xfs: remove i_iocount

We now have an i_dio_count filed and surrounding infrastructure to wait
for direct I/O completion instead of i_icount, and we have never needed
to iocount waits for buffered I/O given that we only set the page uptodate
after finishing all required work.  Thus remove i_iocount, and replace
the actually needed waits with calls to inode_dio_wait.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Alex Elder <aelder@sgi.com>

9 files changed, 9 insertions, 67 deletions

diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index e1ff0770784e..46bba3e0af47 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -38,40 +38,6 @@
 #include <linux/pagevec.h>
 #include <linux/writeback.h>
 
-
-/*
- * Prime number of hash buckets since address is used as the key.
- */
-#define NVSYNC          37
-#define to_ioend_wq(v)  (&xfs_ioend_wq[((unsigned long)v) % NVSYNC])
-static wait_queue_head_t xfs_ioend_wq[NVSYNC];
-
-void __init
-xfs_ioend_init(void)
-{
-        int i;
-
-        for (i = 0; i < NVSYNC; i++)
-                init_waitqueue_head(&xfs_ioend_wq[i]);
-}
-
-void
-xfs_ioend_wait(
-        xfs_inode_t     *ip)
-{
-        wait_queue_head_t *wq = to_ioend_wq(ip);
-
-        wait_event(*wq, (atomic_read(&ip->i_iocount) == 0));
-}
-
-STATIC void
-xfs_ioend_wake(
-        xfs_inode_t     *ip)
-{
-        if (atomic_dec_and_test(&ip->i_iocount))
-                wake_up(to_ioend_wq(ip));
-}
-
 void
 xfs_count_page_state(
         struct page             *page,
@@ -115,7 +81,6 @@ xfs_destroy_ioend(
         xfs_ioend_t             *ioend)
 {
         struct buffer_head      *bh, *next;
-        struct xfs_inode        *ip = XFS_I(ioend->io_inode);
 
         for (bh = ioend->io_buffer_head; bh; bh = next) {
                 next = bh->b_private;
@@ -127,7 +92,7 @@ xfs_destroy_ioend(
                         aio_complete(ioend->io_iocb, ioend->io_result, 0);
                 inode_dio_done(ioend->io_inode);
         }
-        xfs_ioend_wake(ip);
+
         mempool_free(ioend, xfs_ioend_pool);
 }
 
@@ -298,7 +263,6 @@ xfs_alloc_ioend(
         ioend->io_inode = inode;
         ioend->io_buffer_head = NULL;
         ioend->io_buffer_tail = NULL;
-        atomic_inc(&XFS_I(ioend->io_inode)->i_iocount);
         ioend->io_offset = 0;
         ioend->io_size = 0;
         ioend->io_iocb = NULL;
@@ -558,7 +522,6 @@ xfs_cancel_ioend(
                         unlock_buffer(bh);
                 } while ((bh = next_bh) != NULL);
 
-                xfs_ioend_wake(XFS_I(ioend->io_inode));
                 mempool_free(ioend, xfs_ioend_pool);
         } while ((ioend = next) != NULL);
 }
diff --git a/fs/xfs/xfs_aops.h b/fs/xfs/xfs_aops.h
index ce3dcb50762e..116dd5c37034 100644
--- a/fs/xfs/xfs_aops.h
+++ b/fs/xfs/xfs_aops.h
@@ -61,9 +61,6 @@ typedef struct xfs_ioend {
 extern const struct address_space_operations xfs_address_space_operations;
 extern int xfs_get_blocks(struct inode *, sector_t, struct buffer_head *, int);
 
-extern void xfs_ioend_init(void);
-extern void xfs_ioend_wait(struct xfs_inode *);
-
 extern void xfs_count_page_state(struct page *, int *, int *);
 
 #endif /* __XFS_AOPS_H__ */
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index cbbac5cc9c26..ee63c4fb3639 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -149,10 +149,6 @@ xfs_file_fsync(
 
         xfs_iflags_clear(ip, XFS_ITRUNCATED);
 
-        xfs_ilock(ip, XFS_IOLOCK_SHARED);
-        xfs_ioend_wait(ip);
-        xfs_iunlock(ip, XFS_IOLOCK_SHARED);
-
         if (mp->m_flags & XFS_MOUNT_BARRIER) {
                 /*
                  * If we have an RT and/or log subvolume we need to make sure
@@ -758,7 +754,7 @@ restart:
  * the dio layer.  To avoid the problem with aio, we also need to wait for
  * outstanding IOs to complete so that unwritten extent conversion is completed
  * before we try to map the overlapping block. This is currently implemented by
- * hitting it with a big hammer (i.e. xfs_ioend_wait()).
+ * hitting it with a big hammer (i.e. inode_dio_wait()).
  *
  * Returns with locks held indicated by @iolock and errors indicated by
  * negative return values.
@@ -821,7 +817,7 @@ xfs_file_dio_aio_write(
          * otherwise demote the lock if we had to flush cached pages
          */
         if (unaligned_io)
-                xfs_ioend_wait(ip);
+                inode_dio_wait(inode);
         else if (*iolock == XFS_IOLOCK_EXCL) {
                 xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
                 *iolock = XFS_IOLOCK_SHARED;
diff --git a/fs/xfs/xfs_iget.c b/fs/xfs/xfs_iget.c
index 7759812c1bbe..0fa98b1c70ea 100644
--- a/fs/xfs/xfs_iget.c
+++ b/fs/xfs/xfs_iget.c
@@ -75,7 +75,6 @@ xfs_inode_alloc(
                 return NULL;
         }
 
-        ASSERT(atomic_read(&ip->i_iocount) == 0);
         ASSERT(atomic_read(&ip->i_pincount) == 0);
         ASSERT(!spin_is_locked(&ip->i_flags_lock));
         ASSERT(completion_done(&ip->i_flush));
@@ -150,7 +149,6 @@ xfs_inode_free(
         }
 
         /* asserts to verify all state is correct here */
-        ASSERT(atomic_read(&ip->i_iocount) == 0);
         ASSERT(atomic_read(&ip->i_pincount) == 0);
         ASSERT(!spin_is_locked(&ip->i_flags_lock));
         ASSERT(completion_done(&ip->i_flush));
diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index 2380a4bcbece..760140d1dd66 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -257,7 +257,6 @@ typedef struct xfs_inode {
 
         xfs_fsize_t             i_size;         /* in-memory size */
         xfs_fsize_t             i_new_size;     /* size when write completes */
-        atomic_t                i_iocount;      /* outstanding I/O count */
 
         /* VFS inode */
         struct inode            i_vnode;        /* embedded VFS inode */
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 32aca87bde5e..e041e917c1d9 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -840,9 +840,9 @@ xfs_setattr_size(
         }
 
         /*
-         * Wait for all I/O to complete.
+         * Wait for all direct I/O to complete.
          */
-        xfs_ioend_wait(ip);
+        inode_dio_wait(inode);
 
         error = -block_truncate_page(inode->i_mapping, iattr->ia_size,
                                      xfs_get_blocks);
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 2366c54cc4fa..54d5e102ffe1 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -796,8 +796,6 @@ xfs_fs_destroy_inode(
         if (is_bad_inode(inode))
                 goto out_reclaim;
 
-        xfs_ioend_wait(ip);
-
         ASSERT(XFS_FORCED_SHUTDOWN(ip->i_mount) || ip->i_delayed_blks == 0);
 
         /*
@@ -837,7 +835,6 @@ xfs_fs_inode_init_once(
         inode_init_once(VFS_I(ip));
 
         /* xfs inode */
-        atomic_set(&ip->i_iocount, 0);
         atomic_set(&ip->i_pincount, 0);
         spin_lock_init(&ip->i_flags_lock);
         init_waitqueue_head(&ip->i_ipin_wait);
@@ -914,9 +911,8 @@ xfs_fs_write_inode(
                  * of forcing it all the way to stable storage using a
                  * synchronous transaction we let the log force inside the
                  * ->sync_fs call do that for thus, which reduces the number
-                 * of synchronous log foces dramatically.
+                 * of synchronous log forces dramatically.
                  */
-                xfs_ioend_wait(ip);
                 error = xfs_log_inode(ip);
                 if (error)
                         goto out;
@@ -1681,7 +1677,6 @@ init_xfs_fs(void)
         printk(KERN_INFO XFS_VERSION_STRING " with "
                          XFS_BUILD_OPTIONS " enabled\n");
 
-        xfs_ioend_init();
         xfs_dir_startup();
 
         error = xfs_init_zones();
diff --git a/fs/xfs/xfs_sync.c b/fs/xfs/xfs_sync.c
index 90cc197e0433..bf2b38c21caa 100644
--- a/fs/xfs/xfs_sync.c
+++ b/fs/xfs/xfs_sync.c
@@ -227,21 +227,17 @@ xfs_sync_inode_data(
         int                     error = 0;
 
         if (!mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
-                goto out_wait;
+                return 0;
 
         if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED)) {
                 if (flags & SYNC_TRYLOCK)
-                        goto out_wait;
+                        return 0;
                 xfs_ilock(ip, XFS_IOLOCK_SHARED);
         }
 
         error = xfs_flush_pages(ip, 0, -1, (flags & SYNC_WAIT) ?
                                 0 : XBF_ASYNC, FI_NONE);
         xfs_iunlock(ip, XFS_IOLOCK_SHARED);
-
- out_wait:
-        if (flags & SYNC_WAIT)
-                xfs_ioend_wait(ip);
         return error;
 }
 
diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c
index 51fc429527bc..c2ff0fc86567 100644
--- a/fs/xfs/xfs_vnodeops.c
+++ b/fs/xfs/xfs_vnodeops.c
@@ -647,8 +647,6 @@ xfs_inactive(
         if (truncate) {
                 xfs_ilock(ip, XFS_IOLOCK_EXCL);
 
-                xfs_ioend_wait(ip);
-
                 error = xfs_trans_reserve(tp, 0,
                                           XFS_ITRUNCATE_LOG_RES(mp),
                                           0, XFS_TRANS_PERM_LOG_RES,
@@ -2076,7 +2074,7 @@ xfs_free_file_space(
         if (need_iolock) {
                 xfs_ilock(ip, XFS_IOLOCK_EXCL);
                 /* wait for the completion of any pending DIOs */
-                xfs_ioend_wait(ip);
+                inode_dio_wait(VFS_I(ip));
         }
 
         rounding = max_t(uint, 1 << mp->m_sb.sb_blocklog, PAGE_CACHE_SIZE);