mapping->a_ops = &ext2_nobh_aops;
+ else
+ inode->i_mapping->a_ops = &ext2_aops;
+ }
+ } else {
+ inode->i_op = &ext2_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 (bh);
+ ext2_set_inode_flags(inode);
+ return;
+
+bad_inode:
+ make_bad_inode(inode);
+ return;
+}
+
+static int ext2_update_inode(struct inode * inode, int do_sync)
+{
+ struct ext2_inode_info *ei = EXT2_I(inode);
+ struct super_block *sb = inode->i_sb;
+ ino_t ino = inode->i_ino;
+ uid_t uid = inode->i_uid;
+ gid_t gid = inode->i_gid;
+ struct buffer_head * bh;
+ struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh);
+ int n;
+ int err = 0;
+
+ if (IS_ERR(raw_inode))
+ return -EIO;
+
+ /* For fields not not tracking in the in-memory inode,
+ * initialise them to zero for new inodes. */
+ if (ei->i_state & EXT2_STATE_NEW)
+ memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size);
+
+ raw_inode->i_mode = cpu_to_le16(inode->i_mode);
+ if (!(test_opt(sb, NO_UID32))) {
+ raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid));
+ raw_inode->i_gid_low = cpu_to_le16(low_16_bits(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(uid));
+ raw_inode->i_gid_high = cpu_to_le16(high_16_bits(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(uid));
+ raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid));
+ raw_inode->i_uid_high = 0;
+ raw_inode->i_gid_high = 0;
+ }
+ raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
+ raw_inode->i_size = cpu_to_le32(inode->i_size);
+ raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
+ raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
+ raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
+
+ raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
+ raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
+ raw_inode->i_flags = cpu_to_le32(ei->i_flags);
+ raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);
+ raw_inode->i_frag = ei->i_frag_no;
+ raw_inode->i_fsize = ei->i_frag_size;
+ raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
+ if (!S_ISREG(inode->i_mode))
+ raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
+ else {
+ raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32);
+ if (inode->i_size > 0x7fffffffULL) {
+ if (!EXT2_HAS_RO_COMPAT_FEATURE(sb,
+ EXT2_FEATURE_RO_COMPAT_LARGE_FILE) ||
+ EXT2_SB(sb)->s_es->s_rev_level ==
+ cpu_to_le32(EXT2_GOOD_OLD_REV)) {
+ /* If this is the first large file
+ * created, add a flag to the superblock.
+ */
+ lock_kernel();
+ ext2_update_dynamic_rev(sb);
+ EXT2_SET_RO_COMPAT_FEATURE(sb,
+ EXT2_FEATURE_RO_COMPAT_LARGE_FILE);
+ unlock_kernel();
+ ext2_write_super(sb);
+ }
+ }
+ }
+
+ 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 (n = 0; n < EXT2_N_BLOCKS; n++)
+ raw_inode->i_block[n] = ei->i_data[n];
+ mark_buffer_dirty(bh);
+ if (do_sync) {
+ sync_dirty_buffer(bh);
+ if (buffer_req(bh) && !buffer_uptodate(bh)) {
+ printk ("IO error syncing ext2 inode [%s:%08lx]\n",
+ sb->s_id, (unsigned long) ino);
+ err = -EIO;
+ }
+ }
+ ei->i_state &= ~EXT2_STATE_NEW;
+ brelse (bh);
+ return err;
+}
+
+int ext2_write_inode(struct inode *inode, int wait)
+{
+ return ext2_update_inode(inode, wait);
+}
+
+int ext2_sync_inode(struct inode *inode)
+{
+ struct writeback_control wbc = {
+ .sync_mode = WB_SYNC_ALL,
+ .nr_to_write = 0, /* sys_fsync did this */
+ };
+ return sync_inode(inode, &wbc);
+}
+
+int ext2_setattr(struct dentry *dentry, struct iattr *iattr)
+{
+ struct inode *inode = dentry->d_inode;
+ int error;
+
+ error = inode_change_ok(inode, iattr);
+ if (error)
+ return error;
+ if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) ||
+ (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) {
+ error = DQUOT_TRANSFER(inode, iattr) ? -EDQUOT : 0;
+ if (error)
+ return error;
+ }
+ error = inode_setattr(inode, iattr);
+ if (!error && (iattr->ia_valid & ATTR_MODE))
+ error = ext2_acl_chmod(inode);
+ return error;
+}