1 files changed, 123 insertions, 185 deletions

diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index aeb9d72ebf6e..b1498ab5a399 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -52,16 +52,11 @@ STATIC void	xfs_icsb_balance_counter(xfs_mount_t *, xfs_sb_field_t,
                                                 int);
 STATIC void     xfs_icsb_balance_counter_locked(xfs_mount_t *, xfs_sb_field_t,
                                                 int);
-STATIC int      xfs_icsb_modify_counters(xfs_mount_t *, xfs_sb_field_t,
-                                                int64_t, int);
 STATIC void     xfs_icsb_disable_counter(xfs_mount_t *, xfs_sb_field_t);
-
 #else
 
 #define xfs_icsb_balance_counter(mp, a, b)              do { } while (0)
 #define xfs_icsb_balance_counter_locked(mp, a, b)       do { } while (0)
-#define xfs_icsb_modify_counters(mp, a, b, c)           do { } while (0)
-
 #endif
 
 static const struct {
@@ -199,6 +194,8 @@ xfs_uuid_unmount(
 
 /*
  * Reference counting access wrappers to the perag structures.
+ * Because we never free per-ag structures, the only thing we
+ * have to protect against changes is the tree structure itself.
  */
 struct xfs_perag *
 xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno)
@@ -206,19 +203,43 @@ xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno)
         struct xfs_perag        *pag;
         int                     ref = 0;
 
-        spin_lock(&mp->m_perag_lock);
+        rcu_read_lock();
         pag = radix_tree_lookup(&mp->m_perag_tree, agno);
         if (pag) {
                 ASSERT(atomic_read(&pag->pag_ref) >= 0);
-                /* catch leaks in the positive direction during testing */
-                ASSERT(atomic_read(&pag->pag_ref) < 1000);
                 ref = atomic_inc_return(&pag->pag_ref);
         }
-        spin_unlock(&mp->m_perag_lock);
+        rcu_read_unlock();
         trace_xfs_perag_get(mp, agno, ref, _RET_IP_);
         return pag;
 }
 
+/*
+ * search from @first to find the next perag with the given tag set.
+ */
+struct xfs_perag *
+xfs_perag_get_tag(
+        struct xfs_mount        *mp,
+        xfs_agnumber_t          first,
+        int                     tag)
+{
+        struct xfs_perag        *pag;
+        int                     found;
+        int                     ref;
+
+        rcu_read_lock();
+        found = radix_tree_gang_lookup_tag(&mp->m_perag_tree,
+                                        (void **)&pag, first, 1, tag);
+        if (found <= 0) {
+                rcu_read_unlock();
+                return NULL;
+        }
+        ref = atomic_inc_return(&pag->pag_ref);
+        rcu_read_unlock();
+        trace_xfs_perag_get_tag(mp, pag->pag_agno, ref, _RET_IP_);
+        return pag;
+}
+
 void
 xfs_perag_put(struct xfs_perag *pag)
 {
@@ -229,10 +250,18 @@ xfs_perag_put(struct xfs_perag *pag)
         trace_xfs_perag_put(pag->pag_mount, pag->pag_agno, ref, _RET_IP_);
 }
 
+STATIC void
+__xfs_free_perag(
+        struct rcu_head *head)
+{
+        struct xfs_perag *pag = container_of(head, struct xfs_perag, rcu_head);
+
+        ASSERT(atomic_read(&pag->pag_ref) == 0);
+        kmem_free(pag);
+}
+
 /*
- * Free up the resources associated with a mount structure.  Assume that
- * the structure was initially zeroed, so we can tell which fields got
- * initialized.
+ * Free up the per-ag resources associated with the mount structure.
  */
 STATIC void
 xfs_free_perag(
@@ -244,10 +273,9 @@ xfs_free_perag(
         for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
                 spin_lock(&mp->m_perag_lock);
                 pag = radix_tree_delete(&mp->m_perag_tree, agno);
-                ASSERT(pag);
-                ASSERT(atomic_read(&pag->pag_ref) == 0);
                 spin_unlock(&mp->m_perag_lock);
-                kmem_free(pag);
+                ASSERT(pag);
+                call_rcu(&pag->rcu_head, __xfs_free_perag);
         }
 }
 
@@ -444,7 +472,10 @@ xfs_initialize_perag(
                 pag->pag_agno = index;
                 pag->pag_mount = mp;
                 rwlock_init(&pag->pag_ici_lock);
+                mutex_init(&pag->pag_ici_reclaim_lock);
                 INIT_RADIX_TREE(&pag->pag_ici_root, GFP_ATOMIC);
+                spin_lock_init(&pag->pag_buf_lock);
+                pag->pag_buf_tree = RB_ROOT;
 
                 if (radix_tree_preload(GFP_NOFS))
                         goto out_unwind;
@@ -639,7 +670,6 @@ int
 xfs_readsb(xfs_mount_t *mp, int flags)
 {
         unsigned int    sector_size;
-        unsigned int    extra_flags;
         xfs_buf_t       *bp;
         int             error;
 
@@ -652,28 +682,24 @@ xfs_readsb(xfs_mount_t *mp, int flags)
          * access to the superblock.
          */
         sector_size = xfs_getsize_buftarg(mp->m_ddev_targp);
-        extra_flags = XBF_LOCK | XBF_FS_MANAGED | XBF_MAPPED;
 
-        bp = xfs_buf_read(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");
-                error = bp ? XFS_BUF_GETERROR(bp) : ENOMEM;
-                goto fail;
+reread:
+        bp = xfs_buf_read_uncached(mp, mp->m_ddev_targp,
+                                        XFS_SB_DADDR, sector_size, 0);
+        if (!bp) {
+                xfs_fs_mount_cmn_err(flags, "SB buffer read failed");
+                return EIO;
         }
-        ASSERT(XFS_BUF_ISBUSY(bp));
-        ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
 
         /*
          * Initialize the mount structure from the superblock.
          * But first do some basic consistency checking.
          */
         xfs_sb_from_disk(&mp->m_sb, XFS_BUF_TO_SBP(bp));
-
         error = xfs_mount_validate_sb(mp, &(mp->m_sb), flags);
         if (error) {
                 xfs_fs_mount_cmn_err(flags, "SB validate failed");
-                goto fail;
+                goto release_buf;
         }
 
         /*
@@ -684,7 +710,7 @@ xfs_readsb(xfs_mount_t *mp, int flags)
                         "device supports only %u byte sectors (not %u)",
                         sector_size, mp->m_sb.sb_sectsize);
                 error = ENOSYS;
-                goto fail;
+                goto release_buf;
         }
 
         /*
@@ -692,33 +718,20 @@ xfs_readsb(xfs_mount_t *mp, int flags)
          * re-read the superblock so the buffer is correctly sized.
          */
         if (sector_size < mp->m_sb.sb_sectsize) {
-                XFS_BUF_UNMANAGE(bp);
                 xfs_buf_relse(bp);
                 sector_size = mp->m_sb.sb_sectsize;
-                bp = xfs_buf_read(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");
-                        error = bp ? XFS_BUF_GETERROR(bp) : ENOMEM;
-                        goto fail;
-                }
-                ASSERT(XFS_BUF_ISBUSY(bp));
-                ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
+                goto reread;
         }
 
         /* Initialize per-cpu counters */
         xfs_icsb_reinit_counters(mp);
 
         mp->m_sb_bp = bp;
-        xfs_buf_relse(bp);
-        ASSERT(XFS_BUF_VALUSEMA(bp) > 0);
+        xfs_buf_unlock(bp);
         return 0;
 
- fail:
-        if (bp) {
-                XFS_BUF_UNMANAGE(bp);
-                xfs_buf_relse(bp);
-        }
+release_buf:
+        xfs_buf_relse(bp);
         return error;
 }
 
@@ -991,42 +1004,35 @@ xfs_check_sizes(xfs_mount_t *mp)
 {
         xfs_buf_t       *bp;
         xfs_daddr_t     d;
-        int             error;
 
         d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
         if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_dblocks) {
-                cmn_err(CE_WARN, "XFS: size check 1 failed");
+                cmn_err(CE_WARN, "XFS: filesystem size mismatch detected");
                 return XFS_ERROR(EFBIG);
         }
-        error = xfs_read_buf(mp, mp->m_ddev_targp,
-                             d - XFS_FSS_TO_BB(mp, 1),
-                             XFS_FSS_TO_BB(mp, 1), 0, &bp);
-        if (!error) {
-                xfs_buf_relse(bp);
-        } else {
-                cmn_err(CE_WARN, "XFS: size check 2 failed");
-                if (error == ENOSPC)
-                        error = XFS_ERROR(EFBIG);
-                return error;
+        bp = xfs_buf_read_uncached(mp, mp->m_ddev_targp,
+                                        d - XFS_FSS_TO_BB(mp, 1),
+                                        BBTOB(XFS_FSS_TO_BB(mp, 1)), 0);
+        if (!bp) {
+                cmn_err(CE_WARN, "XFS: last sector read failed");
+                return EIO;
         }
+        xfs_buf_relse(bp);
 
         if (mp->m_logdev_targp != mp->m_ddev_targp) {
                 d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_logblocks);
                 if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_logblocks) {
-                        cmn_err(CE_WARN, "XFS: size check 3 failed");
+                        cmn_err(CE_WARN, "XFS: log size mismatch detected");
                         return XFS_ERROR(EFBIG);
                 }
-                error = xfs_read_buf(mp, mp->m_logdev_targp,
-                                     d - XFS_FSB_TO_BB(mp, 1),
-                                     XFS_FSB_TO_BB(mp, 1), 0, &bp);
-                if (!error) {
-                        xfs_buf_relse(bp);
-                } else {
-                        cmn_err(CE_WARN, "XFS: size check 3 failed");
-                        if (error == ENOSPC)
-                                error = XFS_ERROR(EFBIG);
-                        return error;
+                bp = xfs_buf_read_uncached(mp, mp->m_logdev_targp,
+                                        d - XFS_FSB_TO_BB(mp, 1),
+                                        XFS_FSB_TO_B(mp, 1), 0);
+                if (!bp) {
+                        cmn_err(CE_WARN, "XFS: log device read failed");
+                        return EIO;
                 }
+                xfs_buf_relse(bp);
         }
         return 0;
 }
@@ -1601,7 +1607,7 @@ xfs_unmountfs_writesb(xfs_mount_t *mp)
                 XFS_BUF_UNASYNC(sbp);
                 ASSERT(XFS_BUF_TARGET(sbp) == mp->m_ddev_targp);
                 xfsbdstrat(mp, sbp);
-                error = xfs_iowait(sbp);
+                error = xfs_buf_iowait(sbp);
                 if (error)
                         xfs_ioerror_alert("xfs_unmountfs_writesb",
                                           mp, sbp, XFS_BUF_ADDR(sbp));
@@ -1832,135 +1838,72 @@ xfs_mod_incore_sb_unlocked(
  */
 int
 xfs_mod_incore_sb(
-        xfs_mount_t     *mp,
-        xfs_sb_field_t  field,
-        int64_t         delta,
-        int             rsvd)
+        struct xfs_mount        *mp,
+        xfs_sb_field_t          field,
+        int64_t                 delta,
+        int                     rsvd)
 {
-        int     status;
+        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 */
+        ASSERT(field < XFS_SBS_ICOUNT || field > XFS_SBS_FDBLOCKS);
 #endif
-        default:
-                spin_lock(&mp->m_sb_lock);
-                status = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
-                spin_unlock(&mp->m_sb_lock);
-                break;
-        }
+        spin_lock(&mp->m_sb_lock);
+        status = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
+        spin_unlock(&mp->m_sb_lock);
 
         return status;
 }
 
 /*
- * xfs_mod_incore_sb_batch() is used to change more than one field
- * in the in-core superblock structure at a time.  This modification
- * is protected by a lock internal to this module.  The fields and
- * changes to those fields are specified in the array of xfs_mod_sb
- * structures passed in.
+ * Change more than one field in the in-core superblock structure at a time.
  *
- * Either all of the specified deltas will be applied or none of
- * them will.  If any modified field dips below 0, then all modifications
- * will be backed out and EINVAL will be returned.
+ * The fields and changes to those fields are specified in the array of
+ * xfs_mod_sb structures passed in.  Either all of the specified deltas
+ * will be applied or none of them will.  If any modified field dips below 0,
+ * then all modifications will be backed out and EINVAL will be returned.
+ *
+ * Note that this function may not be used for the superblock values that
+ * are tracked with the in-memory per-cpu counters - a direct call to
+ * xfs_icsb_modify_counters is required for these.
  */
 int
-xfs_mod_incore_sb_batch(xfs_mount_t *mp, xfs_mod_sb_t *msb, uint nmsb, int rsvd)
+xfs_mod_incore_sb_batch(
+        struct xfs_mount        *mp,
+        xfs_mod_sb_t            *msb,
+        uint                    nmsb,
+        int                     rsvd)
 {
-        int             status=0;
-        xfs_mod_sb_t    *msbp;
+        xfs_mod_sb_t            *msbp = &msb[0];
+        int                     error = 0;
 
         /*
-         * Loop through the array of mod structures and apply each
-         * individually.  If any fail, then back out all those
-         * which have already been applied.  Do all of this within
-         * the scope of the m_sb_lock so that all of the changes will
-         * be atomic.
+         * Loop through the array of mod structures and apply each individually.
+         * If any fail, then back out all those which have already been applied.
+         * Do all of this within the scope of the m_sb_lock so that all of the
+         * changes will be atomic.
          */
         spin_lock(&mp->m_sb_lock);
-        msbp = &msb[0];
         for (msbp = &msbp[0]; msbp < (msb + nmsb); msbp++) {
-                /*
-                 * Apply the delta at index n.  If it fails, break
-                 * 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)) {
-                                spin_unlock(&mp->m_sb_lock);
-                                status = xfs_icsb_modify_counters(mp,
-                                                        msbp->msb_field,
-                                                        msbp->msb_delta, rsvd);
-                                spin_lock(&mp->m_sb_lock);
-                                break;
-                        }
-                        /* FALLTHROUGH */
-#endif
-                default:
-                        status = xfs_mod_incore_sb_unlocked(mp,
-                                                msbp->msb_field,
-                                                msbp->msb_delta, rsvd);
-                        break;
-                }
+                ASSERT(msbp->msb_field < XFS_SBS_ICOUNT ||
+                       msbp->msb_field > XFS_SBS_FDBLOCKS);
 
-                if (status != 0) {
-                        break;
-                }
+                error = xfs_mod_incore_sb_unlocked(mp, msbp->msb_field,
+                                                   msbp->msb_delta, rsvd);
+                if (error)
+                        goto unwind;
         }
+        spin_unlock(&mp->m_sb_lock);
+        return 0;
 
-        /*
-         * If we didn't complete the loop above, then back out
-         * any changes made to the superblock.  If you add code
-         * between the loop above and here, make sure that you
-         * preserve the value of status. Loop back until
-         * we step below the beginning of the array.  Make sure
-         * we don't touch anything back there.
-         */
-        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)) {
-                                        spin_unlock(&mp->m_sb_lock);
-                                        status = xfs_icsb_modify_counters(mp,
-                                                        msbp->msb_field,
-                                                        -(msbp->msb_delta),
-                                                        rsvd);
-                                        spin_lock(&mp->m_sb_lock);
-                                        break;
-                                }
-                                /* FALLTHROUGH */
-#endif
-                        default:
-                                status = xfs_mod_incore_sb_unlocked(mp,
-                                                        msbp->msb_field,
-                                                        -(msbp->msb_delta),
-                                                        rsvd);
-                                break;
-                        }
-                        ASSERT(status == 0);
-                        msbp--;
-                }
+unwind:
+        while (--msbp >= msb) {
+                error = xfs_mod_incore_sb_unlocked(mp, msbp->msb_field,
+                                                   -msbp->msb_delta, rsvd);
+                ASSERT(error == 0);
         }
         spin_unlock(&mp->m_sb_lock);
-        return status;
+        return error;
 }
 
 /*
@@ -1998,18 +1941,13 @@ xfs_getsb(
  */
 void
 xfs_freesb(
-        xfs_mount_t     *mp)
+        struct xfs_mount        *mp)
 {
-        xfs_buf_t       *bp;
+        struct xfs_buf          *bp = mp->m_sb_bp;
 
-        /*
-         * Use xfs_getsb() so that the buffer will be locked
-         * when we call xfs_buf_relse().
-         */
-        bp = xfs_getsb(mp, 0);
-        XFS_BUF_UNMANAGE(bp);
-        xfs_buf_relse(bp);
+        xfs_buf_lock(bp);
         mp->m_sb_bp = NULL;
+        xfs_buf_relse(bp);
 }
 
 /*
@@ -2496,7 +2434,7 @@ xfs_icsb_balance_counter(
         spin_unlock(&mp->m_sb_lock);
 }
 
-STATIC int
+int
 xfs_icsb_modify_counters(
         xfs_mount_t     *mp,
         xfs_sb_field_t  field,