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authorJeff Layton <jlayton@redhat.com>2010-10-11 15:07:19 -0400
committerSteve French <sfrench@us.ibm.com>2010-10-12 18:08:01 +0000
commitd7c86ff8cd00abc730fe5d031f43dc9138b6324e (patch)
treea1f264ce2f33e3ac77a459291b9a5e45a63e3bff /fs/cifs
parenta5e18bc36e9e05ce0338d370a2ce4290910e43ea (diff)
downloadlinux-d7c86ff8cd00abc730fe5d031f43dc9138b6324e.tar.bz2
cifs: don't use vfsmount to pin superblock for oplock breaks
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@redhat.com> Reviewed-by: Suresh Jayaraman <sjayaraman@suse.de> Acked-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Signed-off-by: Steve French <sfrench@us.ibm.com>
Diffstat (limited to 'fs/cifs')
-rw-r--r--fs/cifs/cifs_fs_sb.h1
-rw-r--r--fs/cifs/cifsfs.c18
-rw-r--r--fs/cifs/cifsfs.h6
-rw-r--r--fs/cifs/cifsglob.h1
-rw-r--r--fs/cifs/cifsproto.h2
-rw-r--r--fs/cifs/dir.c10
-rw-r--r--fs/cifs/file.c9
7 files changed, 29 insertions, 18 deletions
diff --git a/fs/cifs/cifs_fs_sb.h b/fs/cifs/cifs_fs_sb.h
index 586ee3d527d2..525ba59a4105 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 3258c822328b..cbd468c880c4 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 786bdf36aebf..85544bcab517 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 8289e61937a2..e2b760ef22ff 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 29a2ee8ae51f..7f416abd34cf 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 6887c412c61a..c205ec9293ea 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 c302b9c52644..fd78a355f634 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 = {