xfs: make xfs_*read_agf return EAGAIN to ALLOC_FLAG_TRYLOCK callers

Refactor xfs_read_agf and xfs_alloc_read_agf to return EAGAIN if the
caller passed TRYLOCK and we weren't able to get the lock; and change
the callers to recognize this.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
This commit is contained in:
Darrick J. Wong
2020-01-23 17:01:19 -08:00
parent ee647f85cb
commit f48e2df8a8
3 changed files with 25 additions and 33 deletions

View File

@@ -2502,12 +2502,11 @@ xfs_alloc_fix_freelist(
if (!pag->pagf_init) {
error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp);
if (error)
if (error) {
/* Couldn't lock the AGF so skip this AG. */
if (error == -EAGAIN)
error = 0;
goto out_no_agbp;
if (!pag->pagf_init) {
ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);
ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
goto out_agbp_relse;
}
}
@@ -2533,11 +2532,10 @@ xfs_alloc_fix_freelist(
*/
if (!agbp) {
error = xfs_alloc_read_agf(mp, tp, args->agno, flags, &agbp);
if (error)
goto out_no_agbp;
if (!agbp) {
ASSERT(flags & XFS_ALLOC_FLAG_TRYLOCK);
ASSERT(!(flags & XFS_ALLOC_FLAG_FREEING));
if (error) {
/* Couldn't lock the AGF so skip this AG. */
if (error == -EAGAIN)
error = 0;
goto out_no_agbp;
}
}
@@ -2768,11 +2766,10 @@ xfs_alloc_pagf_init(
xfs_buf_t *bp;
int error;
if ((error = xfs_alloc_read_agf(mp, tp, agno, flags, &bp)))
return error;
if (bp)
error = xfs_alloc_read_agf(mp, tp, agno, flags, &bp);
if (!error)
xfs_trans_brelse(tp, bp);
return 0;
return error;
}
/*
@@ -2961,12 +2958,6 @@ xfs_read_agf(
error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
XFS_FSS_TO_BB(mp, 1), flags, bpp, &xfs_agf_buf_ops);
/*
* Callers of xfs_read_agf() currently interpret a NULL bpp as EAGAIN
* and need to be converted to check for EAGAIN specifically.
*/
if (error == -EAGAIN)
return 0;
if (error)
return error;
@@ -2992,14 +2983,15 @@ xfs_alloc_read_agf(
trace_xfs_alloc_read_agf(mp, agno);
/* We don't support trylock when freeing. */
ASSERT((flags & (XFS_ALLOC_FLAG_FREEING | XFS_ALLOC_FLAG_TRYLOCK)) !=
(XFS_ALLOC_FLAG_FREEING | XFS_ALLOC_FLAG_TRYLOCK));
ASSERT(agno != NULLAGNUMBER);
error = xfs_read_agf(mp, tp, agno,
(flags & XFS_ALLOC_FLAG_TRYLOCK) ? XBF_TRYLOCK : 0,
bpp);
if (error)
return error;
if (!*bpp)
return 0;
ASSERT(!(*bpp)->b_error);
agf = XFS_BUF_TO_AGF(*bpp);