From: Chandan Babu R <chandanrlinux@gmail.com>
To: linux-xfs@vger.kernel.org
Cc: Chandan Babu R <chandanrlinux@gmail.com>,
djwong@kernel.org, hch@lst.de, allison.henderson@oracle.com,
"Darrick J . Wong" <darrick.wong@oracle.com>
Subject: [PATCH V15 05/16] xfs: Check for extent overflow when removing dir entries
Date: Tue, 26 Jan 2021 12:02:21 +0530 [thread overview]
Message-ID: <20210126063232.3648053-6-chandanrlinux@gmail.com> (raw)
In-Reply-To: <20210126063232.3648053-1-chandanrlinux@gmail.com>
Directory entry removal must always succeed; Hence XFS does the
following during low disk space scenario:
1. Data/Free blocks linger until a future remove operation.
2. Dabtree blocks would be swapped with the last block in the leaf space
and then the new last block will be unmapped.
This facility is reused during low inode extent count scenario i.e. this
commit causes xfs_bmap_del_extent_real() to return -ENOSPC error code so
that the above mentioned behaviour is exercised causing no change to the
directory's extent count.
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>
---
fs/xfs/libxfs/xfs_bmap.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 32aeacf6f055..6c8f17a0e247 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -5151,6 +5151,24 @@ xfs_bmap_del_extent_real(
/*
* Deleting the middle of the extent.
*/
+
+ /*
+ * For directories, -ENOSPC is returned since a directory entry
+ * remove operation must not fail due to low extent count
+ * availability. -ENOSPC will be handled by higher layers of XFS
+ * by letting the corresponding empty Data/Free blocks to linger
+ * 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.
+ */
+ error = xfs_iext_count_may_overflow(ip, whichfork, 1);
+ if (error) {
+ ASSERT(S_ISDIR(VFS_I(ip)->i_mode) &&
+ whichfork == XFS_DATA_FORK);
+ error = -ENOSPC;
+ goto done;
+ }
+
old = got;
got.br_blockcount = del->br_startoff - got.br_startoff;
--
2.29.2
next prev parent reply other threads:[~2021-01-26 18:33 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-26 6:32 [PATCH V15 00/16] Bail out if transaction can cause extent count to overflow Chandan Babu R
2021-01-26 6:32 ` [PATCH V15 01/16] xfs: Add helper for checking per-inode extent count overflow Chandan Babu R
2021-01-26 6:32 ` [PATCH V15 02/16] xfs: Check for extent overflow when trivally adding a new extent Chandan Babu R
2021-01-26 6:32 ` [PATCH V15 03/16] xfs: Check for extent overflow when punching a hole Chandan Babu R
2021-01-26 6:32 ` [PATCH V15 04/16] xfs: Check for extent overflow when adding dir entries Chandan Babu R
2021-01-27 0:39 ` Allison Henderson
2021-01-26 6:32 ` Chandan Babu R [this message]
2021-01-27 0:39 ` [PATCH V15 05/16] xfs: Check for extent overflow when removing " Allison Henderson
2021-01-26 6:32 ` [PATCH V15 06/16] xfs: Check for extent overflow when renaming " Chandan Babu R
2021-01-27 0:39 ` Allison Henderson
2021-01-26 6:32 ` [PATCH V15 07/16] xfs: Check for extent overflow when adding/removing xattrs Chandan Babu R
2021-01-26 6:32 ` [PATCH V15 08/16] xfs: Check for extent overflow when writing to unwritten extent Chandan Babu R
2021-01-26 6:32 ` [PATCH V15 09/16] xfs: Check for extent overflow when moving extent from cow to data fork Chandan Babu R
2021-01-26 6:32 ` [PATCH V15 10/16] xfs: Check for extent overflow when remapping an extent Chandan Babu R
2021-01-26 6:32 ` [PATCH V15 11/16] xfs: Check for extent overflow when swapping extents Chandan Babu R
2021-01-26 6:32 ` [PATCH V15 12/16] xfs: Introduce error injection to reduce maximum inode fork extent count Chandan Babu R
2021-01-26 6:32 ` [PATCH V15 13/16] xfs: Remove duplicate assert statement in xfs_bmap_btalloc() Chandan Babu R
2021-01-26 6:32 ` [PATCH V15 14/16] xfs: Compute bmap extent alignments in a separate function Chandan Babu R
2021-01-27 0:39 ` Allison Henderson
2021-01-26 6:32 ` [PATCH V15 15/16] xfs: Process allocated extent " Chandan Babu R
2021-01-26 6:32 ` [PATCH V15 16/16] xfs: Introduce error injection to allocate only minlen size extents for files Chandan Babu R
2021-01-28 2:35 ` Allison Henderson
2021-01-26 18:00 ` [PATCH V15 00/16] Bail out if transaction can cause extent count to overflow Darrick J. Wong
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