diff options
| -rw-r--r-- | fs/cifs/cifsfs.c | 24 | ||||
| -rw-r--r-- | fs/cifs/cifsfs.h | 4 | ||||
| -rw-r--r-- | fs/cifs/file.c | 6 |
3 files changed, 33 insertions, 1 deletions
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index d7561e03870..c0f65e84873 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -87,6 +87,30 @@ extern mempool_t *cifs_mid_poolp; struct workqueue_struct *cifsiod_wq; +/* + * Bumps refcount for cifs super block. + * Note that it should be only called if a referece to VFS super block is + * already held, e.g. in open-type syscalls context. Otherwise it can race with + * atomic_dec_and_test in deactivate_locked_super. + */ +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) { diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h index 65365358c97..f7117657827 100644 --- a/fs/cifs/cifsfs.h +++ b/fs/cifs/cifsfs.h @@ -41,6 +41,10 @@ extern struct file_system_type cifs_fs_type; 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 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; extern struct inode *cifs_root_iget(struct super_block *); diff --git a/fs/cifs/file.c b/fs/cifs/file.c index cab00544c7e..0898d99b5f7 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -265,6 +265,8 @@ cifs_new_fileinfo(__u16 fileHandle, struct file *file, mutex_init(&pCifsFile->fh_mutex); INIT_WORK(&pCifsFile->oplock_break, cifs_oplock_break); + cifs_sb_active(inode->i_sb); + spin_lock(&cifs_file_list_lock); list_add(&pCifsFile->tlist, &(tlink_tcon(tlink)->openFileList)); /* if readable file instance put first in list*/ @@ -293,7 +295,8 @@ void cifsFileInfo_put(struct cifsFileInfo *cifs_file) struct inode *inode = cifs_file->dentry->d_inode; struct cifs_tcon *tcon = tlink_tcon(cifs_file->tlink); struct cifsInodeInfo *cifsi = CIFS_I(inode); - struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb); + struct super_block *sb = inode->i_sb; + struct cifs_sb_info *cifs_sb = CIFS_SB(sb); struct cifsLockInfo *li, *tmp; spin_lock(&cifs_file_list_lock); @@ -345,6 +348,7 @@ void cifsFileInfo_put(struct cifsFileInfo *cifs_file) cifs_put_tlink(cifs_file->tlink); dput(cifs_file->dentry); + cifs_sb_deactive(sb); kfree(cifs_file); } |