1 files changed, 125 insertions, 115 deletions

diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index 286e36e21dae..aa1d353def29 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -188,8 +188,8 @@ _xfs_buf_initialize(
         atomic_set(&bp->b_hold, 1);
         init_completion(&bp->b_iowait);
         INIT_LIST_HEAD(&bp->b_list);
-        INIT_LIST_HEAD(&bp->b_hash_list);
-        init_MUTEX_LOCKED(&bp->b_sema); /* held, no waiters */
+        RB_CLEAR_NODE(&bp->b_rbnode);
+        sema_init(&bp->b_sema, 0); /* held, no waiters */
         XB_SET_OWNER(bp);
         bp->b_target = target;
         bp->b_file_offset = range_base;
@@ -262,8 +262,6 @@ xfs_buf_free(
 {
         trace_xfs_buf_free(bp, _RET_IP_);
 
-        ASSERT(list_empty(&bp->b_hash_list));
-
         if (bp->b_flags & (_XBF_PAGE_CACHE|_XBF_PAGES)) {
                 uint            i;
 
@@ -422,8 +420,10 @@ _xfs_buf_find(
 {
         xfs_off_t               range_base;
         size_t                  range_length;
-        xfs_bufhash_t           *hash;
-        xfs_buf_t               *bp, *n;
+        struct xfs_perag        *pag;
+        struct rb_node          **rbp;
+        struct rb_node          *parent;
+        xfs_buf_t               *bp;
 
         range_base = (ioff << BBSHIFT);
         range_length = (isize << BBSHIFT);
@@ -432,14 +432,37 @@ _xfs_buf_find(
         ASSERT(!(range_length < (1 << btp->bt_sshift)));
         ASSERT(!(range_base & (xfs_off_t)btp->bt_smask));
 
-        hash = &btp->bt_hash[hash_long((unsigned long)ioff, btp->bt_hashshift)];
-
-        spin_lock(&hash->bh_lock);
-
-        list_for_each_entry_safe(bp, n, &hash->bh_list, b_hash_list) {
-                ASSERT(btp == bp->b_target);
-                if (bp->b_file_offset == range_base &&
-                    bp->b_buffer_length == range_length) {
+        /* get tree root */
+        pag = xfs_perag_get(btp->bt_mount,
+                                xfs_daddr_to_agno(btp->bt_mount, ioff));
+
+        /* walk tree */
+        spin_lock(&pag->pag_buf_lock);
+        rbp = &pag->pag_buf_tree.rb_node;
+        parent = NULL;
+        bp = NULL;
+        while (*rbp) {
+                parent = *rbp;
+                bp = rb_entry(parent, struct xfs_buf, b_rbnode);
+
+                if (range_base < bp->b_file_offset)
+                        rbp = &(*rbp)->rb_left;
+                else if (range_base > bp->b_file_offset)
+                        rbp = &(*rbp)->rb_right;
+                else {
+                        /*
+                         * found a block offset match. If the range doesn't
+                         * match, the only way this is allowed is if the buffer
+                         * in the cache is stale and the transaction that made
+                         * it stale has not yet committed. i.e. we are
+                         * reallocating a busy extent. Skip this buffer and
+                         * continue searching to the right for an exact match.
+                         */
+                        if (bp->b_buffer_length != range_length) {
+                                ASSERT(bp->b_flags & XBF_STALE);
+                                rbp = &(*rbp)->rb_right;
+                                continue;
+                        }
                         atomic_inc(&bp->b_hold);
                         goto found;
                 }
@@ -449,17 +472,21 @@ _xfs_buf_find(
         if (new_bp) {
                 _xfs_buf_initialize(new_bp, btp, range_base,
                                 range_length, flags);
-                new_bp->b_hash = hash;
-                list_add(&new_bp->b_hash_list, &hash->bh_list);
+                rb_link_node(&new_bp->b_rbnode, parent, rbp);
+                rb_insert_color(&new_bp->b_rbnode, &pag->pag_buf_tree);
+                /* the buffer keeps the perag reference until it is freed */
+                new_bp->b_pag = pag;
+                spin_unlock(&pag->pag_buf_lock);
         } else {
                 XFS_STATS_INC(xb_miss_locked);
+                spin_unlock(&pag->pag_buf_lock);
+                xfs_perag_put(pag);
         }
-
-        spin_unlock(&hash->bh_lock);
         return new_bp;
 
 found:
-        spin_unlock(&hash->bh_lock);
+        spin_unlock(&pag->pag_buf_lock);
+        xfs_perag_put(pag);
 
         /* Attempt to get the semaphore without sleeping,
          * if this does not work then we need to drop the
@@ -625,8 +652,7 @@ void
 xfs_buf_readahead(
         xfs_buftarg_t           *target,
         xfs_off_t               ioff,
-        size_t                  isize,
-        xfs_buf_flags_t         flags)
+        size_t                  isize)
 {
         struct backing_dev_info *bdi;
 
@@ -634,8 +660,42 @@ xfs_buf_readahead(
         if (bdi_read_congested(bdi))
                 return;
 
-        flags |= (XBF_TRYLOCK|XBF_ASYNC|XBF_READ_AHEAD);
-        xfs_buf_read(target, ioff, isize, flags);
+        xfs_buf_read(target, ioff, isize,
+                     XBF_TRYLOCK|XBF_ASYNC|XBF_READ_AHEAD|XBF_DONT_BLOCK);
+}
+
+/*
+ * Read an uncached buffer from disk. Allocates and returns a locked
+ * buffer containing the disk contents or nothing.
+ */
+struct xfs_buf *
+xfs_buf_read_uncached(
+        struct xfs_mount        *mp,
+        struct xfs_buftarg      *target,
+        xfs_daddr_t             daddr,
+        size_t                  length,
+        int                     flags)
+{
+        xfs_buf_t               *bp;
+        int                     error;
+
+        bp = xfs_buf_get_uncached(target, length, flags);
+        if (!bp)
+                return NULL;
+
+        /* set up the buffer for a read IO */
+        xfs_buf_lock(bp);
+        XFS_BUF_SET_ADDR(bp, daddr);
+        XFS_BUF_READ(bp);
+        XFS_BUF_BUSY(bp);
+
+        xfsbdstrat(mp, bp);
+        error = xfs_buf_iowait(bp);
+        if (error || bp->b_error) {
+                xfs_buf_relse(bp);
+                return NULL;
+        }
+        return bp;
 }
 
 xfs_buf_t *
@@ -707,9 +767,10 @@ xfs_buf_associate_memory(
 }
 
 xfs_buf_t *
-xfs_buf_get_noaddr(
+xfs_buf_get_uncached(
+        struct xfs_buftarg      *target,
         size_t                  len,
-        xfs_buftarg_t           *target)
+        int                     flags)
 {
         unsigned long           page_count = PAGE_ALIGN(len) >> PAGE_SHIFT;
         int                     error, i;
@@ -725,7 +786,7 @@ xfs_buf_get_noaddr(
                 goto fail_free_buf;
 
         for (i = 0; i < page_count; i++) {
-                bp->b_pages[i] = alloc_page(GFP_KERNEL);
+                bp->b_pages[i] = alloc_page(xb_to_gfp(flags));
                 if (!bp->b_pages[i])
                         goto fail_free_mem;
         }
@@ -740,7 +801,7 @@ xfs_buf_get_noaddr(
 
         xfs_buf_unlock(bp);
 
-        trace_xfs_buf_get_noaddr(bp, _RET_IP_);
+        trace_xfs_buf_get_uncached(bp, _RET_IP_);
         return bp;
 
  fail_free_mem:
@@ -774,29 +835,30 @@ void
 xfs_buf_rele(
         xfs_buf_t               *bp)
 {
-        xfs_bufhash_t           *hash = bp->b_hash;
+        struct xfs_perag        *pag = bp->b_pag;
 
         trace_xfs_buf_rele(bp, _RET_IP_);
 
-        if (unlikely(!hash)) {
+        if (!pag) {
                 ASSERT(!bp->b_relse);
+                ASSERT(RB_EMPTY_NODE(&bp->b_rbnode));
                 if (atomic_dec_and_test(&bp->b_hold))
                         xfs_buf_free(bp);
                 return;
         }
 
+        ASSERT(!RB_EMPTY_NODE(&bp->b_rbnode));
         ASSERT(atomic_read(&bp->b_hold) > 0);
-        if (atomic_dec_and_lock(&bp->b_hold, &hash->bh_lock)) {
+        if (atomic_dec_and_lock(&bp->b_hold, &pag->pag_buf_lock)) {
                 if (bp->b_relse) {
                         atomic_inc(&bp->b_hold);
-                        spin_unlock(&hash->bh_lock);
-                        (*(bp->b_relse)) (bp);
-                } else if (bp->b_flags & XBF_FS_MANAGED) {
-                        spin_unlock(&hash->bh_lock);
+                        spin_unlock(&pag->pag_buf_lock);
+                        bp->b_relse(bp);
                 } else {
                         ASSERT(!(bp->b_flags & (XBF_DELWRI|_XBF_DELWRI_Q)));
-                        list_del_init(&bp->b_hash_list);
-                        spin_unlock(&hash->bh_lock);
+                        rb_erase(&bp->b_rbnode, &pag->pag_buf_tree);
+                        spin_unlock(&pag->pag_buf_lock);
+                        xfs_perag_put(pag);
                         xfs_buf_free(bp);
                 }
         }
@@ -859,7 +921,7 @@ xfs_buf_lock(
         trace_xfs_buf_lock(bp, _RET_IP_);
 
         if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE))
-                xfs_log_force(bp->b_mount, 0);
+                xfs_log_force(bp->b_target->bt_mount, 0);
         if (atomic_read(&bp->b_io_remaining))
                 blk_run_address_space(bp->b_target->bt_mapping);
         down(&bp->b_sema);
@@ -924,19 +986,7 @@ xfs_buf_iodone_work(
         xfs_buf_t               *bp =
                 container_of(work, xfs_buf_t, b_iodone_work);
 
-        /*
-         * We can get an EOPNOTSUPP to ordered writes.  Here we clear the
-         * ordered flag and reissue them.  Because we can't tell the higher
-         * layers directly that they should not issue ordered I/O anymore, they
-         * need to check if the _XFS_BARRIER_FAILED flag was set during I/O completion.
-         */
-        if ((bp->b_error == EOPNOTSUPP) &&
-            (bp->b_flags & (XBF_ORDERED|XBF_ASYNC)) == (XBF_ORDERED|XBF_ASYNC)) {
-                trace_xfs_buf_ordered_retry(bp, _RET_IP_);
-                bp->b_flags &= ~XBF_ORDERED;
-                bp->b_flags |= _XFS_BARRIER_FAILED;
-                xfs_buf_iorequest(bp);
-        } else if (bp->b_iodone)
+        if (bp->b_iodone)
                 (*(bp->b_iodone))(bp);
         else if (bp->b_flags & XBF_ASYNC)
                 xfs_buf_relse(bp);
@@ -982,7 +1032,6 @@ xfs_bwrite(
 {
         int                     error;
 
-        bp->b_mount = mp;
         bp->b_flags |= XBF_WRITE;
         bp->b_flags &= ~(XBF_ASYNC | XBF_READ);
 
@@ -1003,8 +1052,6 @@ xfs_bdwrite(
 {
         trace_xfs_buf_bdwrite(bp, _RET_IP_);
 
-        bp->b_mount = mp;
-
         bp->b_flags &= ~XBF_READ;
         bp->b_flags |= (XBF_DELWRI | XBF_ASYNC);
 
@@ -1013,7 +1060,7 @@ xfs_bdwrite(
 
 /*
  * Called when we want to stop a buffer from getting written or read.
- * We attach the EIO error, muck with its flags, and call biodone
+ * We attach the EIO error, muck with its flags, and call xfs_buf_ioend
  * so that the proper iodone callbacks get called.
  */
 STATIC int
@@ -1030,21 +1077,21 @@ xfs_bioerror(
         XFS_BUF_ERROR(bp, EIO);
 
         /*
-         * We're calling biodone, so delete XBF_DONE flag.
+         * We're calling xfs_buf_ioend, so delete XBF_DONE flag.
          */
         XFS_BUF_UNREAD(bp);
         XFS_BUF_UNDELAYWRITE(bp);
         XFS_BUF_UNDONE(bp);
         XFS_BUF_STALE(bp);
 
-        xfs_biodone(bp);
+        xfs_buf_ioend(bp, 0);
 
         return EIO;
 }
 
 /*
  * Same as xfs_bioerror, except that we are releasing the buffer
- * here ourselves, and avoiding the biodone call.
+ * here ourselves, and avoiding the xfs_buf_ioend call.
  * This is meant for userdata errors; metadata bufs come with
  * iodone functions attached, so that we can track down errors.
  */
@@ -1093,7 +1140,7 @@ int
 xfs_bdstrat_cb(
         struct xfs_buf  *bp)
 {
-        if (XFS_FORCED_SHUTDOWN(bp->b_mount)) {
+        if (XFS_FORCED_SHUTDOWN(bp->b_target->bt_mount)) {
                 trace_xfs_bdstrat_shut(bp, _RET_IP_);
                 /*
                  * Metadata write that didn't get logged but
@@ -1195,7 +1242,7 @@ _xfs_buf_ioapply(
 
         if (bp->b_flags & XBF_ORDERED) {
                 ASSERT(!(bp->b_flags & XBF_READ));
-                rw = WRITE_BARRIER;
+                rw = WRITE_FLUSH_FUA;
         } else if (bp->b_flags & XBF_LOG_BUFFER) {
                 ASSERT(!(bp->b_flags & XBF_READ_AHEAD));
                 bp->b_flags &= ~_XBF_RUN_QUEUES;
@@ -1399,62 +1446,24 @@ xfs_buf_iomove(
  */
 void
 xfs_wait_buftarg(
-        xfs_buftarg_t   *btp)
-{
-        xfs_buf_t       *bp, *n;
-        xfs_bufhash_t   *hash;
-        uint            i;
-
-        for (i = 0; i < (1 << btp->bt_hashshift); i++) {
-                hash = &btp->bt_hash[i];
-again:
-                spin_lock(&hash->bh_lock);
-                list_for_each_entry_safe(bp, n, &hash->bh_list, b_hash_list) {
-                        ASSERT(btp == bp->b_target);
-                        if (!(bp->b_flags & XBF_FS_MANAGED)) {
-                                spin_unlock(&hash->bh_lock);
-                                /*
-                                 * Catch superblock reference count leaks
-                                 * immediately
-                                 */
-                                BUG_ON(bp->b_bn == 0);
-                                delay(100);
-                                goto again;
-                        }
-                }
-                spin_unlock(&hash->bh_lock);
-        }
-}
-
-/*
- *      Allocate buffer hash table for a given target.
- *      For devices containing metadata (i.e. not the log/realtime devices)
- *      we need to allocate a much larger hash table.
- */
-STATIC void
-xfs_alloc_bufhash(
-        xfs_buftarg_t           *btp,
-        int                     external)
+        struct xfs_buftarg      *btp)
 {
-        unsigned int            i;
+        struct xfs_perag        *pag;
+        uint                    i;
 
-        btp->bt_hashshift = external ? 3 : 12;  /* 8 or 4096 buckets */
-        btp->bt_hash = kmem_zalloc_large((1 << btp->bt_hashshift) *
-                                         sizeof(xfs_bufhash_t));
-        for (i = 0; i < (1 << btp->bt_hashshift); i++) {
-                spin_lock_init(&btp->bt_hash[i].bh_lock);
-                INIT_LIST_HEAD(&btp->bt_hash[i].bh_list);
+        for (i = 0; i < btp->bt_mount->m_sb.sb_agcount; i++) {
+                pag = xfs_perag_get(btp->bt_mount, i);
+                spin_lock(&pag->pag_buf_lock);
+                while (rb_first(&pag->pag_buf_tree)) {
+                        spin_unlock(&pag->pag_buf_lock);
+                        delay(100);
+                        spin_lock(&pag->pag_buf_lock);
+                }
+                spin_unlock(&pag->pag_buf_lock);
+                xfs_perag_put(pag);
         }
 }
 
-STATIC void
-xfs_free_bufhash(
-        xfs_buftarg_t           *btp)
-{
-        kmem_free_large(btp->bt_hash);
-        btp->bt_hash = NULL;
-}
-
 /*
  *      buftarg list for delwrite queue processing
  */
@@ -1487,7 +1496,6 @@ xfs_free_buftarg(
         xfs_flush_buftarg(btp, 1);
         if (mp->m_flags & XFS_MOUNT_BARRIER)
                 xfs_blkdev_issue_flush(btp);
-        xfs_free_bufhash(btp);
         iput(btp->bt_mapping->host);
 
         /* Unregister the buftarg first so that we don't get a
@@ -1572,6 +1580,7 @@ xfs_mapping_buftarg(
                         XFS_BUFTARG_NAME(btp));
                 return ENOMEM;
         }
+        inode->i_ino = get_next_ino();
         inode->i_mode = S_IFBLK;
         inode->i_bdev = bdev;
         inode->i_rdev = bdev->bd_dev;
@@ -1609,6 +1618,7 @@ out_error:
 
 xfs_buftarg_t *
 xfs_alloc_buftarg(
+        struct xfs_mount        *mp,
         struct block_device     *bdev,
         int                     external,
         const char              *fsname)
@@ -1617,6 +1627,7 @@ xfs_alloc_buftarg(
 
         btp = kmem_zalloc(sizeof(*btp), KM_SLEEP);
 
+        btp->bt_mount = mp;
         btp->bt_dev =  bdev->bd_dev;
         btp->bt_bdev = bdev;
         if (xfs_setsize_buftarg_early(btp, bdev))
@@ -1625,7 +1636,6 @@ xfs_alloc_buftarg(
                 goto error;
         if (xfs_alloc_delwrite_queue(btp, fsname))
                 goto error;
-        xfs_alloc_bufhash(btp, external);
         return btp;
 
 error:
@@ -1771,7 +1781,6 @@ xfs_buf_delwri_split(
         INIT_LIST_HEAD(list);
         spin_lock(dwlk);
         list_for_each_entry_safe(bp, n, dwq, b_list) {
-                trace_xfs_buf_delwri_split(bp, _RET_IP_);
                 ASSERT(bp->b_flags & XBF_DELWRI);
 
                 if (!XFS_BUF_ISPINNED(bp) && !xfs_buf_cond_lock(bp)) {
@@ -1785,6 +1794,7 @@ xfs_buf_delwri_split(
                                          _XBF_RUN_QUEUES);
                         bp->b_flags |= XBF_WRITE;
                         list_move_tail(&bp->b_list, list);
+                        trace_xfs_buf_delwri_split(bp, _RET_IP_);
                 } else
                         skipped++;
         }
@@ -1916,7 +1926,7 @@ xfs_flush_buftarg(
                         bp = list_first_entry(&wait_list, struct xfs_buf, b_list);
 
                         list_del_init(&bp->b_list);
-                        xfs_iowait(bp);
+                        xfs_buf_iowait(bp);
                         xfs_buf_relse(bp);
                 }
         }
@@ -1933,7 +1943,7 @@ xfs_buf_init(void)
                 goto out;
 
         xfslogd_workqueue = alloc_workqueue("xfslogd",
-                                        WQ_RESCUER | WQ_HIGHPRI, 1);
+                                        WQ_MEM_RECLAIM | WQ_HIGHPRI, 1);
         if (!xfslogd_workqueue)
                 goto out_free_buf_zone;