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>

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 134ff2f..7e5bc87 100644 (file)
--- 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;
 }