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xfs: use for_each_perag_wrap in xfs_filestream_pick_ag

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xfs_filestream_pick_ag() is now ready to rework to use
for_each_perag_wrap() for iterating the perags during the AG
selection scan.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
This commit is contained in:
Dave Chinner 2023-02-13 09:14:55 +11:00
parent 3054face13
commit eb70aa2d8e
1 changed files with 41 additions and 60 deletions
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101
fs/xfs/xfs_filestream.c
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@ -83,9 +83,9 @@ xfs_filestream_pick_ag(
struct xfs_perag *max_pag = NULL;
xfs_extlen_t minlen = *longest;
xfs_extlen_t free = 0, minfree, maxfree = 0;
xfs_agnumber_t startag = *agp;
xfs_agnumber_t ag = startag;
int err, trylock, nscan;
xfs_agnumber_t start_agno = *agp;
xfs_agnumber_t agno;
int err, trylock;
ASSERT(S_ISDIR(VFS_I(ip)->i_mode));
@ -97,13 +97,9 @@ xfs_filestream_pick_ag(
/* For the first pass, don't sleep trying to init the per-AG. */
trylock = XFS_ALLOC_FLAG_TRYLOCK;
for (nscan = 0; 1; nscan++) {
trace_xfs_filestream_scan(mp, ip->i_ino, ag);
err = 0;
pag = xfs_perag_grab(mp, ag);
if (!pag)
goto next_ag;
restart:
for_each_perag_wrap(mp, start_agno, agno, pag) {
trace_xfs_filestream_scan(mp, ip->i_ino, agno);
*longest = 0;
err = xfs_bmap_longest_free_extent(pag, NULL, longest);
if (err) {
@ -111,6 +107,7 @@ xfs_filestream_pick_ag(
if (err != -EAGAIN)
break;
/* Couldn't lock the AGF, skip this AG. */
err = 0;
goto next_ag;
}
@ -129,77 +126,61 @@ xfs_filestream_pick_ag(
* loop, and it guards against two filestreams being established
* in the same AG as each other.
*/
if (atomic_inc_return(&pag->pagf_fstrms) > 1) {
atomic_dec(&pag->pagf_fstrms);
xfs_perag_rele(pag);
goto next_ag;
}
if (((minlen && *longest >= minlen) ||
(!minlen && pag->pagf_freeblks >= minfree)) &&
(!xfs_perag_prefers_metadata(pag) ||
!(flags & XFS_PICK_USERDATA) ||
(flags & XFS_PICK_LOWSPACE))) {
/* Break out, retaining the reference on the AG. */
free = pag->pagf_freeblks;
break;
if (atomic_inc_return(&pag->pagf_fstrms) <= 1) {
if (((minlen && *longest >= minlen) ||
(!minlen && pag->pagf_freeblks >= minfree)) &&
(!xfs_perag_prefers_metadata(pag) ||
!(flags & XFS_PICK_USERDATA) ||
(flags & XFS_PICK_LOWSPACE))) {
/* Break out, retaining the reference on the AG. */
free = pag->pagf_freeblks;
break;
}
}
/* Drop the reference on this AG, it's not usable. */
atomic_dec(&pag->pagf_fstrms);
next_ag:
/* Move to the next AG, wrapping to AG 0 if necessary. */
if (++ag >= mp->m_sb.sb_agcount)
ag = 0;
}
/* If a full pass of the AGs hasn't been done yet, continue. */
if (ag != startag)
continue;
if (err) {
xfs_perag_rele(pag);
if (max_pag)
xfs_perag_rele(max_pag);
return err;
}
if (!pag) {
/* Allow sleeping in xfs_alloc_read_agf() on the 2nd pass. */
if (trylock != 0) {
if (trylock) {
trylock = 0;
continue;
goto restart;
}
/* Finally, if lowspace wasn't set, set it for the 3rd pass. */
if (!(flags & XFS_PICK_LOWSPACE)) {
flags |= XFS_PICK_LOWSPACE;
continue;
goto restart;
}
/*
* Take the AG with the most free space, regardless of whether
* it's already in use by another filestream.
* No unassociated AGs are available, so select the AG with the
* most free space, regardless of whether it's already in use by
* another filestream. It none suit, return NULLAGNUMBER.
*/
if (max_pag) {
pag = max_pag;
atomic_inc(&pag->pagf_fstrms);
free = maxfree;
break;
if (!max_pag) {
*agp = NULLAGNUMBER;
trace_xfs_filestream_pick(ip, *agp, free, 0);
return 0;
}
/* take AG 0 if none matched */
trace_xfs_filestream_pick(ip, *agp, free, nscan);
*agp = 0;
return 0;
}
trace_xfs_filestream_pick(ip, pag ? pag->pag_agno : NULLAGNUMBER,
free, nscan);
if (max_pag)
pag = max_pag;
free = maxfree;
atomic_inc(&pag->pagf_fstrms);
} else if (max_pag) {
xfs_perag_rele(max_pag);
if (err)
return err;
if (!pag) {
*agp = NULLAGNUMBER;
return 0;
}
trace_xfs_filestream_pick(ip, pag->pag_agno, free, 0);
err = -ENOMEM;
item = kmem_alloc(sizeof(*item), KM_MAYFAIL);
if (!item)