xfs: cleanup xfs_file_aio_write

With all the size field updates out of the way xfs_file_aio_write can
be further simplified by pushing all iolock handling into
xfs_file_dio_aio_write and xfs_file_buffered_aio_write and using
the generic generic_write_sync helper for synchronous writes.

Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>

1 files changed, 37 insertions, 45 deletions

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 134ff2fe4f4d..7e5bc872f2b4 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -724,8 +724,7 @@ xfs_file_dio_aio_write(
         const struct iovec      *iovp,
         unsigned long           nr_segs,
         loff_t                  pos,
-        size_t                  ocount,
-        int                     *iolock)
+        size_t                  ocount)
 {
         struct file             *file = iocb->ki_filp;
         struct address_space    *mapping = file->f_mapping;
@@ -735,10 +734,10 @@ xfs_file_dio_aio_write(
         ssize_t                 ret = 0;
         size_t                  count = ocount;
         int                     unaligned_io = 0;
+        int                     iolock;
         struct xfs_buftarg      *target = XFS_IS_REALTIME_INODE(ip) ?
                                         mp->m_rtdev_targp : mp->m_ddev_targp;
 
-        *iolock = 0;
         if ((pos & target->bt_smask) || (count & target->bt_smask))
                 return -XFS_ERROR(EINVAL);
 
@@ -753,31 +752,31 @@ xfs_file_dio_aio_write(
          * EOF zeroing cases and fill out the new inode size as appropriate.
          */
         if (unaligned_io || mapping->nrpages)
-                *iolock = XFS_IOLOCK_EXCL;
+                iolock = XFS_IOLOCK_EXCL;
         else
-                *iolock = XFS_IOLOCK_SHARED;
-        xfs_rw_ilock(ip, *iolock);
+                iolock = XFS_IOLOCK_SHARED;
+        xfs_rw_ilock(ip, iolock);
 
         /*
          * Recheck if there are cached pages that need invalidate after we got
          * the iolock to protect against other threads adding new pages while
          * we were waiting for the iolock.
          */
-        if (mapping->nrpages && *iolock == XFS_IOLOCK_SHARED) {
-                xfs_rw_iunlock(ip, *iolock);
-                *iolock = XFS_IOLOCK_EXCL;
-                xfs_rw_ilock(ip, *iolock);
+        if (mapping->nrpages && iolock == XFS_IOLOCK_SHARED) {
+                xfs_rw_iunlock(ip, iolock);
+                iolock = XFS_IOLOCK_EXCL;
+                xfs_rw_ilock(ip, iolock);
         }
 
-        ret = xfs_file_aio_write_checks(file, &pos, &count, iolock);
+        ret = xfs_file_aio_write_checks(file, &pos, &count, &iolock);
         if (ret)
-                return ret;
+                goto out;
 
         if (mapping->nrpages) {
                 ret = -xfs_flushinval_pages(ip, (pos & PAGE_CACHE_MASK), -1,
                                                         FI_REMAPF_LOCKED);
                 if (ret)
-                        return ret;
+                        goto out;
         }
 
         /*
@@ -786,15 +785,18 @@ xfs_file_dio_aio_write(
          */
         if (unaligned_io)
                 inode_dio_wait(inode);
-        else if (*iolock == XFS_IOLOCK_EXCL) {
+        else if (iolock == XFS_IOLOCK_EXCL) {
                 xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
-                *iolock = XFS_IOLOCK_SHARED;
+                iolock = XFS_IOLOCK_SHARED;
         }
 
         trace_xfs_file_direct_write(ip, count, iocb->ki_pos, 0);
         ret = generic_file_direct_write(iocb, iovp,
                         &nr_segs, pos, &iocb->ki_pos, count, ocount);
 
+out:
+        xfs_rw_iunlock(ip, iolock);
+
         /* No fallback to buffered IO on errors for XFS. */
         ASSERT(ret < 0 || ret == count);
         return ret;
@@ -806,8 +808,7 @@ xfs_file_buffered_aio_write(
         const struct iovec      *iovp,
         unsigned long           nr_segs,
         loff_t                  pos,
-        size_t                  ocount,
-        int                     *iolock)
+        size_t                  ocount)
 {
         struct file             *file = iocb->ki_filp;
         struct address_space    *mapping = file->f_mapping;
@@ -815,14 +816,14 @@ xfs_file_buffered_aio_write(
         struct xfs_inode        *ip = XFS_I(inode);
         ssize_t                 ret;
         int                     enospc = 0;
+        int                     iolock = XFS_IOLOCK_EXCL;
         size_t                  count = ocount;
 
-        *iolock = XFS_IOLOCK_EXCL;
-        xfs_rw_ilock(ip, *iolock);
+        xfs_rw_ilock(ip, iolock);
 
-        ret = xfs_file_aio_write_checks(file, &pos, &count, iolock);
+        ret = xfs_file_aio_write_checks(file, &pos, &count, &iolock);
         if (ret)
-                return ret;
+                goto out;
 
         /* We can write back this queue in page reclaim */
         current->backing_dev_info = mapping->backing_dev_info;
@@ -836,13 +837,15 @@ write_retry:
          * page locks and retry *once*
          */
         if (ret == -ENOSPC && !enospc) {
-                ret = -xfs_flush_pages(ip, 0, -1, 0, FI_NONE);
-                if (ret)
-                        return ret;
                 enospc = 1;
-                goto write_retry;
+                ret = -xfs_flush_pages(ip, 0, -1, 0, FI_NONE);
+                if (!ret)
+                        goto write_retry;
         }
+
         current->backing_dev_info = NULL;
+out:
+        xfs_rw_iunlock(ip, iolock);
         return ret;
 }
 
@@ -858,7 +861,6 @@ xfs_file_aio_write(
         struct inode            *inode = mapping->host;
         struct xfs_inode        *ip = XFS_I(inode);
         ssize_t                 ret;
-        int                     iolock;
         size_t                  ocount = 0;
 
         XFS_STATS_INC(xs_write_calls);
@@ -878,32 +880,22 @@ xfs_file_aio_write(
                 return -EIO;
 
         if (unlikely(file->f_flags & O_DIRECT))
-                ret = xfs_file_dio_aio_write(iocb, iovp, nr_segs, pos,
-                                                ocount, &iolock);
+                ret = xfs_file_dio_aio_write(iocb, iovp, nr_segs, pos, ocount);
         else
                 ret = xfs_file_buffered_aio_write(iocb, iovp, nr_segs, pos,
-                                                ocount, &iolock);
+                                                  ocount);
 
-        if (ret <= 0)
-                goto out_unlock;
-
-        XFS_STATS_ADD(xs_write_bytes, ret);
+        if (ret > 0) {
+                ssize_t err;
 
-        /* Handle various SYNC-type writes */
-        if ((file->f_flags & O_DSYNC) || IS_SYNC(inode)) {
-                loff_t end = pos + ret - 1;
-                int error;
+                XFS_STATS_ADD(xs_write_bytes, ret);
 
-                xfs_rw_iunlock(ip, iolock);
-                error = xfs_file_fsync(file, pos, end,
-                                      (file->f_flags & __O_SYNC) ? 0 : 1);
-                xfs_rw_ilock(ip, iolock);
-                if (error)
-                        ret = error;
+                /* Handle various SYNC-type writes */
+                err = generic_write_sync(file, pos, ret);
+                if (err < 0)
+                        ret = err;
         }
 
-out_unlock:
-        xfs_rw_iunlock(ip, iolock);
         return ret;
 }