xfs: refactor unlinked list search and mapping to a separate function

There's a loop that searches an unlinked bucket list to find the inode
that points to a given inode.  Hoist this into a separate function;
later we'll use our iunlink backref cache to bypass the slow list
operation.  No functional changes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
This commit is contained in:
Darrick J. Wong 2019-02-07 10:37:15 -08:00
parent f2fc16a3d7
commit 23ffa52cc7
1 changed files with 96 additions and 38 deletions

View File

@ -2082,6 +2082,97 @@ xfs_iunlink(
return xfs_iunlink_update_bucket(tp, agno, agibp, bucket_index, agino);
}
/* Return the imap, dinode pointer, and buffer for an inode. */
STATIC int
xfs_iunlink_map_ino(
struct xfs_trans *tp,
xfs_agnumber_t agno,
xfs_agino_t agino,
struct xfs_imap *imap,
struct xfs_dinode **dipp,
struct xfs_buf **bpp)
{
struct xfs_mount *mp = tp->t_mountp;
int error;
imap->im_blkno = 0;
error = xfs_imap(mp, tp, XFS_AGINO_TO_INO(mp, agno, agino), imap, 0);
if (error) {
xfs_warn(mp, "%s: xfs_imap returned error %d.",
__func__, error);
return error;
}
error = xfs_imap_to_bp(mp, tp, imap, dipp, bpp, 0, 0);
if (error) {
xfs_warn(mp, "%s: xfs_imap_to_bp returned error %d.",
__func__, error);
return error;
}
return 0;
}
/*
* Walk the unlinked chain from @head_agino until we find the inode that
* points to @target_agino. Return the inode number, map, dinode pointer,
* and inode cluster buffer of that inode as @agino, @imap, @dipp, and @bpp.
*
* @tp, @pag, @head_agino, and @target_agino are input parameters.
* @agino, @imap, @dipp, and @bpp are all output parameters.
*
* Do not call this function if @target_agino is the head of the list.
*/
STATIC int
xfs_iunlink_map_prev(
struct xfs_trans *tp,
xfs_agnumber_t agno,
xfs_agino_t head_agino,
xfs_agino_t target_agino,
xfs_agino_t *agino,
struct xfs_imap *imap,
struct xfs_dinode **dipp,
struct xfs_buf **bpp)
{
struct xfs_mount *mp = tp->t_mountp;
xfs_agino_t next_agino;
int error;
ASSERT(head_agino != target_agino);
*bpp = NULL;
next_agino = head_agino;
while (next_agino != target_agino) {
xfs_agino_t unlinked_agino;
if (*bpp)
xfs_trans_brelse(tp, *bpp);
*agino = next_agino;
error = xfs_iunlink_map_ino(tp, agno, next_agino, imap, dipp,
bpp);
if (error)
return error;
unlinked_agino = be32_to_cpu((*dipp)->di_next_unlinked);
/*
* Make sure this pointer is valid and isn't an obvious
* infinite loop.
*/
if (!xfs_verify_agino(mp, agno, unlinked_agino) ||
next_agino == unlinked_agino) {
XFS_CORRUPTION_ERROR(__func__,
XFS_ERRLEVEL_LOW, mp,
*dipp, sizeof(**dipp));
error = -EFSCORRUPTED;
return error;
}
next_agino = unlinked_agino;
}
return 0;
}
/*
* Pull the on-disk inode from the AGI unlinked list.
*/
@ -2095,7 +2186,6 @@ xfs_iunlink_remove(
struct xfs_buf *agibp;
struct xfs_buf *last_ibp;
struct xfs_dinode *last_dip = NULL;
xfs_ino_t next_ino;
xfs_agnumber_t agno = XFS_INO_TO_AGNO(mp, ip->i_ino);
xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
xfs_agino_t next_agino;
@ -2138,43 +2228,11 @@ xfs_iunlink_remove(
struct xfs_imap imap;
xfs_agino_t prev_agino;
/*
* We need to search the list for the inode being freed.
*/
last_ibp = NULL;
while (next_agino != agino) {
if (last_ibp)
xfs_trans_brelse(tp, last_ibp);
imap.im_blkno = 0;
next_ino = XFS_AGINO_TO_INO(mp, agno, next_agino);
error = xfs_imap(mp, tp, next_ino, &imap, 0);
if (error) {
xfs_warn(mp,
"%s: xfs_imap returned error %d.",
__func__, error);
return error;
}
error = xfs_imap_to_bp(mp, tp, &imap, &last_dip,
&last_ibp, 0, 0);
if (error) {
xfs_warn(mp,
"%s: xfs_imap_to_bp returned error %d.",
__func__, error);
return error;
}
prev_agino = next_agino;
next_agino = be32_to_cpu(last_dip->di_next_unlinked);
if (!xfs_verify_agino(mp, agno, next_agino)) {
XFS_CORRUPTION_ERROR(__func__,
XFS_ERRLEVEL_LOW, mp,
last_dip, sizeof(*last_dip));
return -EFSCORRUPTED;
}
}
/* We need to search the list for the inode being freed. */
error = xfs_iunlink_map_prev(tp, agno, next_agino, agino,
&prev_agino, &imap, &last_dip, &last_ibp);
if (error)
return error;
/*
* Now last_ibp points to the buffer previous to us on the