From: Chandan Babu R <chandanrlinux@gmail.com>
To: linux-xfs@vger.kernel.org
Cc: Chandan Babu R <chandanrlinux@gmail.com>,
darrick.wong@oracle.com, david@fromorbit.com
Subject: [PATCH V5 08/12] xfs: Check for extent overflow when remapping an extent
Date: Sat, 3 Oct 2020 11:26:29 +0530 [thread overview]
Message-ID: <20201003055633.9379-9-chandanrlinux@gmail.com> (raw)
In-Reply-To: <20201003055633.9379-1-chandanrlinux@gmail.com>
Remapping an extent involves unmapping the existing extent and mapping
in the new extent. When unmapping, an extent containing the entire unmap
range can be split into two extents,
i.e. | Old extent | hole | Old extent |
Hence extent count increases by 1.
Mapping in the new extent into the destination file can increase the
extent count by 1.
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>
---
fs/xfs/libxfs/xfs_inode_fork.h | 15 +++++++++++++++
fs/xfs/xfs_reflink.c | 5 +++++
2 files changed, 20 insertions(+)
diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h
index b99e67e7b59b..ded3c1b56c94 100644
--- a/fs/xfs/libxfs/xfs_inode_fork.h
+++ b/fs/xfs/libxfs/xfs_inode_fork.h
@@ -87,6 +87,21 @@ struct xfs_ifork {
*/
#define XFS_IEXT_REFLINK_END_COW_CNT (2)
+/*
+ * Remapping an extent involves unmapping the existing extent and mapping in the
+ * new extent.
+ *
+ * When unmapping, an extent containing the entire unmap range can be split into
+ * two extents,
+ * i.e. | Old extent | hole | Old extent |
+ * Hence extent count increases by 1.
+ *
+ * Mapping in the new extent into the destination file can increase the extent
+ * count by 1.
+ */
+#define XFS_IEXT_REFLINK_REMAP_CNT(smap_real, dmap_written) \
+ (((smap_real) ? 1 : 0) + ((dmap_written) ? 1 : 0))
+
/*
* Fork handling.
*/
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 4f0198f636ad..c9f9ff68b5bb 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -1099,6 +1099,11 @@ xfs_reflink_remap_extent(
goto out_cancel;
}
+ error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
+ XFS_IEXT_REFLINK_REMAP_CNT(smap_real, dmap_written));
+ if (error)
+ goto out_cancel;
+
if (smap_real) {
/*
* If the extent we're unmapping is backed by storage (written
--
2.28.0
next prev parent reply other threads:[~2020-10-03 5:57 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-03 5:56 [PATCH V5 00/12] Bail out if transaction can cause extent count to overflow Chandan Babu R
2020-10-03 5:56 ` [PATCH V5 01/12] xfs: Add helper for checking per-inode extent count overflow Chandan Babu R
2020-10-03 5:56 ` [PATCH V5 02/12] xfs: Check for extent overflow when trivally adding a new extent Chandan Babu R
2020-10-06 4:18 ` Darrick J. Wong
2020-10-03 5:56 ` [PATCH V5 03/12] xfs: Check for extent overflow when punching a hole Chandan Babu R
2020-10-06 4:18 ` Darrick J. Wong
2020-10-03 5:56 ` [PATCH V5 04/12] xfs: Check for extent overflow when adding/removing xattrs Chandan Babu R
2020-10-06 4:23 ` Darrick J. Wong
2020-10-06 9:21 ` Chandan Babu R
2020-10-03 5:56 ` [PATCH V5 05/12] xfs: Check for extent overflow when adding/removing dir entries Chandan Babu R
2020-10-03 5:56 ` [PATCH V5 06/12] xfs: Check for extent overflow when writing to unwritten extent Chandan Babu R
2020-10-03 5:56 ` [PATCH V5 07/12] xfs: Check for extent overflow when moving extent from cow to data fork Chandan Babu R
2020-10-03 5:56 ` Chandan Babu R [this message]
2020-10-03 5:56 ` [PATCH V5 09/12] xfs: Check for extent overflow when swapping extents Chandan Babu R
2020-10-06 4:23 ` Darrick J. Wong
2020-10-03 5:56 ` [PATCH V5 10/12] xfs: Introduce error injection to reduce maximum inode fork extent count Chandan Babu R
2020-10-06 4:24 ` Darrick J. Wong
2020-10-03 5:56 ` [PATCH V5 11/12] xfs: Set tp->t_firstblock only once during a transaction's lifetime Chandan Babu R
2020-10-06 4:26 ` Darrick J. Wong
2020-10-06 5:17 ` Chandan Babu R
2020-10-03 5:56 ` [PATCH V5 12/12] xfs: Introduce error injection to allocate only minlen size extents for files Chandan Babu R
2020-10-06 4:25 ` Chandan Babu R
2020-10-06 4:27 ` Darrick J. Wong
2020-10-06 4:34 ` Darrick J. Wong
2020-10-06 9:17 ` Chandan Babu R
2020-10-07 5:09 ` Chandan Babu R
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