X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=fs%2Fxfs%2Fxfs_mount.c;fp=fs%2Fxfs%2Fxfs_mount.c;h=62188ea392c77592db41e80661693cc3784e4f0d;hb=64ba3f394c830ec48a1c31b53dcae312c56f1604;hp=9dfae18d995f5f5654c4230ec1de58530c73ba8c;hpb=be1e6109ac94a859551f8e1774eb9a8469fe055c;p=linux-2.6.git

diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 9dfae18d9..62188ea39 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -24,12 +24,14 @@
 #include "xfs_trans.h"
 #include "xfs_sb.h"
 #include "xfs_ag.h"
+#include "xfs_dir.h"
 #include "xfs_dir2.h"
 #include "xfs_dmapi.h"
 #include "xfs_mount.h"
 #include "xfs_bmap_btree.h"
 #include "xfs_alloc_btree.h"
 #include "xfs_ialloc_btree.h"
+#include "xfs_dir_sf.h"
 #include "xfs_dir2_sf.h"
 #include "xfs_attr_sf.h"
 #include "xfs_dinode.h"
@@ -49,32 +51,11 @@ STATIC int	xfs_uuid_mount(xfs_mount_t *);
 STATIC void	xfs_uuid_unmount(xfs_mount_t *mp);
 STATIC void	xfs_unmountfs_wait(xfs_mount_t *);
 
-
-#ifdef HAVE_PERCPU_SB
-STATIC void	xfs_icsb_destroy_counters(xfs_mount_t *);
-STATIC void	xfs_icsb_balance_counter(xfs_mount_t *, xfs_sb_field_t, int);
-STATIC void	xfs_icsb_sync_counters(xfs_mount_t *);
-STATIC int	xfs_icsb_modify_counters(xfs_mount_t *, xfs_sb_field_t,
-						int, int);
-STATIC int	xfs_icsb_modify_counters_locked(xfs_mount_t *, xfs_sb_field_t,
-						int, int);
-STATIC int	xfs_icsb_disable_counter(xfs_mount_t *, xfs_sb_field_t);
-
-#else
-
-#define xfs_icsb_destroy_counters(mp)			do { } while (0)
-#define xfs_icsb_balance_counter(mp, a, b)		do { } while (0)
-#define xfs_icsb_sync_counters(mp)			do { } while (0)
-#define xfs_icsb_modify_counters(mp, a, b, c)		do { } while (0)
-#define xfs_icsb_modify_counters_locked(mp, a, b, c)	do { } while (0)
-
-#endif
-
 static const struct {
-	short offset;
-	short type;	/* 0 = integer
-			 * 1 = binary / string (no translation)
-			 */
+    short offset;
+    short type;     /* 0 = integer
+		* 1 = binary / string (no translation)
+		*/
 } xfs_sb_info[] = {
     { offsetof(xfs_sb_t, sb_magicnum),   0 },
     { offsetof(xfs_sb_t, sb_blocksize),  0 },
@@ -132,11 +113,7 @@ xfs_mount_init(void)
 {
 	xfs_mount_t *mp;
 
-	mp = kmem_zalloc(sizeof(xfs_mount_t), KM_SLEEP);
-
-	if (xfs_icsb_init_counters(mp)) {
-		mp->m_flags |= XFS_MOUNT_NO_PERCPU_SB;
-	}
+	mp = kmem_zalloc(sizeof(*mp), KM_SLEEP);
 
 	AIL_LOCKINIT(&mp->m_ail_lock, "xfs_ail");
 	spinlock_init(&mp->m_sb_lock, "xfs_sb");
@@ -159,8 +136,8 @@ xfs_mount_init(void)
  */
 void
 xfs_mount_free(
-	xfs_mount_t	*mp,
-	int		remove_bhv)
+	xfs_mount_t *mp,
+	int	    remove_bhv)
 {
 	if (mp->m_ihash)
 		xfs_ihash_free(mp);
@@ -194,13 +171,12 @@ xfs_mount_free(
 		kmem_free(mp->m_logname, strlen(mp->m_logname) + 1);
 
 	if (remove_bhv) {
-		struct bhv_vfs	*vfsp = XFS_MTOVFS(mp);
+		struct vfs	*vfsp = XFS_MTOVFS(mp);
 
 		bhv_remove_all_vfsops(vfsp, 0);
 		VFS_REMOVEBHV(vfsp, &mp->m_bhv);
 	}
 
-	xfs_icsb_destroy_counters(mp);
 	kmem_free(mp, sizeof(xfs_mount_t));
 }
 
@@ -211,8 +187,7 @@ xfs_mount_free(
 STATIC int
 xfs_mount_validate_sb(
 	xfs_mount_t	*mp,
-	xfs_sb_t	*sbp,
-	int		flags)
+	xfs_sb_t	*sbp)
 {
 	/*
 	 * If the log device and data device have the
@@ -222,29 +197,33 @@ xfs_mount_validate_sb(
 	 * a volume filesystem in a non-volume manner.
 	 */
 	if (sbp->sb_magicnum != XFS_SB_MAGIC) {
-		xfs_fs_mount_cmn_err(flags, "bad magic number");
+		cmn_err(CE_WARN, "XFS: bad magic number");
 		return XFS_ERROR(EWRONGFS);
 	}
 
 	if (!XFS_SB_GOOD_VERSION(sbp)) {
-		xfs_fs_mount_cmn_err(flags, "bad version");
+		cmn_err(CE_WARN, "XFS: bad version");
 		return XFS_ERROR(EWRONGFS);
 	}
 
 	if (unlikely(
 	    sbp->sb_logstart == 0 && mp->m_logdev_targp == mp->m_ddev_targp)) {
-		xfs_fs_mount_cmn_err(flags,
-			"filesystem is marked as having an external log; "
-			"specify logdev on the\nmount command line.");
-		return XFS_ERROR(EINVAL);
+		cmn_err(CE_WARN,
+	"XFS: filesystem is marked as having an external log; "
+	"specify logdev on the\nmount command line.");
+		XFS_CORRUPTION_ERROR("xfs_mount_validate_sb(1)",
+				     XFS_ERRLEVEL_HIGH, mp, sbp);
+		return XFS_ERROR(EFSCORRUPTED);
 	}
 
 	if (unlikely(
 	    sbp->sb_logstart != 0 && mp->m_logdev_targp != mp->m_ddev_targp)) {
-		xfs_fs_mount_cmn_err(flags,
-			"filesystem is marked as having an internal log; "
-			"do not specify logdev on\nthe mount command line.");
-		return XFS_ERROR(EINVAL);
+		cmn_err(CE_WARN,
+	"XFS: filesystem is marked as having an internal log; "
+	"don't specify logdev on\nthe mount command line.");
+		XFS_CORRUPTION_ERROR("xfs_mount_validate_sb(2)",
+				     XFS_ERRLEVEL_HIGH, mp, sbp);
+		return XFS_ERROR(EFSCORRUPTED);
 	}
 
 	/*
@@ -263,13 +242,12 @@ xfs_mount_validate_sb(
 	    sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG			||
 	    sbp->sb_inodesize < XFS_DINODE_MIN_SIZE			||
 	    sbp->sb_inodesize > XFS_DINODE_MAX_SIZE			||
-	    sbp->sb_inodelog < XFS_DINODE_MIN_LOG			||
-	    sbp->sb_inodelog > XFS_DINODE_MAX_LOG			||
-	    (sbp->sb_blocklog - sbp->sb_inodelog != sbp->sb_inopblog)	||
 	    (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE)	||
 	    (sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE)	||
-	    (sbp->sb_imax_pct > 100 /* zero sb_imax_pct is valid */))) {
-		xfs_fs_mount_cmn_err(flags, "SB sanity check 1 failed");
+	    sbp->sb_imax_pct > 100)) {
+		cmn_err(CE_WARN, "XFS: SB sanity check 1 failed");
+		XFS_CORRUPTION_ERROR("xfs_mount_validate_sb(3)",
+				     XFS_ERRLEVEL_LOW, mp, sbp);
 		return XFS_ERROR(EFSCORRUPTED);
 	}
 
@@ -282,7 +260,9 @@ xfs_mount_validate_sb(
 	     (xfs_drfsbno_t)sbp->sb_agcount * sbp->sb_agblocks ||
 	    sbp->sb_dblocks < (xfs_drfsbno_t)(sbp->sb_agcount - 1) *
 			      sbp->sb_agblocks + XFS_MIN_AG_BLOCKS)) {
-		xfs_fs_mount_cmn_err(flags, "SB sanity check 2 failed");
+		cmn_err(CE_WARN, "XFS: SB sanity check 2 failed");
+		XFS_ERROR_REPORT("xfs_mount_validate_sb(4)",
+				 XFS_ERRLEVEL_LOW, mp);
 		return XFS_ERROR(EFSCORRUPTED);
 	}
 
@@ -298,13 +278,15 @@ xfs_mount_validate_sb(
 	    (sbp->sb_dblocks << (sbp->sb_blocklog - BBSHIFT)) > UINT_MAX ||
 	    (sbp->sb_rblocks << (sbp->sb_blocklog - BBSHIFT)) > UINT_MAX)) {
 #endif
-		xfs_fs_mount_cmn_err(flags,
-			"file system too large to be mounted on this system.");
+		cmn_err(CE_WARN,
+	"XFS: File system is too large to be mounted on this system.");
 		return XFS_ERROR(E2BIG);
 	}
 
 	if (unlikely(sbp->sb_inprogress)) {
-		xfs_fs_mount_cmn_err(flags, "file system busy");
+		cmn_err(CE_WARN, "XFS: file system busy");
+		XFS_ERROR_REPORT("xfs_mount_validate_sb(5)",
+				 XFS_ERRLEVEL_LOW, mp);
 		return XFS_ERROR(EFSCORRUPTED);
 	}
 
@@ -312,8 +294,8 @@ xfs_mount_validate_sb(
 	 * Version 1 directory format has never worked on Linux.
 	 */
 	if (unlikely(!XFS_SB_VERSION_HASDIRV2(sbp))) {
-		xfs_fs_mount_cmn_err(flags,
-			"file system using version 1 directory format");
+		cmn_err(CE_WARN,
+	"XFS: Attempted to mount file system using version 1 directory format");
 		return XFS_ERROR(ENOSYS);
 	}
 
@@ -321,11 +303,11 @@ xfs_mount_validate_sb(
 	 * Until this is fixed only page-sized or smaller data blocks work.
 	 */
 	if (unlikely(sbp->sb_blocksize > PAGE_SIZE)) {
-		xfs_fs_mount_cmn_err(flags,
-			"file system with blocksize %d bytes",
+		cmn_err(CE_WARN,
+		"XFS: Attempted to mount file system with blocksize %d bytes",
 			sbp->sb_blocksize);
-		xfs_fs_mount_cmn_err(flags,
-			"only pagesize (%ld) or less will currently work.",
+		cmn_err(CE_WARN,
+		"XFS: Only page-sized (%ld) or less blocksizes currently work.",
 			PAGE_SIZE);
 		return XFS_ERROR(ENOSYS);
 	}
@@ -335,7 +317,7 @@ xfs_mount_validate_sb(
 
 xfs_agnumber_t
 xfs_initialize_perag(
-	bhv_vfs_t	*vfs,
+	struct vfs	*vfs,
 	xfs_mount_t	*mp,
 	xfs_agnumber_t	agcount)
 {
@@ -382,7 +364,7 @@ xfs_initialize_perag(
 				break;
 			}
 
-			/* This ag is preferred for inodes */
+			/* This ag is prefered for inodes */
 			pag = &mp->m_perag[index];
 			pag->pagi_inodeok = 1;
 			if (index < max_metadata)
@@ -473,7 +455,7 @@ xfs_xlatesb(
  * Does the initial read of the superblock.
  */
 int
-xfs_readsb(xfs_mount_t *mp, int flags)
+xfs_readsb(xfs_mount_t *mp)
 {
 	unsigned int	sector_size;
 	unsigned int	extra_flags;
@@ -495,7 +477,7 @@ xfs_readsb(xfs_mount_t *mp, int flags)
 	bp = xfs_buf_read_flags(mp->m_ddev_targp, XFS_SB_DADDR,
 				BTOBB(sector_size), extra_flags);
 	if (!bp || XFS_BUF_ISERROR(bp)) {
-		xfs_fs_mount_cmn_err(flags, "SB read failed");
+		cmn_err(CE_WARN, "XFS: SB read failed");
 		error = bp ? XFS_BUF_GETERROR(bp) : ENOMEM;
 		goto fail;
 	}
@@ -509,9 +491,9 @@ xfs_readsb(xfs_mount_t *mp, int flags)
 	sbp = XFS_BUF_TO_SBP(bp);
 	xfs_xlatesb(XFS_BUF_PTR(bp), &(mp->m_sb), 1, XFS_SB_ALL_BITS);
 
-	error = xfs_mount_validate_sb(mp, &(mp->m_sb), flags);
+	error = xfs_mount_validate_sb(mp, &(mp->m_sb));
 	if (error) {
-		xfs_fs_mount_cmn_err(flags, "SB validate failed");
+		cmn_err(CE_WARN, "XFS: SB validate failed");
 		goto fail;
 	}
 
@@ -519,8 +501,8 @@ xfs_readsb(xfs_mount_t *mp, int flags)
 	 * We must be able to do sector-sized and sector-aligned IO.
 	 */
 	if (sector_size > mp->m_sb.sb_sectsize) {
-		xfs_fs_mount_cmn_err(flags,
-			"device supports only %u byte sectors (not %u)",
+		cmn_err(CE_WARN,
+			"XFS: device supports only %u byte sectors (not %u)",
 			sector_size, mp->m_sb.sb_sectsize);
 		error = ENOSYS;
 		goto fail;
@@ -537,7 +519,7 @@ xfs_readsb(xfs_mount_t *mp, int flags)
 		bp = xfs_buf_read_flags(mp->m_ddev_targp, XFS_SB_DADDR,
 					BTOBB(sector_size), extra_flags);
 		if (!bp || XFS_BUF_ISERROR(bp)) {
-			xfs_fs_mount_cmn_err(flags, "SB re-read failed");
+			cmn_err(CE_WARN, "XFS: SB re-read failed");
 			error = bp ? XFS_BUF_GETERROR(bp) : ENOMEM;
 			goto fail;
 		}
@@ -545,10 +527,6 @@ xfs_readsb(xfs_mount_t *mp, int flags)
 		ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
 	}
 
-	xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, 0);
-	xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0);
-	xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, 0);
-
 	mp->m_sb_bp = bp;
 	xfs_buf_relse(bp);
 	ASSERT(XFS_BUF_VALUSEMA(bp) > 0);
@@ -649,14 +627,14 @@ xfs_mount_common(xfs_mount_t *mp, xfs_sb_t *sbp)
  */
 int
 xfs_mountfs(
-	bhv_vfs_t	*vfsp,
+	vfs_t		*vfsp,
 	xfs_mount_t	*mp,
 	int		mfsi_flags)
 {
 	xfs_buf_t	*bp;
 	xfs_sb_t	*sbp = &(mp->m_sb);
 	xfs_inode_t	*rip;
-	bhv_vnode_t	*rvp = NULL;
+	vnode_t		*rvp = NULL;
 	int		readio_log, writeio_log;
 	xfs_daddr_t	d;
 	__uint64_t	ret64;
@@ -667,7 +645,7 @@ xfs_mountfs(
 	int		error = 0;
 
 	if (mp->m_sb_bp == NULL) {
-		if ((error = xfs_readsb(mp, mfsi_flags))) {
+		if ((error = xfs_readsb(mp))) {
 			return error;
 		}
 	}
@@ -932,7 +910,18 @@ xfs_mountfs(
 	vfsp->vfs_altfsid = (xfs_fsid_t *)mp->m_fixedfsid;
 	mp->m_dmevmask = 0;	/* not persistent; set after each mount */
 
-	xfs_dir_mount(mp);
+	/*
+	 * Select the right directory manager.
+	 */
+	mp->m_dirops =
+		XFS_SB_VERSION_HASDIRV2(&mp->m_sb) ?
+			xfsv2_dirops :
+			xfsv1_dirops;
+
+	/*
+	 * Initialize directory manager's entries.
+	 */
+	XFS_DIR_MOUNT(mp);
 
 	/*
 	 * Initialize the attribute manager's entries.
@@ -993,9 +982,8 @@ xfs_mountfs(
 
 	if (unlikely((rip->i_d.di_mode & S_IFMT) != S_IFDIR)) {
 		cmn_err(CE_WARN, "XFS: corrupted root inode");
-		cmn_err(CE_WARN, "Device %s - root %llu is not a directory",
-			XFS_BUFTARG_NAME(mp->m_ddev_targp),
-			(unsigned long long)rip->i_ino);
+		prdev("Root inode %llu is not a directory",
+		      mp->m_ddev_targp, (unsigned long long)rip->i_ino);
 		xfs_iunlock(rip, XFS_ILOCK_EXCL);
 		XFS_ERROR_REPORT("xfs_mountfs_int(2)", XFS_ERRLEVEL_LOW,
 				 mp);
@@ -1082,7 +1070,7 @@ xfs_mountfs(
 int
 xfs_unmountfs(xfs_mount_t *mp, struct cred *cr)
 {
-	struct bhv_vfs	*vfsp = XFS_MTOVFS(mp);
+	struct vfs	*vfsp = XFS_MTOVFS(mp);
 #if defined(DEBUG) || defined(INDUCE_IO_ERROR)
 	int64_t		fsid;
 #endif
@@ -1166,9 +1154,6 @@ xfs_unmountfs_writesb(xfs_mount_t *mp)
 	sbp = xfs_getsb(mp, 0);
 	if (!(XFS_MTOVFS(mp)->vfs_flag & VFS_RDONLY ||
 		XFS_FORCED_SHUTDOWN(mp))) {
-
-		xfs_icsb_sync_counters(mp);
-
 		/*
 		 * mark shared-readonly if desired
 		 */
@@ -1243,7 +1228,6 @@ xfs_mod_sb(xfs_trans_t *tp, __int64_t fields)
 	xfs_trans_log_buf(tp, bp, first, last);
 }
 
-
 /*
  * xfs_mod_incore_sb_unlocked() is a utility routine common used to apply
  * a delta to a specified field in the in-core superblock.  Simply
@@ -1253,7 +1237,7 @@ xfs_mod_sb(xfs_trans_t *tp, __int64_t fields)
  *
  * The SB_LOCK must be held when this routine is called.
  */
-int
+STATIC int
 xfs_mod_incore_sb_unlocked(xfs_mount_t *mp, xfs_sb_field_t field,
 			int delta, int rsvd)
 {
@@ -1288,8 +1272,7 @@ xfs_mod_incore_sb_unlocked(xfs_mount_t *mp, xfs_sb_field_t field,
 		return 0;
 	case XFS_SBS_FDBLOCKS:
 
-		lcounter = (long long)
-			mp->m_sb.sb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
+		lcounter = (long long)mp->m_sb.sb_fdblocks;
 		res_used = (long long)(mp->m_resblks - mp->m_resblks_avail);
 
 		if (delta > 0) {		/* Putting blocks back */
@@ -1323,7 +1306,7 @@ xfs_mod_incore_sb_unlocked(xfs_mount_t *mp, xfs_sb_field_t field,
 			}
 		}
 
-		mp->m_sb.sb_fdblocks = lcounter + XFS_ALLOC_SET_ASIDE(mp);
+		mp->m_sb.sb_fdblocks = lcounter;
 		return 0;
 	case XFS_SBS_FREXTENTS:
 		lcounter = (long long)mp->m_sb.sb_frextents;
@@ -1423,26 +1406,9 @@ xfs_mod_incore_sb(xfs_mount_t *mp, xfs_sb_field_t field, int delta, int rsvd)
 	unsigned long	s;
 	int	status;
 
-	/* check for per-cpu counters */
-	switch (field) {
-#ifdef HAVE_PERCPU_SB
-	case XFS_SBS_ICOUNT:
-	case XFS_SBS_IFREE:
-	case XFS_SBS_FDBLOCKS:
-		if (!(mp->m_flags & XFS_MOUNT_NO_PERCPU_SB)) {
-			status = xfs_icsb_modify_counters(mp, field,
-							delta, rsvd);
-			break;
-		}
-		/* FALLTHROUGH */
-#endif
-	default:
-		s = XFS_SB_LOCK(mp);
-		status = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
-		XFS_SB_UNLOCK(mp, s);
-		break;
-	}
-
+	s = XFS_SB_LOCK(mp);
+	status = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
+	XFS_SB_UNLOCK(mp, s);
 	return status;
 }
 
@@ -1479,26 +1445,8 @@ xfs_mod_incore_sb_batch(xfs_mount_t *mp, xfs_mod_sb_t *msb, uint nmsb, int rsvd)
 		 * from the loop so we'll fall into the undo loop
 		 * below.
 		 */
-		switch (msbp->msb_field) {
-#ifdef HAVE_PERCPU_SB
-		case XFS_SBS_ICOUNT:
-		case XFS_SBS_IFREE:
-		case XFS_SBS_FDBLOCKS:
-			if (!(mp->m_flags & XFS_MOUNT_NO_PERCPU_SB)) {
-				status = xfs_icsb_modify_counters_locked(mp,
-							msbp->msb_field,
-							msbp->msb_delta, rsvd);
-				break;
-			}
-			/* FALLTHROUGH */
-#endif
-		default:
-			status = xfs_mod_incore_sb_unlocked(mp,
-						msbp->msb_field,
-						msbp->msb_delta, rsvd);
-			break;
-		}
-
+		status = xfs_mod_incore_sb_unlocked(mp, msbp->msb_field,
+						    msbp->msb_delta, rsvd);
 		if (status != 0) {
 			break;
 		}
@@ -1515,28 +1463,8 @@ xfs_mod_incore_sb_batch(xfs_mount_t *mp, xfs_mod_sb_t *msb, uint nmsb, int rsvd)
 	if (status != 0) {
 		msbp--;
 		while (msbp >= msb) {
-			switch (msbp->msb_field) {
-#ifdef HAVE_PERCPU_SB
-			case XFS_SBS_ICOUNT:
-			case XFS_SBS_IFREE:
-			case XFS_SBS_FDBLOCKS:
-				if (!(mp->m_flags & XFS_MOUNT_NO_PERCPU_SB)) {
-					status =
-					    xfs_icsb_modify_counters_locked(mp,
-							msbp->msb_field,
-							-(msbp->msb_delta),
-							rsvd);
-					break;
-				}
-				/* FALLTHROUGH */
-#endif
-			default:
-				status = xfs_mod_incore_sb_unlocked(mp,
-							msbp->msb_field,
-							-(msbp->msb_delta),
-							rsvd);
-				break;
-			}
+			status = xfs_mod_incore_sb_unlocked(mp,
+				    msbp->msb_field, -(msbp->msb_delta), rsvd);
 			ASSERT(status == 0);
 			msbp--;
 		}
@@ -1649,529 +1577,3 @@ xfs_mount_log_sbunit(
 	xfs_mod_sb(tp, fields);
 	xfs_trans_commit(tp, 0, NULL);
 }
-
-
-#ifdef HAVE_PERCPU_SB
-/*
- * Per-cpu incore superblock counters
- *
- * Simple concept, difficult implementation
- *
- * Basically, replace the incore superblock counters with a distributed per cpu
- * counter for contended fields (e.g.  free block count).
- *
- * Difficulties arise in that the incore sb is used for ENOSPC checking, and
- * hence needs to be accurately read when we are running low on space. Hence
- * there is a method to enable and disable the per-cpu counters based on how
- * much "stuff" is available in them.
- *
- * Basically, a counter is enabled if there is enough free resource to justify
- * running a per-cpu fast-path. If the per-cpu counter runs out (i.e. a local
- * ENOSPC), then we disable the counters to synchronise all callers and
- * re-distribute the available resources.
- *
- * If, once we redistributed the available resources, we still get a failure,
- * we disable the per-cpu counter and go through the slow path.
- *
- * The slow path is the current xfs_mod_incore_sb() function.  This means that
- * when we disable a per-cpu counter, we need to drain it's resources back to
- * the global superblock. We do this after disabling the counter to prevent
- * more threads from queueing up on the counter.
- *
- * Essentially, this means that we still need a lock in the fast path to enable
- * synchronisation between the global counters and the per-cpu counters. This
- * is not a problem because the lock will be local to a CPU almost all the time
- * and have little contention except when we get to ENOSPC conditions.
- *
- * Basically, this lock becomes a barrier that enables us to lock out the fast
- * path while we do things like enabling and disabling counters and
- * synchronising the counters.
- *
- * Locking rules:
- *
- * 	1. XFS_SB_LOCK() before picking up per-cpu locks
- * 	2. per-cpu locks always picked up via for_each_online_cpu() order
- * 	3. accurate counter sync requires XFS_SB_LOCK + per cpu locks
- * 	4. modifying per-cpu counters requires holding per-cpu lock
- * 	5. modifying global counters requires holding XFS_SB_LOCK
- *	6. enabling or disabling a counter requires holding the XFS_SB_LOCK
- *	   and _none_ of the per-cpu locks.
- *
- * Disabled counters are only ever re-enabled by a balance operation
- * that results in more free resources per CPU than a given threshold.
- * To ensure counters don't remain disabled, they are rebalanced when
- * the global resource goes above a higher threshold (i.e. some hysteresis
- * is present to prevent thrashing).
- */
-
-#ifdef CONFIG_HOTPLUG_CPU
-/*
- * hot-plug CPU notifier support.
- *
- * We need a notifier per filesystem as we need to be able to identify
- * the filesystem to balance the counters out. This is achieved by
- * having a notifier block embedded in the xfs_mount_t and doing pointer
- * magic to get the mount pointer from the notifier block address.
- */
-STATIC int
-xfs_icsb_cpu_notify(
-	struct notifier_block *nfb,
-	unsigned long action,
-	void *hcpu)
-{
-	xfs_icsb_cnts_t *cntp;
-	xfs_mount_t	*mp;
-	int		s;
-
-	mp = (xfs_mount_t *)container_of(nfb, xfs_mount_t, m_icsb_notifier);
-	cntp = (xfs_icsb_cnts_t *)
-			per_cpu_ptr(mp->m_sb_cnts, (unsigned long)hcpu);
-	switch (action) {
-	case CPU_UP_PREPARE:
-		/* Easy Case - initialize the area and locks, and
-		 * then rebalance when online does everything else for us. */
-		memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
-		break;
-	case CPU_ONLINE:
-		xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, 0);
-		xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0);
-		xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, 0);
-		break;
-	case CPU_DEAD:
-		/* Disable all the counters, then fold the dead cpu's
-		 * count into the total on the global superblock and
-		 * re-enable the counters. */
-		s = XFS_SB_LOCK(mp);
-		xfs_icsb_disable_counter(mp, XFS_SBS_ICOUNT);
-		xfs_icsb_disable_counter(mp, XFS_SBS_IFREE);
-		xfs_icsb_disable_counter(mp, XFS_SBS_FDBLOCKS);
-
-		mp->m_sb.sb_icount += cntp->icsb_icount;
-		mp->m_sb.sb_ifree += cntp->icsb_ifree;
-		mp->m_sb.sb_fdblocks += cntp->icsb_fdblocks;
-
-		memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
-
-		xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, XFS_ICSB_SB_LOCKED);
-		xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, XFS_ICSB_SB_LOCKED);
-		xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, XFS_ICSB_SB_LOCKED);
-		XFS_SB_UNLOCK(mp, s);
-		break;
-	}
-
-	return NOTIFY_OK;
-}
-#endif /* CONFIG_HOTPLUG_CPU */
-
-int
-xfs_icsb_init_counters(
-	xfs_mount_t	*mp)
-{
-	xfs_icsb_cnts_t *cntp;
-	int		i;
-
-	mp->m_sb_cnts = alloc_percpu(xfs_icsb_cnts_t);
-	if (mp->m_sb_cnts == NULL)
-		return -ENOMEM;
-
-#ifdef CONFIG_HOTPLUG_CPU
-	mp->m_icsb_notifier.notifier_call = xfs_icsb_cpu_notify;
-	mp->m_icsb_notifier.priority = 0;
-	register_hotcpu_notifier(&mp->m_icsb_notifier);
-#endif /* CONFIG_HOTPLUG_CPU */
-
-	for_each_online_cpu(i) {
-		cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
-		memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
-	}
-	/*
-	 * start with all counters disabled so that the
-	 * initial balance kicks us off correctly
-	 */
-	mp->m_icsb_counters = -1;
-	return 0;
-}
-
-STATIC void
-xfs_icsb_destroy_counters(
-	xfs_mount_t	*mp)
-{
-	if (mp->m_sb_cnts) {
-		unregister_hotcpu_notifier(&mp->m_icsb_notifier);
-		free_percpu(mp->m_sb_cnts);
-	}
-}
-
-STATIC inline void
-xfs_icsb_lock_cntr(
-	xfs_icsb_cnts_t	*icsbp)
-{
-	while (test_and_set_bit(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags)) {
-		ndelay(1000);
-	}
-}
-
-STATIC inline void
-xfs_icsb_unlock_cntr(
-	xfs_icsb_cnts_t	*icsbp)
-{
-	clear_bit(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags);
-}
-
-
-STATIC inline void
-xfs_icsb_lock_all_counters(
-	xfs_mount_t	*mp)
-{
-	xfs_icsb_cnts_t *cntp;
-	int		i;
-
-	for_each_online_cpu(i) {
-		cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
-		xfs_icsb_lock_cntr(cntp);
-	}
-}
-
-STATIC inline void
-xfs_icsb_unlock_all_counters(
-	xfs_mount_t	*mp)
-{
-	xfs_icsb_cnts_t *cntp;
-	int		i;
-
-	for_each_online_cpu(i) {
-		cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
-		xfs_icsb_unlock_cntr(cntp);
-	}
-}
-
-STATIC void
-xfs_icsb_count(
-	xfs_mount_t	*mp,
-	xfs_icsb_cnts_t	*cnt,
-	int		flags)
-{
-	xfs_icsb_cnts_t *cntp;
-	int		i;
-
-	memset(cnt, 0, sizeof(xfs_icsb_cnts_t));
-
-	if (!(flags & XFS_ICSB_LAZY_COUNT))
-		xfs_icsb_lock_all_counters(mp);
-
-	for_each_online_cpu(i) {
-		cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
-		cnt->icsb_icount += cntp->icsb_icount;
-		cnt->icsb_ifree += cntp->icsb_ifree;
-		cnt->icsb_fdblocks += cntp->icsb_fdblocks;
-	}
-
-	if (!(flags & XFS_ICSB_LAZY_COUNT))
-		xfs_icsb_unlock_all_counters(mp);
-}
-
-STATIC int
-xfs_icsb_counter_disabled(
-	xfs_mount_t	*mp,
-	xfs_sb_field_t	field)
-{
-	ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
-	return test_bit(field, &mp->m_icsb_counters);
-}
-
-STATIC int
-xfs_icsb_disable_counter(
-	xfs_mount_t	*mp,
-	xfs_sb_field_t	field)
-{
-	xfs_icsb_cnts_t	cnt;
-
-	ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
-
-	xfs_icsb_lock_all_counters(mp);
-	if (!test_and_set_bit(field, &mp->m_icsb_counters)) {
-		/* drain back to superblock */
-
-		xfs_icsb_count(mp, &cnt, XFS_ICSB_SB_LOCKED|XFS_ICSB_LAZY_COUNT);
-		switch(field) {
-		case XFS_SBS_ICOUNT:
-			mp->m_sb.sb_icount = cnt.icsb_icount;
-			break;
-		case XFS_SBS_IFREE:
-			mp->m_sb.sb_ifree = cnt.icsb_ifree;
-			break;
-		case XFS_SBS_FDBLOCKS:
-			mp->m_sb.sb_fdblocks = cnt.icsb_fdblocks;
-			break;
-		default:
-			BUG();
-		}
-	}
-
-	xfs_icsb_unlock_all_counters(mp);
-
-	return 0;
-}
-
-STATIC void
-xfs_icsb_enable_counter(
-	xfs_mount_t	*mp,
-	xfs_sb_field_t	field,
-	uint64_t	count,
-	uint64_t	resid)
-{
-	xfs_icsb_cnts_t	*cntp;
-	int		i;
-
-	ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
-
-	xfs_icsb_lock_all_counters(mp);
-	for_each_online_cpu(i) {
-		cntp = per_cpu_ptr(mp->m_sb_cnts, i);
-		switch (field) {
-		case XFS_SBS_ICOUNT:
-			cntp->icsb_icount = count + resid;
-			break;
-		case XFS_SBS_IFREE:
-			cntp->icsb_ifree = count + resid;
-			break;
-		case XFS_SBS_FDBLOCKS:
-			cntp->icsb_fdblocks = count + resid;
-			break;
-		default:
-			BUG();
-			break;
-		}
-		resid = 0;
-	}
-	clear_bit(field, &mp->m_icsb_counters);
-	xfs_icsb_unlock_all_counters(mp);
-}
-
-STATIC void
-xfs_icsb_sync_counters_int(
-	xfs_mount_t	*mp,
-	int		flags)
-{
-	xfs_icsb_cnts_t	cnt;
-	int		s;
-
-	/* Pass 1: lock all counters */
-	if ((flags & XFS_ICSB_SB_LOCKED) == 0)
-		s = XFS_SB_LOCK(mp);
-
-	xfs_icsb_count(mp, &cnt, flags);
-
-	/* Step 3: update mp->m_sb fields */
-	if (!xfs_icsb_counter_disabled(mp, XFS_SBS_ICOUNT))
-		mp->m_sb.sb_icount = cnt.icsb_icount;
-	if (!xfs_icsb_counter_disabled(mp, XFS_SBS_IFREE))
-		mp->m_sb.sb_ifree = cnt.icsb_ifree;
-	if (!xfs_icsb_counter_disabled(mp, XFS_SBS_FDBLOCKS))
-		mp->m_sb.sb_fdblocks = cnt.icsb_fdblocks;
-
-	if ((flags & XFS_ICSB_SB_LOCKED) == 0)
-		XFS_SB_UNLOCK(mp, s);
-}
-
-/*
- * Accurate update of per-cpu counters to incore superblock
- */
-STATIC void
-xfs_icsb_sync_counters(
-	xfs_mount_t	*mp)
-{
-	xfs_icsb_sync_counters_int(mp, 0);
-}
-
-/*
- * lazy addition used for things like df, background sb syncs, etc
- */
-void
-xfs_icsb_sync_counters_lazy(
-	xfs_mount_t	*mp)
-{
-	xfs_icsb_sync_counters_int(mp, XFS_ICSB_LAZY_COUNT);
-}
-
-/*
- * Balance and enable/disable counters as necessary.
- *
- * Thresholds for re-enabling counters are somewhat magic.
- * inode counts are chosen to be the same number as single
- * on disk allocation chunk per CPU, and free blocks is
- * something far enough zero that we aren't going thrash
- * when we get near ENOSPC.
- */
-#define XFS_ICSB_INO_CNTR_REENABLE	64
-#define XFS_ICSB_FDBLK_CNTR_REENABLE(mp) \
-		(512 + XFS_ALLOC_SET_ASIDE(mp))
-STATIC void
-xfs_icsb_balance_counter(
-	xfs_mount_t	*mp,
-	xfs_sb_field_t  field,
-	int		flags)
-{
-	uint64_t	count, resid;
-	int		weight = num_online_cpus();
-	int		s;
-
-	if (!(flags & XFS_ICSB_SB_LOCKED))
-		s = XFS_SB_LOCK(mp);
-
-	/* disable counter and sync counter */
-	xfs_icsb_disable_counter(mp, field);
-
-	/* update counters  - first CPU gets residual*/
-	switch (field) {
-	case XFS_SBS_ICOUNT:
-		count = mp->m_sb.sb_icount;
-		resid = do_div(count, weight);
-		if (count < XFS_ICSB_INO_CNTR_REENABLE)
-			goto out;
-		break;
-	case XFS_SBS_IFREE:
-		count = mp->m_sb.sb_ifree;
-		resid = do_div(count, weight);
-		if (count < XFS_ICSB_INO_CNTR_REENABLE)
-			goto out;
-		break;
-	case XFS_SBS_FDBLOCKS:
-		count = mp->m_sb.sb_fdblocks;
-		resid = do_div(count, weight);
-		if (count < XFS_ICSB_FDBLK_CNTR_REENABLE(mp))
-			goto out;
-		break;
-	default:
-		BUG();
-		count = resid = 0;	/* quiet, gcc */
-		break;
-	}
-
-	xfs_icsb_enable_counter(mp, field, count, resid);
-out:
-	if (!(flags & XFS_ICSB_SB_LOCKED))
-		XFS_SB_UNLOCK(mp, s);
-}
-
-STATIC int
-xfs_icsb_modify_counters_int(
-	xfs_mount_t	*mp,
-	xfs_sb_field_t	field,
-	int		delta,
-	int		rsvd,
-	int		flags)
-{
-	xfs_icsb_cnts_t	*icsbp;
-	long long	lcounter;	/* long counter for 64 bit fields */
-	int		cpu, s, locked = 0;
-	int		ret = 0, balance_done = 0;
-
-again:
-	cpu = get_cpu();
-	icsbp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, cpu),
-	xfs_icsb_lock_cntr(icsbp);
-	if (unlikely(xfs_icsb_counter_disabled(mp, field)))
-		goto slow_path;
-
-	switch (field) {
-	case XFS_SBS_ICOUNT:
-		lcounter = icsbp->icsb_icount;
-		lcounter += delta;
-		if (unlikely(lcounter < 0))
-			goto slow_path;
-		icsbp->icsb_icount = lcounter;
-		break;
-
-	case XFS_SBS_IFREE:
-		lcounter = icsbp->icsb_ifree;
-		lcounter += delta;
-		if (unlikely(lcounter < 0))
-			goto slow_path;
-		icsbp->icsb_ifree = lcounter;
-		break;
-
-	case XFS_SBS_FDBLOCKS:
-		BUG_ON((mp->m_resblks - mp->m_resblks_avail) != 0);
-
-		lcounter = icsbp->icsb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
-		lcounter += delta;
-		if (unlikely(lcounter < 0))
-			goto slow_path;
-		icsbp->icsb_fdblocks = lcounter + XFS_ALLOC_SET_ASIDE(mp);
-		break;
-	default:
-		BUG();
-		break;
-	}
-	xfs_icsb_unlock_cntr(icsbp);
-	put_cpu();
-	if (locked)
-		XFS_SB_UNLOCK(mp, s);
-	return 0;
-
-	/*
-	 * The slow path needs to be run with the SBLOCK
-	 * held so that we prevent other threads from
-	 * attempting to run this path at the same time.
-	 * this provides exclusion for the balancing code,
-	 * and exclusive fallback if the balance does not
-	 * provide enough resources to continue in an unlocked
-	 * manner.
-	 */
-slow_path:
-	xfs_icsb_unlock_cntr(icsbp);
-	put_cpu();
-
-	/* need to hold superblock incase we need
-	 * to disable a counter */
-	if (!(flags & XFS_ICSB_SB_LOCKED)) {
-		s = XFS_SB_LOCK(mp);
-		locked = 1;
-		flags |= XFS_ICSB_SB_LOCKED;
-	}
-	if (!balance_done) {
-		xfs_icsb_balance_counter(mp, field, flags);
-		balance_done = 1;
-		goto again;
-	} else {
-		/*
-		 * we might not have enough on this local
-		 * cpu to allocate for a bulk request.
-		 * We need to drain this field from all CPUs
-		 * and disable the counter fastpath
-		 */
-		xfs_icsb_disable_counter(mp, field);
-	}
-
-	ret = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
-
-	if (locked)
-		XFS_SB_UNLOCK(mp, s);
-	return ret;
-}
-
-STATIC int
-xfs_icsb_modify_counters(
-	xfs_mount_t	*mp,
-	xfs_sb_field_t	field,
-	int		delta,
-	int		rsvd)
-{
-	return xfs_icsb_modify_counters_int(mp, field, delta, rsvd, 0);
-}
-
-/*
- * Called when superblock is already locked
- */
-STATIC int
-xfs_icsb_modify_counters_locked(
-	xfs_mount_t	*mp,
-	xfs_sb_field_t	field,
-	int		delta,
-	int		rsvd)
-{
-	return xfs_icsb_modify_counters_int(mp, field, delta,
-						rsvd, XFS_ICSB_SB_LOCKED);
-}
-#endif