[PATCH 01/11] xfs: refactor messy xfs_inode_free_quota_* functions

Darrick J. Wong
2021-01-23T18:52:58Z

From: Darrick J. Wong <djwong@kernel.org>

The functions to run an eof/cowblocks scan to try to reduce quota usage
are kind of a mess -- the logic repeatedly initializes an eofb structure
and there are logic bugs in the code that result in the cowblocks scan
never actually happening.

Replace all three functions with a single function that fills out an
eofb if we're low on quota and runs both eof and cowblocks scans.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
fs/xfs/xfs_file.c | 15 ++++++---------
fs/xfs/xfs_icache.c | 46 ++++++++++++++++------------------------------
fs/xfs/xfs_icache.h | 4 ++--
3 files changed, 24 insertions(+), 41 deletions(-)

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 5d4a66c72c78..69879237533b 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -713,7 +713,7 @@ xfs_file_buffered_write(
struct inode *inode = mapping->host;
struct xfs_inode *ip = XFS_I(inode);
ssize_t ret;
- int enospc = 0;
+ bool cleared_space = false;
int iolock;

if (iocb->ki_flags & IOCB_NOWAIT)
@@ -745,19 +745,16 @@ xfs_file_buffered_write(
* also behaves as a filter to prevent too many eofblocks scans from
* running at the same time.
*/
- if (ret == -EDQUOT && !enospc) {
+ if (ret == -EDQUOT && !cleared_space) {
xfs_iunlock(ip, iolock);
- enospc = xfs_inode_free_quota_eofblocks(ip);
- if (enospc)
- goto write_retry;
- enospc = xfs_inode_free_quota_cowblocks(ip);
- if (enospc)
+ cleared_space = xfs_inode_free_quota_blocks(ip);
+ if (cleared_space)
goto write_retry;
iolock = 0;
- } else if (ret == -ENOSPC && !enospc) {
+ } else if (ret == -ENOSPC && !cleared_space) {
struct xfs_eofblocks eofb = {0};

- enospc = 1;
+ cleared_space = true;
xfs_flush_inodes(ip->i_mount);

xfs_iunlock(ip, iolock);
diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index deb99300d171..c71eb15e3835 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -1397,33 +1397,31 @@ xfs_icache_free_eofblocks(
}

/*
- * Run eofblocks scans on the quotas applicable to the inode. For inodes with
- * multiple quotas, we don't know exactly which quota caused an allocation
+ * Run cow/eofblocks scans on the quotas applicable to the inode. For inodes
+ * with multiple quotas, we don't know exactly which quota caused an allocation
* failure. We make a best effort by including each quota under low free space
* conditions (less than 1% free space) in the scan.
*/
-static int
-__xfs_inode_free_quota_eofblocks(
- struct xfs_inode *ip,
- int (*execute)(struct xfs_mount *mp,
- struct xfs_eofblocks *eofb))
+bool
+xfs_inode_free_quota_blocks(
+ struct xfs_inode *ip)
{
- int scan = 0;
- struct xfs_eofblocks eofb = {0};
- struct xfs_dquot *dq;
+ struct xfs_eofblocks eofb = {0};
+ struct xfs_dquot *dq;
+ bool do_work = false;

/*
* Run a sync scan to increase effectiveness and use the union filter to
* cover all applicable quotas in a single scan.
*/
- eofb.eof_flags = XFS_EOF_FLAGS_UNION|XFS_EOF_FLAGS_SYNC;
+ eofb.eof_flags = XFS_EOF_FLAGS_UNION | XFS_EOF_FLAGS_SYNC;

if (XFS_IS_UQUOTA_ENFORCED(ip->i_mount)) {
dq = xfs_inode_dquot(ip, XFS_DQTYPE_USER);
if (dq && xfs_dquot_lowsp(dq)) {
eofb.eof_uid = VFS_I(ip)->i_uid;
eofb.eof_flags |= XFS_EOF_FLAGS_UID;
- scan = 1;
+ do_work = true;
}
}

@@ -1432,21 +1430,16 @@ __xfs_inode_free_quota_eofblocks(
if (dq && xfs_dquot_lowsp(dq)) {
eofb.eof_gid = VFS_I(ip)->i_gid;
eofb.eof_flags |= XFS_EOF_FLAGS_GID;
- scan = 1;
+ do_work = true;
}
}

- if (scan)
- execute(ip->i_mount, &eofb);
+ if (!do_work)
+ return false;

- return scan;
-}
-
-int
-xfs_inode_free_quota_eofblocks(
- struct xfs_inode *ip)
-{
- return __xfs_inode_free_quota_eofblocks(ip, xfs_icache_free_eofblocks);
+ xfs_icache_free_eofblocks(ip->i_mount, &eofb);
+ xfs_icache_free_cowblocks(ip->i_mount, &eofb);
+ return true;
}

static inline unsigned long
@@ -1646,13 +1639,6 @@ xfs_icache_free_cowblocks(
XFS_ICI_COWBLOCKS_TAG);
}

-int
-xfs_inode_free_quota_cowblocks(
- struct xfs_inode *ip)
-{
- return __xfs_inode_free_quota_eofblocks(ip, xfs_icache_free_cowblocks);
-}
-
void
xfs_inode_set_cowblocks_tag(
xfs_inode_t *ip)
diff --git a/fs/xfs/xfs_icache.h b/fs/xfs/xfs_icache.h
index 3a4c8b382cd0..3f7ddbca8638 100644
--- a/fs/xfs/xfs_icache.h
+++ b/fs/xfs/xfs_icache.h
@@ -54,17 +54,17 @@ long xfs_reclaim_inodes_nr(struct xfs_mount *mp, int nr_to_scan);

void xfs_inode_set_reclaim_tag(struct xfs_inode *ip);

+bool xfs_inode_free_quota_blocks(struct xfs_inode *ip);
+
void xfs_inode_set_eofblocks_tag(struct xfs_inode *ip);
void xfs_inode_clear_eofblocks_tag(struct xfs_inode *ip);
int xfs_icache_free_eofblocks(struct xfs_mount *, struct xfs_eofblocks *);
-int xfs_inode_free_quota_eofblocks(struct xfs_inode *ip);
void xfs_eofblocks_worker(struct work_struct *);
void xfs_queue_eofblocks(struct xfs_mount *);

void xfs_inode_set_cowblocks_tag(struct xfs_inode *ip);
void xfs_inode_clear_cowblocks_tag(struct xfs_inode *ip);
int xfs_icache_free_cowblocks(struct xfs_mount *, struct xfs_eofblocks *);
-int xfs_inode_free_quota_cowblocks(struct xfs_inode *ip);
void xfs_cowblocks_worker(struct work_struct *);
void xfs_queue_cowblocks(struct xfs_mount *);