The generic callers of direct_IO lock i_mutex before doing a write. NFS
doesn't use the generic write code, so it doesn't follow this
convention. This is now a problem because the interface introduced for
swap-over-NFS calls direct_IO for a write without holding i_mutex, but
other implementations of direct_IO will expect to have it locked.
Signed-off-by: Omar Sandoval <osandov@xxxxxxxxxxx>
---
fs/nfs/direct.c | 12 +++++-------
fs/nfs/file.c | 8 ++++++--
2 files changed, 11 insertions(+), 9 deletions(-)
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 10bf072..9402b96 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -906,17 +906,15 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter,
if (!count)
goto out;
- mutex_lock(&inode->i_mutex);
-
result = nfs_sync_mapping(mapping);
if (result)
- goto out_unlock;
+ goto out;
if (mapping->nrpages) {
result = invalidate_inode_pages2_range(mapping,
pos >> PAGE_CACHE_SHIFT, end);
if (result)
- goto out_unlock;
+ goto out;
}
task_io_account_write(count);
@@ -924,7 +922,7 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter,
result = -ENOMEM;
dreq = nfs_direct_req_alloc();
if (!dreq)
- goto out_unlock;
+ goto out;
dreq->inode = inode;
dreq->bytes_left = count;
@@ -960,12 +958,12 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter,
}
}
nfs_direct_req_release(dreq);
+
+ mutex_lock(&inode->i_mutex);
return result;
out_release:
nfs_direct_req_release(dreq);
-out_unlock:
- mutex_unlock(&inode->i_mutex);
out:
return result;
}
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 2ab6f00..8b80276 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -675,8 +675,12 @@ ssize_t nfs_file_write(struct kiocb *iocb, struct iov_iter *from)
if (result)
return result;
- if (file->f_flags & O_DIRECT)
- return nfs_file_direct_write(iocb, from, pos);
+ if (file->f_flags & O_DIRECT) {
+ mutex_lock(&inode->i_mutex);
+ result = nfs_file_direct_write(iocb, from, pos);
+ mutex_unlock(&inode->i_mutex);
+ return result;
+ }
dprintk("NFS: write(%pD2, %zu@%Ld)\n",
file, count, (long long) pos);
--
2.1.3
--
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