Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs

* 'for-linus' of git://oss.sgi.com/xfs/xfs:
  xfs: correctly decrement the extent buffer index in xfs_bmap_del_extent
  xfs: check for valid indices in xfs_iext_get_ext and xfs_iext_idx_to_irec
  xfs: fix up asserts in xfs_iflush_fork
  xfs: do not do pointer arithmetic on extent records
  xfs: do not use unchecked extent indices in xfs_bunmapi
  xfs: do not use unchecked extent indices in xfs_bmapi
  xfs: do not use unchecked extent indices in xfs_bmap_add_extent_*
  xfs: remove if_lastex
  xfs: remove the unused XFS_BMAPI_RSVBLOCKS flag
  xfs: do not discard alloc btree blocks
  xfs: add online discard support

Documentation/filesystems/xfs.txt

@@ -39,6 +39,12 @@ When mounting an XFS filesystem, the following options are accepted.
 	drive level write caching to be enabled, for devices that
 	support write barriers.
 
+  discard
+	Issue command to let the block device reclaim space freed by the
+	filesystem.  This is useful for SSD devices, thinly provisioned
+	LUNs and virtual machine images, but may have a performance
+	impact.  This option is incompatible with the nodelaylog option.
+
   dmapi
 	Enable the DMAPI (Data Management API) event callouts.
 	Use with the "mtpt" option.

fs/xfs/linux-2.6/xfs_discard.c

@@ -191,3 +191,32 @@ xfs_ioc_trim(
 		return -XFS_ERROR(EFAULT);
 	return 0;
 }
+
+int
+xfs_discard_extents(
+	struct xfs_mount	*mp,
+	struct list_head	*list)
+{
+	struct xfs_busy_extent	*busyp;
+	int			error = 0;
+
+	list_for_each_entry(busyp, list, list) {
+		trace_xfs_discard_extent(mp, busyp->agno, busyp->bno,
+					 busyp->length);
+
+		error = -blkdev_issue_discard(mp->m_ddev_targp->bt_bdev,
+				XFS_AGB_TO_DADDR(mp, busyp->agno, busyp->bno),
+				XFS_FSB_TO_BB(mp, busyp->length),
+				GFP_NOFS, 0);
+		if (error && error != EOPNOTSUPP) {
+			xfs_info(mp,
+	 "discard failed for extent [0x%llu,%u], error %d",
+				 (unsigned long long)busyp->bno,
+				 busyp->length,
+				 error);
+			return error;
+		}
+	}
+
+	return 0;
+}

fs/xfs/linux-2.6/xfs_discard.h

@@ -2,7 +2,9 @@
 #define XFS_DISCARD_H 1
 
 struct fstrim_range;
+struct list_head;
 
 extern int	xfs_ioc_trim(struct xfs_mount *, struct fstrim_range __user *);
+extern int	xfs_discard_extents(struct xfs_mount *, struct list_head *);
 
 #endif /* XFS_DISCARD_H */

fs/xfs/linux-2.6/xfs_super.c

@@ -110,8 +110,10 @@ mempool_t *xfs_ioend_pool;
 #define MNTOPT_GQUOTANOENF "gqnoenforce"/* group quota limit enforcement */
 #define MNTOPT_PQUOTANOENF "pqnoenforce"/* project quota limit enforcement */
 #define MNTOPT_QUOTANOENF  "qnoenforce"	/* same as uqnoenforce */
-#define MNTOPT_DELAYLOG   "delaylog"	/* Delayed loging enabled */
-#define MNTOPT_NODELAYLOG "nodelaylog"	/* Delayed loging disabled */
+#define MNTOPT_DELAYLOG    "delaylog"	/* Delayed logging enabled */
+#define MNTOPT_NODELAYLOG  "nodelaylog"	/* Delayed logging disabled */
+#define MNTOPT_DISCARD	   "discard"	/* Discard unused blocks */
+#define MNTOPT_NODISCARD   "nodiscard"	/* Do not discard unused blocks */
 
 /*
  * Table driven mount option parser.
@@ -355,6 +357,10 @@ xfs_parseargs(
 			mp->m_flags |= XFS_MOUNT_DELAYLOG;
 		} else if (!strcmp(this_char, MNTOPT_NODELAYLOG)) {
 			mp->m_flags &= ~XFS_MOUNT_DELAYLOG;
+		} else if (!strcmp(this_char, MNTOPT_DISCARD)) {
+			mp->m_flags |= XFS_MOUNT_DISCARD;
+		} else if (!strcmp(this_char, MNTOPT_NODISCARD)) {
+			mp->m_flags &= ~XFS_MOUNT_DISCARD;
 		} else if (!strcmp(this_char, "ihashsize")) {
 			xfs_warn(mp,
 	"ihashsize no longer used, option is deprecated.");
@@ -388,6 +394,13 @@ xfs_parseargs(
 		return EINVAL;
 	}
 
+	if ((mp->m_flags & XFS_MOUNT_DISCARD) &&
+	    !(mp->m_flags & XFS_MOUNT_DELAYLOG)) {
+		xfs_warn(mp,
+	"the discard option is incompatible with the nodelaylog option");
+		return EINVAL;
+	}
+
 #ifndef CONFIG_XFS_QUOTA
 	if (XFS_IS_QUOTA_RUNNING(mp)) {
 		xfs_warn(mp, "quota support not available in this kernel.");
@@ -488,6 +501,7 @@ xfs_showargs(
 		{ XFS_MOUNT_FILESTREAMS,	"," MNTOPT_FILESTREAM },
 		{ XFS_MOUNT_GRPID,		"," MNTOPT_GRPID },
 		{ XFS_MOUNT_DELAYLOG,		"," MNTOPT_DELAYLOG },
+		{ XFS_MOUNT_DISCARD,		"," MNTOPT_DISCARD },
 		{ 0, NULL }
 	};
 	static struct proc_xfs_info xfs_info_unset[] = {

fs/xfs/xfs_ag.h

@@ -187,6 +187,9 @@ struct xfs_busy_extent {
 	xfs_agnumber_t	agno;
 	xfs_agblock_t	bno;
 	xfs_extlen_t	length;
+	unsigned int	flags;
+#define XFS_ALLOC_BUSY_DISCARDED	0x01	/* undergoing a discard op. */
+#define XFS_ALLOC_BUSY_SKIP_DISCARD	0x02	/* do not discard */
 };
 
 /*

fs/xfs/xfs_alloc.c

@@ -2469,7 +2469,7 @@ xfs_free_extent(
 
 	error = xfs_free_ag_extent(tp, args.agbp, args.agno, args.agbno, len, 0);
 	if (!error)
-		xfs_alloc_busy_insert(tp, args.agno, args.agbno, len);
+		xfs_alloc_busy_insert(tp, args.agno, args.agbno, len, 0);
 error0:
 	xfs_perag_put(args.pag);
 	return error;
@@ -2480,7 +2480,8 @@ xfs_alloc_busy_insert(
 	struct xfs_trans	*tp,
 	xfs_agnumber_t		agno,
 	xfs_agblock_t		bno,
-	xfs_extlen_t		len)
+	xfs_extlen_t		len,
+	unsigned int		flags)
 {
 	struct xfs_busy_extent	*new;
 	struct xfs_busy_extent	*busyp;
@@ -2504,6 +2505,7 @@ xfs_alloc_busy_insert(
 	new->bno = bno;
 	new->length = len;
 	INIT_LIST_HEAD(&new->list);
+	new->flags = flags;
 
 	/* trace before insert to be able to see failed inserts */
 	trace_xfs_alloc_busy(tp->t_mountp, agno, bno, len);
@@ -2608,6 +2610,18 @@ xfs_alloc_busy_update_extent(
 	xfs_agblock_t		bbno = busyp->bno;
 	xfs_agblock_t		bend = bbno + busyp->length;
 
+	/*
+	 * This extent is currently being discarded.  Give the thread
+	 * performing the discard a chance to mark the extent unbusy
+	 * and retry.
+	 */
+	if (busyp->flags & XFS_ALLOC_BUSY_DISCARDED) {
+		spin_unlock(&pag->pagb_lock);
+		delay(1);
+		spin_lock(&pag->pagb_lock);
+		return false;
+	}
+
 	/*
 	 * If there is a busy extent overlapping a user allocation, we have
 	 * no choice but to force the log and retry the search.
@@ -2813,7 +2827,8 @@ restart:
 		 * If this is a metadata allocation, try to reuse the busy
 		 * extent instead of trimming the allocation.
 		 */
-		if (!args->userdata) {
+		if (!args->userdata &&
+		    !(busyp->flags & XFS_ALLOC_BUSY_DISCARDED)) {
 			if (!xfs_alloc_busy_update_extent(args->mp, args->pag,
 							  busyp, fbno, flen,
 							  false))
@@ -2979,10 +2994,16 @@ xfs_alloc_busy_clear_one(
 	kmem_free(busyp);
 }
 
+/*
+ * Remove all extents on the passed in list from the busy extents tree.
+ * If do_discard is set skip extents that need to be discarded, and mark
+ * these as undergoing a discard operation instead.
+ */
 void
 xfs_alloc_busy_clear(
 	struct xfs_mount	*mp,
-	struct list_head	*list)
+	struct list_head	*list,
+	bool			do_discard)
 {
 	struct xfs_busy_extent	*busyp, *n;
 	struct xfs_perag	*pag = NULL;
@@ -2999,7 +3020,11 @@ xfs_alloc_busy_clear(
 			agno = busyp->agno;
 		}
 
-		xfs_alloc_busy_clear_one(mp, pag, busyp);
+		if (do_discard && busyp->length &&
+		    !(busyp->flags & XFS_ALLOC_BUSY_SKIP_DISCARD))
+			busyp->flags = XFS_ALLOC_BUSY_DISCARDED;
+		else
+			xfs_alloc_busy_clear_one(mp, pag, busyp);
 	}
 
 	if (pag) {

fs/xfs/xfs_alloc.h

@@ -137,10 +137,11 @@ xfs_alloc_longest_free_extent(struct xfs_mount *mp,
 #ifdef __KERNEL__
 void
 xfs_alloc_busy_insert(struct xfs_trans *tp, xfs_agnumber_t agno,
-	xfs_agblock_t bno, xfs_extlen_t len);
+	xfs_agblock_t bno, xfs_extlen_t len, unsigned int flags);
 
 void
-xfs_alloc_busy_clear(struct xfs_mount *mp, struct list_head *list);
+xfs_alloc_busy_clear(struct xfs_mount *mp, struct list_head *list,
+	bool do_discard);
 
 int
 xfs_alloc_busy_search(struct xfs_mount *mp, xfs_agnumber_t agno,

fs/xfs/xfs_alloc_btree.c

@@ -120,7 +120,8 @@ xfs_allocbt_free_block(
 	if (error)
 		return error;
 
-	xfs_alloc_busy_insert(cur->bc_tp, be32_to_cpu(agf->agf_seqno), bno, 1);
+	xfs_alloc_busy_insert(cur->bc_tp, be32_to_cpu(agf->agf_seqno), bno, 1,
+			      XFS_ALLOC_BUSY_SKIP_DISCARD);
 	xfs_trans_agbtree_delta(cur->bc_tp, -1);
 	return 0;
 }

fs/xfs/xfs_bmap.h

@@ -69,7 +69,6 @@ typedef	struct xfs_bmap_free
 #define XFS_BMAPI_ENTIRE	0x004	/* return entire extent, not trimmed */
 #define XFS_BMAPI_METADATA	0x008	/* mapping metadata not user data */
 #define XFS_BMAPI_ATTRFORK	0x010	/* use attribute fork not data */
-#define XFS_BMAPI_RSVBLOCKS	0x020	/* OK to alloc. reserved data blocks */
 #define	XFS_BMAPI_PREALLOC	0x040	/* preallocation op: unwritten space */
 #define	XFS_BMAPI_IGSTATE	0x080	/* Ignore state - */
 					/* combine contig. space */
@@ -87,7 +86,6 @@ typedef	struct xfs_bmap_free
 	{ XFS_BMAPI_ENTIRE,	"ENTIRE" }, \
 	{ XFS_BMAPI_METADATA,	"METADATA" }, \
 	{ XFS_BMAPI_ATTRFORK,	"ATTRFORK" }, \
-	{ XFS_BMAPI_RSVBLOCKS,	"RSVBLOCKS" }, \
 	{ XFS_BMAPI_PREALLOC,	"PREALLOC" }, \
 	{ XFS_BMAPI_IGSTATE,	"IGSTATE" }, \
 	{ XFS_BMAPI_CONTIG,	"CONTIG" }, \

fs/xfs/xfs_inode.c

@@ -920,7 +920,6 @@ xfs_iread_extents(
 	/*
 	 * We know that the size is valid (it's checked in iformat_btree)
 	 */
-	ifp->if_lastex = NULLEXTNUM;
 	ifp->if_bytes = ifp->if_real_bytes = 0;
 	ifp->if_flags |= XFS_IFEXTENTS;
 	xfs_iext_add(ifp, 0, nextents);
@@ -2558,12 +2557,9 @@ xfs_iflush_fork(
 	case XFS_DINODE_FMT_EXTENTS:
 		ASSERT((ifp->if_flags & XFS_IFEXTENTS) ||
 		       !(iip->ili_format.ilf_fields & extflag[whichfork]));
-		ASSERT((xfs_iext_get_ext(ifp, 0) != NULL) ||
-			(ifp->if_bytes == 0));
-		ASSERT((xfs_iext_get_ext(ifp, 0) == NULL) ||
-			(ifp->if_bytes > 0));
 		if ((iip->ili_format.ilf_fields & extflag[whichfork]) &&
 		    (ifp->if_bytes > 0)) {
+			ASSERT(xfs_iext_get_ext(ifp, 0));
 			ASSERT(XFS_IFORK_NEXTENTS(ip, whichfork) > 0);
 			(void)xfs_iextents_copy(ip, (xfs_bmbt_rec_t *)cp,
 				whichfork);
@@ -3112,6 +3108,8 @@ xfs_iext_get_ext(
 	xfs_extnum_t	idx)		/* index of target extent */
 {
 	ASSERT(idx >= 0);
+	ASSERT(idx < ifp->if_bytes / sizeof(xfs_bmbt_rec_t));
+
 	if ((ifp->if_flags & XFS_IFEXTIREC) && (idx == 0)) {
 		return ifp->if_u1.if_ext_irec->er_extbuf;
 	} else if (ifp->if_flags & XFS_IFEXTIREC) {
@@ -3191,7 +3189,6 @@ xfs_iext_add(
 		}
 		ifp->if_u1.if_extents = ifp->if_u2.if_inline_ext;
 		ifp->if_real_bytes = 0;
-		ifp->if_lastex = nextents + ext_diff;
 	}
 	/*
 	 * Otherwise use a linear (direct) extent list.
@@ -3886,8 +3883,10 @@ xfs_iext_idx_to_irec(
 	xfs_extnum_t	page_idx = *idxp; /* extent index in target list */
 
 	ASSERT(ifp->if_flags & XFS_IFEXTIREC);
-	ASSERT(page_idx >= 0 && page_idx <=
-		ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t));
+	ASSERT(page_idx >= 0);
+	ASSERT(page_idx <= ifp->if_bytes / sizeof(xfs_bmbt_rec_t));
+	ASSERT(page_idx < ifp->if_bytes / sizeof(xfs_bmbt_rec_t) || realloc);
+
 	nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
 	erp_idx = 0;
 	low = 0;

fs/xfs/xfs_inode.h

@@ -67,7 +67,6 @@ typedef struct xfs_ifork {
 	short			if_broot_bytes;	/* bytes allocated for root */
 	unsigned char		if_flags;	/* per-fork flags */
 	unsigned char		if_ext_max;	/* max # of extent records */
-	xfs_extnum_t		if_lastex;	/* last if_extents used */
 	union {
 		xfs_bmbt_rec_host_t *if_extents;/* linear map file exts */
 		xfs_ext_irec_t	*if_ext_irec;	/* irec map file exts */

fs/xfs/xfs_log_cil.c

@@ -29,6 +29,7 @@
 #include "xfs_mount.h"
 #include "xfs_error.h"
 #include "xfs_alloc.h"
+#include "xfs_discard.h"
 
 /*
  * Perform initial CIL structure initialisation. If the CIL is not
@@ -361,18 +362,28 @@ xlog_cil_committed(
 	int	abort)
 {
 	struct xfs_cil_ctx	*ctx = args;
+	struct xfs_mount	*mp = ctx->cil->xc_log->l_mp;
 
 	xfs_trans_committed_bulk(ctx->cil->xc_log->l_ailp, ctx->lv_chain,
 					ctx->start_lsn, abort);
 
 	xfs_alloc_busy_sort(&ctx->busy_extents);
-	xfs_alloc_busy_clear(ctx->cil->xc_log->l_mp, &ctx->busy_extents);
+	xfs_alloc_busy_clear(mp, &ctx->busy_extents,
+			     (mp->m_flags & XFS_MOUNT_DISCARD) && !abort);
 
 	spin_lock(&ctx->cil->xc_cil_lock);
 	list_del(&ctx->committing);
 	spin_unlock(&ctx->cil->xc_cil_lock);
 
 	xlog_cil_free_logvec(ctx->lv_chain);
+
+	if (!list_empty(&ctx->busy_extents)) {
+		ASSERT(mp->m_flags & XFS_MOUNT_DISCARD);
+
+		xfs_discard_extents(mp, &ctx->busy_extents);
+		xfs_alloc_busy_clear(mp, &ctx->busy_extents, false);
+	}
+
 	kmem_free(ctx);
 }
 

fs/xfs/xfs_mount.h

@@ -224,6 +224,7 @@ typedef struct xfs_mount {
 #define XFS_MOUNT_FS_SHUTDOWN	(1ULL << 4)	/* atomic stop of all filesystem
 						   operations, typically for
 						   disk errors in metadata */
+#define XFS_MOUNT_DISCARD	(1ULL << 5)	/* discard unused blocks */
 #define XFS_MOUNT_RETERR	(1ULL << 6)     /* return alignment errors to
 						   user */
 #define XFS_MOUNT_NOALIGN	(1ULL << 7)	/* turn off stripe alignment

fs/xfs/xfs_trans.c

@@ -609,7 +609,7 @@ xfs_trans_free(
 	struct xfs_trans	*tp)
 {
 	xfs_alloc_busy_sort(&tp->t_busy);
-	xfs_alloc_busy_clear(tp->t_mountp, &tp->t_busy);
+	xfs_alloc_busy_clear(tp->t_mountp, &tp->t_busy, false);
 
 	atomic_dec(&tp->t_mountp->m_active_trans);
 	xfs_trans_free_dqinfo(tp);