[PATCH] xfs: Check for deallayed allocations before setting extsize

From: Ojaswin Mujoo
Date: Thu Oct 03 2024 - 06:12:35 EST


Extsize is allowed to be set on files with no data in it. For this,
we were checking if the files have extents but missed to check if
delayed extents were present. This patch adds that check.

**Without the patch (SUCCEEDS)**

$ xfs_io -c 'open -f testfile' -c 'pwrite 0 1024' -c 'extsize 65536'

wrote 1024/1024 bytes at offset 0
1 KiB, 1 ops; 0.0002 sec (4.628 MiB/sec and 4739.3365 ops/sec)

**With the patch (FAILS as expected)**

$ xfs_io -c 'open -f testfile' -c 'pwrite 0 1024' -c 'extsize 65536'

wrote 1024/1024 bytes at offset 0
1 KiB, 1 ops; 0.0002 sec (4.628 MiB/sec and 4739.3365 ops/sec)
xfs_io: FS_IOC_FSSETXATTR testfile: Invalid argument

Signed-off-by: Ojaswin Mujoo <ojaswin@xxxxxxxxxxxxx>
---
fs/xfs/xfs_ioctl.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 7226d27e8afc..55b574b43617 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -602,7 +602,8 @@ xfs_ioctl_setattr_check_extsize(
if (!fa->fsx_valid)
return 0;

- if (S_ISREG(VFS_I(ip)->i_mode) && ip->i_df.if_nextents &&
+ if (S_ISREG(VFS_I(ip)->i_mode) &&
+ (ip->i_df.if_nextents || ip->i_delayed_blks) &&
XFS_FSB_TO_B(mp, ip->i_extsize) != fa->fsx_extsize)
return -EINVAL;

--
2.43.5