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xfs: use ->t_firstblock in xattr ops

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Similar to the dirops code, the xattr code uses an on-stack
firstblock variable for the various operations. This code rolls the
underlying transaction in various places, however, which means we
cannot simply replace the local firstblock vars with ->t_firstblock.
Doing so (without further changes) would invalidate the memory
pointed to by xfs_da_args.firstblock as soon as the first
transaction rolls.

To avoid this problem, remove xfs_da_args.firstblock and replace all
such accesses with ->t_firstblock at the same time. This ensures
that accesses to the current firstblock always occur through the
current transaction rather than a potentially invalid xfs_da_args
pointer.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
This commit is contained in:
Brian Foster
2018-07-11 22:26:22 -07:00
committed by Darrick J. Wong
parent 825d75cd8c
commit 766139032f
7 changed files with 33 additions and 38 deletions
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5
fs/xfs/libxfs/xfs_dir2.c
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@@ -272,7 +272,6 @@ xfs_dir_createname(
args->total = total;
args->whichfork = XFS_DATA_FORK;
args->trans = tp;
args->firstblock = &tp->t_firstblock;
args->op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT;
if (!inum)
args->op_flags |= XFS_DA_OP_JUSTCHECK;
@@ -439,7 +438,6 @@ xfs_dir_removename(
args->hashval = dp->i_mount->m_dirnameops->hashname(name);
args->inumber = ino;
args->dp = dp;
args->firstblock = &tp->t_firstblock;
args->total = total;
args->whichfork = XFS_DATA_FORK;
args->trans = tp;
@@ -502,7 +500,6 @@ xfs_dir_replace(
args->hashval = dp->i_mount->m_dirnameops->hashname(name);
args->inumber = inum;
args->dp = dp;
args->firstblock = &tp->t_firstblock;
args->total = total;
args->whichfork = XFS_DATA_FORK;
args->trans = tp;
@@ -660,7 +657,7 @@ xfs_dir2_shrink_inode(
/* Unmap the fsblock(s). */
error = xfs_bunmapi(tp, dp, da, args->geo->fsbcount, 0, 0,
args->firstblock, &done);
&tp->t_firstblock, &done);
if (error) {
/*
* ENOSPC actually can happen if we're in a removename with no