diff options
| author | Chandan Babu R <chandanrlinux@gmail.com> | 2021-01-22 16:48:13 -0800 |
|---|---|---|
| committer | Darrick J. Wong <djwong@kernel.org> | 2021-01-22 16:54:47 -0800 |
| commit | 02092a2f034fdeabab524ae39c2de86ba9ffa15a (patch) | |
| tree | effa9f9f29c418bdbe8e33b957b32b83b5434626 /fs/xfs/libxfs/xfs_bmap.c | |
| parent | 0dbc5cb1a91cc8c44b1c75429f5b9351837114fd (diff) | |
xfs: Check for extent overflow when renaming dir entries
A rename operation is essentially a directory entry remove operation
from the perspective of parent directory (i.e. src_dp) of rename's
source. Hence the only place where we check for extent count overflow
for src_dp is in xfs_bmap_del_extent_real(). xfs_bmap_del_extent_real()
returns -ENOSPC when it detects a possible extent count overflow and in
response, the higher layers of directory handling code do the following:
1. Data/Free blocks: XFS lets these blocks linger until a future remove
operation removes them.
2. Dabtree blocks: XFS swaps the blocks with the last block in the Leaf
space and unmaps the last block.
For target_dp, there are two cases depending on whether the destination
directory entry exists or not.
When destination directory entry does not exist (i.e. target_ip ==
NULL), extent count overflow check is performed only when transaction
has a non-zero sized space reservation associated with it. With a
zero-sized space reservation, XFS allows a rename operation to continue
only when the directory has sufficient free space in its data/leaf/free
space blocks to hold the new entry.
When destination directory entry exists (i.e. target_ip != NULL), all
we need to do is change the inode number associated with the already
existing entry. Hence there is no need to perform an extent count
overflow check.
Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Diffstat (limited to 'fs/xfs/libxfs/xfs_bmap.c')
| -rw-r--r-- | fs/xfs/libxfs/xfs_bmap.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c index 6c8f17a0e247..8ebe5f13279c 100644 --- a/fs/xfs/libxfs/xfs_bmap.c +++ b/fs/xfs/libxfs/xfs_bmap.c @@ -5160,6 +5160,9 @@ xfs_bmap_del_extent_real( * until a future remove operation. Dabtree blocks would be * swapped with the last block in the leaf space and then the * new last block will be unmapped. + * + * The above logic also applies to the source directory entry of + * a rename operation. */ error = xfs_iext_count_may_overflow(ip, whichfork, 1); if (error) { |