CIFS: Reopen file before get SMB2 MTU credits for async IO

Currently we get MTU credits before we check an open file if it needs to be reopened. Reopening the file in such conditions leads to a possibility of being stuck waiting indefinitely for credits in the transport layer. Fix this by reopening the file first if needed and then getting MTU credits for async IO. Signed-off-by: Pavel Shilovsky <[email protected]> Signed-off-by: Steve French <[email protected]>
sm00th · Mar 6, 2019 · 3e95299 · 3e95299
1 parent f0b93cb
commit 3e95299
Showing 1 changed file with 30 additions and 9 deletions.
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
@@ -2650,6 +2650,14 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from,
 		struct cifs_credits credits_on_stack;
 		struct cifs_credits *credits = &credits_on_stack;
 
+		if (open_file->invalidHandle) {
+			rc = cifs_reopen_file(open_file, false);
+			if (rc == -EAGAIN)
+				continue;
+			else if (rc)
+				break;
+		}
+
 		rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,
 						   &wsize, credits);
 		if (rc)
@@ -2751,9 +2759,8 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from,
 
 		if (!rc) {
 			if (wdata->cfile->invalidHandle)
-				rc = cifs_reopen_file(wdata->cfile, false);
-
-			if (!rc)
+				rc = -EAGAIN;
+			else
 				rc = server->ops->async_writev(wdata,
 					cifs_uncached_writedata_release);
 		}
@@ -3355,6 +3362,14 @@ cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file,
 		iov_iter_advance(&direct_iov, offset - ctx->pos);
 
 	do {
+		if (open_file->invalidHandle) {
+			rc = cifs_reopen_file(open_file, true);
+			if (rc == -EAGAIN)
+				continue;
+			else if (rc)
+				break;
+		}
+
 		rc = server->ops->wait_mtu_credits(server, cifs_sb->rsize,
 						   &rsize, credits);
 		if (rc)
@@ -3438,9 +3453,8 @@ cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file,
 
 		if (!rc) {
 			if (rdata->cfile->invalidHandle)
-				rc = cifs_reopen_file(rdata->cfile, true);
-
-			if (!rc)
+				rc = -EAGAIN;
+			else
 				rc = server->ops->async_readv(rdata);
 		}
 
@@ -4127,6 +4141,14 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
 		struct cifs_credits credits_on_stack;
 		struct cifs_credits *credits = &credits_on_stack;
 
+		if (open_file->invalidHandle) {
+			rc = cifs_reopen_file(open_file, true);
+			if (rc == -EAGAIN)
+				continue;
+			else if (rc)
+				break;
+		}
+
 		rc = server->ops->wait_mtu_credits(server, cifs_sb->rsize,
 						   &rsize, credits);
 		if (rc)
@@ -4185,9 +4207,8 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
 
 		if (!rc) {
 			if (rdata->cfile->invalidHandle)
-				rc = cifs_reopen_file(rdata->cfile, true);
-
-			if (!rc)
+				rc = -EAGAIN;
+			else
 				rc = server->ops->async_readv(rdata);
 		}