Filesystems aren't really supposed to do anything with a vfsmount. It's
considered a layering violation since vfsmounts are entirely managed at
the VFS layer.
CIFS currently keeps an active reference to a vfsmount in order to
prevent the superblock vanishing before an oplock break has completed.
What we really want to do instead is to keep sb->s_active high until the
oplock break has completed. This patch borrows the scheme that NFS uses
for handling sillyrenames.
An atomic_t is added to the cifs_sb_info. When it transitions from 0 to
1, an extra reference to the superblock is taken (by bumping the
s_active value). When it transitions from 1 to 0, that reference is
dropped and a the superblock teardown may proceed if there are no more
references to it.
Also, the vfsmount pointer is removed from cifsFileInfo and from
cifs_new_fileinfo, and some bogus forward declarations are removed from
cifsfs.h.
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
Reviewed-by: Suresh Jayaraman <sjayaraman@xxxxxxx>
Acked-by: Dave Kleikamp <shaggy@xxxxxxxxxxxxxxxxxx>
---
fs/cifs/cifs_fs_sb.h | 1 +
fs/cifs/cifsfs.c | 18 ++++++++++++++++++
fs/cifs/cifsfs.h | 6 ++----
fs/cifs/cifsglob.h | 1 -
fs/cifs/cifsproto.h | 2 +-
fs/cifs/dir.c | 10 +++-------
fs/cifs/file.c | 9 ++++-----
7 files changed, 29 insertions(+), 18 deletions(-)
diff --git a/fs/cifs/cifs_fs_sb.h b/fs/cifs/cifs_fs_sb.h
index 586ee3d..525ba59 100644
--- a/fs/cifs/cifs_fs_sb.h
+++ b/fs/cifs/cifs_fs_sb.h
@@ -48,6 +48,7 @@ struct cifs_sb_info {
struct nls_table *local_nls;
unsigned int rsize;
unsigned int wsize;
+ atomic_t active;
uid_t mnt_uid;
gid_t mnt_gid;
mode_t mnt_file_mode;
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 1aca2d7..3facf25 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -83,6 +83,24 @@ extern mempool_t *cifs_sm_req_poolp;
extern mempool_t *cifs_req_poolp;
extern mempool_t *cifs_mid_poolp;
+void
+cifs_sb_active(struct super_block *sb)
+{
+ struct cifs_sb_info *server = CIFS_SB(sb);
+
+ if (atomic_inc_return(&server->active) == 1)
+ atomic_inc(&sb->s_active);
+}
+
+void
+cifs_sb_deactive(struct super_block *sb)
+{
+ struct cifs_sb_info *server = CIFS_SB(sb);
+
+ if (atomic_dec_and_test(&server->active))
+ deactivate_super(sb);
+}
+
static int
cifs_read_super(struct super_block *sb, void *data,
const char *devname, int silent)
diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h
index 786bdf3..85544bc 100644
--- a/fs/cifs/cifsfs.h
+++ b/fs/cifs/cifsfs.h
@@ -42,10 +42,8 @@ extern const struct address_space_operations cifs_addr_ops;
extern const struct address_space_operations cifs_addr_ops_smallbuf;
/* Functions related to super block operations */
-/* extern const struct super_operations cifs_super_ops;*/
-extern void cifs_read_inode(struct inode *);
-/*extern void cifs_delete_inode(struct inode *);*/ /* BB not needed yet */
-/* extern void cifs_write_inode(struct inode *); */ /* BB not needed yet */
+extern void cifs_sb_active(struct super_block *sb);
+extern void cifs_sb_deactive(struct super_block *sb);
/* Functions related to inodes */
extern const struct inode_operations cifs_dir_inode_ops;
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 8fa4ccf..1e24ddc 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -388,7 +388,6 @@ struct cifsFileInfo {
/* lock scope id (0 if none) */
struct file *pfile; /* needed for writepage */
struct dentry *dentry;
- struct vfsmount *mnt;
struct tcon_link *tlink;
struct mutex lock_mutex;
struct list_head llist; /* list of byte range locks we have. */
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 29a2ee8..7f416ab 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -107,7 +107,7 @@ extern struct timespec cnvrtDosUnixTm(__le16 le_date, __le16 le_time,
extern struct cifsFileInfo *cifs_new_fileinfo(struct inode *newinode,
__u16 fileHandle, struct file *file,
- struct vfsmount *mnt, struct tcon_link *tlink,
+ struct tcon_link *tlink,
unsigned int oflags, __u32 oplock);
extern int cifs_posix_open(char *full_path, struct inode **pinode,
struct super_block *sb,
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 6887c41..c205ec9 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -132,8 +132,7 @@ cifs_bp_rename_retry:
struct cifsFileInfo *
cifs_new_fileinfo(struct inode *newinode, __u16 fileHandle, struct file *file,
- struct vfsmount *mnt, struct tcon_link *tlink,
- unsigned int oflags, __u32 oplock)
+ struct tcon_link *tlink, unsigned int oflags, __u32 oplock)
{
struct dentry *dentry = file->f_path.dentry;
struct cifsFileInfo *pCifsFile;
@@ -147,7 +146,6 @@ cifs_new_fileinfo(struct inode *newinode, __u16 fileHandle, struct file *file,
pCifsFile->pid = current->tgid;
pCifsFile->uid = current_fsuid();
pCifsFile->dentry = dget(dentry);
- pCifsFile->mnt = mnt;
pCifsFile->pfile = file;
pCifsFile->invalidHandle = false;
pCifsFile->closePend = false;
@@ -485,8 +483,7 @@ cifs_create_set_dentry:
}
pfile_info = cifs_new_fileinfo(newinode, fileHandle, filp,
- nd->path.mnt, tlink, oflags,
- oplock);
+ tlink, oflags, oplock);
if (pfile_info == NULL) {
fput(filp);
CIFSSMBClose(xid, tcon, fileHandle);
@@ -760,8 +757,7 @@ cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
}
cfile = cifs_new_fileinfo(newInode, fileHandle, filp,
- nd->path.mnt, tlink,
- nd->intent.open.flags,
+ tlink, nd->intent.open.flags,
oplock);
if (cfile == NULL) {
fput(filp);
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index c302b9c..fd78a35 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -282,7 +282,6 @@ int cifs_open(struct inode *inode, struct file *file)
}
pCifsFile = cifs_new_fileinfo(inode, netfid, file,
- file->f_path.mnt,
tlink, oflags, oplock);
if (pCifsFile == NULL) {
CIFSSMBClose(xid, tcon, netfid);
@@ -375,8 +374,8 @@ int cifs_open(struct inode *inode, struct file *file)
if (rc != 0)
goto out;
- pCifsFile = cifs_new_fileinfo(inode, netfid, file, file->f_path.mnt,
- tlink, file->f_flags, oplock);
+ pCifsFile = cifs_new_fileinfo(inode, netfid, file, tlink,
+ file->f_flags, oplock);
if (pCifsFile == NULL) {
rc = -ENOMEM;
goto out;
@@ -2381,14 +2380,14 @@ void cifs_oplock_break(struct work_struct *work)
void cifs_oplock_break_get(struct cifsFileInfo *cfile)
{
- mntget(cfile->mnt);
+ cifs_sb_active(cfile->dentry->d_sb);
cifsFileInfo_get(cfile);
}
void cifs_oplock_break_put(struct cifsFileInfo *cfile)
{
- mntput(cfile->mnt);
cifsFileInfo_put(cfile);
+ cifs_sb_deactive(cfile->dentry->d_sb);
}
const struct address_space_operations cifs_addr_ops = {
--
1.7.2.3
--
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