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path: root/fs/xfs/linux-2.6/xfs_aops.c
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Diffstat (limited to 'fs/xfs/linux-2.6/xfs_aops.c')
-rw-r--r--fs/xfs/linux-2.6/xfs_aops.c221
1 files changed, 172 insertions, 49 deletions
diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c
index 66abe36c121..9083357f9e4 100644
--- a/fs/xfs/linux-2.6/xfs_aops.c
+++ b/fs/xfs/linux-2.6/xfs_aops.c
@@ -39,6 +39,7 @@
#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>
@@ -163,14 +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)
{
@@ -181,16 +185,40 @@ 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);
+ return 0;
+}
+
+/*
+ * Schedule IO completion handling on a xfsdatad if this was
+ * the final hold on this ioend. If we are asked to wait,
+ * flush the workqueue.
+ */
+STATIC void
+xfs_finish_ioend(
+ xfs_ioend_t *ioend,
+ int wait)
+{
+ if (atomic_dec_and_test(&ioend->io_remaining)) {
+ 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);
+ }
}
/*
@@ -198,11 +226,11 @@ xfs_setfilesize(
*/
STATIC void
xfs_end_io(
- struct work_struct *work)
+ 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_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
@@ -210,7 +238,6 @@ xfs_end_io(
*/
if (ioend->io_type == IOMAP_UNWRITTEN &&
likely(!ioend->io_error && !XFS_FORCED_SHUTDOWN(ip->i_mount))) {
- int error;
error = xfs_iomap_write_unwritten(ip, ioend->io_offset,
ioend->io_size);
@@ -222,30 +249,23 @@ xfs_end_io(
* We might have to update the on-disk file size after extending
* writes.
*/
- if (ioend->io_type != IOMAP_READ)
- xfs_setfilesize(ioend);
- xfs_destroy_ioend(ioend);
-}
-
-/*
- * Schedule IO completion handling on a xfsdatad if this was
- * the final hold on this ioend. If we are asked to wait,
- * flush the workqueue.
- */
-STATIC void
-xfs_finish_ioend(
- xfs_ioend_t *ioend,
- int wait)
-{
- if (atomic_dec_and_test(&ioend->io_remaining)) {
- 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);
+ 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);
}
/*
@@ -341,7 +361,7 @@ 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(wbc->sync_mode == WB_SYNC_ALL ?
WRITE_SYNC_PLUG : WRITE, bio);
@@ -874,6 +894,118 @@ 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;
+
+ 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 */
+ 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 */
+ 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
@@ -1125,7 +1257,7 @@ error:
*/
if (err != -EAGAIN) {
if (!unmapped)
- block_invalidatepage(page, 0);
+ xfs_aops_discard_page(page);
ClearPageUptodate(page);
}
return err;
@@ -1535,15 +1667,6 @@ xfs_vm_readpages(
return mpage_readpages(mapping, pages, nr_pages, xfs_get_blocks);
}
-STATIC void
-xfs_vm_invalidatepage(
- struct page *page,
- unsigned long offset)
-{
- trace_xfs_invalidatepage(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,