cifs: add shutdown support

Various filesystem support the shutdown ioctl which is used by various
xfstests. The shutdown ioctl sets a flag on the superblock which
prevents open, unlink, symlink, hardlink, rmdir, create etc.
on the file system until unmount and remounted. The two flags supported
in this patch are:

  FSOP_GOING_FLAGS_LOGFLUSH and FSOP_GOING_FLAGS_NOLOGFLUSH

which require very little other than blocking new operations (since
we do not cache writes to metadata on the client with cifs.ko).
FSOP_GOING_FLAGS_DEFAULT is not supported yet, but could be added in
the future but would need to call syncfs or equivalent to write out
pending data on the mount.

With this patch various xfstests now work including tests 043 through
046 for example.

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>

1 files changed, 23 insertions, 2 deletions

diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index b4326ffcefce..728ff45b6667 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -26,7 +26,6 @@
 #include <linux/sched/signal.h>
 #include <linux/wait_bit.h>
 #include <linux/fiemap.h>
-
 #include <asm/div64.h>
 #include "cifsfs.h"
 #include "cifspdu.h"
@@ -38,7 +37,7 @@
 #include "cifs_unicode.h"
 #include "fscache.h"
 #include "fs_context.h"
-
+#include "cifs_ioctl.h"
 
 static void cifs_set_ops(struct inode *inode)
 {
@@ -1623,6 +1622,9 @@ int cifs_unlink(struct inode *dir, struct dentry *dentry)
 
 	cifs_dbg(FYI, "cifs_unlink, dir=0x%p, dentry=0x%p\n", dir, dentry);
 
+	if (unlikely(cifs_forced_shutdown(cifs_sb)))
+		return -EIO;
+
 	tlink = cifs_sb_tlink(cifs_sb);
 	if (IS_ERR(tlink))
 		return PTR_ERR(tlink);
@@ -1876,6 +1878,8 @@ int cifs_mkdir(struct user_namespace *mnt_userns, struct inode *inode,
 		 mode, inode);
 
 	cifs_sb = CIFS_SB(inode->i_sb);
+	if (unlikely(cifs_forced_shutdown(cifs_sb)))
+		return -EIO;
 	tlink = cifs_sb_tlink(cifs_sb);
 	if (IS_ERR(tlink))
 		return PTR_ERR(tlink);
@@ -1958,6 +1962,11 @@ int cifs_rmdir(struct inode *inode, struct dentry *direntry)
 	}
 
 	cifs_sb = CIFS_SB(inode->i_sb);
+	if (unlikely(cifs_forced_shutdown(cifs_sb))) {
+		rc = -EIO;
+		goto rmdir_exit;
+	}
+
 	tlink = cifs_sb_tlink(cifs_sb);
 	if (IS_ERR(tlink)) {
 		rc = PTR_ERR(tlink);
@@ -2092,6 +2101,9 @@ cifs_rename2(struct user_namespace *mnt_userns, struct inode *source_dir,
 		return -EINVAL;
 
 	cifs_sb = CIFS_SB(source_dir->i_sb);
+	if (unlikely(cifs_forced_shutdown(cifs_sb)))
+		return -EIO;
+
 	tlink = cifs_sb_tlink(cifs_sb);
 	if (IS_ERR(tlink))
 		return PTR_ERR(tlink);
@@ -2408,6 +2420,9 @@ int cifs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 	struct inode *inode = d_inode(dentry);
 	int rc;
 
+	if (unlikely(cifs_forced_shutdown(CIFS_SB(inode->i_sb))))
+		return -EIO;
+
 	/*
 	 * We need to be sure that all dirty pages are written and the server
 	 * has actual ctime, mtime and file length.
@@ -2480,6 +2495,9 @@ int cifs_fiemap(struct inode *inode, struct fiemap_extent_info *fei, u64 start,
 	struct cifsFileInfo *cfile;
 	int rc;
 
+	if (unlikely(cifs_forced_shutdown(cifs_sb)))
+		return -EIO;
+
 	/*
 	 * We need to be sure that all dirty pages are written as they
 	 * might fill holes on the server.
@@ -2966,6 +2984,9 @@ cifs_setattr(struct user_namespace *mnt_userns, struct dentry *direntry,
 	struct cifs_tcon *pTcon = cifs_sb_master_tcon(cifs_sb);
 	int rc, retries = 0;
 
+	if (unlikely(cifs_forced_shutdown(cifs_sb)))
+		return -EIO;
+
 	do {
 		if (pTcon->unix_ext)
 			rc = cifs_setattr_unix(direntry, attrs);