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xfs: Check for extent overflow when punching a hole

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The extent mapping the file offset at which a hole has to be
inserted will be split into two extents causing extent count to
increase by 1.

Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
This commit is contained in:
Chandan Babu R
2021-01-22 16:48:11 -08:00
committed by Darrick J. Wong
parent 727e1acd29
commit 85ef08b5a6
3 changed files with 26 additions and 6 deletions
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7
fs/xfs/libxfs/xfs_inode_fork.h
View File

@@ -40,6 +40,13 @@ struct xfs_ifork {
*/ */
#define XFS_IEXT_ADD_NOSPLIT_CNT (1) #define XFS_IEXT_ADD_NOSPLIT_CNT (1)
/*
* Punching out an extent from the middle of an existing extent can cause the
* extent count to increase by 1.
* i.e. | Old extent | Hole | Old extent |
*/
#define XFS_IEXT_PUNCH_HOLE_CNT (1)
/* /*
* Fork handling. * Fork handling.
*/ */

11
fs/xfs/xfs_bmap_item.c
View File

@@ -471,6 +471,7 @@ xfs_bui_item_recover(
xfs_exntst_t state; xfs_exntst_t state;
unsigned int bui_type; unsigned int bui_type;
int whichfork; int whichfork;
int iext_delta;
int error = 0; int error = 0;
if (!xfs_bui_validate(mp, buip)) { if (!xfs_bui_validate(mp, buip)) {
@@ -508,12 +509,14 @@ xfs_bui_item_recover(
xfs_ilock(ip, XFS_ILOCK_EXCL); xfs_ilock(ip, XFS_ILOCK_EXCL);
xfs_trans_ijoin(tp, ip, 0); xfs_trans_ijoin(tp, ip, 0);
if (bui_type == XFS_BMAP_MAP) { if (bui_type == XFS_BMAP_MAP)
error = xfs_iext_count_may_overflow(ip, whichfork, iext_delta = XFS_IEXT_ADD_NOSPLIT_CNT;
XFS_IEXT_ADD_NOSPLIT_CNT); else
iext_delta = XFS_IEXT_PUNCH_HOLE_CNT;
error = xfs_iext_count_may_overflow(ip, whichfork, iext_delta);
if (error) if (error)
goto err_cancel; goto err_cancel;
}
count = bmap->me_len; count = bmap->me_len;
error = xfs_trans_log_finish_bmap_update(tp, budp, bui_type, ip, error = xfs_trans_log_finish_bmap_update(tp, budp, bui_type, ip,

10
fs/xfs/xfs_bmap_util.c
View File

@@ -891,6 +891,11 @@ xfs_unmap_extent(
xfs_trans_ijoin(tp, ip, 0); xfs_trans_ijoin(tp, ip, 0);
error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
XFS_IEXT_PUNCH_HOLE_CNT);
if (error)
goto out_trans_cancel;
error = xfs_bunmapi(tp, ip, startoffset_fsb, len_fsb, 0, 2, done); error = xfs_bunmapi(tp, ip, startoffset_fsb, len_fsb, 0, 2, done);
if (error) if (error)
goto out_trans_cancel; goto out_trans_cancel;
@@ -1168,6 +1173,11 @@ xfs_insert_file_space(
xfs_ilock(ip, XFS_ILOCK_EXCL); xfs_ilock(ip, XFS_ILOCK_EXCL);
xfs_trans_ijoin(tp, ip, 0); xfs_trans_ijoin(tp, ip, 0);
error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
XFS_IEXT_PUNCH_HOLE_CNT);
if (error)
goto out_trans_cancel;
/* /*
* The extent shifting code works on extent granularity. So, if stop_fsb * The extent shifting code works on extent granularity. So, if stop_fsb
* is not the starting block of extent, we need to split the extent at * is not the starting block of extent, we need to split the extent at