| /* |
| * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com |
| * Written by Alex Tomas <alex@clusterfs.com> |
| * |
| * Architecture independence: |
| * Copyright (c) 2005, Bull S.A. |
| * Written by Pierre Peiffer <pierre.peiffer@bull.net> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public Licens |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- |
| */ |
| |
| /* |
| * Extents support for EXT4 |
| * |
| * TODO: |
| * - ext4*_error() should be used in some situations |
| * - analyze all BUG()/BUG_ON(), use -EIO where appropriate |
| * - smart tree reduction |
| */ |
| |
| #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/slab.h> |
| #include <linux/falloc.h> |
| #include <asm/uaccess.h> |
| #include <linux/fiemap.h> |
| #include "ext4_jbd2.h" |
| #include "ext4_extents.h" |
| |
| #include <trace/events/ext4.h> |
| |
| static int ext4_ext_truncate_extend_restart(handle_t *handle, |
| struct inode *inode, |
| int needed) |
| { |
| int err; |
| |
| if (!ext4_handle_valid(handle)) |
| return 0; |
| if (handle->h_buffer_credits > needed) |
| return 0; |
| err = ext4_journal_extend(handle, needed); |
| if (err <= 0) |
| return err; |
| err = ext4_truncate_restart_trans(handle, inode, needed); |
| if (err == 0) |
| err = -EAGAIN; |
| |
| return err; |
| } |
| |
| /* |
| * could return: |
| * - EROFS |
| * - ENOMEM |
| */ |
| static int ext4_ext_get_access(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path) |
| { |
| if (path->p_bh) { |
| /* path points to block */ |
| return ext4_journal_get_write_access(handle, path->p_bh); |
| } |
| /* path points to leaf/index in inode body */ |
| /* we use in-core data, no need to protect them */ |
| return 0; |
| } |
| |
| /* |
| * could return: |
| * - EROFS |
| * - ENOMEM |
| * - EIO |
| */ |
| static int ext4_ext_dirty(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path) |
| { |
| int err; |
| if (path->p_bh) { |
| /* path points to block */ |
| err = ext4_handle_dirty_metadata(handle, inode, path->p_bh); |
| } else { |
| /* path points to leaf/index in inode body */ |
| err = ext4_mark_inode_dirty(handle, inode); |
| } |
| return err; |
| } |
| |
| static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode, |
| struct ext4_ext_path *path, |
| ext4_lblk_t block) |
| { |
| struct ext4_inode_info *ei = EXT4_I(inode); |
| ext4_fsblk_t bg_start; |
| ext4_fsblk_t last_block; |
| ext4_grpblk_t colour; |
| ext4_group_t block_group; |
| int flex_size = ext4_flex_bg_size(EXT4_SB(inode->i_sb)); |
| int depth; |
| |
| if (path) { |
| struct ext4_extent *ex; |
| depth = path->p_depth; |
| |
| /* |
| * Try to predict block placement assuming that we are |
| * filling in a file which will eventually be |
| * non-sparse --- i.e., in the case of libbfd writing |
| * an ELF object sections out-of-order but in a way |
| * the eventually results in a contiguous object or |
| * executable file, or some database extending a table |
| * space file. However, this is actually somewhat |
| * non-ideal if we are writing a sparse file such as |
| * qemu or KVM writing a raw image file that is going |
| * to stay fairly sparse, since it will end up |
| * fragmenting the file system's free space. Maybe we |
| * should have some hueristics or some way to allow |
| * userspace to pass a hint to file system, |
| * especially if the latter case turns out to be |
| * common. |
| */ |
| ex = path[depth].p_ext; |
| if (ex) { |
| ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex); |
| ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block); |
| |
| if (block > ext_block) |
| return ext_pblk + (block - ext_block); |
| else |
| return ext_pblk - (ext_block - block); |
| } |
| |
| /* it looks like index is empty; |
| * try to find starting block from index itself */ |
| if (path[depth].p_bh) |
| return path[depth].p_bh->b_blocknr; |
| } |
| |
| /* OK. use inode's group */ |
| block_group = ei->i_block_group; |
| if (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) { |
| /* |
| * If there are at least EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME |
| * block groups per flexgroup, reserve the first block |
| * group for directories and special files. Regular |
| * files will start at the second block group. This |
| * tends to speed up directory access and improves |
| * fsck times. |
| */ |
| block_group &= ~(flex_size-1); |
| if (S_ISREG(inode->i_mode)) |
| block_group++; |
| } |
| bg_start = ext4_group_first_block_no(inode->i_sb, block_group); |
| last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1; |
| |
| /* |
| * If we are doing delayed allocation, we don't need take |
| * colour into account. |
| */ |
| if (test_opt(inode->i_sb, DELALLOC)) |
| return bg_start; |
| |
| 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 + block; |
| } |
| |
| /* |
| * Allocation for a meta data block |
| */ |
| static ext4_fsblk_t |
| ext4_ext_new_meta_block(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path, |
| struct ext4_extent *ex, int *err) |
| { |
| ext4_fsblk_t goal, newblock; |
| |
| goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block)); |
| newblock = ext4_new_meta_blocks(handle, inode, goal, NULL, err); |
| return newblock; |
| } |
| |
| static inline int ext4_ext_space_block(struct inode *inode, int check) |
| { |
| int size; |
| |
| size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) |
| / sizeof(struct ext4_extent); |
| if (!check) { |
| #ifdef AGGRESSIVE_TEST |
| if (size > 6) |
| size = 6; |
| #endif |
| } |
| return size; |
| } |
| |
| static inline int ext4_ext_space_block_idx(struct inode *inode, int check) |
| { |
| int size; |
| |
| size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) |
| / sizeof(struct ext4_extent_idx); |
| if (!check) { |
| #ifdef AGGRESSIVE_TEST |
| if (size > 5) |
| size = 5; |
| #endif |
| } |
| return size; |
| } |
| |
| static inline int ext4_ext_space_root(struct inode *inode, int check) |
| { |
| int size; |
| |
| size = sizeof(EXT4_I(inode)->i_data); |
| size -= sizeof(struct ext4_extent_header); |
| size /= sizeof(struct ext4_extent); |
| if (!check) { |
| #ifdef AGGRESSIVE_TEST |
| if (size > 3) |
| size = 3; |
| #endif |
| } |
| return size; |
| } |
| |
| static inline int ext4_ext_space_root_idx(struct inode *inode, int check) |
| { |
| int size; |
| |
| size = sizeof(EXT4_I(inode)->i_data); |
| size -= sizeof(struct ext4_extent_header); |
| size /= sizeof(struct ext4_extent_idx); |
| if (!check) { |
| #ifdef AGGRESSIVE_TEST |
| if (size > 4) |
| size = 4; |
| #endif |
| } |
| return size; |
| } |
| |
| /* |
| * Calculate the number of metadata blocks needed |
| * to allocate @blocks |
| * Worse case is one block per extent |
| */ |
| int ext4_ext_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock) |
| { |
| struct ext4_inode_info *ei = EXT4_I(inode); |
| int idxs, num = 0; |
| |
| idxs = ((inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) |
| / sizeof(struct ext4_extent_idx)); |
| |
| /* |
| * If the new delayed allocation block is contiguous with the |
| * previous da block, it can share index blocks with the |
| * previous block, so we only need to allocate a new index |
| * block every idxs leaf blocks. At ldxs**2 blocks, we need |
| * an additional index block, and at ldxs**3 blocks, yet |
| * another index blocks. |
| */ |
| if (ei->i_da_metadata_calc_len && |
| ei->i_da_metadata_calc_last_lblock+1 == lblock) { |
| if ((ei->i_da_metadata_calc_len % idxs) == 0) |
| num++; |
| if ((ei->i_da_metadata_calc_len % (idxs*idxs)) == 0) |
| num++; |
| if ((ei->i_da_metadata_calc_len % (idxs*idxs*idxs)) == 0) { |
| num++; |
| ei->i_da_metadata_calc_len = 0; |
| } else |
| ei->i_da_metadata_calc_len++; |
| ei->i_da_metadata_calc_last_lblock++; |
| return num; |
| } |
| |
| /* |
| * In the worst case we need a new set of index blocks at |
| * every level of the inode's extent tree. |
| */ |
| ei->i_da_metadata_calc_len = 1; |
| ei->i_da_metadata_calc_last_lblock = lblock; |
| return ext_depth(inode) + 1; |
| } |
| |
| static int |
| ext4_ext_max_entries(struct inode *inode, int depth) |
| { |
| int max; |
| |
| if (depth == ext_depth(inode)) { |
| if (depth == 0) |
| max = ext4_ext_space_root(inode, 1); |
| else |
| max = ext4_ext_space_root_idx(inode, 1); |
| } else { |
| if (depth == 0) |
| max = ext4_ext_space_block(inode, 1); |
| else |
| max = ext4_ext_space_block_idx(inode, 1); |
| } |
| |
| return max; |
| } |
| |
| static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext) |
| { |
| ext4_fsblk_t block = ext4_ext_pblock(ext); |
| int len = ext4_ext_get_actual_len(ext); |
| |
| return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len); |
| } |
| |
| static int ext4_valid_extent_idx(struct inode *inode, |
| struct ext4_extent_idx *ext_idx) |
| { |
| ext4_fsblk_t block = ext4_idx_pblock(ext_idx); |
| |
| return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1); |
| } |
| |
| static int ext4_valid_extent_entries(struct inode *inode, |
| struct ext4_extent_header *eh, |
| int depth) |
| { |
| struct ext4_extent *ext; |
| struct ext4_extent_idx *ext_idx; |
| unsigned short entries; |
| if (eh->eh_entries == 0) |
| return 1; |
| |
| entries = le16_to_cpu(eh->eh_entries); |
| |
| if (depth == 0) { |
| /* leaf entries */ |
| ext = EXT_FIRST_EXTENT(eh); |
| while (entries) { |
| if (!ext4_valid_extent(inode, ext)) |
| return 0; |
| ext++; |
| entries--; |
| } |
| } else { |
| ext_idx = EXT_FIRST_INDEX(eh); |
| while (entries) { |
| if (!ext4_valid_extent_idx(inode, ext_idx)) |
| return 0; |
| ext_idx++; |
| entries--; |
| } |
| } |
| return 1; |
| } |
| |
| static int __ext4_ext_check(const char *function, unsigned int line, |
| struct inode *inode, struct ext4_extent_header *eh, |
| int depth) |
| { |
| const char *error_msg; |
| int max = 0; |
| |
| if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) { |
| error_msg = "invalid magic"; |
| goto corrupted; |
| } |
| if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) { |
| error_msg = "unexpected eh_depth"; |
| goto corrupted; |
| } |
| if (unlikely(eh->eh_max == 0)) { |
| error_msg = "invalid eh_max"; |
| goto corrupted; |
| } |
| max = ext4_ext_max_entries(inode, depth); |
| if (unlikely(le16_to_cpu(eh->eh_max) > max)) { |
| error_msg = "too large eh_max"; |
| goto corrupted; |
| } |
| if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) { |
| error_msg = "invalid eh_entries"; |
| goto corrupted; |
| } |
| if (!ext4_valid_extent_entries(inode, eh, depth)) { |
| error_msg = "invalid extent entries"; |
| goto corrupted; |
| } |
| return 0; |
| |
| corrupted: |
| ext4_error_inode(inode, function, line, 0, |
| "bad header/extent: %s - magic %x, " |
| "entries %u, max %u(%u), depth %u(%u)", |
| error_msg, le16_to_cpu(eh->eh_magic), |
| le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max), |
| max, le16_to_cpu(eh->eh_depth), depth); |
| |
| return -EIO; |
| } |
| |
| #define ext4_ext_check(inode, eh, depth) \ |
| __ext4_ext_check(__func__, __LINE__, inode, eh, depth) |
| |
| int ext4_ext_check_inode(struct inode *inode) |
| { |
| return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode)); |
| } |
| |
| #ifdef EXT_DEBUG |
| static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path) |
| { |
| int k, l = path->p_depth; |
| |
| ext_debug("path:"); |
| for (k = 0; k <= l; k++, path++) { |
| if (path->p_idx) { |
| ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block), |
| ext4_idx_pblock(path->p_idx)); |
| } else if (path->p_ext) { |
| ext_debug(" %d:[%d]%d:%llu ", |
| le32_to_cpu(path->p_ext->ee_block), |
| ext4_ext_is_uninitialized(path->p_ext), |
| ext4_ext_get_actual_len(path->p_ext), |
| ext4_ext_pblock(path->p_ext)); |
| } else |
| ext_debug(" []"); |
| } |
| ext_debug("\n"); |
| } |
| |
| static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path) |
| { |
| int depth = ext_depth(inode); |
| struct ext4_extent_header *eh; |
| struct ext4_extent *ex; |
| int i; |
| |
| if (!path) |
| return; |
| |
| eh = path[depth].p_hdr; |
| ex = EXT_FIRST_EXTENT(eh); |
| |
| ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino); |
| |
| for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) { |
| ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block), |
| ext4_ext_is_uninitialized(ex), |
| ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex)); |
| } |
| ext_debug("\n"); |
| } |
| #else |
| #define ext4_ext_show_path(inode, path) |
| #define ext4_ext_show_leaf(inode, path) |
| #endif |
| |
| void ext4_ext_drop_refs(struct ext4_ext_path *path) |
| { |
| int depth = path->p_depth; |
| int i; |
| |
| for (i = 0; i <= depth; i++, path++) |
| if (path->p_bh) { |
| brelse(path->p_bh); |
| path->p_bh = NULL; |
| } |
| } |
| |
| /* |
| * ext4_ext_binsearch_idx: |
| * binary search for the closest index of the given block |
| * the header must be checked before calling this |
| */ |
| static void |
| ext4_ext_binsearch_idx(struct inode *inode, |
| struct ext4_ext_path *path, ext4_lblk_t block) |
| { |
| struct ext4_extent_header *eh = path->p_hdr; |
| struct ext4_extent_idx *r, *l, *m; |
| |
| |
| ext_debug("binsearch for %u(idx): ", block); |
| |
| l = EXT_FIRST_INDEX(eh) + 1; |
| r = EXT_LAST_INDEX(eh); |
| while (l <= r) { |
| m = l + (r - l) / 2; |
| if (block < le32_to_cpu(m->ei_block)) |
| r = m - 1; |
| else |
| l = m + 1; |
| ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block), |
| m, le32_to_cpu(m->ei_block), |
| r, le32_to_cpu(r->ei_block)); |
| } |
| |
| path->p_idx = l - 1; |
| ext_debug(" -> %d->%lld ", le32_to_cpu(path->p_idx->ei_block), |
| ext4_idx_pblock(path->p_idx)); |
| |
| #ifdef CHECK_BINSEARCH |
| { |
| struct ext4_extent_idx *chix, *ix; |
| int k; |
| |
| chix = ix = EXT_FIRST_INDEX(eh); |
| for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) { |
| if (k != 0 && |
| le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) { |
| printk(KERN_DEBUG "k=%d, ix=0x%p, " |
| "first=0x%p\n", k, |
| ix, EXT_FIRST_INDEX(eh)); |
| printk(KERN_DEBUG "%u <= %u\n", |
| le32_to_cpu(ix->ei_block), |
| le32_to_cpu(ix[-1].ei_block)); |
| } |
| BUG_ON(k && le32_to_cpu(ix->ei_block) |
| <= le32_to_cpu(ix[-1].ei_block)); |
| if (block < le32_to_cpu(ix->ei_block)) |
| break; |
| chix = ix; |
| } |
| BUG_ON(chix != path->p_idx); |
| } |
| #endif |
| |
| } |
| |
| /* |
| * ext4_ext_binsearch: |
| * binary search for closest extent of the given block |
| * the header must be checked before calling this |
| */ |
| static void |
| ext4_ext_binsearch(struct inode *inode, |
| struct ext4_ext_path *path, ext4_lblk_t block) |
| { |
| struct ext4_extent_header *eh = path->p_hdr; |
| struct ext4_extent *r, *l, *m; |
| |
| if (eh->eh_entries == 0) { |
| /* |
| * this leaf is empty: |
| * we get such a leaf in split/add case |
| */ |
| return; |
| } |
| |
| ext_debug("binsearch for %u: ", block); |
| |
| l = EXT_FIRST_EXTENT(eh) + 1; |
| r = EXT_LAST_EXTENT(eh); |
| |
| while (l <= r) { |
| m = l + (r - l) / 2; |
| if (block < le32_to_cpu(m->ee_block)) |
| r = m - 1; |
| else |
| l = m + 1; |
| ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block), |
| m, le32_to_cpu(m->ee_block), |
| r, le32_to_cpu(r->ee_block)); |
| } |
| |
| path->p_ext = l - 1; |
| ext_debug(" -> %d:%llu:[%d]%d ", |
| le32_to_cpu(path->p_ext->ee_block), |
| ext4_ext_pblock(path->p_ext), |
| ext4_ext_is_uninitialized(path->p_ext), |
| ext4_ext_get_actual_len(path->p_ext)); |
| |
| #ifdef CHECK_BINSEARCH |
| { |
| struct ext4_extent *chex, *ex; |
| int k; |
| |
| chex = ex = EXT_FIRST_EXTENT(eh); |
| for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) { |
| BUG_ON(k && le32_to_cpu(ex->ee_block) |
| <= le32_to_cpu(ex[-1].ee_block)); |
| if (block < le32_to_cpu(ex->ee_block)) |
| break; |
| chex = ex; |
| } |
| BUG_ON(chex != path->p_ext); |
| } |
| #endif |
| |
| } |
| |
| int ext4_ext_tree_init(handle_t *handle, struct inode *inode) |
| { |
| struct ext4_extent_header *eh; |
| |
| eh = ext_inode_hdr(inode); |
| eh->eh_depth = 0; |
| eh->eh_entries = 0; |
| eh->eh_magic = EXT4_EXT_MAGIC; |
| eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0)); |
| ext4_mark_inode_dirty(handle, inode); |
| ext4_ext_invalidate_cache(inode); |
| return 0; |
| } |
| |
| struct ext4_ext_path * |
| ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block, |
| struct ext4_ext_path *path) |
| { |
| struct ext4_extent_header *eh; |
| struct buffer_head *bh; |
| short int depth, i, ppos = 0, alloc = 0; |
| |
| eh = ext_inode_hdr(inode); |
| depth = ext_depth(inode); |
| |
| /* account possible depth increase */ |
| if (!path) { |
| path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2), |
| GFP_NOFS); |
| if (!path) |
| return ERR_PTR(-ENOMEM); |
| alloc = 1; |
| } |
| path[0].p_hdr = eh; |
| path[0].p_bh = NULL; |
| |
| i = depth; |
| /* walk through the tree */ |
| while (i) { |
| int need_to_validate = 0; |
| |
| ext_debug("depth %d: num %d, max %d\n", |
| ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); |
| |
| ext4_ext_binsearch_idx(inode, path + ppos, block); |
| path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx); |
| path[ppos].p_depth = i; |
| path[ppos].p_ext = NULL; |
| |
| bh = sb_getblk(inode->i_sb, path[ppos].p_block); |
| if (unlikely(!bh)) |
| goto err; |
| if (!bh_uptodate_or_lock(bh)) { |
| trace_ext4_ext_load_extent(inode, block, |
| path[ppos].p_block); |
| if (bh_submit_read(bh) < 0) { |
| put_bh(bh); |
| goto err; |
| } |
| /* validate the extent entries */ |
| need_to_validate = 1; |
| } |
| eh = ext_block_hdr(bh); |
| ppos++; |
| if (unlikely(ppos > depth)) { |
| put_bh(bh); |
| EXT4_ERROR_INODE(inode, |
| "ppos %d > depth %d", ppos, depth); |
| goto err; |
| } |
| path[ppos].p_bh = bh; |
| path[ppos].p_hdr = eh; |
| i--; |
| |
| if (need_to_validate && ext4_ext_check(inode, eh, i)) |
| goto err; |
| } |
| |
| path[ppos].p_depth = i; |
| path[ppos].p_ext = NULL; |
| path[ppos].p_idx = NULL; |
| |
| /* find extent */ |
| ext4_ext_binsearch(inode, path + ppos, block); |
| /* if not an empty leaf */ |
| if (path[ppos].p_ext) |
| path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext); |
| |
| ext4_ext_show_path(inode, path); |
| |
| return path; |
| |
| err: |
| ext4_ext_drop_refs(path); |
| if (alloc) |
| kfree(path); |
| return ERR_PTR(-EIO); |
| } |
| |
| /* |
| * ext4_ext_insert_index: |
| * insert new index [@logical;@ptr] into the block at @curp; |
| * check where to insert: before @curp or after @curp |
| */ |
| static int ext4_ext_insert_index(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *curp, |
| int logical, ext4_fsblk_t ptr) |
| { |
| struct ext4_extent_idx *ix; |
| int len, err; |
| |
| err = ext4_ext_get_access(handle, inode, curp); |
| if (err) |
| return err; |
| |
| if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) { |
| EXT4_ERROR_INODE(inode, |
| "logical %d == ei_block %d!", |
| logical, le32_to_cpu(curp->p_idx->ei_block)); |
| return -EIO; |
| } |
| len = EXT_MAX_INDEX(curp->p_hdr) - curp->p_idx; |
| if (logical > le32_to_cpu(curp->p_idx->ei_block)) { |
| /* insert after */ |
| if (curp->p_idx != EXT_LAST_INDEX(curp->p_hdr)) { |
| len = (len - 1) * sizeof(struct ext4_extent_idx); |
| len = len < 0 ? 0 : len; |
| ext_debug("insert new index %d after: %llu. " |
| "move %d from 0x%p to 0x%p\n", |
| logical, ptr, len, |
| (curp->p_idx + 1), (curp->p_idx + 2)); |
| memmove(curp->p_idx + 2, curp->p_idx + 1, len); |
| } |
| ix = curp->p_idx + 1; |
| } else { |
| /* insert before */ |
| len = len * sizeof(struct ext4_extent_idx); |
| len = len < 0 ? 0 : len; |
| ext_debug("insert new index %d before: %llu. " |
| "move %d from 0x%p to 0x%p\n", |
| logical, ptr, len, |
| curp->p_idx, (curp->p_idx + 1)); |
| memmove(curp->p_idx + 1, curp->p_idx, len); |
| ix = curp->p_idx; |
| } |
| |
| ix->ei_block = cpu_to_le32(logical); |
| ext4_idx_store_pblock(ix, ptr); |
| le16_add_cpu(&curp->p_hdr->eh_entries, 1); |
| |
| if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries) |
| > le16_to_cpu(curp->p_hdr->eh_max))) { |
| EXT4_ERROR_INODE(inode, |
| "logical %d == ei_block %d!", |
| logical, le32_to_cpu(curp->p_idx->ei_block)); |
| return -EIO; |
| } |
| if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) { |
| EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!"); |
| return -EIO; |
| } |
| |
| err = ext4_ext_dirty(handle, inode, curp); |
| ext4_std_error(inode->i_sb, err); |
| |
| return err; |
| } |
| |
| /* |
| * ext4_ext_split: |
| * inserts new subtree into the path, using free index entry |
| * at depth @at: |
| * - allocates all needed blocks (new leaf and all intermediate index blocks) |
| * - makes decision where to split |
| * - moves remaining extents and index entries (right to the split point) |
| * into the newly allocated blocks |
| * - initializes subtree |
| */ |
| static int ext4_ext_split(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path, |
| struct ext4_extent *newext, int at) |
| { |
| struct buffer_head *bh = NULL; |
| int depth = ext_depth(inode); |
| struct ext4_extent_header *neh; |
| struct ext4_extent_idx *fidx; |
| struct ext4_extent *ex; |
| int i = at, k, m, a; |
| ext4_fsblk_t newblock, oldblock; |
| __le32 border; |
| ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */ |
| int err = 0; |
| |
| /* make decision: where to split? */ |
| /* FIXME: now decision is simplest: at current extent */ |
| |
| /* if current leaf will be split, then we should use |
| * border from split point */ |
| if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) { |
| EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!"); |
| return -EIO; |
| } |
| if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) { |
| border = path[depth].p_ext[1].ee_block; |
| ext_debug("leaf will be split." |
| " next leaf starts at %d\n", |
| le32_to_cpu(border)); |
| } else { |
| border = newext->ee_block; |
| ext_debug("leaf will be added." |
| " next leaf starts at %d\n", |
| le32_to_cpu(border)); |
| } |
| |
| /* |
| * If error occurs, then we break processing |
| * and mark filesystem read-only. index won't |
| * be inserted and tree will be in consistent |
| * state. Next mount will repair buffers too. |
| */ |
| |
| /* |
| * Get array to track all allocated blocks. |
| * We need this to handle errors and free blocks |
| * upon them. |
| */ |
| ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS); |
| if (!ablocks) |
| return -ENOMEM; |
| |
| /* allocate all needed blocks */ |
| ext_debug("allocate %d blocks for indexes/leaf\n", depth - at); |
| for (a = 0; a < depth - at; a++) { |
| newblock = ext4_ext_new_meta_block(handle, inode, path, |
| newext, &err); |
| if (newblock == 0) |
| goto cleanup; |
| ablocks[a] = newblock; |
| } |
| |
| /* initialize new leaf */ |
| newblock = ablocks[--a]; |
| if (unlikely(newblock == 0)) { |
| EXT4_ERROR_INODE(inode, "newblock == 0!"); |
| err = -EIO; |
| goto cleanup; |
| } |
| bh = sb_getblk(inode->i_sb, newblock); |
| if (!bh) { |
| err = -EIO; |
| goto cleanup; |
| } |
| lock_buffer(bh); |
| |
| err = ext4_journal_get_create_access(handle, bh); |
| if (err) |
| goto cleanup; |
| |
| neh = ext_block_hdr(bh); |
| neh->eh_entries = 0; |
| neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0)); |
| neh->eh_magic = EXT4_EXT_MAGIC; |
| neh->eh_depth = 0; |
| ex = EXT_FIRST_EXTENT(neh); |
| |
| /* move remainder of path[depth] to the new leaf */ |
| if (unlikely(path[depth].p_hdr->eh_entries != |
| path[depth].p_hdr->eh_max)) { |
| EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!", |
| path[depth].p_hdr->eh_entries, |
| path[depth].p_hdr->eh_max); |
| err = -EIO; |
| goto cleanup; |
| } |
| /* start copy from next extent */ |
| /* TODO: we could do it by single memmove */ |
| m = 0; |
| path[depth].p_ext++; |
| while (path[depth].p_ext <= |
| EXT_MAX_EXTENT(path[depth].p_hdr)) { |
| ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n", |
| le32_to_cpu(path[depth].p_ext->ee_block), |
| ext4_ext_pblock(path[depth].p_ext), |
| ext4_ext_is_uninitialized(path[depth].p_ext), |
| ext4_ext_get_actual_len(path[depth].p_ext), |
| newblock); |
| /*memmove(ex++, path[depth].p_ext++, |
| sizeof(struct ext4_extent)); |
| neh->eh_entries++;*/ |
| path[depth].p_ext++; |
| m++; |
| } |
| if (m) { |
| memmove(ex, path[depth].p_ext-m, sizeof(struct ext4_extent)*m); |
| le16_add_cpu(&neh->eh_entries, m); |
| } |
| |
| set_buffer_uptodate(bh); |
| unlock_buffer(bh); |
| |
| err = ext4_handle_dirty_metadata(handle, inode, bh); |
| if (err) |
| goto cleanup; |
| brelse(bh); |
| bh = NULL; |
| |
| /* correct old leaf */ |
| if (m) { |
| err = ext4_ext_get_access(handle, inode, path + depth); |
| if (err) |
| goto cleanup; |
| le16_add_cpu(&path[depth].p_hdr->eh_entries, -m); |
| err = ext4_ext_dirty(handle, inode, path + depth); |
| if (err) |
| goto cleanup; |
| |
| } |
| |
| /* create intermediate indexes */ |
| k = depth - at - 1; |
| if (unlikely(k < 0)) { |
| EXT4_ERROR_INODE(inode, "k %d < 0!", k); |
| err = -EIO; |
| goto cleanup; |
| } |
| if (k) |
| ext_debug("create %d intermediate indices\n", k); |
| /* insert new index into current index block */ |
| /* current depth stored in i var */ |
| i = depth - 1; |
| while (k--) { |
| oldblock = newblock; |
| newblock = ablocks[--a]; |
| bh = sb_getblk(inode->i_sb, newblock); |
| if (!bh) { |
| err = -EIO; |
| goto cleanup; |
| } |
| lock_buffer(bh); |
| |
| err = ext4_journal_get_create_access(handle, bh); |
| if (err) |
| goto cleanup; |
| |
| neh = ext_block_hdr(bh); |
| neh->eh_entries = cpu_to_le16(1); |
| neh->eh_magic = EXT4_EXT_MAGIC; |
| neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0)); |
| neh->eh_depth = cpu_to_le16(depth - i); |
| fidx = EXT_FIRST_INDEX(neh); |
| fidx->ei_block = border; |
| ext4_idx_store_pblock(fidx, oldblock); |
| |
| ext_debug("int.index at %d (block %llu): %u -> %llu\n", |
| i, newblock, le32_to_cpu(border), oldblock); |
| /* copy indexes */ |
| m = 0; |
| path[i].p_idx++; |
| |
| ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx, |
| EXT_MAX_INDEX(path[i].p_hdr)); |
| if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) != |
| EXT_LAST_INDEX(path[i].p_hdr))) { |
| EXT4_ERROR_INODE(inode, |
| "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!", |
| le32_to_cpu(path[i].p_ext->ee_block)); |
| err = -EIO; |
| goto cleanup; |
| } |
| while (path[i].p_idx <= EXT_MAX_INDEX(path[i].p_hdr)) { |
| ext_debug("%d: move %d:%llu in new index %llu\n", i, |
| le32_to_cpu(path[i].p_idx->ei_block), |
| ext4_idx_pblock(path[i].p_idx), |
| newblock); |
| /*memmove(++fidx, path[i].p_idx++, |
| sizeof(struct ext4_extent_idx)); |
| neh->eh_entries++; |
| BUG_ON(neh->eh_entries > neh->eh_max);*/ |
| path[i].p_idx++; |
| m++; |
| } |
| if (m) { |
| memmove(++fidx, path[i].p_idx - m, |
| sizeof(struct ext4_extent_idx) * m); |
| le16_add_cpu(&neh->eh_entries, m); |
| } |
| set_buffer_uptodate(bh); |
| unlock_buffer(bh); |
| |
| err = ext4_handle_dirty_metadata(handle, inode, bh); |
| if (err) |
| goto cleanup; |
| brelse(bh); |
| bh = NULL; |
| |
| /* correct old index */ |
| if (m) { |
| err = ext4_ext_get_access(handle, inode, path + i); |
| if (err) |
| goto cleanup; |
| le16_add_cpu(&path[i].p_hdr->eh_entries, -m); |
| err = ext4_ext_dirty(handle, inode, path + i); |
| if (err) |
| goto cleanup; |
| } |
| |
| i--; |
| } |
| |
| /* insert new index */ |
| err = ext4_ext_insert_index(handle, inode, path + at, |
| le32_to_cpu(border), newblock); |
| |
| cleanup: |
| if (bh) { |
| if (buffer_locked(bh)) |
| unlock_buffer(bh); |
| brelse(bh); |
| } |
| |
| if (err) { |
| /* free all allocated blocks in error case */ |
| for (i = 0; i < depth; i++) { |
| if (!ablocks[i]) |
| continue; |
| ext4_free_blocks(handle, inode, NULL, ablocks[i], 1, |
| EXT4_FREE_BLOCKS_METADATA); |
| } |
| } |
| kfree(ablocks); |
| |
| return err; |
| } |
| |
| /* |
| * ext4_ext_grow_indepth: |
| * implements tree growing procedure: |
| * - allocates new block |
| * - moves top-level data (index block or leaf) into the new block |
| * - initializes new top-level, creating index that points to the |
| * just created block |
| */ |
| static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path, |
| struct ext4_extent *newext) |
| { |
| struct ext4_ext_path *curp = path; |
| struct ext4_extent_header *neh; |
| struct buffer_head *bh; |
| ext4_fsblk_t newblock; |
| int err = 0; |
| |
| newblock = ext4_ext_new_meta_block(handle, inode, path, newext, &err); |
| if (newblock == 0) |
| return err; |
| |
| bh = sb_getblk(inode->i_sb, newblock); |
| if (!bh) { |
| err = -EIO; |
| ext4_std_error(inode->i_sb, err); |
| return err; |
| } |
| lock_buffer(bh); |
| |
| err = ext4_journal_get_create_access(handle, bh); |
| if (err) { |
| unlock_buffer(bh); |
| goto out; |
| } |
| |
| /* move top-level index/leaf into new block */ |
| memmove(bh->b_data, curp->p_hdr, sizeof(EXT4_I(inode)->i_data)); |
| |
| /* set size of new block */ |
| neh = ext_block_hdr(bh); |
| /* old root could have indexes or leaves |
| * so calculate e_max right way */ |
| if (ext_depth(inode)) |
| neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0)); |
| else |
| neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0)); |
| neh->eh_magic = EXT4_EXT_MAGIC; |
| set_buffer_uptodate(bh); |
| unlock_buffer(bh); |
| |
| err = ext4_handle_dirty_metadata(handle, inode, bh); |
| if (err) |
| goto out; |
| |
| /* create index in new top-level index: num,max,pointer */ |
| err = ext4_ext_get_access(handle, inode, curp); |
| if (err) |
| goto out; |
| |
| curp->p_hdr->eh_magic = EXT4_EXT_MAGIC; |
| curp->p_hdr->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0)); |
| curp->p_hdr->eh_entries = cpu_to_le16(1); |
| curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr); |
| |
| if (path[0].p_hdr->eh_depth) |
| curp->p_idx->ei_block = |
| EXT_FIRST_INDEX(path[0].p_hdr)->ei_block; |
| else |
| curp->p_idx->ei_block = |
| EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block; |
| ext4_idx_store_pblock(curp->p_idx, newblock); |
| |
| neh = ext_inode_hdr(inode); |
| ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n", |
| le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max), |
| le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block), |
| ext4_idx_pblock(EXT_FIRST_INDEX(neh))); |
| |
| neh->eh_depth = cpu_to_le16(path->p_depth + 1); |
| err = ext4_ext_dirty(handle, inode, curp); |
| out: |
| brelse(bh); |
| |
| return err; |
| } |
| |
| /* |
| * ext4_ext_create_new_leaf: |
| * finds empty index and adds new leaf. |
| * if no free index is found, then it requests in-depth growing. |
| */ |
| static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path, |
| struct ext4_extent *newext) |
| { |
| struct ext4_ext_path *curp; |
| int depth, i, err = 0; |
| |
| repeat: |
| i = depth = ext_depth(inode); |
| |
| /* walk up to the tree and look for free index entry */ |
| curp = path + depth; |
| while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) { |
| i--; |
| curp--; |
| } |
| |
| /* we use already allocated block for index block, |
| * so subsequent data blocks should be contiguous */ |
| if (EXT_HAS_FREE_INDEX(curp)) { |
| /* if we found index with free entry, then use that |
| * entry: create all needed subtree and add new leaf */ |
| err = ext4_ext_split(handle, inode, path, newext, i); |
| if (err) |
| goto out; |
| |
| /* refill path */ |
| ext4_ext_drop_refs(path); |
| path = ext4_ext_find_extent(inode, |
| (ext4_lblk_t)le32_to_cpu(newext->ee_block), |
| path); |
| if (IS_ERR(path)) |
| err = PTR_ERR(path); |
| } else { |
| /* tree is full, time to grow in depth */ |
| err = ext4_ext_grow_indepth(handle, inode, path, newext); |
| if (err) |
| goto out; |
| |
| /* refill path */ |
| ext4_ext_drop_refs(path); |
| path = ext4_ext_find_extent(inode, |
| (ext4_lblk_t)le32_to_cpu(newext->ee_block), |
| path); |
| if (IS_ERR(path)) { |
| err = PTR_ERR(path); |
| goto out; |
| } |
| |
| /* |
| * only first (depth 0 -> 1) produces free space; |
| * in all other cases we have to split the grown tree |
| */ |
| depth = ext_depth(inode); |
| if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) { |
| /* now we need to split */ |
| goto repeat; |
| } |
| } |
| |
| out: |
| return err; |
| } |
| |
| /* |
| * search the closest allocated block to the left for *logical |
| * and returns it at @logical + it's physical address at @phys |
| * if *logical is the smallest allocated block, the function |
| * returns 0 at @phys |
| * return value contains 0 (success) or error code |
| */ |
| static int ext4_ext_search_left(struct inode *inode, |
| struct ext4_ext_path *path, |
| ext4_lblk_t *logical, ext4_fsblk_t *phys) |
| { |
| struct ext4_extent_idx *ix; |
| struct ext4_extent *ex; |
| int depth, ee_len; |
| |
| if (unlikely(path == NULL)) { |
| EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical); |
| return -EIO; |
| } |
| depth = path->p_depth; |
| *phys = 0; |
| |
| if (depth == 0 && path->p_ext == NULL) |
| return 0; |
| |
| /* usually extent in the path covers blocks smaller |
| * then *logical, but it can be that extent is the |
| * first one in the file */ |
| |
| ex = path[depth].p_ext; |
| ee_len = ext4_ext_get_actual_len(ex); |
| if (*logical < le32_to_cpu(ex->ee_block)) { |
| if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) { |
| EXT4_ERROR_INODE(inode, |
| "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!", |
| *logical, le32_to_cpu(ex->ee_block)); |
| return -EIO; |
| } |
| while (--depth >= 0) { |
| ix = path[depth].p_idx; |
| if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) { |
| EXT4_ERROR_INODE(inode, |
| "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!", |
| ix != NULL ? ix->ei_block : 0, |
| EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ? |
| EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block : 0, |
| depth); |
| return -EIO; |
| } |
| } |
| return 0; |
| } |
| |
| if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) { |
| EXT4_ERROR_INODE(inode, |
| "logical %d < ee_block %d + ee_len %d!", |
| *logical, le32_to_cpu(ex->ee_block), ee_len); |
| return -EIO; |
| } |
| |
| *logical = le32_to_cpu(ex->ee_block) + ee_len - 1; |
| *phys = ext4_ext_pblock(ex) + ee_len - 1; |
| return 0; |
| } |
| |
| /* |
| * search the closest allocated block to the right for *logical |
| * and returns it at @logical + it's physical address at @phys |
| * if *logical is the smallest allocated block, the function |
| * returns 0 at @phys |
| * return value contains 0 (success) or error code |
| */ |
| static int ext4_ext_search_right(struct inode *inode, |
| struct ext4_ext_path *path, |
| ext4_lblk_t *logical, ext4_fsblk_t *phys) |
| { |
| struct buffer_head *bh = NULL; |
| struct ext4_extent_header *eh; |
| struct ext4_extent_idx *ix; |
| struct ext4_extent *ex; |
| ext4_fsblk_t block; |
| int depth; /* Note, NOT eh_depth; depth from top of tree */ |
| int ee_len; |
| |
| if (unlikely(path == NULL)) { |
| EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical); |
| return -EIO; |
| } |
| depth = path->p_depth; |
| *phys = 0; |
| |
| if (depth == 0 && path->p_ext == NULL) |
| return 0; |
| |
| /* usually extent in the path covers blocks smaller |
| * then *logical, but it can be that extent is the |
| * first one in the file */ |
| |
| ex = path[depth].p_ext; |
| ee_len = ext4_ext_get_actual_len(ex); |
| if (*logical < le32_to_cpu(ex->ee_block)) { |
| if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) { |
| EXT4_ERROR_INODE(inode, |
| "first_extent(path[%d].p_hdr) != ex", |
| depth); |
| return -EIO; |
| } |
| while (--depth >= 0) { |
| ix = path[depth].p_idx; |
| if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) { |
| EXT4_ERROR_INODE(inode, |
| "ix != EXT_FIRST_INDEX *logical %d!", |
| *logical); |
| return -EIO; |
| } |
| } |
| *logical = le32_to_cpu(ex->ee_block); |
| *phys = ext4_ext_pblock(ex); |
| return 0; |
| } |
| |
| if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) { |
| EXT4_ERROR_INODE(inode, |
| "logical %d < ee_block %d + ee_len %d!", |
| *logical, le32_to_cpu(ex->ee_block), ee_len); |
| return -EIO; |
| } |
| |
| if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) { |
| /* next allocated block in this leaf */ |
| ex++; |
| *logical = le32_to_cpu(ex->ee_block); |
| *phys = ext4_ext_pblock(ex); |
| return 0; |
| } |
| |
| /* go up and search for index to the right */ |
| while (--depth >= 0) { |
| ix = path[depth].p_idx; |
| if (ix != EXT_LAST_INDEX(path[depth].p_hdr)) |
| goto got_index; |
| } |
| |
| /* we've gone up to the root and found no index to the right */ |
| return 0; |
| |
| got_index: |
| /* we've found index to the right, let's |
| * follow it and find the closest allocated |
| * block to the right */ |
| ix++; |
| block = ext4_idx_pblock(ix); |
| while (++depth < path->p_depth) { |
| bh = sb_bread(inode->i_sb, block); |
| if (bh == NULL) |
| return -EIO; |
| eh = ext_block_hdr(bh); |
| /* subtract from p_depth to get proper eh_depth */ |
| if (ext4_ext_check(inode, eh, path->p_depth - depth)) { |
| put_bh(bh); |
| return -EIO; |
| } |
| ix = EXT_FIRST_INDEX(eh); |
| block = ext4_idx_pblock(ix); |
| put_bh(bh); |
| } |
| |
| bh = sb_bread(inode->i_sb, block); |
| if (bh == NULL) |
| return -EIO; |
| eh = ext_block_hdr(bh); |
| if (ext4_ext_check(inode, eh, path->p_depth - depth)) { |
| put_bh(bh); |
| return -EIO; |
| } |
| ex = EXT_FIRST_EXTENT(eh); |
| *logical = le32_to_cpu(ex->ee_block); |
| *phys = ext4_ext_pblock(ex); |
| put_bh(bh); |
| return 0; |
| } |
| |
| /* |
| * ext4_ext_next_allocated_block: |
| * returns allocated block in subsequent extent or EXT_MAX_BLOCK. |
| * NOTE: it considers block number from index entry as |
| * allocated block. Thus, index entries have to be consistent |
| * with leaves. |
| */ |
| static ext4_lblk_t |
| ext4_ext_next_allocated_block(struct ext4_ext_path *path) |
| { |
| int depth; |
| |
| BUG_ON(path == NULL); |
| depth = path->p_depth; |
| |
| if (depth == 0 && path->p_ext == NULL) |
| return EXT_MAX_BLOCK; |
| |
| while (depth >= 0) { |
| if (depth == path->p_depth) { |
| /* leaf */ |
| if (path[depth].p_ext != |
| EXT_LAST_EXTENT(path[depth].p_hdr)) |
| return le32_to_cpu(path[depth].p_ext[1].ee_block); |
| } else { |
| /* index */ |
| if (path[depth].p_idx != |
| EXT_LAST_INDEX(path[depth].p_hdr)) |
| return le32_to_cpu(path[depth].p_idx[1].ei_block); |
| } |
| depth--; |
| } |
| |
| return EXT_MAX_BLOCK; |
| } |
| |
| /* |
| * ext4_ext_next_leaf_block: |
| * returns first allocated block from next leaf or EXT_MAX_BLOCK |
| */ |
| static ext4_lblk_t ext4_ext_next_leaf_block(struct inode *inode, |
| struct ext4_ext_path *path) |
| { |
| int depth; |
| |
| BUG_ON(path == NULL); |
| depth = path->p_depth; |
| |
| /* zero-tree has no leaf blocks at all */ |
| if (depth == 0) |
| return EXT_MAX_BLOCK; |
| |
| /* go to index block */ |
| depth--; |
| |
| while (depth >= 0) { |
| if (path[depth].p_idx != |
| EXT_LAST_INDEX(path[depth].p_hdr)) |
| return (ext4_lblk_t) |
| le32_to_cpu(path[depth].p_idx[1].ei_block); |
| depth--; |
| } |
| |
| return EXT_MAX_BLOCK; |
| } |
| |
| /* |
| * ext4_ext_correct_indexes: |
| * if leaf gets modified and modified extent is first in the leaf, |
| * then we have to correct all indexes above. |
| * TODO: do we need to correct tree in all cases? |
| */ |
| static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path) |
| { |
| struct ext4_extent_header *eh; |
| int depth = ext_depth(inode); |
| struct ext4_extent *ex; |
| __le32 border; |
| int k, err = 0; |
| |
| eh = path[depth].p_hdr; |
| ex = path[depth].p_ext; |
| |
| if (unlikely(ex == NULL || eh == NULL)) { |
| EXT4_ERROR_INODE(inode, |
| "ex %p == NULL or eh %p == NULL", ex, eh); |
| return -EIO; |
| } |
| |
| if (depth == 0) { |
| /* there is no tree at all */ |
| return 0; |
| } |
| |
| if (ex != EXT_FIRST_EXTENT(eh)) { |
| /* we correct tree if first leaf got modified only */ |
| return 0; |
| } |
| |
| /* |
| * TODO: we need correction if border is smaller than current one |
| */ |
| k = depth - 1; |
| border = path[depth].p_ext->ee_block; |
| err = ext4_ext_get_access(handle, inode, path + k); |
| if (err) |
| return err; |
| path[k].p_idx->ei_block = border; |
| err = ext4_ext_dirty(handle, inode, path + k); |
| if (err) |
| return err; |
| |
| while (k--) { |
| /* change all left-side indexes */ |
| if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr)) |
| break; |
| err = ext4_ext_get_access(handle, inode, path + k); |
| if (err) |
| break; |
| path[k].p_idx->ei_block = border; |
| err = ext4_ext_dirty(handle, inode, path + k); |
| if (err) |
| break; |
| } |
| |
| return err; |
| } |
| |
| int |
| ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1, |
| struct ext4_extent *ex2) |
| { |
| unsigned short ext1_ee_len, ext2_ee_len, max_len; |
| |
| /* |
| * Make sure that either both extents are uninitialized, or |
| * both are _not_. |
| */ |
| if (ext4_ext_is_uninitialized(ex1) ^ ext4_ext_is_uninitialized(ex2)) |
| return 0; |
| |
| if (ext4_ext_is_uninitialized(ex1)) |
| max_len = EXT_UNINIT_MAX_LEN; |
| else |
| max_len = EXT_INIT_MAX_LEN; |
| |
| ext1_ee_len = ext4_ext_get_actual_len(ex1); |
| ext2_ee_len = ext4_ext_get_actual_len(ex2); |
| |
| if (le32_to_cpu(ex1->ee_block) + ext1_ee_len != |
| le32_to_cpu(ex2->ee_block)) |
| return 0; |
| |
| /* |
| * To allow future support for preallocated extents to be added |
| * as an RO_COMPAT feature, refuse to merge to extents if |
| * this can result in the top bit of ee_len being set. |
| */ |
| if (ext1_ee_len + ext2_ee_len > max_len) |
| return 0; |
| #ifdef AGGRESSIVE_TEST |
| if (ext1_ee_len >= 4) |
| return 0; |
| #endif |
| |
| if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2)) |
| return 1; |
| return 0; |
| } |
| |
| /* |
| * This function tries to merge the "ex" extent to the next extent in the tree. |
| * It always tries to merge towards right. If you want to merge towards |
| * left, pass "ex - 1" as argument instead of "ex". |
| * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns |
| * 1 if they got merged. |
| */ |
| static int ext4_ext_try_to_merge(struct inode *inode, |
| struct ext4_ext_path *path, |
| struct ext4_extent *ex) |
| { |
| struct ext4_extent_header *eh; |
| unsigned int depth, len; |
| int merge_done = 0; |
| int uninitialized = 0; |
| |
| depth = ext_depth(inode); |
| BUG_ON(path[depth].p_hdr == NULL); |
| eh = path[depth].p_hdr; |
| |
| while (ex < EXT_LAST_EXTENT(eh)) { |
| if (!ext4_can_extents_be_merged(inode, ex, ex + 1)) |
| break; |
| /* merge with next extent! */ |
| if (ext4_ext_is_uninitialized(ex)) |
| uninitialized = 1; |
| ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) |
| + ext4_ext_get_actual_len(ex + 1)); |
| if (uninitialized) |
| ext4_ext_mark_uninitialized(ex); |
| |
| if (ex + 1 < EXT_LAST_EXTENT(eh)) { |
| len = (EXT_LAST_EXTENT(eh) - ex - 1) |
| * sizeof(struct ext4_extent); |
| memmove(ex + 1, ex + 2, len); |
| } |
| le16_add_cpu(&eh->eh_entries, -1); |
| merge_done = 1; |
| WARN_ON(eh->eh_entries == 0); |
| if (!eh->eh_entries) |
| EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!"); |
| } |
| |
| return merge_done; |
| } |
| |
| /* |
| * check if a portion of the "newext" extent overlaps with an |
| * existing extent. |
| * |
| * If there is an overlap discovered, it updates the length of the newext |
| * such that there will be no overlap, and then returns 1. |
| * If there is no overlap found, it returns 0. |
| */ |
| static unsigned int ext4_ext_check_overlap(struct inode *inode, |
| struct ext4_extent *newext, |
| struct ext4_ext_path *path) |
| { |
| ext4_lblk_t b1, b2; |
| unsigned int depth, len1; |
| unsigned int ret = 0; |
| |
| b1 = le32_to_cpu(newext->ee_block); |
| len1 = ext4_ext_get_actual_len(newext); |
| depth = ext_depth(inode); |
| if (!path[depth].p_ext) |
| goto out; |
| b2 = le32_to_cpu(path[depth].p_ext->ee_block); |
| |
| /* |
| * get the next allocated block if the extent in the path |
| * is before the requested block(s) |
| */ |
| if (b2 < b1) { |
| b2 = ext4_ext_next_allocated_block(path); |
| if (b2 == EXT_MAX_BLOCK) |
| goto out; |
| } |
| |
| /* check for wrap through zero on extent logical start block*/ |
| if (b1 + len1 < b1) { |
| len1 = EXT_MAX_BLOCK - b1; |
| newext->ee_len = cpu_to_le16(len1); |
| ret = 1; |
| } |
| |
| /* check for overlap */ |
| if (b1 + len1 > b2) { |
| newext->ee_len = cpu_to_le16(b2 - b1); |
| ret = 1; |
| } |
| out: |
| return ret; |
| } |
| |
| /* |
| * ext4_ext_insert_extent: |
| * tries to merge requsted extent into the existing extent or |
| * inserts requested extent as new one into the tree, |
| * creating new leaf in the no-space case. |
| */ |
| int ext4_ext_insert_extent(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path, |
| struct ext4_extent *newext, int flag) |
| { |
| struct ext4_extent_header *eh; |
| struct ext4_extent *ex, *fex; |
| struct ext4_extent *nearex; /* nearest extent */ |
| struct ext4_ext_path *npath = NULL; |
| int depth, len, err; |
| ext4_lblk_t next; |
| unsigned uninitialized = 0; |
| |
| if (unlikely(ext4_ext_get_actual_len(newext) == 0)) { |
| EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0"); |
| return -EIO; |
| } |
| depth = ext_depth(inode); |
| ex = path[depth].p_ext; |
| if (unlikely(path[depth].p_hdr == NULL)) { |
| EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); |
| return -EIO; |
| } |
| |
| /* try to insert block into found extent and return */ |
| if (ex && !(flag & EXT4_GET_BLOCKS_PRE_IO) |
| && ext4_can_extents_be_merged(inode, ex, newext)) { |
| ext_debug("append [%d]%d block to %d:[%d]%d (from %llu)\n", |
| ext4_ext_is_uninitialized(newext), |
| ext4_ext_get_actual_len(newext), |
| le32_to_cpu(ex->ee_block), |
| ext4_ext_is_uninitialized(ex), |
| ext4_ext_get_actual_len(ex), |
| ext4_ext_pblock(ex)); |
| err = ext4_ext_get_access(handle, inode, path + depth); |
| if (err) |
| return err; |
| |
| /* |
| * ext4_can_extents_be_merged should have checked that either |
| * both extents are uninitialized, or both aren't. Thus we |
| * need to check only one of them here. |
| */ |
| if (ext4_ext_is_uninitialized(ex)) |
| uninitialized = 1; |
| ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex) |
| + ext4_ext_get_actual_len(newext)); |
| if (uninitialized) |
| ext4_ext_mark_uninitialized(ex); |
| eh = path[depth].p_hdr; |
| nearex = ex; |
| goto merge; |
| } |
| |
| repeat: |
| depth = ext_depth(inode); |
| eh = path[depth].p_hdr; |
| if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) |
| goto has_space; |
| |
| /* probably next leaf has space for us? */ |
| fex = EXT_LAST_EXTENT(eh); |
| next = ext4_ext_next_leaf_block(inode, path); |
| if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block) |
| && next != EXT_MAX_BLOCK) { |
| ext_debug("next leaf block - %d\n", next); |
| BUG_ON(npath != NULL); |
| npath = ext4_ext_find_extent(inode, next, NULL); |
| if (IS_ERR(npath)) |
| return PTR_ERR(npath); |
| BUG_ON(npath->p_depth != path->p_depth); |
| eh = npath[depth].p_hdr; |
| if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) { |
| ext_debug("next leaf isnt full(%d)\n", |
| le16_to_cpu(eh->eh_entries)); |
| path = npath; |
| goto repeat; |
| } |
| ext_debug("next leaf has no free space(%d,%d)\n", |
| le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); |
| } |
| |
| /* |
| * There is no free space in the found leaf. |
| * We're gonna add a new leaf in the tree. |
| */ |
| err = ext4_ext_create_new_leaf(handle, inode, path, newext); |
| if (err) |
| goto cleanup; |
| depth = ext_depth(inode); |
| eh = path[depth].p_hdr; |
| |
| has_space: |
| nearex = path[depth].p_ext; |
| |
| err = ext4_ext_get_access(handle, inode, path + depth); |
| if (err) |
| goto cleanup; |
| |
| if (!nearex) { |
| /* there is no extent in this leaf, create first one */ |
| ext_debug("first extent in the leaf: %d:%llu:[%d]%d\n", |
| le32_to_cpu(newext->ee_block), |
| ext4_ext_pblock(newext), |
| ext4_ext_is_uninitialized(newext), |
| ext4_ext_get_actual_len(newext)); |
| path[depth].p_ext = EXT_FIRST_EXTENT(eh); |
| } else if (le32_to_cpu(newext->ee_block) |
| > le32_to_cpu(nearex->ee_block)) { |
| /* BUG_ON(newext->ee_block == nearex->ee_block); */ |
| if (nearex != EXT_LAST_EXTENT(eh)) { |
| len = EXT_MAX_EXTENT(eh) - nearex; |
| len = (len - 1) * sizeof(struct ext4_extent); |
| len = len < 0 ? 0 : len; |
| ext_debug("insert %d:%llu:[%d]%d after: nearest 0x%p, " |
| "move %d from 0x%p to 0x%p\n", |
| le32_to_cpu(newext->ee_block), |
| ext4_ext_pblock(newext), |
| ext4_ext_is_uninitialized(newext), |
| ext4_ext_get_actual_len(newext), |
| nearex, len, nearex + 1, nearex + 2); |
| memmove(nearex + 2, nearex + 1, len); |
| } |
| path[depth].p_ext = nearex + 1; |
| } else { |
| BUG_ON(newext->ee_block == nearex->ee_block); |
| len = (EXT_MAX_EXTENT(eh) - nearex) * sizeof(struct ext4_extent); |
| len = len < 0 ? 0 : len; |
| ext_debug("insert %d:%llu:[%d]%d before: nearest 0x%p, " |
| "move %d from 0x%p to 0x%p\n", |
| le32_to_cpu(newext->ee_block), |
| ext4_ext_pblock(newext), |
| ext4_ext_is_uninitialized(newext), |
| ext4_ext_get_actual_len(newext), |
| nearex, len, nearex + 1, nearex + 2); |
| memmove(nearex + 1, nearex, len); |
| path[depth].p_ext = nearex; |
| } |
| |
| le16_add_cpu(&eh->eh_entries, 1); |
| nearex = path[depth].p_ext; |
| nearex->ee_block = newext->ee_block; |
| ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext)); |
| nearex->ee_len = newext->ee_len; |
| |
| merge: |
| /* try to merge extents to the right */ |
| if (!(flag & EXT4_GET_BLOCKS_PRE_IO)) |
| ext4_ext_try_to_merge(inode, path, nearex); |
| |
| /* try to merge extents to the left */ |
| |
| /* time to correct all indexes above */ |
| err = ext4_ext_correct_indexes(handle, inode, path); |
| if (err) |
| goto cleanup; |
| |
| err = ext4_ext_dirty(handle, inode, path + depth); |
| |
| cleanup: |
| if (npath) { |
| ext4_ext_drop_refs(npath); |
| kfree(npath); |
| } |
| ext4_ext_invalidate_cache(inode); |
| return err; |
| } |
| |
| static int ext4_ext_walk_space(struct inode *inode, ext4_lblk_t block, |
| ext4_lblk_t num, ext_prepare_callback func, |
| void *cbdata) |
| { |
| struct ext4_ext_path *path = NULL; |
| struct ext4_ext_cache cbex; |
| struct ext4_extent *ex; |
| ext4_lblk_t next, start = 0, end = 0; |
| ext4_lblk_t last = block + num; |
| int depth, exists, err = 0; |
| |
| BUG_ON(func == NULL); |
| BUG_ON(inode == NULL); |
| |
| while (block < last && block != EXT_MAX_BLOCK) { |
| num = last - block; |
| /* find extent for this block */ |
| down_read(&EXT4_I(inode)->i_data_sem); |
| path = ext4_ext_find_extent(inode, block, path); |
| up_read(&EXT4_I(inode)->i_data_sem); |
| if (IS_ERR(path)) { |
| err = PTR_ERR(path); |
| path = NULL; |
| break; |
| } |
| |
| depth = ext_depth(inode); |
| if (unlikely(path[depth].p_hdr == NULL)) { |
| EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); |
| err = -EIO; |
| break; |
| } |
| ex = path[depth].p_ext; |
| next = ext4_ext_next_allocated_block(path); |
| |
| exists = 0; |
| if (!ex) { |
| /* there is no extent yet, so try to allocate |
| * all requested space */ |
| start = block; |
| end = block + num; |
| } else if (le32_to_cpu(ex->ee_block) > block) { |
| /* need to allocate space before found extent */ |
| start = block; |
| end = le32_to_cpu(ex->ee_block); |
| if (block + num < end) |
| end = block + num; |
| } else if (block >= le32_to_cpu(ex->ee_block) |
| + ext4_ext_get_actual_len(ex)) { |
| /* need to allocate space after found extent */ |
| start = block; |
| end = block + num; |
| if (end >= next) |
| end = next; |
| } else if (block >= le32_to_cpu(ex->ee_block)) { |
| /* |
| * some part of requested space is covered |
| * by found extent |
| */ |
| start = block; |
| end = le32_to_cpu(ex->ee_block) |
| + ext4_ext_get_actual_len(ex); |
| if (block + num < end) |
| end = block + num; |
| exists = 1; |
| } else { |
| BUG(); |
| } |
| BUG_ON(end <= start); |
| |
| if (!exists) { |
| cbex.ec_block = start; |
| cbex.ec_len = end - start; |
| cbex.ec_start = 0; |
| } else { |
| cbex.ec_block = le32_to_cpu(ex->ee_block); |
| cbex.ec_len = ext4_ext_get_actual_len(ex); |
| cbex.ec_start = ext4_ext_pblock(ex); |
| } |
| |
| if (unlikely(cbex.ec_len == 0)) { |
| EXT4_ERROR_INODE(inode, "cbex.ec_len == 0"); |
| err = -EIO; |
| break; |
| } |
| err = func(inode, path, &cbex, ex, cbdata); |
| ext4_ext_drop_refs(path); |
| |
| if (err < 0) |
| break; |
| |
| if (err == EXT_REPEAT) |
| continue; |
| else if (err == EXT_BREAK) { |
| err = 0; |
| break; |
| } |
| |
| if (ext_depth(inode) != depth) { |
| /* depth was changed. we have to realloc path */ |
| kfree(path); |
| path = NULL; |
| } |
| |
| block = cbex.ec_block + cbex.ec_len; |
| } |
| |
| if (path) { |
| ext4_ext_drop_refs(path); |
| kfree(path); |
| } |
| |
| return err; |
| } |
| |
| static void |
| ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block, |
| __u32 len, ext4_fsblk_t start) |
| { |
| struct ext4_ext_cache *cex; |
| BUG_ON(len == 0); |
| spin_lock(&EXT4_I(inode)->i_block_reservation_lock); |
| cex = &EXT4_I(inode)->i_cached_extent; |
| cex->ec_block = block; |
| cex->ec_len = len; |
| cex->ec_start = start; |
| spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); |
| } |
| |
| /* |
| * ext4_ext_put_gap_in_cache: |
| * calculate boundaries of the gap that the requested block fits into |
| * and cache this gap |
| */ |
| static void |
| ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path, |
| ext4_lblk_t block) |
| { |
| int depth = ext_depth(inode); |
| unsigned long len; |
| ext4_lblk_t lblock; |
| struct ext4_extent *ex; |
| |
| ex = path[depth].p_ext; |
| if (ex == NULL) { |
| /* there is no extent yet, so gap is [0;-] */ |
| lblock = 0; |
| len = EXT_MAX_BLOCK; |
| ext_debug("cache gap(whole file):"); |
| } else if (block < le32_to_cpu(ex->ee_block)) { |
| lblock = block; |
| len = le32_to_cpu(ex->ee_block) - block; |
| ext_debug("cache gap(before): %u [%u:%u]", |
| block, |
| le32_to_cpu(ex->ee_block), |
| ext4_ext_get_actual_len(ex)); |
| } else if (block >= le32_to_cpu(ex->ee_block) |
| + ext4_ext_get_actual_len(ex)) { |
| ext4_lblk_t next; |
| lblock = le32_to_cpu(ex->ee_block) |
| + ext4_ext_get_actual_len(ex); |
| |
| next = ext4_ext_next_allocated_block(path); |
| ext_debug("cache gap(after): [%u:%u] %u", |
| le32_to_cpu(ex->ee_block), |
| ext4_ext_get_actual_len(ex), |
| block); |
| BUG_ON(next == lblock); |
| len = next - lblock; |
| } else { |
| lblock = len = 0; |
| BUG(); |
| } |
| |
| ext_debug(" -> %u:%lu\n", lblock, len); |
| ext4_ext_put_in_cache(inode, lblock, len, 0); |
| } |
| |
| /* |
| * Return 0 if cache is invalid; 1 if the cache is valid |
| */ |
| static int |
| ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block, |
| struct ext4_extent *ex) |
| { |
| struct ext4_ext_cache *cex; |
| int ret = 0; |
| |
| /* |
| * We borrow i_block_reservation_lock to protect i_cached_extent |
| */ |
| spin_lock(&EXT4_I(inode)->i_block_reservation_lock); |
| cex = &EXT4_I(inode)->i_cached_extent; |
| |
| /* has cache valid data? */ |
| if (cex->ec_len == 0) |
| goto errout; |
| |
| if (in_range(block, cex->ec_block, cex->ec_len)) { |
| ex->ee_block = cpu_to_le32(cex->ec_block); |
| ext4_ext_store_pblock(ex, cex->ec_start); |
| ex->ee_len = cpu_to_le16(cex->ec_len); |
| ext_debug("%u cached by %u:%u:%llu\n", |
| block, |
| cex->ec_block, cex->ec_len, cex->ec_start); |
| ret = 1; |
| } |
| errout: |
| spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); |
| return ret; |
| } |
| |
| /* |
| * ext4_ext_rm_idx: |
| * removes index from the index block. |
| * It's used in truncate case only, thus all requests are for |
| * last index in the block only. |
| */ |
| static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path) |
| { |
| int err; |
| ext4_fsblk_t leaf; |
| |
| /* free index block */ |
| path--; |
| leaf = ext4_idx_pblock(path->p_idx); |
| if (unlikely(path->p_hdr->eh_entries == 0)) { |
| EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0"); |
| return -EIO; |
| } |
| err = ext4_ext_get_access(handle, inode, path); |
| if (err) |
| return err; |
| le16_add_cpu(&path->p_hdr->eh_entries, -1); |
| err = ext4_ext_dirty(handle, inode, path); |
| if (err) |
| return err; |
| ext_debug("index is empty, remove it, free block %llu\n", leaf); |
| ext4_free_blocks(handle, inode, NULL, leaf, 1, |
| EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET); |
| return err; |
| } |
| |
| /* |
| * ext4_ext_calc_credits_for_single_extent: |
| * This routine returns max. credits that needed to insert an extent |
| * to the extent tree. |
| * When pass the actual path, the caller should calculate credits |
| * under i_data_sem. |
| */ |
| int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks, |
| struct ext4_ext_path *path) |
| { |
| if (path) { |
| int depth = ext_depth(inode); |
| int ret = 0; |
| |
| /* probably there is space in leaf? */ |
| if (le16_to_cpu(path[depth].p_hdr->eh_entries) |
| < le16_to_cpu(path[depth].p_hdr->eh_max)) { |
| |
| /* |
| * There are some space in the leaf tree, no |
| * need to account for leaf block credit |
| * |
| * bitmaps and block group descriptor blocks |
| * and other metadat blocks still need to be |
| * accounted. |
| */ |
| /* 1 bitmap, 1 block group descriptor */ |
| ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb); |
| return ret; |
| } |
| } |
| |
| return ext4_chunk_trans_blocks(inode, nrblocks); |
| } |
| |
| /* |
| * How many index/leaf blocks need to change/allocate to modify nrblocks? |
| * |
| * if nrblocks are fit in a single extent (chunk flag is 1), then |
| * in the worse case, each tree level index/leaf need to be changed |
| * if the tree split due to insert a new extent, then the old tree |
| * index/leaf need to be updated too |
| * |
| * If the nrblocks are discontiguous, they could cause |
| * the whole tree split more than once, but this is really rare. |
| */ |
| int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks, int chunk) |
| { |
| int index; |
| int depth = ext_depth(inode); |
| |
| if (chunk) |
| index = depth * 2; |
| else |
| index = depth * 3; |
| |
| return index; |
| } |
| |
| static int ext4_remove_blocks(handle_t *handle, struct inode *inode, |
| struct ext4_extent *ex, |
| ext4_lblk_t from, ext4_lblk_t to) |
| { |
| unsigned short ee_len = ext4_ext_get_actual_len(ex); |
| int flags = EXT4_FREE_BLOCKS_FORGET; |
| |
| if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) |
| flags |= EXT4_FREE_BLOCKS_METADATA; |
| #ifdef EXTENTS_STATS |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| spin_lock(&sbi->s_ext_stats_lock); |
| sbi->s_ext_blocks += ee_len; |
| sbi->s_ext_extents++; |
| if (ee_len < sbi->s_ext_min) |
| sbi->s_ext_min = ee_len; |
| if (ee_len > sbi->s_ext_max) |
| sbi->s_ext_max = ee_len; |
| if (ext_depth(inode) > sbi->s_depth_max) |
| sbi->s_depth_max = ext_depth(inode); |
| spin_unlock(&sbi->s_ext_stats_lock); |
| } |
| #endif |
| if (from >= le32_to_cpu(ex->ee_block) |
| && to == le32_to_cpu(ex->ee_block) + ee_len - 1) { |
| /* tail removal */ |
| ext4_lblk_t num; |
| ext4_fsblk_t start; |
| |
| num = le32_to_cpu(ex->ee_block) + ee_len - from; |
| start = ext4_ext_pblock(ex) + ee_len - num; |
| ext_debug("free last %u blocks starting %llu\n", num, start); |
| ext4_free_blocks(handle, inode, NULL, start, num, flags); |
| } else if (from == le32_to_cpu(ex->ee_block) |
| && to <= le32_to_cpu(ex->ee_block) + ee_len - 1) { |
| printk(KERN_INFO "strange request: removal %u-%u from %u:%u\n", |
| from, to, le32_to_cpu(ex->ee_block), ee_len); |
| } else { |
| printk(KERN_INFO "strange request: removal(2) " |
| "%u-%u from %u:%u\n", |
| from, to, le32_to_cpu(ex->ee_block), ee_len); |
| } |
| return 0; |
| } |
| |
| static int |
| ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, |
| struct ext4_ext_path *path, ext4_lblk_t start) |
| { |
| int err = 0, correct_index = 0; |
| int depth = ext_depth(inode), credits; |
| struct ext4_extent_header *eh; |
| ext4_lblk_t a, b, block; |
| unsigned num; |
| ext4_lblk_t ex_ee_block; |
| unsigned short ex_ee_len; |
| unsigned uninitialized = 0; |
| struct ext4_extent *ex; |
| |
| /* the header must be checked already in ext4_ext_remove_space() */ |
| ext_debug("truncate since %u in leaf\n", start); |
| if (!path[depth].p_hdr) |
| path[depth].p_hdr = ext_block_hdr(path[depth].p_bh); |
| eh = path[depth].p_hdr; |
| if (unlikely(path[depth].p_hdr == NULL)) { |
| EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth); |
| return -EIO; |
| } |
| /* find where to start removing */ |
| ex = EXT_LAST_EXTENT(eh); |
| |
| ex_ee_block = le32_to_cpu(ex->ee_block); |
| ex_ee_len = ext4_ext_get_actual_len(ex); |
| |
| while (ex >= EXT_FIRST_EXTENT(eh) && |
| ex_ee_block + ex_ee_len > start) { |
| |
| if (ext4_ext_is_uninitialized(ex)) |
| uninitialized = 1; |
| else |
| uninitialized = 0; |
| |
| ext_debug("remove ext %u:[%d]%d\n", ex_ee_block, |
| uninitialized, ex_ee_len); |
| path[depth].p_ext = ex; |
| |
| a = ex_ee_block > start ? ex_ee_block : start; |
| b = ex_ee_block + ex_ee_len - 1 < EXT_MAX_BLOCK ? |
| ex_ee_block + ex_ee_len - 1 : EXT_MAX_BLOCK; |
| |
| ext_debug(" border %u:%u\n", a, b); |
| |
| if (a != ex_ee_block && b != ex_ee_block + ex_ee_len - 1) { |
| block = 0; |
| num = 0; |
| BUG(); |
| } else if (a != ex_ee_block) { |
| /* remove tail of the extent */ |
| block = ex_ee_block; |
| num = a - block; |
| } else if (b != ex_ee_block + ex_ee_len - 1) { |
| /* remove head of the extent */ |
| block = a; |
| num = b - a; |
| /* there is no "make a hole" API yet */ |
| BUG(); |
| } else { |
| /* remove whole extent: excellent! */ |
| block = ex_ee_block; |
| num = 0; |
| BUG_ON(a != ex_ee_block); |
| BUG_ON(b != ex_ee_block + ex_ee_len - 1); |
| } |
| |
| /* |
| * 3 for leaf, sb, and inode plus 2 (bmap and group |
| * descriptor) for each block group; assume two block |
| * groups plus ex_ee_len/blocks_per_block_group for |
| * the worst case |
| */ |
| credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb)); |
| if (ex == EXT_FIRST_EXTENT(eh)) { |
| correct_index = 1; |
| credits += (ext_depth(inode)) + 1; |
| } |
| credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb); |
| |
| err = ext4_ext_truncate_extend_restart(handle, inode, credits); |
| if (err) |
| goto out; |
| |
| err = ext4_ext_get_access(handle, inode, path + depth); |
| if (err) |
| goto out; |
| |
| err = ext4_remove_blocks(handle, inode, ex, a, b); |
| if (err) |
| goto out; |
| |
| if (num == 0) { |
| /* this extent is removed; mark slot entirely unused */ |
| ext4_ext_store_pblock(ex, 0); |
| le16_add_cpu(&eh->eh_entries, -1); |
| } |
| |
| ex->ee_block = cpu_to_le32(block); |
| ex->ee_len = cpu_to_le16(num); |
| /* |
| * Do not mark uninitialized if all the blocks in the |
| * extent have been removed. |
| */ |
| if (uninitialized && num) |
| ext4_ext_mark_uninitialized(ex); |
| |
| err = ext4_ext_dirty(handle, inode, path + depth); |
| if (err) |
| goto out; |
| |
| ext_debug("new extent: %u:%u:%llu\n", block, num, |
| ext4_ext_pblock(ex)); |
| ex--; |
| ex_ee_block = le32_to_cpu(ex->ee_block); |
| ex_ee_len = ext4_ext_get_actual_len(ex); |
| } |
| |
| if (correct_index && eh->eh_entries) |
| err = ext4_ext_correct_indexes(handle, inode, path); |
| |
| /* if this leaf is free, then we should |
| * remove it from index block above */ |
| if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL) |
| err = ext4_ext_rm_idx(handle, inode, path + depth); |
| |
| out: |
| return err; |
| } |
| |
| /* |
| * ext4_ext_more_to_rm: |
| * returns 1 if current index has to be freed (even partial) |
| */ |
| static int |
| ext4_ext_more_to_rm(struct ext4_ext_path *path) |
| { |
| BUG_ON(path->p_idx == NULL); |
| |
| if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr)) |
| return 0; |
| |
| /* |
| * if truncate on deeper level happened, it wasn't partial, |
| * so we have to consider current index for truncation |
| */ |
| if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block) |
| return 0; |
| return 1; |
| } |
| |
| static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start) |
| { |
| struct super_block *sb = inode->i_sb; |
| int depth = ext_depth(inode); |
| struct ext4_ext_path *path; |
| handle_t *handle; |
| int i, err; |
| |
| ext_debug("truncate since %u\n", start); |
| |
| /* probably first extent we're gonna free will be last in block */ |
| handle = ext4_journal_start(inode, depth + 1); |
| if (IS_ERR(handle)) |
| return PTR_ERR(handle); |
| |
| again: |
| ext4_ext_invalidate_cache(inode); |
| |
| /* |
| * We start scanning from right side, freeing all the blocks |
| * after i_size and walking into the tree depth-wise. |
| */ |
| depth = ext_depth(inode); |
| path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_NOFS); |
| if (path == NULL) { |
| ext4_journal_stop(handle); |
| return -ENOMEM; |
| } |
| path[0].p_depth = depth; |
| path[0].p_hdr = ext_inode_hdr(inode); |
| if (ext4_ext_check(inode, path[0].p_hdr, depth)) { |
| err = -EIO; |
| goto out; |
| } |
| i = err = 0; |
| |
| while (i >= 0 && err == 0) { |
| if (i == depth) { |
| /* this is leaf block */ |
| err = ext4_ext_rm_leaf(handle, inode, path, start); |
| /* root level has p_bh == NULL, brelse() eats this */ |
| brelse(path[i].p_bh); |
| path[i].p_bh = NULL; |
| i--; |
| continue; |
| } |
| |
| /* this is index block */ |
| if (!path[i].p_hdr) { |
| ext_debug("initialize header\n"); |
| path[i].p_hdr = ext_block_hdr(path[i].p_bh); |
| } |
| |
| if (!path[i].p_idx) { |
| /* this level hasn't been touched yet */ |
| path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr); |
| path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1; |
| ext_debug("init index ptr: hdr 0x%p, num %d\n", |
| path[i].p_hdr, |
| le16_to_cpu(path[i].p_hdr->eh_entries)); |
| } else { |
| /* we were already here, see at next index */ |
| path[i].p_idx--; |
| } |
| |
| ext_debug("level %d - index, first 0x%p, cur 0x%p\n", |
| i, EXT_FIRST_INDEX(path[i].p_hdr), |
| path[i].p_idx); |
| if (ext4_ext_more_to_rm(path + i)) { |
| struct buffer_head *bh; |
| /* go to the next level */ |
| ext_debug("move to level %d (block %llu)\n", |
| i + 1, ext4_idx_pblock(path[i].p_idx)); |
| memset(path + i + 1, 0, sizeof(*path)); |
| bh = sb_bread(sb, ext4_idx_pblock(path[i].p_idx)); |
| if (!bh) { |
| /* should we reset i_size? */ |
| err = -EIO; |
| break; |
| } |
| if (WARN_ON(i + 1 > depth)) { |
| err = -EIO; |
| break; |
| } |
| if (ext4_ext_check(inode, ext_block_hdr(bh), |
| depth - i - 1)) { |
| err = -EIO; |
| break; |
| } |
| path[i + 1].p_bh = bh; |
| |
| /* save actual number of indexes since this |
| * number is changed at the next iteration */ |
| path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries); |
| i++; |
| } else { |
| /* we finished processing this index, go up */ |
| if (path[i].p_hdr->eh_entries == 0 && i > 0) { |
| /* index is empty, remove it; |
| * handle must be already prepared by the |
| * truncatei_leaf() */ |
| err = ext4_ext_rm_idx(handle, inode, path + i); |
| } |
| /* root level has p_bh == NULL, brelse() eats this */ |
| brelse(path[i].p_bh); |
| path[i].p_bh = NULL; |
| i--; |
| ext_debug("return to level %d\n", i); |
| } |
| } |
| |
| /* TODO: flexible tree reduction should be here */ |
| if (path->p_hdr->eh_entries == 0) { |
| /* |
| * truncate to zero freed all the tree, |
| * so we need to correct eh_depth |
| */ |
| err = ext4_ext_get_access(handle, inode, path); |
| if (err == 0) { |
| ext_inode_hdr(inode)->eh_depth = 0; |
| ext_inode_hdr(inode)->eh_max = |
| cpu_to_le16(ext4_ext_space_root(inode, 0)); |
| err = ext4_ext_dirty(handle, inode, path); |
| } |
| } |
| out: |
| ext4_ext_drop_refs(path); |
| kfree(path); |
| if (err == -EAGAIN) |
| goto again; |
| ext4_journal_stop(handle); |
| |
| return err; |
| } |
| |
| /* |
| * called at mount time |
| */ |
| void ext4_ext_init(struct super_block *sb) |
| { |
| /* |
| * possible initialization would be here |
| */ |
| |
| if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) { |
| #if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS) |
| printk(KERN_INFO "EXT4-fs: file extents enabled"); |
| #ifdef AGGRESSIVE_TEST |
| printk(", aggressive tests"); |
| #endif |
| #ifdef CHECK_BINSEARCH |
| printk(", check binsearch"); |
| #endif |
| #ifdef EXTENTS_STATS |
| printk(", stats"); |
| #endif |
| printk("\n"); |
| #endif |
| #ifdef EXTENTS_STATS |
| spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock); |
| EXT4_SB(sb)->s_ext_min = 1 << 30; |
| EXT4_SB(sb)->s_ext_max = 0; |
| #endif |
| } |
| } |
| |
| /* |
| * called at umount time |
| */ |
| void ext4_ext_release(struct super_block *sb) |
| { |
| if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) |
| return; |
| |
| #ifdef EXTENTS_STATS |
| if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) { |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n", |
| sbi->s_ext_blocks, sbi->s_ext_extents, |
| sbi->s_ext_blocks / sbi->s_ext_extents); |
| printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n", |
| sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max); |
| } |
| #endif |
| } |
| |
| /* FIXME!! we need to try to merge to left or right after zero-out */ |
| static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex) |
| { |
| ext4_fsblk_t ee_pblock; |
| unsigned int ee_len; |
| int ret; |
| |
| ee_len = ext4_ext_get_actual_len(ex); |
| ee_pblock = ext4_ext_pblock(ex); |
| |
| ret = sb_issue_zeroout(inode->i_sb, ee_pblock, ee_len, GFP_NOFS); |
| if (ret > 0) |
| ret = 0; |
| |
| return ret; |
| } |
| |
| #define EXT4_EXT_ZERO_LEN 7 |
| /* |
| * This function is called by ext4_ext_map_blocks() if someone tries to write |
| * to an uninitialized extent. It may result in splitting the uninitialized |
| * extent into multiple extents (upto three - one initialized and two |
| * uninitialized). |
| * There are three possibilities: |
| * a> There is no split required: Entire extent should be initialized |
| * b> Splits in two extents: Write is happening at either end of the extent |
| * c> Splits in three extents: Somone is writing in middle of the extent |
| */ |
| static int ext4_ext_convert_to_initialized(handle_t *handle, |
| struct inode *inode, |
| struct ext4_map_blocks *map, |
| struct ext4_ext_path *path) |
| { |
| struct ext4_extent *ex, newex, orig_ex; |
| struct ext4_extent *ex1 = NULL; |
| struct ext4_extent *ex2 = NULL; |
| struct ext4_extent *ex3 = NULL; |
| struct ext4_extent_header *eh; |
| ext4_lblk_t ee_block, eof_block; |
| unsigned int allocated, ee_len, depth; |
| ext4_fsblk_t newblock; |
| int err = 0; |
| int ret = 0; |
| int may_zeroout; |
| |
| ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical" |
| "block %llu, max_blocks %u\n", inode->i_ino, |
| (unsigned long long)map->m_lblk, map->m_len); |
| |
| eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >> |
| inode->i_sb->s_blocksize_bits; |
| if (eof_block < map->m_lblk + map->m_len) |
| eof_block = map->m_lblk + map->m_len; |
| |
| depth = ext_depth(inode); |
| eh = path[depth].p_hdr; |
| ex = path[depth].p_ext; |
| ee_block = le32_to_cpu(ex->ee_block); |
| ee_len = ext4_ext_get_actual_len(ex); |
| allocated = ee_len - (map->m_lblk - ee_block); |
| newblock = map->m_lblk - ee_block + ext4_ext_pblock(ex); |
| |
| ex2 = ex; |
| orig_ex.ee_block = ex->ee_block; |
| orig_ex.ee_len = cpu_to_le16(ee_len); |
| ext4_ext_store_pblock(&orig_ex, ext4_ext_pblock(ex)); |
| |
| /* |
| * It is safe to convert extent to initialized via explicit |
| * zeroout only if extent is fully insde i_size or new_size. |
| */ |
| may_zeroout = ee_block + ee_len <= eof_block; |
| |
| err = ext4_ext_get_access(handle, inode, path + depth); |
| if (err) |
| goto out; |
| /* If extent has less than 2*EXT4_EXT_ZERO_LEN zerout directly */ |
| if (ee_len <= 2*EXT4_EXT_ZERO_LEN && may_zeroout) { |
| err = ext4_ext_zeroout(inode, &orig_ex); |
| if (err) |
| goto fix_extent_len; |
| /* update the extent length and mark as initialized */ |
| ex->ee_block = orig_ex.ee_block; |
| ex->ee_len = orig_ex.ee_len; |
| ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex)); |
| ext4_ext_dirty(handle, inode, path + depth); |
| /* zeroed the full extent */ |
| return allocated; |
| } |
| |
| /* ex1: ee_block to map->m_lblk - 1 : uninitialized */ |
| if (map->m_lblk > ee_block) { |
| ex1 = ex; |
| ex1->ee_len = cpu_to_le16(map->m_lblk - ee_block); |
| ext4_ext_mark_uninitialized(ex1); |
| ex2 = &newex; |
| } |
| /* |
| * for sanity, update the length of the ex2 extent before |
| * we insert ex3, if ex1 is NULL. This is to avoid temporary |
| * overlap of blocks. |
| */ |
| if (!ex1 && allocated > map->m_len) |
| ex2->ee_len = cpu_to_le16(map->m_len); |
| /* ex3: to ee_block + ee_len : uninitialised */ |
| if (allocated > map->m_len) { |
| unsigned int newdepth; |
| /* If extent has less than EXT4_EXT_ZERO_LEN zerout directly */ |
| if (allocated <= EXT4_EXT_ZERO_LEN && may_zeroout) { |
| /* |
| * map->m_lblk == ee_block is handled by the zerouout |
| * at the beginning. |
| * Mark first half uninitialized. |
| * Mark second half initialized and zero out the |
| * initialized extent |
| */ |
| ex->ee_block = orig_ex.ee_block; |
| ex->ee_len = cpu_to_le16(ee_len - allocated); |
| ext4_ext_mark_uninitialized(ex); |
| ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex)); |
| ext4_ext_dirty(handle, inode, path + depth); |
| |
| ex3 = &newex; |
| ex3->ee_block = cpu_to_le32(map->m_lblk); |
| ext4_ext_store_pblock(ex3, newblock); |
| ex3->ee_len = cpu_to_le16(allocated); |
| err = ext4_ext_insert_extent(handle, inode, path, |
| ex3, 0); |
| if (err == -ENOSPC) { |
| err = ext4_ext_zeroout(inode, &orig_ex); |
| if (err) |
| goto fix_extent_len; |
| ex->ee_block = orig_ex.ee_block; |
| ex->ee_len = orig_ex.ee_len; |
| ext4_ext_store_pblock(ex, |
| ext4_ext_pblock(&orig_ex)); |
| ext4_ext_dirty(handle, inode, path + depth); |
| /* blocks available from map->m_lblk */ |
| return allocated; |
| |
| } else if (err) |
| goto fix_extent_len; |
| |
| /* |
| * We need to zero out the second half because |
| * an fallocate request can update file size and |
| * converting the second half to initialized extent |
| * implies that we can leak some junk data to user |
| * space. |
| */ |
| err = ext4_ext_zeroout(inode, ex3); |
| if (err) { |
| /* |
| * We should actually mark the |
| * second half as uninit and return error |
| * Insert would have changed the extent |
| */ |
| depth = ext_depth(inode); |
| ext4_ext_drop_refs(path); |
| path = ext4_ext_find_extent(inode, map->m_lblk, |
| path); |
| if (IS_ERR(path)) { |
| err = PTR_ERR(path); |
| return err; |
| } |
| /* get the second half extent details */ |
| ex = path[depth].p_ext; |
| err = ext4_ext_get_access(handle, inode, |
| path + depth); |
| if (err) |
| return err; |
| ext4_ext_mark_uninitialized(ex); |
| ext4_ext_dirty(handle, inode, path + depth); |
| return err; |
| } |
| |
| /* zeroed the second half */ |
| return allocated; |
| } |
| ex3 = &newex; |
| ex3->ee_block = cpu_to_le32(map->m_lblk + map->m_len); |
| ext4_ext_store_pblock(ex3, newblock + map->m_len); |
| ex3->ee_len = cpu_to_le16(allocated - map->m_len); |
| ext4_ext_mark_uninitialized(ex3); |
| err = ext4_ext_insert_extent(handle, inode, path, ex3, 0); |
| if (err == -ENOSPC && may_zeroout) { |
| err = ext4_ext_zeroout(inode, &orig_ex); |
| if (err) |
| goto fix_extent_len; |
| /* update the extent length and mark as initialized */ |
| ex->ee_block = orig_ex.ee_block; |
| ex->ee_len = orig_ex.ee_len; |
| ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex)); |
| ext4_ext_dirty(handle, inode, path + depth); |
| /* zeroed the full extent */ |
| /* blocks available from map->m_lblk */ |
| return allocated; |
| |
| } else if (err) |
| goto fix_extent_len; |
| /* |
| * The depth, and hence eh & ex might change |
| * as part of the insert above. |
| */ |
| newdepth = ext_depth(inode); |
| /* |
| * update the extent length after successful insert of the |
| * split extent |
| */ |
| ee_len -= ext4_ext_get_actual_len(ex3); |
| orig_ex.ee_len = cpu_to_le16(ee_len); |
| may_zeroout = ee_block + ee_len <= eof_block; |
| |
| depth = newdepth; |
| ext4_ext_drop_refs(path); |
| path = ext4_ext_find_extent(inode, map->m_lblk, path); |
| if (IS_ERR(path)) { |
| err = PTR_ERR(path); |
| goto out; |
| } |
| eh = path[depth].p_hdr; |
| ex = path[depth].p_ext; |
| if (ex2 != &newex) |
| ex2 = ex; |
| |
| err = ext4_ext_get_access(handle, inode, path + depth); |
| if (err) |
| goto out; |
| |
| allocated = map->m_len; |
| |
| /* If extent has less than EXT4_EXT_ZERO_LEN and we are trying |
| * to insert a extent in the middle zerout directly |
| * otherwise give the extent a chance to merge to left |
| */ |
| if (le16_to_cpu(orig_ex.ee_len) <= EXT4_EXT_ZERO_LEN && |
| map->m_lblk != ee_block && may_zeroout) { |
| err = ext4_ext_zeroout(inode, &orig_ex); |
| if (err) |
| goto fix_extent_len; |
| /* update the extent length and mark as initialized */ |
| ex->ee_block = orig_ex.ee_block; |
| ex->ee_len = orig_ex.ee_len; |
| ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex)); |
| ext4_ext_dirty(handle, inode, path + depth); |
| /* zero out the first half */ |
| /* blocks available from map->m_lblk */ |
| return allocated; |
| } |
| } |
| /* |
| * If there was a change of depth as part of the |
| * insertion of ex3 above, we need to update the length |
| * of the ex1 extent again here |
| */ |
| if (ex1 && ex1 != ex) { |
| ex1 = ex; |
| ex1->ee_len = cpu_to_le16(map->m_lblk - ee_block); |
| ext4_ext_mark_uninitialized(ex1); |
| ex2 = &newex; |
| } |
| /* ex2: map->m_lblk to map->m_lblk + maxblocks-1 : initialised */ |
| ex2->ee_block = cpu_to_le32(map->m_lblk); |
| ext4_ext_store_pblock(ex2, newblock); |
| ex2->ee_len = cpu_to_le16(allocated); |
| if (ex2 != ex) |
| goto insert; |
| /* |
| * New (initialized) extent starts from the first block |
| * in the current extent. i.e., ex2 == ex |
| * We have to see if it can be merged with the extent |
| * on the left. |
| */ |
| if (ex2 > EXT_FIRST_EXTENT(eh)) { |
| /* |
| * To merge left, pass "ex2 - 1" to try_to_merge(), |
| * since it merges towards right _only_. |
| */ |
| ret = ext4_ext_try_to_merge(inode, path, ex2 - 1); |
| if (ret) { |
| err = ext4_ext_correct_indexes(handle, inode, path); |
| if (err) |
| goto out; |
| depth = ext_depth(inode); |
| ex2--; |
| } |
| } |
| /* |
| * Try to Merge towards right. This might be required |
| * only when the whole extent is being written to. |
| * i.e. ex2 == ex and ex3 == NULL. |
| */ |
| if (!ex3) { |
| ret = ext4_ext_try_to_merge(inode, path, ex2); |
| if (ret) { |
| err = ext4_ext_correct_indexes(handle, inode, path); |
| if (err) |
| goto out; |
| } |
| } |
| /* Mark modified extent as dirty */ |
| err = ext4_ext_dirty(handle, inode, path + depth); |
| goto out; |
| insert: |
| err = ext4_ext_insert_extent(handle, inode, path, &newex, 0); |
| if (err == -ENOSPC && may_zeroout) { |
| err = ext4_ext_zeroout(inode, &orig_ex); |
| if (err) |
| goto fix_extent_len; |
| /* update the extent length and mark as initialized */ |
| ex->ee_block = orig_ex.ee_block; |
| ex->ee_len = orig_ex.ee_len; |
| ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex)); |
| ext4_ext_dirty(handle, inode, path + depth); |
| /* zero out the first half */ |
| return allocated; |
| } else if (err) |
| goto fix_extent_len; |
| out: |
| ext4_ext_show_leaf(inode, path); |
| return err ? err : allocated; |
| |
| fix_extent_len: |
| ex->ee_block = orig_ex.ee_block; |
| ex->ee_len = orig_ex.ee_len; |
| ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex)); |
| ext4_ext_mark_uninitialized(ex); |
| ext4_ext_dirty(handle, inode, path + depth); |
| return err; |
| } |
| |
| /* |
| * This function is called by ext4_ext_map_blocks() from |
| * ext4_get_blocks_dio_write() when DIO to write |
| * to an uninitialized extent. |
| * |
| * Writing to an uninitialized extent may result in splitting the uninitialized |
| * extent into multiple /initialized uninitialized extents (up to three) |
| * There are three possibilities: |
| * a> There is no split required: Entire extent should be uninitialized |
| * b> Splits in two extents: Write is happening at either end of the extent |
| * c> Splits in three extents: Somone is writing in middle of the extent |
| * |
| * One of more index blocks maybe needed if the extent tree grow after |
| * the uninitialized extent split. To prevent ENOSPC occur at the IO |
| * complete, we need to split the uninitialized extent before DIO submit |
| * the IO. The uninitialized extent called at this time will be split |
| * into three uninitialized extent(at most). After IO complete, the part |
| * being filled will be convert to initialized by the end_io callback function |
| * via ext4_convert_unwritten_extents(). |
| * |
| * Returns the size of uninitialized extent to be written on success. |
| */ |
| static int ext4_split_unwritten_extents(handle_t *handle, |
| struct inode *inode, |
| struct ext4_map_blocks *map, |
| struct ext4_ext_path *path, |
| int flags) |
| { |
| struct ext4_extent *ex, newex, orig_ex; |
| struct ext4_extent *ex1 = NULL; |
| struct ext4_extent *ex2 = NULL; |
| struct ext4_extent *ex3 = NULL; |
| ext4_lblk_t ee_block, eof_block; |
| unsigned int allocated, ee_len, depth; |
| ext4_fsblk_t newblock; |
| int err = 0; |
| int may_zeroout; |
| |
| ext_debug("ext4_split_unwritten_extents: inode %lu, logical" |
| "block %llu, max_blocks %u\n", inode->i_ino, |
| (unsigned long long)map->m_lblk, map->m_len); |
| |
| eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >> |
| inode->i_sb->s_blocksize_bits; |
| if (eof_block < map->m_lblk + map->m_len) |
| eof_block = map->m_lblk + map->m_len; |
| |
| depth = ext_depth(inode); |
| ex = path[depth].p_ext; |
| ee_block = le32_to_cpu(ex->ee_block); |
| ee_len = ext4_ext_get_actual_len(ex); |
| allocated = ee_len - (map->m_lblk - ee_block); |
| newblock = map->m_lblk - ee_block + ext4_ext_pblock(ex); |
| |
| ex2 = ex; |
| orig_ex.ee_block = ex->ee_block; |
| orig_ex.ee_len = cpu_to_le16(ee_len); |
| ext4_ext_store_pblock(&orig_ex, ext4_ext_pblock(ex)); |
| |
| /* |
| * It is safe to convert extent to initialized via explicit |
| * zeroout only if extent is fully insde i_size or new_size. |
| */ |
| may_zeroout = ee_block + ee_len <= eof_block; |
| |
| /* |
| * If the uninitialized extent begins at the same logical |
| * block where the write begins, and the write completely |
| * covers the extent, then we don't need to split it. |
| */ |
| if ((map->m_lblk == ee_block) && (allocated <= map->m_len)) |
| return allocated; |
| |
| err = ext4_ext_get_access(handle, inode, path + depth); |
| if (err) |
| goto out; |
| /* ex1: ee_block to map->m_lblk - 1 : uninitialized */ |
| if (map->m_lblk > ee_block) { |
| ex1 = ex; |
| ex1->ee_len = cpu_to_le16(map->m_lblk - ee_block); |
| ext4_ext_mark_uninitialized(ex1); |
| ex2 = &newex; |
| } |
| /* |
| * for sanity, update the length of the ex2 extent before |
| * we insert ex3, if ex1 is NULL. This is to avoid temporary |
| * overlap of blocks. |
| */ |
| if (!ex1 && allocated > map->m_len) |
| ex2->ee_len = cpu_to_le16(map->m_len); |
| /* ex3: to ee_block + ee_len : uninitialised */ |
| if (allocated > map->m_len) { |
| unsigned int newdepth; |
| ex3 = &newex; |
| ex3->ee_block = cpu_to_le32(map->m_lblk + map->m_len); |
| ext4_ext_store_pblock(ex3, newblock + map->m_len); |
| ex3->ee_len = cpu_to_le16(allocated - map->m_len); |
| ext4_ext_mark_uninitialized(ex3); |
| err = ext4_ext_insert_extent(handle, inode, path, ex3, flags); |
| if (err == -ENOSPC && may_zeroout) { |
| err = ext4_ext_zeroout(inode, &orig_ex); |
| if (err) |
| goto fix_extent_len; |
| /* update the extent length and mark as initialized */ |
| ex->ee_block = orig_ex.ee_block; |
| ex->ee_len = orig_ex.ee_len; |
| ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex)); |
| ext4_ext_dirty(handle, inode, path + depth); |
| /* zeroed the full extent */ |
| /* blocks available from map->m_lblk */ |
| return allocated; |
| |
| } else if (err) |
| goto fix_extent_len; |
| /* |
| * The depth, and hence eh & ex might change |
| * as part of the insert above. |
| */ |
| newdepth = ext_depth(inode); |
| /* |
| * update the extent length after successful insert of the |
| * split extent |
| */ |
| ee_len -= ext4_ext_get_actual_len(ex3); |
| orig_ex.ee_len = cpu_to_le16(ee_len); |
| may_zeroout = ee_block + ee_len <= eof_block; |
| |
| depth = newdepth; |
| ext4_ext_drop_refs(path); |
| path = ext4_ext_find_extent(inode, map->m_lblk, path); |
| if (IS_ERR(path)) { |
| err = PTR_ERR(path); |
| goto out; |
| } |
| ex = path[depth].p_ext; |
| if (ex2 != &newex) |
| ex2 = ex; |
| |
| err = ext4_ext_get_access(handle, inode, path + depth); |
| if (err) |
| goto out; |
| |
| allocated = map->m_len; |
| } |
| /* |
| * If there was a change of depth as part of the |
| * insertion of ex3 above, we need to update the length |
| * of the ex1 extent again here |
| */ |
| if (ex1 && ex1 != ex) { |
| ex1 = ex; |
| ex1->ee_len = cpu_to_le16(map->m_lblk - ee_block); |
| ext4_ext_mark_uninitialized(ex1); |
| ex2 = &newex; |
| } |
| /* |
| * ex2: map->m_lblk to map->m_lblk + map->m_len-1 : to be written |
| * using direct I/O, uninitialised still. |
| */ |
| ex2->ee_block = cpu_to_le32(map->m_lblk); |
| ext4_ext_store_pblock(ex2, newblock); |
| ex2->ee_len = cpu_to_le16(allocated); |
| ext4_ext_mark_uninitialized(ex2); |
| if (ex2 != ex) |
| goto insert; |
| /* Mark modified extent as dirty */ |
| err = ext4_ext_dirty(handle, inode, path + depth); |
| ext_debug("out here\n"); |
| goto out; |
| insert: |
| err = ext4_ext_insert_extent(handle, inode, path, &newex, flags); |
| if (err == -ENOSPC && may_zeroout) { |
| err = ext4_ext_zeroout(inode, &orig_ex); |
| if (err) |
| goto fix_extent_len; |
| /* update the extent length and mark as initialized */ |
| ex->ee_block = orig_ex.ee_block; |
| ex->ee_len = orig_ex.ee_len; |
| ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex)); |
| ext4_ext_dirty(handle, inode, path + depth); |
| /* zero out the first half */ |
| return allocated; |
| } else if (err) |
| goto fix_extent_len; |
| out: |
| ext4_ext_show_leaf(inode, path); |
| return err ? err : allocated; |
| |
| fix_extent_len: |
| ex->ee_block = orig_ex.ee_block; |
| ex->ee_len = orig_ex.ee_len; |
| ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex)); |
| ext4_ext_mark_uninitialized(ex); |
| ext4_ext_dirty(handle, inode, path + depth); |
| return err; |
| } |
| static int ext4_convert_unwritten_extents_endio(handle_t *handle, |
| struct inode *inode, |
| struct ext4_ext_path *path) |
| { |
| struct ext4_extent *ex; |
| struct ext4_extent_header *eh; |
| int depth; |
| int err = 0; |
| int ret = 0; |
| |
| depth = ext_depth(inode); |
| eh = path[depth].p_hdr; |
| ex = path[depth].p_ext; |
| |
| err = ext4_ext_get_access(handle, inode, path + depth); |
| if (err) |
| goto out; |
| /* first mark the extent as initialized */ |
| ext4_ext_mark_initialized(ex); |
| |
| /* |
| * We have to see if it can be merged with the extent |
| * on the left. |
| */ |
| if (ex > EXT_FIRST_EXTENT(eh)) { |
| /* |
| * To merge left, pass "ex - 1" to try_to_merge(), |
| * since it merges towards right _only_. |
| */ |
| ret = ext4_ext_try_to_merge(inode, path, ex - 1); |
| if (ret) { |
| err = ext4_ext_correct_indexes(handle, inode, path); |
| if (err) |
| goto out; |
| depth = ext_depth(inode); |
| ex--; |
| } |
| } |
| /* |
| * Try to Merge towards right. |
| */ |
| ret = ext4_ext_try_to_merge(inode, path, ex); |
| if (ret) { |
| err = ext4_ext_correct_indexes(handle, inode, path); |
| if (err) |
| goto out; |
| depth = ext_depth(inode); |
| } |
| /* Mark modified extent as dirty */ |
| err = ext4_ext_dirty(handle, inode, path + depth); |
| out: |
| ext4_ext_show_leaf(inode, path); |
| return err; |
| } |
| |
| static void unmap_underlying_metadata_blocks(struct block_device *bdev, |
| sector_t block, int count) |
| { |
| int i; |
| for (i = 0; i < count; i++) |
| unmap_underlying_metadata(bdev, block + i); |
| } |
| |
| /* |
| * Handle EOFBLOCKS_FL flag, clearing it if necessary |
| */ |
| static int check_eofblocks_fl(handle_t *handle, struct inode *inode, |
| ext4_lblk_t lblk, |
| struct ext4_ext_path *path, |
| unsigned int len) |
| { |
| int i, depth; |
| struct ext4_extent_header *eh; |
| struct ext4_extent *last_ex; |
| |
| if (!ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS)) |
| return 0; |
| |
| depth = ext_depth(inode); |
| eh = path[depth].p_hdr; |
| |
| if (unlikely(!eh->eh_entries)) { |
| EXT4_ERROR_INODE(inode, "eh->eh_entries == 0 and " |
| "EOFBLOCKS_FL set"); |
| return -EIO; |
| } |
| last_ex = EXT_LAST_EXTENT(eh); |
| /* |
| * We should clear the EOFBLOCKS_FL flag if we are writing the |
| * last block in the last extent in the file. We test this by |
| * first checking to see if the caller to |
| * ext4_ext_get_blocks() was interested in the last block (or |
| * a block beyond the last block) in the current extent. If |
| * this turns out to be false, we can bail out from this |
| * function immediately. |
| */ |
| if (lblk + len < le32_to_cpu(last_ex->ee_block) + |
| ext4_ext_get_actual_len(last_ex)) |
| return 0; |
| /* |
| * If the caller does appear to be planning to write at or |
| * beyond the end of the current extent, we then test to see |
| * if the current extent is the last extent in the file, by |
| * checking to make sure it was reached via the rightmost node |
| * at each level of the tree. |
| */ |
| for (i = depth-1; i >= 0; i--) |
| if (path[i].p_idx != EXT_LAST_INDEX(path[i].p_hdr)) |
| return 0; |
| ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS); |
| return ext4_mark_inode_dirty(handle, inode); |
| } |
| |
| static int |
| ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode, |
| struct ext4_map_blocks *map, |
| struct ext4_ext_path *path, int flags, |
| unsigned int allocated, ext4_fsblk_t newblock) |
| { |
| int ret = 0; |
| int err = 0; |
| ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio; |
| |
| ext_debug("ext4_ext_handle_uninitialized_extents: inode %lu, logical" |
| "block %llu, max_blocks %u, flags %d, allocated %u", |
| inode->i_ino, (unsigned long long)map->m_lblk, map->m_len, |
| flags, allocated); |
| ext4_ext_show_leaf(inode, path); |
| |
| /* get_block() before submit the IO, split the extent */ |
| if ((flags & EXT4_GET_BLOCKS_PRE_IO)) { |
| ret = ext4_split_unwritten_extents(handle, inode, map, |
| path, flags); |
| /* |
| * Flag the inode(non aio case) or end_io struct (aio case) |
| * that this IO needs to convertion to written when IO is |
| * completed |
| */ |
| if (io && !(io->flag & EXT4_IO_END_UNWRITTEN)) { |
| io->flag = EXT4_IO_END_UNWRITTEN; |
| atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten); |
| } else |
| ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN); |
| if (ext4_should_dioread_nolock(inode)) |
| map->m_flags |= EXT4_MAP_UNINIT; |
| goto out; |
| } |
| /* IO end_io complete, convert the filled extent to written */ |
| if ((flags & EXT4_GET_BLOCKS_CONVERT)) { |
| ret = ext4_convert_unwritten_extents_endio(handle, inode, |
| path); |
| if (ret >= 0) { |
| ext4_update_inode_fsync_trans(handle, inode, 1); |
| err = check_eofblocks_fl(handle, inode, map->m_lblk, |
| path, map->m_len); |
| } else |
| err = ret; |
| goto out2; |
| } |
| /* buffered IO case */ |
| /* |
| * repeat fallocate creation request |
| * we already have an unwritten extent |
| */ |
| if (flags & EXT4_GET_BLOCKS_UNINIT_EXT) |
| goto map_out; |
| |
| /* buffered READ or buffered write_begin() lookup */ |
| if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { |
| /* |
| * We have blocks reserved already. We |
| * return allocated blocks so that delalloc |
| * won't do block reservation for us. But |
| * the buffer head will be unmapped so that |
| * a read from the block returns 0s. |
| */ |
| map->m_flags |= EXT4_MAP_UNWRITTEN; |
| goto out1; |
| } |
| |
| /* buffered write, writepage time, convert*/ |
| ret = ext4_ext_convert_to_initialized(handle, inode, map, path); |
| if (ret >= 0) { |
| ext4_update_inode_fsync_trans(handle, inode, 1); |
| err = check_eofblocks_fl(handle, inode, map->m_lblk, path, |
| map->m_len); |
| if (err < 0) |
| goto out2; |
| } |
| |
| out: |
| if (ret <= 0) { |
| err = ret; |
| goto out2; |
| } else |
| allocated = ret; |
| map->m_flags |= EXT4_MAP_NEW; |
| /* |
| * if we allocated more blocks than requested |
| * we need to make sure we unmap the extra block |
| * allocated. The actual needed block will get |
| * unmapped later when we find the buffer_head marked |
| * new. |
| */ |
| if (allocated > map->m_len) { |
| unmap_underlying_metadata_blocks(inode->i_sb->s_bdev, |
| newblock + map->m_len, |
| allocated - map->m_len); |
| allocated = map->m_len; |
| } |
| |
| /* |
| * If we have done fallocate with the offset that is already |
| * delayed allocated, we would have block reservation |
| * and quota reservation done in the delayed write path. |
| * But fallocate would have already updated quota and block |
| * count for this offset. So cancel these reservation |
| */ |
| if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) |
| ext4_da_update_reserve_space(inode, allocated, 0); |
| |
| map_out: |
| map->m_flags |= EXT4_MAP_MAPPED; |
| out1: |
| if (allocated > map->m_len) |
| allocated = map->m_len; |
| ext4_ext_show_leaf(inode, path); |
| map->m_pblk = newblock; |
| map->m_len = allocated; |
| out2: |
| if (path) { |
| ext4_ext_drop_refs(path); |
| kfree(path); |
| } |
| return err ? err : allocated; |
| } |
| |
| /* |
| * Block allocation/map/preallocation routine for extents based files |
| * |
| * |
| * 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) |
| * |
| * return > 0, number of of blocks already mapped/allocated |
| * if create == 0 and these are pre-allocated blocks |
| * buffer head is unmapped |
| * otherwise blocks are mapped |
| * |
| * return = 0, if plain look up failed (blocks have not been allocated) |
| * buffer head is unmapped |
| * |
| * return < 0, error case. |
| */ |
| int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, |
| struct ext4_map_blocks *map, int flags) |
| { |
| struct ext4_ext_path *path = NULL; |
| struct ext4_extent newex, *ex; |
| ext4_fsblk_t newblock = 0; |
| int err = 0, depth, ret; |
| unsigned int allocated = 0; |
| struct ext4_allocation_request ar; |
| ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio; |
| |
| ext_debug("blocks %u/%u requested for inode %lu\n", |
| map->m_lblk, map->m_len, inode->i_ino); |
| trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags); |
| |
| /* check in cache */ |
| if (ext4_ext_in_cache(inode, map->m_lblk, &newex)) { |
| if (!newex.ee_start_lo && !newex.ee_start_hi) { |
| if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { |
| /* |
| * block isn't allocated yet and |
| * user doesn't want to allocate it |
| */ |
| goto out2; |
| } |
| /* we should allocate requested block */ |
| } else { |
| /* block is already allocated */ |
| newblock = map->m_lblk |
| - le32_to_cpu(newex.ee_block) |
| + ext4_ext_pblock(&newex); |
| /* number of remaining blocks in the extent */ |
| allocated = ext4_ext_get_actual_len(&newex) - |
| (map->m_lblk - le32_to_cpu(newex.ee_block)); |
| goto out; |
| } |
| } |
| |
| /* find extent for this block */ |
| path = ext4_ext_find_extent(inode, map->m_lblk, NULL); |
| if (IS_ERR(path)) { |
| err = PTR_ERR(path); |
| path = NULL; |
| goto out2; |
| } |
| |
| depth = ext_depth(inode); |
| |
| /* |
| * consistent leaf must not be empty; |
| * this situation is possible, though, _during_ tree modification; |
| * this is why assert can't be put in ext4_ext_find_extent() |
| */ |
| if (unlikely(path[depth].p_ext == NULL && depth != 0)) { |
| EXT4_ERROR_INODE(inode, "bad extent address " |
| "lblock: %lu, depth: %d pblock %lld", |
| (unsigned long) map->m_lblk, depth, |
| path[depth].p_block); |
| err = -EIO; |
| goto out2; |
| } |
| |
| ex = path[depth].p_ext; |
| if (ex) { |
| ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block); |
| ext4_fsblk_t ee_start = ext4_ext_pblock(ex); |
| unsigned short ee_len; |
| |
| /* |
| * Uninitialized extents are treated as holes, except that |
| * we split out initialized portions during a write. |
| */ |
| ee_len = ext4_ext_get_actual_len(ex); |
| /* if found extent covers block, simply return it */ |
| if (in_range(map->m_lblk, ee_block, ee_len)) { |
| newblock = map->m_lblk - ee_block + ee_start; |
| /* number of remaining blocks in the extent */ |
| allocated = ee_len - (map->m_lblk - ee_block); |
| ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk, |
| ee_block, ee_len, newblock); |
| |
| /* Do not put uninitialized extent in the cache */ |
| if (!ext4_ext_is_uninitialized(ex)) { |
| ext4_ext_put_in_cache(inode, ee_block, |
| ee_len, ee_start); |
| goto out; |
| } |
| ret = ext4_ext_handle_uninitialized_extents(handle, |
| inode, map, path, flags, allocated, |
| newblock); |
| return ret; |
| } |
| } |
| |
| /* |
| * requested block isn't allocated yet; |
| * we couldn't try to create block if create flag is zero |
| */ |
| if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { |
| /* |
| * put just found gap into cache to speed up |
| * subsequent requests |
| */ |
| ext4_ext_put_gap_in_cache(inode, path, map->m_lblk); |
| goto out2; |
| } |
| /* |
| * Okay, we need to do block allocation. |
| */ |
| |
| /* find neighbour allocated blocks */ |
| ar.lleft = map->m_lblk; |
| err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft); |
| if (err) |
| goto out2; |
| ar.lright = map->m_lblk; |
| err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright); |
| if (err) |
| goto out2; |
| |
| /* |
| * See if request is beyond maximum number of blocks we can have in |
| * a single extent. For an initialized extent this limit is |
| * EXT_INIT_MAX_LEN and for an uninitialized extent this limit is |
| * EXT_UNINIT_MAX_LEN. |
| */ |
| if (map->m_len > EXT_INIT_MAX_LEN && |
| !(flags & EXT4_GET_BLOCKS_UNINIT_EXT)) |
| map->m_len = EXT_INIT_MAX_LEN; |
| else if (map->m_len > EXT_UNINIT_MAX_LEN && |
| (flags & EXT4_GET_BLOCKS_UNINIT_EXT)) |
| map->m_len = EXT_UNINIT_MAX_LEN; |
| |
| /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */ |
| newex.ee_block = cpu_to_le32(map->m_lblk); |
| newex.ee_len = cpu_to_le16(map->m_len); |
| err = ext4_ext_check_overlap(inode, &newex, path); |
| if (err) |
| allocated = ext4_ext_get_actual_len(&newex); |
| else |
| allocated = map->m_len; |
| |
| /* allocate new block */ |
| ar.inode = inode; |
| ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk); |
| ar.logical = map->m_lblk; |
| ar.len = allocated; |
| if (S_ISREG(inode->i_mode)) |
| ar.flags = EXT4_MB_HINT_DATA; |
| else |
| /* disable in-core preallocation for non-regular files */ |
| ar.flags = 0; |
| newblock = ext4_mb_new_blocks(handle, &ar, &err); |
| if (!newblock) |
| goto out2; |
| ext_debug("allocate new block: goal %llu, found %llu/%u\n", |
| ar.goal, newblock, allocated); |
| |
| /* try to insert new extent into found leaf and return */ |
| ext4_ext_store_pblock(&newex, newblock); |
| newex.ee_len = cpu_to_le16(ar.len); |
| /* Mark uninitialized */ |
| if (flags & EXT4_GET_BLOCKS_UNINIT_EXT){ |
| ext4_ext_mark_uninitialized(&newex); |
| /* |
| * io_end structure was created for every IO write to an |
| * uninitialized extent. To avoid unecessary conversion, |
| * here we flag the IO that really needs the conversion. |
| * For non asycn direct IO case, flag the inode state |
| * that we need to perform convertion when IO is done. |
| */ |
| if ((flags & EXT4_GET_BLOCKS_PRE_IO)) { |
| if (io && !(io->flag & EXT4_IO_END_UNWRITTEN)) { |
| io->flag = EXT4_IO_END_UNWRITTEN; |
| atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten); |
| } else |
| ext4_set_inode_state(inode, |
| EXT4_STATE_DIO_UNWRITTEN); |
| } |
| if (ext4_should_dioread_nolock(inode)) |
| map->m_flags |= EXT4_MAP_UNINIT; |
| } |
| |
| err = check_eofblocks_fl(handle, inode, map->m_lblk, path, ar.len); |
| if (err) |
| goto out2; |
| |
| err = ext4_ext_insert_extent(handle, inode, path, &newex, flags); |
| if (err) { |
| /* free data blocks we just allocated */ |
| /* not a good idea to call discard here directly, |
| * but otherwise we'd need to call it every free() */ |
| ext4_discard_preallocations(inode); |
| ext4_free_blocks(handle, inode, NULL, ext4_ext_pblock(&newex), |
| ext4_ext_get_actual_len(&newex), 0); |
| goto out2; |
| } |
| |
| /* previous routine could use block we allocated */ |
| newblock = ext4_ext_pblock(&newex); |
| allocated = ext4_ext_get_actual_len(&newex); |
| if (allocated > map->m_len) |
| allocated = map->m_len; |
| map->m_flags |= EXT4_MAP_NEW; |
| |
| /* |
| * Update reserved blocks/metadata blocks after successful |
| * block allocation which had been deferred till now. |
| */ |
| if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) |
| ext4_da_update_reserve_space(inode, allocated, 1); |
| |
| /* |
| * Cache the extent and update transaction to commit on fdatasync only |
| * when it is _not_ an uninitialized extent. |
| */ |
| if ((flags & EXT4_GET_BLOCKS_UNINIT_EXT) == 0) { |
| ext4_ext_put_in_cache(inode, map->m_lblk, allocated, newblock); |
| ext4_update_inode_fsync_trans(handle, inode, 1); |
| } else |
| ext4_update_inode_fsync_trans(handle, inode, 0); |
| out: |
| if (allocated > map->m_len) |
| allocated = map->m_len; |
| ext4_ext_show_leaf(inode, path); |
| map->m_flags |= EXT4_MAP_MAPPED; |
| map->m_pblk = newblock; |
| map->m_len = allocated; |
| out2: |
| if (path) { |
| ext4_ext_drop_refs(path); |
| kfree(path); |
| } |
| trace_ext4_ext_map_blocks_exit(inode, map->m_lblk, |
| newblock, map->m_len, err ? err : allocated); |
| return err ? err : allocated; |
| } |
| |
| void ext4_ext_truncate(struct inode *inode) |
| { |
| struct address_space *mapping = inode->i_mapping; |
| struct super_block *sb = inode->i_sb; |
| ext4_lblk_t last_block; |
| handle_t *handle; |
| int err = 0; |
| |
| /* |
| * finish any pending end_io work so we won't run the risk of |
| * converting any truncated blocks to initialized later |
| */ |
| ext4_flush_completed_IO(inode); |
| |
| /* |
| * probably first extent we're gonna free will be last in block |
| */ |
| err = ext4_writepage_trans_blocks(inode); |
| handle = ext4_journal_start(inode, err); |
| if (IS_ERR(handle)) |
| return; |
| |
| if (inode->i_size & (sb->s_blocksize - 1)) |
| ext4_block_truncate_page(handle, mapping, inode->i_size); |
| |
| if (ext4_orphan_add(handle, inode)) |
| goto out_stop; |
| |
| down_write(&EXT4_I(inode)->i_data_sem); |
| ext4_ext_invalidate_cache(inode); |
| |
| ext4_discard_preallocations(inode); |
| |
| /* |
| * TODO: optimization is possible here. |
| * Probably we need not scan at all, |
| * because page truncation is enough. |
| */ |
| |
| /* we have to know where to truncate from in crash case */ |
| EXT4_I(inode)->i_disksize = inode->i_size; |
| ext4_mark_inode_dirty(handle, inode); |
| |
| last_block = (inode->i_size + sb->s_blocksize - 1) |
| >> EXT4_BLOCK_SIZE_BITS(sb); |
| err = ext4_ext_remove_space(inode, last_block); |
| |
| /* In a multi-transaction truncate, we only make the final |
| * transaction synchronous. |
| */ |
| if (IS_SYNC(inode)) |
| ext4_handle_sync(handle); |
| |
| out_stop: |
| up_write(&EXT4_I(inode)->i_data_sem); |
| /* |
| * 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); |
| |
| inode->i_mtime = inode->i_ctime = ext4_current_time(inode); |
| ext4_mark_inode_dirty(handle, inode); |
| ext4_journal_stop(handle); |
| } |
| |
| static void ext4_falloc_update_inode(struct inode *inode, |
| int mode, loff_t new_size, int update_ctime) |
| { |
| struct timespec now; |
| |
| if (update_ctime) { |
| now = current_fs_time(inode->i_sb); |
| if (!timespec_equal(&inode->i_ctime, &now)) |
| inode->i_ctime = now; |
| } |
| /* |
| * Update only when preallocation was requested beyond |
| * the file size. |
| */ |
| if (!(mode & FALLOC_FL_KEEP_SIZE)) { |
| if (new_size > i_size_read(inode)) |
| i_size_write(inode, new_size); |
| if (new_size > EXT4_I(inode)->i_disksize) |
| ext4_update_i_disksize(inode, new_size); |
| } else { |
| /* |
| * Mark that we allocate beyond EOF so the subsequent truncate |
| * can proceed even if the new size is the same as i_size. |
| */ |
| if (new_size > i_size_read(inode)) |
| ext4_set_inode_flag(inode, EXT4_INODE_EOFBLOCKS); |
| } |
| |
| } |
| |
| /* |
| * preallocate space for a file. This implements ext4's fallocate file |
| * operation, which gets called from sys_fallocate system call. |
| * For block-mapped files, posix_fallocate should fall back to the method |
| * of writing zeroes to the required new blocks (the same behavior which is |
| * expected for file systems which do not support fallocate() system call). |
| */ |
| long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) |
| { |
| struct inode *inode = file->f_path.dentry->d_inode; |
| handle_t *handle; |
| loff_t new_size; |
| unsigned int max_blocks; |
| int ret = 0; |
| int ret2 = 0; |
| int retries = 0; |
| struct ext4_map_blocks map; |
| unsigned int credits, blkbits = inode->i_blkbits; |
| |
| /* We only support the FALLOC_FL_KEEP_SIZE mode */ |
| if (mode & ~FALLOC_FL_KEEP_SIZE) |
| return -EOPNOTSUPP; |
| |
| /* |
| * currently supporting (pre)allocate mode for extent-based |
| * files _only_ |
| */ |
| if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) |
| return -EOPNOTSUPP; |
| |
| trace_ext4_fallocate_enter(inode, offset, len, mode); |
| map.m_lblk = offset >> blkbits; |
| /* |
| * We can't just convert len to max_blocks because |
| * If blocksize = 4096 offset = 3072 and len = 2048 |
| */ |
| max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) |
| - map.m_lblk; |
| /* |
| * credits to insert 1 extent into extent tree |
| */ |
| credits = ext4_chunk_trans_blocks(inode, max_blocks); |
| mutex_lock(&inode->i_mutex); |
| ret = inode_newsize_ok(inode, (len + offset)); |
| if (ret) { |
| mutex_unlock(&inode->i_mutex); |
| trace_ext4_fallocate_exit(inode, offset, max_blocks, ret); |
| return ret; |
| } |
| retry: |
| while (ret >= 0 && ret < max_blocks) { |
| map.m_lblk = map.m_lblk + ret; |
| map.m_len = max_blocks = max_blocks - ret; |
| handle = ext4_journal_start(inode, credits); |
| if (IS_ERR(handle)) { |
| ret = PTR_ERR(handle); |
| break; |
| } |
| ret = ext4_map_blocks(handle, inode, &map, |
| EXT4_GET_BLOCKS_CREATE_UNINIT_EXT); |
| if (ret <= 0) { |
| #ifdef EXT4FS_DEBUG |
| WARN_ON(ret <= 0); |
| printk(KERN_ERR "%s: ext4_ext_map_blocks " |
| "returned error inode#%lu, block=%u, " |
| "max_blocks=%u", __func__, |
| inode->i_ino, map.m_lblk, max_blocks); |
| #endif |
| ext4_mark_inode_dirty(handle, inode); |
| ret2 = ext4_journal_stop(handle); |
| break; |
| } |
| if ((map.m_lblk + ret) >= (EXT4_BLOCK_ALIGN(offset + len, |
| blkbits) >> blkbits)) |
| new_size = offset + len; |
| else |
| new_size = (map.m_lblk + ret) << blkbits; |
| |
| ext4_falloc_update_inode(inode, mode, new_size, |
| (map.m_flags & EXT4_MAP_NEW)); |
| ext4_mark_inode_dirty(handle, inode); |
| ret2 = ext4_journal_stop(handle); |
| if (ret2) |
| break; |
| } |
| if (ret == -ENOSPC && |
| ext4_should_retry_alloc(inode->i_sb, &retries)) { |
| ret = 0; |
| goto retry; |
| } |
| mutex_unlock(&inode->i_mutex); |
| trace_ext4_fallocate_exit(inode, offset, max_blocks, |
| ret > 0 ? ret2 : ret); |
| return ret > 0 ? ret2 : ret; |
| } |
| |
| /* |
| * This function convert a range of blocks to written extents |
| * The caller of this function will pass the start offset and the size. |
| * all unwritten extents within this range will be converted to |
| * written extents. |
| * |
| * This function is called from the direct IO end io call back |
| * function, to convert the fallocated extents after IO is completed. |
| * Returns 0 on success. |
| */ |
| int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset, |
| ssize_t len) |
| { |
| handle_t *handle; |
| unsigned int max_blocks; |
| int ret = 0; |
| int ret2 = 0; |
| struct ext4_map_blocks map; |
| unsigned int credits, blkbits = inode->i_blkbits; |
| |
| map.m_lblk = offset >> blkbits; |
| /* |
| * We can't just convert len to max_blocks because |
| * If blocksize = 4096 offset = 3072 and len = 2048 |
| */ |
| max_blocks = ((EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) - |
| map.m_lblk); |
| /* |
| * credits to insert 1 extent into extent tree |
| */ |
| credits = ext4_chunk_trans_blocks(inode, max_blocks); |
| while (ret >= 0 && ret < max_blocks) { |
| map.m_lblk += ret; |
| map.m_len = (max_blocks -= ret); |
| handle = ext4_journal_start(inode, credits); |
| if (IS_ERR(handle)) { |
| ret = PTR_ERR(handle); |
| break; |
| } |
| ret = ext4_map_blocks(handle, inode, &map, |
| EXT4_GET_BLOCKS_IO_CONVERT_EXT); |
| if (ret <= 0) { |
| WARN_ON(ret <= 0); |
| printk(KERN_ERR "%s: ext4_ext_map_blocks " |
| "returned error inode#%lu, block=%u, " |
| "max_blocks=%u", __func__, |
| inode->i_ino, map.m_lblk, map.m_len); |
| } |
| ext4_mark_inode_dirty(handle, inode); |
| ret2 = ext4_journal_stop(handle); |
| if (ret <= 0 || ret2 ) |
| break; |
| } |
| return ret > 0 ? ret2 : ret; |
| } |
| |
| /* |
| * Callback function called for each extent to gather FIEMAP information. |
| */ |
| static int ext4_ext_fiemap_cb(struct inode *inode, struct ext4_ext_path *path, |
| struct ext4_ext_cache *newex, struct ext4_extent *ex, |
| void *data) |
| { |
| __u64 logical; |
| __u64 physical; |
| __u64 length; |
| loff_t size; |
| __u32 flags = 0; |
| int ret = 0; |
| struct fiemap_extent_info *fieinfo = data; |
| unsigned char blksize_bits; |
| |
| blksize_bits = inode->i_sb->s_blocksize_bits; |
| logical = (__u64)newex->ec_block << blksize_bits; |
| |
| if (newex->ec_start == 0) { |
| /* |
| * No extent in extent-tree contains block @newex->ec_start, |
| * then the block may stay in 1)a hole or 2)delayed-extent. |
| * |
| * Holes or delayed-extents are processed as follows. |
| * 1. lookup dirty pages with specified range in pagecache. |
| * If no page is got, then there is no delayed-extent and |
| * return with EXT_CONTINUE. |
| * 2. find the 1st mapped buffer, |
| * 3. check if the mapped buffer is both in the request range |
| * and a delayed buffer. If not, there is no delayed-extent, |
| * then return. |
| * 4. a delayed-extent is found, the extent will be collected. |
| */ |
| ext4_lblk_t end = 0; |
| pgoff_t last_offset; |
| pgoff_t offset; |
| pgoff_t index; |
| struct page **pages = NULL; |
| struct buffer_head *bh = NULL; |
| struct buffer_head *head = NULL; |
| unsigned int nr_pages = PAGE_SIZE / sizeof(struct page *); |
| |
| pages = kmalloc(PAGE_SIZE, GFP_KERNEL); |
| if (pages == NULL) |
| return -ENOMEM; |
| |
| offset = logical >> PAGE_SHIFT; |
| repeat: |
| last_offset = offset; |
| head = NULL; |
| ret = find_get_pages_tag(inode->i_mapping, &offset, |
| PAGECACHE_TAG_DIRTY, nr_pages, pages); |
| |
| if (!(flags & FIEMAP_EXTENT_DELALLOC)) { |
| /* First time, try to find a mapped buffer. */ |
| if (ret == 0) { |
| out: |
| for (index = 0; index < ret; index++) |
| page_cache_release(pages[index]); |
| /* just a hole. */ |
| kfree(pages); |
| return EXT_CONTINUE; |
| } |
| |
| /* Try to find the 1st mapped buffer. */ |
| end = ((__u64)pages[0]->index << PAGE_SHIFT) >> |
| blksize_bits; |
| if (!page_has_buffers(pages[0])) |
| goto out; |
| head = page_buffers(pages[0]); |
| if (!head) |
| goto out; |
| |
| bh = head; |
| do { |
| if (buffer_mapped(bh)) { |
| /* get the 1st mapped buffer. */ |
| if (end > newex->ec_block + |
| newex->ec_len) |
| /* The buffer is out of |
| * the request range. |
| */ |
| goto out; |
| goto found_mapped_buffer; |
| } |
| bh = bh->b_this_page; |
| end++; |
| } while (bh != head); |
| |
| /* No mapped buffer found. */ |
| goto out; |
| } else { |
| /*Find contiguous delayed buffers. */ |
| if (ret > 0 && pages[0]->index == last_offset) |
| head = page_buffers(pages[0]); |
| bh = head; |
| } |
| |
| found_mapped_buffer: |
| if (bh != NULL && buffer_delay(bh)) { |
| /* 1st or contiguous delayed buffer found. */ |
| if (!(flags & FIEMAP_EXTENT_DELALLOC)) { |
| /* |
| * 1st delayed buffer found, record |
| * the start of extent. |
| */ |
| flags |= FIEMAP_EXTENT_DELALLOC; |
| newex->ec_block = end; |
| logical = (__u64)end << blksize_bits; |
| } |
| /* Find contiguous delayed buffers. */ |
| do { |
| if (!buffer_delay(bh)) |
| goto found_delayed_extent; |
| bh = bh->b_this_page; |
| end++; |
| } while (bh != head); |
| |
| for (index = 1; index < ret; index++) { |
| if (!page_has_buffers(pages[index])) { |
| bh = NULL; |
| break; |
| } |
| head = page_buffers(pages[index]); |
| if (!head) { |
| bh = NULL; |
| break; |
| } |
| if (pages[index]->index != |
| pages[0]->index + index) { |
| /* Blocks are not contiguous. */ |
| bh = NULL; |
| break; |
| } |
| bh = head; |
| do { |
| if (!buffer_delay(bh)) |
| /* Delayed-extent ends. */ |
| goto found_delayed_extent; |
| bh = bh->b_this_page; |
| end++; |
| } while (bh != head); |
| } |
| } else if (!(flags & FIEMAP_EXTENT_DELALLOC)) |
| /* a hole found. */ |
| goto out; |
| |
| found_delayed_extent: |
| newex->ec_len = min(end - newex->ec_block, |
| (ext4_lblk_t)EXT_INIT_MAX_LEN); |
| if (ret == nr_pages && bh != NULL && |
| newex->ec_len < EXT_INIT_MAX_LEN && |
| buffer_delay(bh)) { |
| /* Have not collected an extent and continue. */ |
| for (index = 0; index < ret; index++) |
| page_cache_release(pages[index]); |
| goto repeat; |
| } |
| |
| for (index = 0; index < ret; index++) |
| page_cache_release(pages[index]); |
| kfree(pages); |
| } |
| |
| physical = (__u64)newex->ec_start << blksize_bits; |
| length = (__u64)newex->ec_len << blksize_bits; |
| |
| if (ex && ext4_ext_is_uninitialized(ex)) |
| flags |= FIEMAP_EXTENT_UNWRITTEN; |
| |
| size = i_size_read(inode); |
| if (logical + length >= size) |
| flags |= FIEMAP_EXTENT_LAST; |
| |
| ret = fiemap_fill_next_extent(fieinfo, logical, physical, |
| length, flags); |
| if (ret < 0) |
| return ret; |
| if (ret == 1) |
| return EXT_BREAK; |
| return EXT_CONTINUE; |
| } |
| |
| /* fiemap flags we can handle specified here */ |
| #define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR) |
| |
| static int ext4_xattr_fiemap(struct inode *inode, |
| struct fiemap_extent_info *fieinfo) |
| { |
| __u64 physical = 0; |
| __u64 length; |
| __u32 flags = FIEMAP_EXTENT_LAST; |
| int blockbits = inode->i_sb->s_blocksize_bits; |
| int error = 0; |
| |
| /* in-inode? */ |
| if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { |
| struct ext4_iloc iloc; |
| int offset; /* offset of xattr in inode */ |
| |
| error = ext4_get_inode_loc(inode, &iloc); |
| if (error) |
| return error; |
| physical = iloc.bh->b_blocknr << blockbits; |
| offset = EXT4_GOOD_OLD_INODE_SIZE + |
| EXT4_I(inode)->i_extra_isize; |
| physical += offset; |
| length = EXT4_SB(inode->i_sb)->s_inode_size - offset; |
| flags |= FIEMAP_EXTENT_DATA_INLINE; |
| brelse(iloc.bh); |
| } else { /* external block */ |
| physical = EXT4_I(inode)->i_file_acl << blockbits; |
| length = inode->i_sb->s_blocksize; |
| } |
| |
| if (physical) |
| error = fiemap_fill_next_extent(fieinfo, 0, physical, |
| length, flags); |
| return (error < 0 ? error : 0); |
| } |
| |
| int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, |
| __u64 start, __u64 len) |
| { |
| ext4_lblk_t start_blk; |
| int error = 0; |
| |
| /* fallback to generic here if not in extents fmt */ |
| if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) |
| return generic_block_fiemap(inode, fieinfo, start, len, |
| ext4_get_block); |
| |
| if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS)) |
| return -EBADR; |
| |
| if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) { |
| error = ext4_xattr_fiemap(inode, fieinfo); |
| } else { |
| ext4_lblk_t len_blks; |
| __u64 last_blk; |
| |
| start_blk = start >> inode->i_sb->s_blocksize_bits; |
| last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits; |
| if (last_blk >= EXT_MAX_BLOCK) |
| last_blk = EXT_MAX_BLOCK-1; |
| len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1; |
| |
| /* |
| * Walk the extent tree gathering extent information. |
| * ext4_ext_fiemap_cb will push extents back to user. |
| */ |
| error = ext4_ext_walk_space(inode, start_blk, len_blks, |
| ext4_ext_fiemap_cb, fieinfo); |
| } |
| |
| return error; |
| } |
| |