1 files changed, 245 insertions, 45 deletions

diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index 77b8be81c769..d50df3a8101c 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -33,6 +33,7 @@
 #include <linux/migrate.h>
 #include <linux/backing-dev.h>
 #include <linux/freezer.h>
+#include <linux/list_sort.h>
 
 #include "xfs_sb.h"
 #include "xfs_inum.h"
@@ -1051,22 +1052,30 @@ xfs_buf_ioerror(
 }
 
 int
-xfs_bawrite(
-        void                    *mp,
+xfs_bwrite(
+        struct xfs_mount        *mp,
         struct xfs_buf          *bp)
 {
-        trace_xfs_buf_bawrite(bp, _RET_IP_);
+        int                     iowait = (bp->b_flags & XBF_ASYNC) == 0;
+        int                     error = 0;
 
-        ASSERT(bp->b_bn != XFS_BUF_DADDR_NULL);
+        bp->b_strat = xfs_bdstrat_cb;
+        bp->b_mount = mp;
+        bp->b_flags |= XBF_WRITE;
+        if (!iowait)
+                bp->b_flags |= _XBF_RUN_QUEUES;
 
         xfs_buf_delwri_dequeue(bp);
+        xfs_buf_iostrategy(bp);
 
-        bp->b_flags &= ~(XBF_READ | XBF_DELWRI | XBF_READ_AHEAD);
-        bp->b_flags |= (XBF_WRITE | XBF_ASYNC | _XBF_RUN_QUEUES);
+        if (iowait) {
+                error = xfs_buf_iowait(bp);
+                if (error)
+                        xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR);
+                xfs_buf_relse(bp);
+        }
 
-        bp->b_mount = mp;
-        bp->b_strat = xfs_bdstrat_cb;
-        return xfs_bdstrat_cb(bp);
+        return error;
 }
 
 void
@@ -1085,6 +1094,126 @@ xfs_bdwrite(
         xfs_buf_delwri_queue(bp, 1);
 }
 
+/*
+ * 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
+ * so that the proper iodone callbacks get called.
+ */
+STATIC int
+xfs_bioerror(
+        xfs_buf_t *bp)
+{
+#ifdef XFSERRORDEBUG
+        ASSERT(XFS_BUF_ISREAD(bp) || bp->b_iodone);
+#endif
+
+        /*
+         * No need to wait until the buffer is unpinned, we aren't flushing it.
+         */
+        XFS_BUF_ERROR(bp, EIO);
+
+        /*
+         * We're calling biodone, so delete XBF_DONE flag.
+         */
+        XFS_BUF_UNREAD(bp);
+        XFS_BUF_UNDELAYWRITE(bp);
+        XFS_BUF_UNDONE(bp);
+        XFS_BUF_STALE(bp);
+
+        XFS_BUF_CLR_BDSTRAT_FUNC(bp);
+        xfs_biodone(bp);
+
+        return EIO;
+}
+
+/*
+ * Same as xfs_bioerror, except that we are releasing the buffer
+ * here ourselves, and avoiding the biodone call.
+ * This is meant for userdata errors; metadata bufs come with
+ * iodone functions attached, so that we can track down errors.
+ */
+STATIC int
+xfs_bioerror_relse(
+        struct xfs_buf  *bp)
+{
+        int64_t         fl = XFS_BUF_BFLAGS(bp);
+        /*
+         * No need to wait until the buffer is unpinned.
+         * We aren't flushing it.
+         *
+         * chunkhold expects B_DONE to be set, whether
+         * we actually finish the I/O or not. We don't want to
+         * change that interface.
+         */
+        XFS_BUF_UNREAD(bp);
+        XFS_BUF_UNDELAYWRITE(bp);
+        XFS_BUF_DONE(bp);
+        XFS_BUF_STALE(bp);
+        XFS_BUF_CLR_IODONE_FUNC(bp);
+        XFS_BUF_CLR_BDSTRAT_FUNC(bp);
+        if (!(fl & XBF_ASYNC)) {
+                /*
+                 * Mark b_error and B_ERROR _both_.
+                 * Lot's of chunkcache code assumes that.
+                 * There's no reason to mark error for
+                 * ASYNC buffers.
+                 */
+                XFS_BUF_ERROR(bp, EIO);
+                XFS_BUF_FINISH_IOWAIT(bp);
+        } else {
+                xfs_buf_relse(bp);
+        }
+
+        return EIO;
+}
+
+
+/*
+ * All xfs metadata buffers except log state machine buffers
+ * get this attached as their b_bdstrat callback function.
+ * This is so that we can catch a buffer
+ * after prematurely unpinning it to forcibly shutdown the filesystem.
+ */
+int
+xfs_bdstrat_cb(
+        struct xfs_buf  *bp)
+{
+        if (XFS_FORCED_SHUTDOWN(bp->b_mount)) {
+                trace_xfs_bdstrat_shut(bp, _RET_IP_);
+                /*
+                 * Metadata write that didn't get logged but
+                 * written delayed anyway. These aren't associated
+                 * with a transaction, and can be ignored.
+                 */
+                if (!bp->b_iodone && !XFS_BUF_ISREAD(bp))
+                        return xfs_bioerror_relse(bp);
+                else
+                        return xfs_bioerror(bp);
+        }
+
+        xfs_buf_iorequest(bp);
+        return 0;
+}
+
+/*
+ * Wrapper around bdstrat so that we can stop data from going to disk in case
+ * we are shutting down the filesystem.  Typically user data goes thru this
+ * path; one of the exceptions is the superblock.
+ */
+void
+xfsbdstrat(
+        struct xfs_mount        *mp,
+        struct xfs_buf          *bp)
+{
+        if (XFS_FORCED_SHUTDOWN(mp)) {
+                trace_xfs_bdstrat_shut(bp, _RET_IP_);
+                xfs_bioerror_relse(bp);
+                return;
+        }
+
+        xfs_buf_iorequest(bp);
+}
+
 STATIC void
 _xfs_buf_ioend(
         xfs_buf_t               *bp,
@@ -1296,7 +1425,7 @@ xfs_buf_iomove(
         xfs_buf_t               *bp,    /* buffer to process            */
         size_t                  boff,   /* starting buffer offset       */
         size_t                  bsize,  /* length to copy               */
-        caddr_t                 data,   /* data address                 */
+        void                    *data,  /* data address                 */
         xfs_buf_rw_t            mode)   /* read/write/zero flag         */
 {
         size_t                  bend, cpoff, csize;
@@ -1378,8 +1507,8 @@ xfs_alloc_bufhash(
 
         btp->bt_hashshift = external ? 3 : 8;   /* 8 or 256 buckets */
         btp->bt_hashmask = (1 << btp->bt_hashshift) - 1;
-        btp->bt_hash = kmem_zalloc((1 << btp->bt_hashshift) *
-                                        sizeof(xfs_bufhash_t), KM_SLEEP | KM_LARGE);
+        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);
@@ -1390,7 +1519,7 @@ STATIC void
 xfs_free_bufhash(
         xfs_buftarg_t           *btp)
 {
-        kmem_free(btp->bt_hash);
+        kmem_free_large(btp->bt_hash);
         btp->bt_hash = NULL;
 }
 
@@ -1595,6 +1724,11 @@ xfs_buf_delwri_queue(
                 list_del(&bp->b_list);
         }
 
+        if (list_empty(dwq)) {
+                /* start xfsbufd as it is about to have something to do */
+                wake_up_process(bp->b_target->bt_task);
+        }
+
         bp->b_flags |= _XBF_DELWRI_Q;
         list_add_tail(&bp->b_list, dwq);
         bp->b_queuetime = jiffies;
@@ -1626,6 +1760,35 @@ xfs_buf_delwri_dequeue(
         trace_xfs_buf_delwri_dequeue(bp, _RET_IP_);
 }
 
+/*
+ * If a delwri buffer needs to be pushed before it has aged out, then promote
+ * it to the head of the delwri queue so that it will be flushed on the next
+ * xfsbufd run. We do this by resetting the queuetime of the buffer to be older
+ * than the age currently needed to flush the buffer. Hence the next time the
+ * xfsbufd sees it is guaranteed to be considered old enough to flush.
+ */
+void
+xfs_buf_delwri_promote(
+        struct xfs_buf  *bp)
+{
+        struct xfs_buftarg *btp = bp->b_target;
+        long            age = xfs_buf_age_centisecs * msecs_to_jiffies(10) + 1;
+
+        ASSERT(bp->b_flags & XBF_DELWRI);
+        ASSERT(bp->b_flags & _XBF_DELWRI_Q);
+
+        /*
+         * Check the buffer age before locking the delayed write queue as we
+         * don't need to promote buffers that are already past the flush age.
+         */
+        if (bp->b_queuetime < jiffies - age)
+                return;
+        bp->b_queuetime = jiffies - age;
+        spin_lock(&btp->bt_delwrite_lock);
+        list_move(&bp->b_list, &btp->bt_delwrite_queue);
+        spin_unlock(&btp->bt_delwrite_lock);
+}
+
 STATIC void
 xfs_buf_runall_queues(
         struct workqueue_struct *queue)
@@ -1644,6 +1807,8 @@ xfsbufd_wakeup(
         list_for_each_entry(btp, &xfs_buftarg_list, bt_list) {
                 if (test_bit(XBT_FORCE_SLEEP, &btp->bt_flags))
                         continue;
+                if (list_empty(&btp->bt_delwrite_queue))
+                        continue;
                 set_bit(XBT_FORCE_FLUSH, &btp->bt_flags);
                 wake_up_process(btp->bt_task);
         }
@@ -1694,20 +1859,53 @@ xfs_buf_delwri_split(
 
 }
 
+/*
+ * Compare function is more complex than it needs to be because
+ * the return value is only 32 bits and we are doing comparisons
+ * on 64 bit values
+ */
+static int
+xfs_buf_cmp(
+        void            *priv,
+        struct list_head *a,
+        struct list_head *b)
+{
+        struct xfs_buf  *ap = container_of(a, struct xfs_buf, b_list);
+        struct xfs_buf  *bp = container_of(b, struct xfs_buf, b_list);
+        xfs_daddr_t             diff;
+
+        diff = ap->b_bn - bp->b_bn;
+        if (diff < 0)
+                return -1;
+        if (diff > 0)
+                return 1;
+        return 0;
+}
+
+void
+xfs_buf_delwri_sort(
+        xfs_buftarg_t   *target,
+        struct list_head *list)
+{
+        list_sort(NULL, list, xfs_buf_cmp);
+}
+
 STATIC int
 xfsbufd(
         void            *data)
 {
-        struct list_head tmp;
-        xfs_buftarg_t   *target = (xfs_buftarg_t *)data;
-        int             count;
-        xfs_buf_t       *bp;
+        xfs_buftarg_t   *target = (xfs_buftarg_t *)data;
 
         current->flags |= PF_MEMALLOC;
 
         set_freezable();
 
         do {
+                long    age = xfs_buf_age_centisecs * msecs_to_jiffies(10);
+                long    tout = xfs_buf_timer_centisecs * msecs_to_jiffies(10);
+                int     count = 0;
+                struct list_head tmp;
+
                 if (unlikely(freezing(current))) {
                         set_bit(XBT_FORCE_SLEEP, &target->bt_flags);
                         refrigerator();
@@ -1715,17 +1913,16 @@ xfsbufd(
                         clear_bit(XBT_FORCE_SLEEP, &target->bt_flags);
                 }
 
-                schedule_timeout_interruptible(
-                        xfs_buf_timer_centisecs * msecs_to_jiffies(10));
-
-                xfs_buf_delwri_split(target, &tmp,
-                                xfs_buf_age_centisecs * msecs_to_jiffies(10));
+                /* sleep for a long time if there is nothing to do. */
+                if (list_empty(&target->bt_delwrite_queue))
+                        tout = MAX_SCHEDULE_TIMEOUT;
+                schedule_timeout_interruptible(tout);
 
-                count = 0;
+                xfs_buf_delwri_split(target, &tmp, age);
+                list_sort(NULL, &tmp, xfs_buf_cmp);
                 while (!list_empty(&tmp)) {
-                        bp = list_entry(tmp.next, xfs_buf_t, b_list);
-                        ASSERT(target == bp->b_target);
-
+                        struct xfs_buf *bp;
+                        bp = list_first_entry(&tmp, struct xfs_buf, b_list);
                         list_del_init(&bp->b_list);
                         xfs_buf_iostrategy(bp);
                         count++;
@@ -1751,42 +1948,45 @@ xfs_flush_buftarg(
         xfs_buftarg_t   *target,
         int             wait)
 {
-        struct list_head tmp;
-        xfs_buf_t       *bp, *n;
+        xfs_buf_t       *bp;
         int             pincount = 0;
+        LIST_HEAD(tmp_list);
+        LIST_HEAD(wait_list);
 
         xfs_buf_runall_queues(xfsconvertd_workqueue);
         xfs_buf_runall_queues(xfsdatad_workqueue);
         xfs_buf_runall_queues(xfslogd_workqueue);
 
         set_bit(XBT_FORCE_FLUSH, &target->bt_flags);
-        pincount = xfs_buf_delwri_split(target, &tmp, 0);
+        pincount = xfs_buf_delwri_split(target, &tmp_list, 0);
 
         /*
-         * Dropped the delayed write list lock, now walk the temporary list
+         * Dropped the delayed write list lock, now walk the temporary list.
+         * All I/O is issued async and then if we need to wait for completion
+         * we do that after issuing all the IO.
          */
-        list_for_each_entry_safe(bp, n, &tmp, b_list) {
+        list_sort(NULL, &tmp_list, xfs_buf_cmp);
+        while (!list_empty(&tmp_list)) {
+                bp = list_first_entry(&tmp_list, struct xfs_buf, b_list);
                 ASSERT(target == bp->b_target);
-                if (wait)
+                list_del_init(&bp->b_list);
+                if (wait) {
                         bp->b_flags &= ~XBF_ASYNC;
-                else
-                        list_del_init(&bp->b_list);
-
+                        list_add(&bp->b_list, &wait_list);
+                }
                 xfs_buf_iostrategy(bp);
         }
 
-        if (wait)
+        if (wait) {
+                /* Expedite and wait for IO to complete. */
                 blk_run_address_space(target->bt_mapping);
+                while (!list_empty(&wait_list)) {
+                        bp = list_first_entry(&wait_list, struct xfs_buf, b_list);
 
-        /*
-         * Remaining list items must be flushed before returning
-         */
-        while (!list_empty(&tmp)) {
-                bp = list_entry(tmp.next, xfs_buf_t, b_list);
-
-                list_del_init(&bp->b_list);
-                xfs_iowait(bp);
-                xfs_buf_relse(bp);
+                        list_del_init(&bp->b_list);
+                        xfs_iowait(bp);
+                        xfs_buf_relse(bp);
+                }
         }
 
         return pincount;