Merge branch 'xfs-quota-eofblocks-scan' into for-next

fs/xfs/xfs_dquot.h

@@ -139,6 +139,21 @@ static inline xfs_dquot_t *xfs_inode_dquot(struct xfs_inode *ip, int type)
 	}
 }
 
+/*
+ * Check whether a dquot is under low free space conditions. We assume the quota
+ * is enabled and enforced.
+ */
+static inline bool xfs_dquot_lowsp(struct xfs_dquot *dqp)
+{
+	int64_t freesp;
+
+	freesp = be64_to_cpu(dqp->q_core.d_blk_hardlimit) - dqp->q_res_bcount;
+	if (freesp < dqp->q_low_space[XFS_QLOWSP_1_PCNT])
+		return true;
+
+	return false;
+}
+
 #define XFS_DQ_IS_LOCKED(dqp)	(mutex_is_locked(&((dqp)->q_qlock)))
 #define XFS_DQ_IS_DIRTY(dqp)	((dqp)->dq_flags & XFS_DQ_DIRTY)
 #define XFS_QM_ISUDQ(dqp)	((dqp)->dq_flags & XFS_DQ_USER)

fs/xfs/xfs_file.c

@@ -38,6 +38,7 @@
 #include "xfs_trace.h"
 #include "xfs_log.h"
 #include "xfs_dinode.h"
+#include "xfs_icache.h"
 
 #include <linux/aio.h>
 #include <linux/dcache.h>
@@ -689,14 +690,28 @@ xfs_file_buffered_aio_write(
 	ret = generic_perform_write(file, from, pos);
 	if (likely(ret >= 0))
 		iocb->ki_pos = pos + ret;
+
 	/*
-	 * If we just got an ENOSPC, try to write back all dirty inodes to
-	 * convert delalloc space to free up some of the excess reserved
-	 * metadata space.
+	 * If we hit a space limit, try to free up some lingering preallocated
+	 * space before returning an error. In the case of ENOSPC, first try to
+	 * write back all dirty inodes to free up some of the excess reserved
+	 * 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.
 	 */
-	if (ret == -ENOSPC && !enospc) {
+	if (ret == -EDQUOT && !enospc) {
+		enospc = xfs_inode_free_quota_eofblocks(ip);
+		if (enospc)
+			goto write_retry;
+	} else if (ret == -ENOSPC && !enospc) {
+		struct xfs_eofblocks eofb = {0};
+
 		enospc = 1;
 		xfs_flush_inodes(ip->i_mount);
+		eofb.eof_scan_owner = ip->i_ino; /* for locking */
+		eofb.eof_flags = XFS_EOF_FLAGS_SYNC;
+		xfs_icache_free_eofblocks(ip->i_mount, &eofb);
 		goto write_retry;
 	}
 

fs/xfs/xfs_fs.h

@@ -375,6 +375,9 @@ struct xfs_fs_eofblocks {
 #define XFS_EOF_FLAGS_GID		(1 << 2) /* filter by gid */
 #define XFS_EOF_FLAGS_PRID		(1 << 3) /* filter by project id */
 #define XFS_EOF_FLAGS_MINFILESIZE	(1 << 4) /* filter by min file size */
+#define XFS_EOF_FLAGS_UNION		(1 << 5) /* union filter algorithm;
+						  * kernel only, not included in
+						  * valid mask */
 #define XFS_EOF_FLAGS_VALID	\
 	(XFS_EOF_FLAGS_SYNC |	\
 	 XFS_EOF_FLAGS_UID |	\

fs/xfs/xfs_icache.c

@@ -33,6 +33,9 @@
 #include "xfs_trace.h"
 #include "xfs_icache.h"
 #include "xfs_bmap_util.h"
+#include "xfs_quota.h"
+#include "xfs_dquot_item.h"
+#include "xfs_dquot.h"
 
 #include <linux/kthread.h>
 #include <linux/freezer.h>
@@ -1203,6 +1206,30 @@ xfs_inode_match_id(
 	return 1;
 }
 
+/*
+ * A union-based inode filtering algorithm. Process the inode if any of the
+ * criteria match. This is for global/internal scans only.
+ */
+STATIC int
+xfs_inode_match_id_union(
+	struct xfs_inode	*ip,
+	struct xfs_eofblocks	*eofb)
+{
+	if ((eofb->eof_flags & XFS_EOF_FLAGS_UID) &&
+	    uid_eq(VFS_I(ip)->i_uid, eofb->eof_uid))
+		return 1;
+
+	if ((eofb->eof_flags & XFS_EOF_FLAGS_GID) &&
+	    gid_eq(VFS_I(ip)->i_gid, eofb->eof_gid))
+		return 1;
+
+	if ((eofb->eof_flags & XFS_EOF_FLAGS_PRID) &&
+	    xfs_get_projid(ip) == eofb->eof_prid)
+		return 1;
+
+	return 0;
+}
+
 STATIC int
 xfs_inode_free_eofblocks(
 	struct xfs_inode	*ip,
@@ -1211,6 +1238,10 @@ xfs_inode_free_eofblocks(
 {
 	int ret;
 	struct xfs_eofblocks *eofb = args;
+	bool need_iolock = true;
+	int match;
+
+	ASSERT(!eofb || (eofb && eofb->eof_scan_owner != 0));
 
 	if (!xfs_can_free_eofblocks(ip, false)) {
 		/* inode could be preallocated or append-only */
@@ -1228,16 +1259,28 @@ xfs_inode_free_eofblocks(
 		return 0;
 
 	if (eofb) {
-		if (!xfs_inode_match_id(ip, eofb))
+		if (eofb->eof_flags & XFS_EOF_FLAGS_UNION)
+			match = xfs_inode_match_id_union(ip, eofb);
+		else
+			match = xfs_inode_match_id(ip, eofb);
+		if (!match)
 			return 0;
 
 		/* skip the inode if the file size is too small */
 		if (eofb->eof_flags & XFS_EOF_FLAGS_MINFILESIZE &&
 		    XFS_ISIZE(ip) < eofb->eof_min_file_size)
 			return 0;
+
+		/*
+		 * A scan owner implies we already hold the iolock. Skip it in
+		 * xfs_free_eofblocks() to avoid deadlock. This also eliminates
+		 * the possibility of EAGAIN being returned.
+		 */
+		if (eofb->eof_scan_owner == ip->i_ino)
+			need_iolock = false;
 	}
 
-	ret = xfs_free_eofblocks(ip->i_mount, ip, true);
+	ret = xfs_free_eofblocks(ip->i_mount, ip, need_iolock);
 
 	/* don't revisit the inode if we're not waiting */
 	if (ret == -EAGAIN && !(flags & SYNC_WAIT))
@@ -1260,6 +1303,55 @@ xfs_icache_free_eofblocks(
 					 eofb, XFS_ICI_EOFBLOCKS_TAG);
 }
 
+/*
+ * 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
+ * failure. We make a best effort by including each quota under low free space
+ * conditions (less than 1% free space) in the scan.
+ */
+int
+xfs_inode_free_quota_eofblocks(
+	struct xfs_inode *ip)
+{
+	int scan = 0;
+	struct xfs_eofblocks eofb = {0};
+	struct xfs_dquot *dq;
+
+	ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
+
+	/*
+	 * Set the scan owner to avoid a potential livelock. Otherwise, the scan
+	 * can repeatedly trylock on the inode we're currently processing. We
+	 * run a sync scan to increase effectiveness and use the union filter to
+	 * cover all applicable quotas in a single scan.
+	 */
+	eofb.eof_scan_owner = ip->i_ino;
+	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_DQ_USER);
+		if (dq && xfs_dquot_lowsp(dq)) {
+			eofb.eof_uid = VFS_I(ip)->i_uid;
+			eofb.eof_flags |= XFS_EOF_FLAGS_UID;
+			scan = 1;
+		}
+	}
+
+	if (XFS_IS_GQUOTA_ENFORCED(ip->i_mount)) {
+		dq = xfs_inode_dquot(ip, XFS_DQ_GROUP);
+		if (dq && xfs_dquot_lowsp(dq)) {
+			eofb.eof_gid = VFS_I(ip)->i_gid;
+			eofb.eof_flags |= XFS_EOF_FLAGS_GID;
+			scan = 1;
+		}
+	}
+
+	if (scan)
+		xfs_icache_free_eofblocks(ip->i_mount, &eofb);
+
+	return scan;
+}
+
 void
 xfs_inode_set_eofblocks_tag(
 	xfs_inode_t	*ip)

fs/xfs/xfs_icache.h

@@ -27,6 +27,7 @@ struct xfs_eofblocks {
 	kgid_t		eof_gid;
 	prid_t		eof_prid;
 	__u64		eof_min_file_size;
+	xfs_ino_t	eof_scan_owner;
 };
 
 #define SYNC_WAIT		0x0001	/* wait for i/o to complete */
@@ -57,6 +58,7 @@ void xfs_inode_set_reclaim_tag(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 *);
 
 int xfs_inode_ag_iterator(struct xfs_mount *mp,
@@ -84,6 +86,7 @@ xfs_fs_eofblocks_from_user(
 	dst->eof_flags = src->eof_flags;
 	dst->eof_prid = src->eof_prid;
 	dst->eof_min_file_size = src->eof_min_file_size;
+	dst->eof_scan_owner = NULLFSINO;
 
 	dst->eof_uid = INVALID_UID;
 	if (src->eof_flags & XFS_EOF_FLAGS_UID) {

fs/xfs/xfs_iomap.c

@@ -397,7 +397,8 @@ xfs_quota_calc_throttle(
 	struct xfs_inode *ip,
 	int type,
 	xfs_fsblock_t *qblocks,
-	int *qshift)
+	int *qshift,
+	int64_t	*qfreesp)
 {
 	int64_t freesp;
 	int shift = 0;
@@ -406,6 +407,7 @@ xfs_quota_calc_throttle(
 	/* over hi wmark, squash the prealloc completely */
 	if (dq->q_res_bcount >= dq->q_prealloc_hi_wmark) {
 		*qblocks = 0;
+		*qfreesp = 0;
 		return;
 	}
 
@@ -418,6 +420,9 @@ xfs_quota_calc_throttle(
 			shift += 2;
 	}
 
+	if (freesp < *qfreesp)
+		*qfreesp = freesp;
+
 	/* only overwrite the throttle values if we are more aggressive */
 	if ((freesp >> shift) < (*qblocks >> *qshift)) {
 		*qblocks = freesp;
@@ -476,15 +481,18 @@ xfs_iomap_prealloc_size(
 	}
 
 	/*
-	 * Check each quota to cap the prealloc size and provide a shift
-	 * value to throttle with.
+	 * Check each quota to cap the prealloc size, provide a shift value to
+	 * throttle with and adjust amount of available space.
 	 */
 	if (xfs_quota_need_throttle(ip, XFS_DQ_USER, alloc_blocks))
-		xfs_quota_calc_throttle(ip, XFS_DQ_USER, &qblocks, &qshift);
+		xfs_quota_calc_throttle(ip, XFS_DQ_USER, &qblocks, &qshift,
+					&freesp);
 	if (xfs_quota_need_throttle(ip, XFS_DQ_GROUP, alloc_blocks))
-		xfs_quota_calc_throttle(ip, XFS_DQ_GROUP, &qblocks, &qshift);
+		xfs_quota_calc_throttle(ip, XFS_DQ_GROUP, &qblocks, &qshift,
+					&freesp);
 	if (xfs_quota_need_throttle(ip, XFS_DQ_PROJ, alloc_blocks))
-		xfs_quota_calc_throttle(ip, XFS_DQ_PROJ, &qblocks, &qshift);
+		xfs_quota_calc_throttle(ip, XFS_DQ_PROJ, &qblocks, &qshift,
+					&freesp);
 
 	/*
 	 * The final prealloc size is set to the minimum of free space available