diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ext4/extents.c | 72 |
1 files changed, 58 insertions, 14 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index aabbb3f..e8755c2 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -1656,16 +1656,60 @@ static int ext4_ext_try_to_merge_right(struct inode *inode, } /* + * This function does a very simple check to see if we can collapse + * an extent tree with a single extent tree leaf block into the inode. + */ +static void ext4_ext_try_to_merge_up(handle_t *handle, + struct inode *inode, + struct ext4_ext_path *path) +{ + size_t s; + unsigned max_root = ext4_ext_space_root(inode, 0); + ext4_fsblk_t blk; + + if ((path[0].p_depth != 1) || + (le16_to_cpu(path[0].p_hdr->eh_entries) != 1) || + (le16_to_cpu(path[1].p_hdr->eh_entries) > max_root)) + return; + + /* + * We need to modify the block allocation bitmap and the block + * group descriptor to release the extent tree block. If we + * can't get the journal credits, give up. + */ + if (ext4_journal_extend(handle, 2)) + return; + + /* + * Copy the extent data up to the inode + */ + blk = ext4_idx_pblock(path[0].p_idx); + s = le16_to_cpu(path[1].p_hdr->eh_entries) * + sizeof(struct ext4_extent_idx); + s += sizeof(struct ext4_extent_header); + + memcpy(path[0].p_hdr, path[1].p_hdr, s); + path[0].p_depth = 0; + path[0].p_ext = EXT_FIRST_EXTENT(path[0].p_hdr) + + (path[1].p_ext - EXT_FIRST_EXTENT(path[1].p_hdr)); + path[0].p_hdr->eh_max = cpu_to_le16(max_root); + + brelse(path[1].p_bh); + ext4_free_blocks(handle, inode, NULL, blk, 1, + EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET); +} + +/* * This function tries to merge the @ex extent to neighbours in the tree. * return 1 if merge left else 0. */ -static int ext4_ext_try_to_merge(struct inode *inode, +static void ext4_ext_try_to_merge(handle_t *handle, + struct inode *inode, struct ext4_ext_path *path, struct ext4_extent *ex) { struct ext4_extent_header *eh; unsigned int depth; int merge_done = 0; - int ret = 0; depth = ext_depth(inode); BUG_ON(path[depth].p_hdr == NULL); @@ -1675,9 +1719,9 @@ static int ext4_ext_try_to_merge(struct inode *inode, merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1); if (!merge_done) - ret = ext4_ext_try_to_merge_right(inode, path, ex); + (void) ext4_ext_try_to_merge_right(inode, path, ex); - return ret; + ext4_ext_try_to_merge_up(handle, inode, path); } /* @@ -1893,7 +1937,7 @@ has_space: merge: /* try to merge extents */ if (!(flag & EXT4_GET_BLOCKS_PRE_IO)) - ext4_ext_try_to_merge(inode, path, nearex); + ext4_ext_try_to_merge(handle, inode, path, nearex); /* time to correct all indexes above */ @@ -1901,7 +1945,7 @@ merge: if (err) goto cleanup; - err = ext4_ext_dirty(handle, inode, path + depth); + err = ext4_ext_dirty(handle, inode, path + path->p_depth); cleanup: if (npath) { @@ -2924,9 +2968,9 @@ static int ext4_split_extent_at(handle_t *handle, ext4_ext_mark_initialized(ex); if (!(flags & EXT4_GET_BLOCKS_PRE_IO)) - ext4_ext_try_to_merge(inode, path, ex); + ext4_ext_try_to_merge(handle, inode, path, ex); - err = ext4_ext_dirty(handle, inode, path + depth); + err = ext4_ext_dirty(handle, inode, path + path->p_depth); goto out; } @@ -2958,8 +3002,8 @@ static int ext4_split_extent_at(handle_t *handle, goto fix_extent_len; /* update the extent length and mark as initialized */ ex->ee_len = cpu_to_le16(ee_len); - ext4_ext_try_to_merge(inode, path, ex); - err = ext4_ext_dirty(handle, inode, path + depth); + ext4_ext_try_to_merge(handle, inode, path, ex); + err = ext4_ext_dirty(handle, inode, path + path->p_depth); goto out; } else if (err) goto fix_extent_len; @@ -3191,8 +3235,8 @@ static int ext4_ext_convert_to_initialized(handle_t *handle, if (err) goto out; ext4_ext_mark_initialized(ex); - ext4_ext_try_to_merge(inode, path, ex); - err = ext4_ext_dirty(handle, inode, path + depth); + ext4_ext_try_to_merge(handle, inode, path, ex); + err = ext4_ext_dirty(handle, inode, path + path->p_depth); goto out; } @@ -3333,10 +3377,10 @@ static int ext4_convert_unwritten_extents_endio(handle_t *handle, /* note: ext4_ext_correct_indexes() isn't needed here because * borders are not changed */ - ext4_ext_try_to_merge(inode, path, ex); + ext4_ext_try_to_merge(handle, inode, path, ex); /* Mark modified extent as dirty */ - err = ext4_ext_dirty(handle, inode, path + depth); + err = ext4_ext_dirty(handle, inode, path + path->p_depth); out: ext4_ext_show_leaf(inode, path); return err; |
