So far this is just a helper to remove complex locking
logic out of fuse_direct_write_iter. Especially needed
by the next patch in the series to that adds the fuse inode
cache IO mode and adds in even more locking complexity.
Signed-off-by: Bernd Schubert <bschubert@xxxxxxx>
---
fs/fuse/file.c | 61 ++++++++++++++++++++++++++++----------------------
1 file changed, 34 insertions(+), 27 deletions(-)
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 546254aaab19f..abc93415ec7e3 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1337,6 +1337,37 @@ static bool fuse_dio_wr_exclusive_lock(struct kiocb *iocb, struct iov_iter *from
return false;
}
+static void fuse_dio_lock(struct kiocb *iocb, struct iov_iter *from,
+ bool *exclusive)
+{
+ struct inode *inode = file_inode(iocb->ki_filp);
+
+ *exclusive = fuse_dio_wr_exclusive_lock(iocb, from);
+ if (*exclusive) {
+ inode_lock(inode);
+ } else {
+ inode_lock_shared(inode);
+ /*
+ * Previous check was without inode lock and might have raced,
+ * check again.
+ */
+ if (fuse_io_past_eof(iocb, from)) {
+ inode_unlock_shared(inode);
+ inode_lock(inode);
+ *exclusive = true;
+ }
+ }
+}
+
+static void fuse_dio_unlock(struct inode *inode, bool exclusive)
+{
+ if (exclusive) {
+ inode_unlock(inode);
+ } else {
+ inode_unlock_shared(inode);
+ }
+}
+
static ssize_t fuse_cache_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
struct file *file = iocb->ki_filp;
@@ -1601,30 +1632,9 @@ static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from)
struct inode *inode = file_inode(iocb->ki_filp);
struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb);
ssize_t res;
- bool exclusive_lock = fuse_dio_wr_exclusive_lock(iocb, from);
-
- /*
- * Take exclusive lock if
- * - Parallel direct writes are disabled - a user space decision
- * - Parallel direct writes are enabled and i_size is being extended.
- * - Shared mmap on direct_io file is supported (FUSE_DIRECT_IO_ALLOW_MMAP).
- * This might not be needed at all, but needs further investigation.
- */
- if (exclusive_lock)
- inode_lock(inode);
- else {
- inode_lock_shared(inode);
-
- /*
- * Previous check was without any lock and might have raced.
- */
- if (fuse_dio_wr_exclusive_lock(iocb, from)) {
- inode_unlock_shared(inode);
- inode_lock(inode);
- exclusive_lock = true;
- }
- }
+ bool exclusive;
+ fuse_dio_lock(iocb, from, &exclusive);
res = generic_write_checks(iocb, from);
if (res > 0) {
if (!is_sync_kiocb(iocb) && iocb->ki_flags & IOCB_DIRECT) {
@@ -1635,10 +1645,7 @@ static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from)
fuse_write_update_attr(inode, iocb->ki_pos, res);
}
}
- if (exclusive_lock)
- inode_unlock(inode);
- else
- inode_unlock_shared(inode);
+ fuse_dio_unlock(inode, exclusive);
return res;
}
--
2.40.1
