xfs: don't take the MMAPLOCK when scrubbing file metadata

The MMAPLOCK stabilizes mappings in a file's pagecache.  Therefore, we
do not need it to check directories, symlinks, extended attributes, or
file-based metadata.  Reduce its usage to the one case that requires it,
which is when we want to scrub the data fork of a regular file.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
This commit is contained in:
Darrick J. Wong 2023-04-11 19:00:22 -07:00
parent 38bb131084
commit 1fc7a0597d
3 changed files with 14 additions and 6 deletions

View file

@ -38,8 +38,8 @@ xchk_setup_inode_bmap(
if (error)
goto out;
sc->ilock_flags = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
xfs_ilock(sc->ip, sc->ilock_flags);
sc->ilock_flags = XFS_IOLOCK_EXCL;
xfs_ilock(sc->ip, XFS_IOLOCK_EXCL);
/*
* We don't want any ephemeral data fork updates sitting around
@ -50,6 +50,9 @@ xchk_setup_inode_bmap(
sc->sm->sm_type == XFS_SCRUB_TYPE_BMBTD) {
struct address_space *mapping = VFS_I(sc->ip)->i_mapping;
sc->ilock_flags |= XFS_MMAPLOCK_EXCL;
xfs_ilock(sc->ip, XFS_MMAPLOCK_EXCL);
inode_dio_wait(VFS_I(sc->ip));
/*

View file

@ -988,7 +988,11 @@ xchk_irele(
xfs_irele(ip);
}
/* Set us up to scrub a file's contents. */
/*
* Set us up to scrub metadata mapped by a file's fork. Callers must not use
* this to operate on user-accessible regular file data because the MMAPLOCK is
* not taken.
*/
int
xchk_setup_inode_contents(
struct xfs_scrub *sc,
@ -1000,9 +1004,10 @@ xchk_setup_inode_contents(
if (error)
return error;
/* Got the inode, lock it and we're ready to go. */
sc->ilock_flags = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
/* Lock the inode so the VFS cannot touch this file. */
sc->ilock_flags = XFS_IOLOCK_EXCL;
xfs_ilock(sc->ip, sc->ilock_flags);
error = xchk_trans_alloc(sc, resblks);
if (error)
goto out;

View file

@ -32,7 +32,7 @@ xchk_prepare_iscrub(
{
int error;
sc->ilock_flags = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
sc->ilock_flags = XFS_IOLOCK_EXCL;
xfs_ilock(sc->ip, sc->ilock_flags);
error = xchk_trans_alloc(sc, 0);