diff options
| author | Theodore Ts'o <tytso@mit.edu> | 2014-09-01 14:40:09 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2014-09-01 14:40:09 -0400 |
| commit | 10809df84a4d868db61af621bae3658494165279 (patch) | |
| tree | 07058f847b286c07f27c82033e7b2d8c0fc1af7a | |
| parent | b7ea89ad0a6b855172158a999d3f5008403f4011 (diff) | |
ext4: teach ext4_ext_find_extent() to realloc path if necessary
This adds additional safety in case for some reason we end reusing a
path structure which isn't big enough for current depth of the inode.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| -rw-r--r-- | fs/ext4/ext4_extents.h | 1 | ||||
| -rw-r--r-- | fs/ext4/extents.c | 20 |
2 files changed, 11 insertions, 10 deletions
diff --git a/fs/ext4/ext4_extents.h b/fs/ext4/ext4_extents.h index a867f5ca9991..3c9381547094 100644 --- a/fs/ext4/ext4_extents.h +++ b/fs/ext4/ext4_extents.h @@ -123,6 +123,7 @@ find_ext4_extent_tail(struct ext4_extent_header *eh) struct ext4_ext_path { ext4_fsblk_t p_block; __u16 p_depth; + __u16 p_maxdepth; struct ext4_extent *p_ext; struct ext4_extent_idx *p_idx; struct ext4_extent_header *p_hdr; diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 538f9a4d96ff..c94c7480053e 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -869,14 +869,20 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block, eh = ext_inode_hdr(inode); depth = ext_depth(inode); - if (path) + if (path) { ext4_ext_drop_refs(path); - else { + if (depth > path[0].p_maxdepth) { + kfree(path); + *orig_path = path = NULL; + } + } + if (!path) { /* account possible depth increase */ path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2), GFP_NOFS); if (unlikely(!path)) return ERR_PTR(-ENOMEM); + path[0].p_maxdepth = depth + 1; } path[0].p_hdr = eh; path[0].p_bh = NULL; @@ -1820,6 +1826,7 @@ static void ext4_ext_try_to_merge_up(handle_t *handle, sizeof(struct ext4_extent_idx); s += sizeof(struct ext4_extent_header); + path[1].p_maxdepth = path[0].p_maxdepth; 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) + @@ -2150,12 +2157,6 @@ static int ext4_fill_fiemap_extents(struct inode *inode, /* find extent for this block */ down_read(&EXT4_I(inode)->i_data_sem); - if (path && ext_depth(inode) != depth) { - /* depth was changed. we have to realloc path */ - kfree(path); - path = NULL; - } - path = ext4_ext_find_extent(inode, block, &path, 0); if (IS_ERR(path)) { up_read(&EXT4_I(inode)->i_data_sem); @@ -2173,7 +2174,6 @@ static int ext4_fill_fiemap_extents(struct inode *inode, } ex = path[depth].p_ext; next = ext4_ext_next_allocated_block(path); - ext4_ext_drop_refs(path); flags = 0; exists = 0; @@ -2897,7 +2897,7 @@ again: ext4_journal_stop(handle); return -ENOMEM; } - path[0].p_depth = depth; + path[0].p_maxdepth = path[0].p_depth = depth; path[0].p_hdr = ext_inode_hdr(inode); i = 0; |