[PATCH 05/11] xfs: pass flags and return gc errors from xfs_blockgc_free_quota

["Darrick J. Wong" <djwong@kernel.org>]

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

Change the signature of xfs_blockgc_free_quota in preparation for the
next few patches.  Callers can now pass EOF_FLAGS into the function to
control scan parameters; and the function will now pass back any
corruption errors seen while scanning, though for our retry loops we'll
just try again unconditionally.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
---
 fs/xfs/xfs_file.c   |   10 +++++-----
 fs/xfs/xfs_icache.c |   26 +++++++++++++++++---------
 fs/xfs/xfs_icache.h |    2 +-
 3 files changed, 23 insertions(+), 15 deletions(-)


diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index d69e5abcc1b4..3be0b1d81325 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -743,14 +743,14 @@ xfs_file_buffered_write(
 	 * metadata space. This reduces the chances that the eofblocks scan
 	 * waits on dirty mappings. Since xfs_flush_inodes() is serialized, this
 	 * also behaves as a filter to prevent too many eofblocks scans from
-	 * running at the same time.
+	 * running at the same time.  Use a synchronous scan to increase the
+	 * effectiveness of the scan.
 	 */
 	if (ret == -EDQUOT && !cleared_space) {
 		xfs_iunlock(ip, iolock);
-		cleared_space = xfs_blockgc_free_quota(ip);
-		if (cleared_space)
-			goto write_retry;
-		iolock = 0;
+		xfs_blockgc_free_quota(ip, XFS_EOF_FLAGS_SYNC);
+		cleared_space = true;
+		goto write_retry;
 	} else if (ret == -ENOSPC && !cleared_space) {
 		struct xfs_eofblocks eofb = {0};
 
diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index aba901d5637b..4a074aa12b52 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -1650,20 +1650,26 @@ xfs_start_block_reaping(
  * 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.
+ *
+ * Callers must not hold any inode's ILOCK.  If requesting a synchronous scan
+ * (XFS_EOF_FLAGS_SYNC), the caller also must not hold any inode's IOLOCK or
+ * MMAPLOCK.
  */
-bool
+int
 xfs_blockgc_free_quota(
-	struct xfs_inode	*ip)
+	struct xfs_inode	*ip,
+	unsigned int		eof_flags)
 {
 	struct xfs_eofblocks	eofb = {0};
 	struct xfs_dquot	*dq;
 	bool			do_work = false;
+	int			error;
 
 	/*
-	 * Run a sync scan to increase effectiveness and use the union filter to
-	 * cover all applicable quotas in a single scan.
+	 * Run a scan to free blocks using 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 | eof_flags;
 
 	if (XFS_IS_UQUOTA_ENFORCED(ip->i_mount)) {
 		dq = xfs_inode_dquot(ip, XFS_DQTYPE_USER);
@@ -1693,9 +1699,11 @@ xfs_blockgc_free_quota(
 	}
 
 	if (!do_work)
-		return false;
+		return 0;
 
-	xfs_icache_free_eofblocks(ip->i_mount, &eofb);
-	xfs_icache_free_cowblocks(ip->i_mount, &eofb);
-	return true;
+	error = xfs_icache_free_eofblocks(ip->i_mount, &eofb);
+	if (error)
+		return error;
+
+	return xfs_icache_free_cowblocks(ip->i_mount, &eofb);
 }
diff --git a/fs/xfs/xfs_icache.h b/fs/xfs/xfs_icache.h
index 21b726a05b0d..d64ea8f5c589 100644
--- a/fs/xfs/xfs_icache.h
+++ b/fs/xfs/xfs_icache.h
@@ -54,7 +54,7 @@ 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_blockgc_free_quota(struct xfs_inode *ip);
+int xfs_blockgc_free_quota(struct xfs_inode *ip, unsigned int eof_flags);
 
 void xfs_inode_set_eofblocks_tag(struct xfs_inode *ip);
 void xfs_inode_clear_eofblocks_tag(struct xfs_inode *ip);