From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
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@xxxxxxxxxx>
---
fs/xfs/libxfs/xfs_alloc.c | 36 ++++++++++++++----------------------
fs/xfs/libxfs/xfs_bmap.c | 11 ++++++-----
fs/xfs/xfs_filestream.c | 11 +++++------
3 files changed, 25 insertions(+), 33 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index 34b65635ee34..d8053bc96c4d 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -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);
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index cfcef076c72f..9a6d7a84689a 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -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;
}
}
diff --git a/fs/xfs/xfs_filestream.c b/fs/xfs/xfs_filestream.c
index 5f12b5d8527a..1a88025e68a3 100644
--- a/fs/xfs/xfs_filestream.c
+++ b/fs/xfs/xfs_filestream.c
@@ -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;
