1 files changed, 213 insertions, 178 deletions

diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c
index c2e30eea74dc..99628508cb11 100644
--- a/fs/xfs/linux-2.6/xfs_aops.c
+++ b/fs/xfs/linux-2.6/xfs_aops.c
@@ -38,6 +38,8 @@
 #include "xfs_rw.h"
 #include "xfs_iomap.h"
 #include "xfs_vnodeops.h"
+#include "xfs_trace.h"
+#include "xfs_bmap.h"
 #include <linux/mpage.h>
 #include <linux/pagevec.h>
 #include <linux/writeback.h>
@@ -76,7 +78,7 @@ xfs_ioend_wake(
                 wake_up(to_ioend_wq(ip));
 }
 
-STATIC void
+void
 xfs_count_page_state(
         struct page             *page,
         int                     *delalloc,
@@ -98,48 +100,6 @@ xfs_count_page_state(
         } while ((bh = bh->b_this_page) != head);
 }
 
-#if defined(XFS_RW_TRACE)
-void
-xfs_page_trace(
-        int             tag,
-        struct inode    *inode,
-        struct page     *page,
-        unsigned long   pgoff)
-{
-        xfs_inode_t     *ip;
-        loff_t          isize = i_size_read(inode);
-        loff_t          offset = page_offset(page);
-        int             delalloc = -1, unmapped = -1, unwritten = -1;
-
-        if (page_has_buffers(page))
-                xfs_count_page_state(page, &delalloc, &unmapped, &unwritten);
-
-        ip = XFS_I(inode);
-        if (!ip->i_rwtrace)
-                return;
-
-        ktrace_enter(ip->i_rwtrace,
-                (void *)((unsigned long)tag),
-                (void *)ip,
-                (void *)inode,
-                (void *)page,
-                (void *)pgoff,
-                (void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
-                (void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
-                (void *)((unsigned long)((isize >> 32) & 0xffffffff)),
-                (void *)((unsigned long)(isize & 0xffffffff)),
-                (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
-                (void *)((unsigned long)(offset & 0xffffffff)),
-                (void *)((unsigned long)delalloc),
-                (void *)((unsigned long)unmapped),
-                (void *)((unsigned long)unwritten),
-                (void *)((unsigned long)current_pid()),
-                (void *)NULL);
-}
-#else
-#define xfs_page_trace(tag, inode, page, pgoff)
-#endif
-
 STATIC struct block_device *
 xfs_find_bdev_for_inode(
         struct xfs_inode        *ip)
@@ -204,14 +164,17 @@ xfs_ioend_new_eof(
 }
 
 /*
- * Update on-disk file size now that data has been written to disk.
- * The current in-memory file size is i_size.  If a write is beyond
- * eof i_new_size will be the intended file size until i_size is
- * updated.  If this write does not extend all the way to the valid
- * file size then restrict this update to the end of the write.
+ * Update on-disk file size now that data has been written to disk.  The
+ * current in-memory file size is i_size.  If a write is beyond eof i_new_size
+ * will be the intended file size until i_size is updated.  If this write does
+ * not extend all the way to the valid file size then restrict this update to
+ * the end of the write.
+ *
+ * This function does not block as blocking on the inode lock in IO completion
+ * can lead to IO completion order dependency deadlocks.. If it can't get the
+ * inode ilock it will return EAGAIN. Callers must handle this.
  */
-
-STATIC void
+STATIC int
 xfs_setfilesize(
         xfs_ioend_t             *ioend)
 {
@@ -222,85 +185,19 @@ xfs_setfilesize(
         ASSERT(ioend->io_type != IOMAP_READ);
 
         if (unlikely(ioend->io_error))
-                return;
+                return 0;
+
+        if (!xfs_ilock_nowait(ip, XFS_ILOCK_EXCL))
+                return EAGAIN;
 
-        xfs_ilock(ip, XFS_ILOCK_EXCL);
         isize = xfs_ioend_new_eof(ioend);
         if (isize) {
                 ip->i_d.di_size = isize;
-                xfs_mark_inode_dirty_sync(ip);
+                xfs_mark_inode_dirty(ip);
         }
 
         xfs_iunlock(ip, XFS_ILOCK_EXCL);
-}
-
-/*
- * Buffered IO write completion for delayed allocate extents.
- */
-STATIC void
-xfs_end_bio_delalloc(
-        struct work_struct      *work)
-{
-        xfs_ioend_t             *ioend =
-                container_of(work, xfs_ioend_t, io_work);
-
-        xfs_setfilesize(ioend);
-        xfs_destroy_ioend(ioend);
-}
-
-/*
- * Buffered IO write completion for regular, written extents.
- */
-STATIC void
-xfs_end_bio_written(
-        struct work_struct      *work)
-{
-        xfs_ioend_t             *ioend =
-                container_of(work, xfs_ioend_t, io_work);
-
-        xfs_setfilesize(ioend);
-        xfs_destroy_ioend(ioend);
-}
-
-/*
- * IO write completion for unwritten extents.
- *
- * Issue transactions to convert a buffer range from unwritten
- * to written extents.
- */
-STATIC void
-xfs_end_bio_unwritten(
-        struct work_struct      *work)
-{
-        xfs_ioend_t             *ioend =
-                container_of(work, xfs_ioend_t, io_work);
-        struct xfs_inode        *ip = XFS_I(ioend->io_inode);
-        xfs_off_t               offset = ioend->io_offset;
-        size_t                  size = ioend->io_size;
-
-        if (likely(!ioend->io_error)) {
-                if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
-                        int error;
-                        error = xfs_iomap_write_unwritten(ip, offset, size);
-                        if (error)
-                                ioend->io_error = error;
-                }
-                xfs_setfilesize(ioend);
-        }
-        xfs_destroy_ioend(ioend);
-}
-
-/*
- * IO read completion for regular, written extents.
- */
-STATIC void
-xfs_end_bio_read(
-        struct work_struct      *work)
-{
-        xfs_ioend_t             *ioend =
-                container_of(work, xfs_ioend_t, io_work);
-
-        xfs_destroy_ioend(ioend);
+        return 0;
 }
 
 /*
@@ -314,10 +211,10 @@ xfs_finish_ioend(
         int             wait)
 {
         if (atomic_dec_and_test(&ioend->io_remaining)) {
-                struct workqueue_struct *wq = xfsdatad_workqueue;
-                if (ioend->io_work.func == xfs_end_bio_unwritten)
-                        wq = xfsconvertd_workqueue;
+                struct workqueue_struct *wq;
 
+                wq = (ioend->io_type == IOMAP_UNWRITTEN) ?
+                        xfsconvertd_workqueue : xfsdatad_workqueue;
                 queue_work(wq, &ioend->io_work);
                 if (wait)
                         flush_workqueue(wq);
@@ -325,6 +222,53 @@ xfs_finish_ioend(
 }
 
 /*
+ * IO write completion.
+ */
+STATIC void
+xfs_end_io(
+        struct work_struct *work)
+{
+        xfs_ioend_t     *ioend = container_of(work, xfs_ioend_t, io_work);
+        struct xfs_inode *ip = XFS_I(ioend->io_inode);
+        int             error = 0;
+
+        /*
+         * For unwritten extents we need to issue transactions to convert a
+         * range to normal written extens after the data I/O has finished.
+         */
+        if (ioend->io_type == IOMAP_UNWRITTEN &&
+            likely(!ioend->io_error && !XFS_FORCED_SHUTDOWN(ip->i_mount))) {
+
+                error = xfs_iomap_write_unwritten(ip, ioend->io_offset,
+                                                 ioend->io_size);
+                if (error)
+                        ioend->io_error = error;
+        }
+
+        /*
+         * We might have to update the on-disk file size after extending
+         * writes.
+         */
+        if (ioend->io_type != IOMAP_READ) {
+                error = xfs_setfilesize(ioend);
+                ASSERT(!error || error == EAGAIN);
+        }
+
+        /*
+         * If we didn't complete processing of the ioend, requeue it to the
+         * tail of the workqueue for another attempt later. Otherwise destroy
+         * it.
+         */
+        if (error == EAGAIN) {
+                atomic_inc(&ioend->io_remaining);
+                xfs_finish_ioend(ioend, 0);
+                /* ensure we don't spin on blocked ioends */
+                delay(1);
+        } else
+                xfs_destroy_ioend(ioend);
+}
+
+/*
  * Allocate and initialise an IO completion structure.
  * We need to track unwritten extent write completion here initially.
  * We'll need to extend this for updating the ondisk inode size later
@@ -355,15 +299,7 @@ xfs_alloc_ioend(
         ioend->io_offset = 0;
         ioend->io_size = 0;
 
-        if (type == IOMAP_UNWRITTEN)
-                INIT_WORK(&ioend->io_work, xfs_end_bio_unwritten);
-        else if (type == IOMAP_DELAY)
-                INIT_WORK(&ioend->io_work, xfs_end_bio_delalloc);
-        else if (type == IOMAP_READ)
-                INIT_WORK(&ioend->io_work, xfs_end_bio_read);
-        else
-                INIT_WORK(&ioend->io_work, xfs_end_bio_written);
-
+        INIT_WORK(&ioend->io_work, xfs_end_io);
         return ioend;
 }
 
@@ -380,7 +316,7 @@ xfs_map_blocks(
         return -xfs_iomap(XFS_I(inode), offset, count, flags, mapp, &nmaps);
 }
 
-STATIC_INLINE int
+STATIC int
 xfs_iomap_valid(
         xfs_iomap_t             *iomapp,
         loff_t                  offset)
@@ -412,8 +348,9 @@ xfs_end_bio(
 
 STATIC void
 xfs_submit_ioend_bio(
-        xfs_ioend_t     *ioend,
-        struct bio      *bio)
+        struct writeback_control *wbc,
+        xfs_ioend_t             *ioend,
+        struct bio              *bio)
 {
         atomic_inc(&ioend->io_remaining);
         bio->bi_private = ioend;
@@ -424,9 +361,10 @@ xfs_submit_ioend_bio(
          * but don't update the inode size until I/O completion.
          */
         if (xfs_ioend_new_eof(ioend))
-                xfs_mark_inode_dirty_sync(XFS_I(ioend->io_inode));
+                xfs_mark_inode_dirty(XFS_I(ioend->io_inode));
 
-        submit_bio(WRITE, bio);
+        submit_bio(wbc->sync_mode == WB_SYNC_ALL ?
+                   WRITE_SYNC_PLUG : WRITE, bio);
         ASSERT(!bio_flagged(bio, BIO_EOPNOTSUPP));
         bio_put(bio);
 }
@@ -505,6 +443,7 @@ static inline int bio_add_buffer(struct bio *bio, struct buffer_head *bh)
  */
 STATIC void
 xfs_submit_ioend(
+        struct writeback_control *wbc,
         xfs_ioend_t             *ioend)
 {
         xfs_ioend_t             *head = ioend;
@@ -533,19 +472,19 @@ xfs_submit_ioend(
  retry:
                                 bio = xfs_alloc_ioend_bio(bh);
                         } else if (bh->b_blocknr != lastblock + 1) {
-                                xfs_submit_ioend_bio(ioend, bio);
+                                xfs_submit_ioend_bio(wbc, ioend, bio);
                                 goto retry;
                         }
 
                         if (bio_add_buffer(bio, bh) != bh->b_size) {
-                                xfs_submit_ioend_bio(ioend, bio);
+                                xfs_submit_ioend_bio(wbc, ioend, bio);
                                 goto retry;
                         }
 
                         lastblock = bh->b_blocknr;
                 }
                 if (bio)
-                        xfs_submit_ioend_bio(ioend, bio);
+                        xfs_submit_ioend_bio(wbc, ioend, bio);
                 xfs_finish_ioend(ioend, 0);
         } while ((ioend = next) != NULL);
 }
@@ -904,16 +843,9 @@ xfs_convert_page(
 
         if (startio) {
                 if (count) {
-                        struct backing_dev_info *bdi;
-
-                        bdi = inode->i_mapping->backing_dev_info;
                         wbc->nr_to_write--;
-                        if (bdi_write_congested(bdi)) {
-                                wbc->encountered_congestion = 1;
-                                done = 1;
-                        } else if (wbc->nr_to_write <= 0) {
+                        if (wbc->nr_to_write <= 0)
                                 done = 1;
-                        }
                 }
                 xfs_start_page_writeback(page, !page_dirty, count);
         }
@@ -962,6 +894,125 @@ xfs_cluster_write(
         }
 }
 
+STATIC void
+xfs_vm_invalidatepage(
+        struct page             *page,
+        unsigned long           offset)
+{
+        trace_xfs_invalidatepage(page->mapping->host, page, offset);
+        block_invalidatepage(page, offset);
+}
+
+/*
+ * If the page has delalloc buffers on it, we need to punch them out before we
+ * invalidate the page. If we don't, we leave a stale delalloc mapping on the
+ * inode that can trip a BUG() in xfs_get_blocks() later on if a direct IO read
+ * is done on that same region - the delalloc extent is returned when none is
+ * supposed to be there.
+ *
+ * We prevent this by truncating away the delalloc regions on the page before
+ * invalidating it. Because they are delalloc, we can do this without needing a
+ * transaction. Indeed - if we get ENOSPC errors, we have to be able to do this
+ * truncation without a transaction as there is no space left for block
+ * reservation (typically why we see a ENOSPC in writeback).
+ *
+ * This is not a performance critical path, so for now just do the punching a
+ * buffer head at a time.
+ */
+STATIC void
+xfs_aops_discard_page(
+        struct page             *page)
+{
+        struct inode            *inode = page->mapping->host;
+        struct xfs_inode        *ip = XFS_I(inode);
+        struct buffer_head      *bh, *head;
+        loff_t                  offset = page_offset(page);
+        ssize_t                 len = 1 << inode->i_blkbits;
+
+        if (!xfs_is_delayed_page(page, IOMAP_DELAY))
+                goto out_invalidate;
+
+        if (XFS_FORCED_SHUTDOWN(ip->i_mount))
+                goto out_invalidate;
+
+        xfs_fs_cmn_err(CE_ALERT, ip->i_mount,
+                "page discard on page %p, inode 0x%llx, offset %llu.",
+                        page, ip->i_ino, offset);
+
+        xfs_ilock(ip, XFS_ILOCK_EXCL);
+        bh = head = page_buffers(page);
+        do {
+                int             done;
+                xfs_fileoff_t   offset_fsb;
+                xfs_bmbt_irec_t imap;
+                int             nimaps = 1;
+                int             error;
+                xfs_fsblock_t   firstblock;
+                xfs_bmap_free_t flist;
+
+                if (!buffer_delay(bh))
+                        goto next_buffer;
+
+                offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset);
+
+                /*
+                 * Map the range first and check that it is a delalloc extent
+                 * before trying to unmap the range. Otherwise we will be
+                 * trying to remove a real extent (which requires a
+                 * transaction) or a hole, which is probably a bad idea...
+                 */
+                error = xfs_bmapi(NULL, ip, offset_fsb, 1,
+                                XFS_BMAPI_ENTIRE,  NULL, 0, &imap,
+                                &nimaps, NULL, NULL);
+
+                if (error) {
+                        /* something screwed, just bail */
+                        if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
+                                xfs_fs_cmn_err(CE_ALERT, ip->i_mount,
+                                "page discard failed delalloc mapping lookup.");
+                        }
+                        break;
+                }
+                if (!nimaps) {
+                        /* nothing there */
+                        goto next_buffer;
+                }
+                if (imap.br_startblock != DELAYSTARTBLOCK) {
+                        /* been converted, ignore */
+                        goto next_buffer;
+                }
+                WARN_ON(imap.br_blockcount == 0);
+
+                /*
+                 * Note: while we initialise the firstblock/flist pair, they
+                 * should never be used because blocks should never be
+                 * allocated or freed for a delalloc extent and hence we need
+                 * don't cancel or finish them after the xfs_bunmapi() call.
+                 */
+                xfs_bmap_init(&flist, &firstblock);
+                error = xfs_bunmapi(NULL, ip, offset_fsb, 1, 0, 1, &firstblock,
+                                        &flist, NULL, &done);
+
+                ASSERT(!flist.xbf_count && !flist.xbf_first);
+                if (error) {
+                        /* something screwed, just bail */
+                        if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
+                                xfs_fs_cmn_err(CE_ALERT, ip->i_mount,
+                        "page discard unable to remove delalloc mapping.");
+                        }
+                        break;
+                }
+next_buffer:
+                offset += len;
+
+        } while ((bh = bh->b_this_page) != head);
+
+        xfs_iunlock(ip, XFS_ILOCK_EXCL);
+out_invalidate:
+        xfs_vm_invalidatepage(page, 0);
+        return;
+}
+
 /*
  * Calling this without startio set means we are being asked to make a dirty
  * page ready for freeing it's buffers.  When called with startio set then
@@ -1198,7 +1249,7 @@ xfs_page_state_convert(
         }
 
         if (iohead)
-                xfs_submit_ioend(iohead);
+                xfs_submit_ioend(wbc, iohead);
 
         return page_dirty;
 
@@ -1213,7 +1264,7 @@ error:
          */
         if (err != -EAGAIN) {
                 if (!unmapped)
-                        block_invalidatepage(page, 0);
+                        xfs_aops_discard_page(page);
                 ClearPageUptodate(page);
         }
         return err;
@@ -1249,7 +1300,7 @@ xfs_vm_writepage(
         int                     delalloc, unmapped, unwritten;
         struct inode            *inode = page->mapping->host;
 
-        xfs_page_trace(XFS_WRITEPAGE_ENTER, inode, page, 0);
+        trace_xfs_writepage(inode, page, 0);
 
         /*
          * We need a transaction if:
@@ -1354,7 +1405,7 @@ xfs_vm_releasepage(
                 .nr_to_write = 1,
         };
 
-        xfs_page_trace(XFS_RELEASEPAGE_ENTER, inode, page, 0);
+        trace_xfs_releasepage(inode, page, 0);
 
         if (!page_has_buffers(page))
                 return 0;
@@ -1535,7 +1586,7 @@ xfs_end_io_direct(
                  * didn't map an unwritten extent so switch it's completion
                  * handler.
                  */
-                INIT_WORK(&ioend->io_work, xfs_end_bio_written);
+                ioend->io_type = IOMAP_NEW;
                 xfs_finish_ioend(ioend, 0);
         }
 
@@ -1562,19 +1613,13 @@ xfs_vm_direct_IO(
 
         bdev = xfs_find_bdev_for_inode(XFS_I(inode));
 
-        if (rw == WRITE) {
-                iocb->private = xfs_alloc_ioend(inode, IOMAP_UNWRITTEN);
-                ret = blockdev_direct_IO_own_locking(rw, iocb, inode,
-                        bdev, iov, offset, nr_segs,
-                        xfs_get_blocks_direct,
-                        xfs_end_io_direct);
-        } else {
-                iocb->private = xfs_alloc_ioend(inode, IOMAP_READ);
-                ret = blockdev_direct_IO_no_locking(rw, iocb, inode,
-                        bdev, iov, offset, nr_segs,
-                        xfs_get_blocks_direct,
-                        xfs_end_io_direct);
-        }
+        iocb->private = xfs_alloc_ioend(inode, rw == WRITE ?
+                                        IOMAP_UNWRITTEN : IOMAP_READ);
+
+        ret = blockdev_direct_IO_no_locking(rw, iocb, inode, bdev, iov,
+                                            offset, nr_segs,
+                                            xfs_get_blocks_direct,
+                                            xfs_end_io_direct);
 
         if (unlikely(ret != -EIOCBQUEUED && iocb->private))
                 xfs_destroy_ioend(iocb->private);
@@ -1629,16 +1674,6 @@ xfs_vm_readpages(
         return mpage_readpages(mapping, pages, nr_pages, xfs_get_blocks);
 }
 
-STATIC void
-xfs_vm_invalidatepage(
-        struct page             *page,
-        unsigned long           offset)
-{
-        xfs_page_trace(XFS_INVALIDPAGE_ENTER,
-                        page->mapping->host, page, offset);
-        block_invalidatepage(page, offset);
-}
-
 const struct address_space_operations xfs_address_space_operations = {
         .readpage               = xfs_vm_readpage,
         .readpages              = xfs_vm_readpages,