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
Родитель ee647f85cb
Коммит f48e2df8a8
3 изменённых файлов: 25 добавлений и 33 удалений

Просмотреть файл

@ -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);

Просмотреть файл

@ -3311,11 +3311,12 @@ xfs_bmap_longest_free_extent(
pag = xfs_perag_get(mp, ag);
if (!pag->pagf_init) {
error = xfs_alloc_pagf_init(mp, tp, ag, XFS_ALLOC_FLAG_TRYLOCK);
if (error)
goto out;
if (!pag->pagf_init) {
*notinit = 1;
if (error) {
/* Couldn't lock the AGF, so skip this AG. */
if (error == -EAGAIN) {
*notinit = 1;
error = 0;
}
goto out;
}
}

Просмотреть файл

@ -159,16 +159,15 @@ xfs_filestream_pick_ag(
if (!pag->pagf_init) {
err = xfs_alloc_pagf_init(mp, NULL, ag, trylock);
if (err && !trylock) {
if (err) {
xfs_perag_put(pag);
return err;
if (err != -EAGAIN)
return err;
/* Couldn't lock the AGF, skip this AG. */
continue;
}
}
/* Might fail sometimes during the 1st pass with trylock set. */
if (!pag->pagf_init)
goto next_ag;
/* Keep track of the AG with the most free blocks. */
if (pag->pagf_freeblks > maxfree) {
maxfree = pag->pagf_freeblks;