diff options
| author | Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> | 2011-03-08 16:39:46 +0530 |
|---|---|---|
| committer | Eric Van Hensbergen <ericvh@gmail.com> | 2011-03-22 15:43:35 -0500 |
| commit | 5a7e0a8cf50cf905403f5a498e86d1f97cfcf51b (patch) | |
| tree | 3f20f98db76f7a221f397630a03e6089c1208510 /fs/9p | |
| parent | f741a79e982cf56d7584435bad663553ffe6715f (diff) | |
fs/9p: Fix race in initializing writeback fid
When two process open the same file we can end up with both of them
allocating the writeback_fid. Add a new mutex which can be used
for synchronizing v9fs_inode member values.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Diffstat (limited to 'fs/9p')
| -rw-r--r-- | fs/9p/v9fs.h | 1 | ||||
| -rw-r--r-- | fs/9p/vfs_file.c | 3 | ||||
| -rw-r--r-- | fs/9p/vfs_inode.c | 4 | ||||
| -rw-r--r-- | fs/9p/vfs_inode_dotl.c | 3 |
4 files changed, 11 insertions, 0 deletions
diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h index bd8496db135..89657e86516 100644 --- a/fs/9p/v9fs.h +++ b/fs/9p/v9fs.h @@ -130,6 +130,7 @@ struct v9fs_inode { #endif unsigned int cache_validity; struct p9_fid *writeback_fid; + struct mutex v_mutex; struct inode vfs_inode; }; diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c index 78bcb97c342..3337d58d0fc 100644 --- a/fs/9p/vfs_file.c +++ b/fs/9p/vfs_file.c @@ -90,6 +90,7 @@ int v9fs_file_open(struct inode *inode, struct file *file) } file->private_data = fid; + mutex_lock(&v9inode->v_mutex); if (v9ses->cache && !v9inode->writeback_fid) { /* * clone a fid and add it to writeback_fid @@ -101,10 +102,12 @@ int v9fs_file_open(struct inode *inode, struct file *file) fid = v9fs_writeback_fid(file->f_path.dentry); if (IS_ERR(fid)) { err = PTR_ERR(fid); + mutex_unlock(&v9inode->v_mutex); goto out_error; } v9inode->writeback_fid = (void *) fid; } + mutex_unlock(&v9inode->v_mutex); #ifdef CONFIG_9P_FSCACHE if (v9ses->cache) v9fs_cache_inode_set_cookie(inode, file); diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index 8a2c232f708..c6cef2495f0 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -221,6 +221,7 @@ struct inode *v9fs_alloc_inode(struct super_block *sb) #endif v9inode->writeback_fid = NULL; v9inode->cache_validity = 0; + mutex_init(&v9inode->v_mutex); return &v9inode->vfs_inode; } @@ -650,6 +651,7 @@ v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode, /* if we are opening a file, assign the open fid to the file */ if (nd && nd->flags & LOOKUP_OPEN) { v9inode = V9FS_I(dentry->d_inode); + mutex_lock(&v9inode->v_mutex); if (v9ses->cache && !v9inode->writeback_fid) { /* * clone a fid and add it to writeback_fid @@ -661,10 +663,12 @@ v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode, inode_fid = v9fs_writeback_fid(dentry); if (IS_ERR(inode_fid)) { err = PTR_ERR(inode_fid); + mutex_unlock(&v9inode->v_mutex); goto error; } v9inode->writeback_fid = (void *) inode_fid; } + mutex_unlock(&v9inode->v_mutex); filp = lookup_instantiate_filp(nd, dentry, generic_file_open); if (IS_ERR(filp)) { err = PTR_ERR(filp); diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c index 67c138e94fe..327c578c7ba 100644 --- a/fs/9p/vfs_inode_dotl.c +++ b/fs/9p/vfs_inode_dotl.c @@ -245,6 +245,7 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, int omode, v9fs_set_create_acl(dentry, dacl, pacl); v9inode = V9FS_I(inode); + mutex_lock(&v9inode->v_mutex); if (v9ses->cache && !v9inode->writeback_fid) { /* * clone a fid and add it to writeback_fid @@ -256,10 +257,12 @@ v9fs_vfs_create_dotl(struct inode *dir, struct dentry *dentry, int omode, inode_fid = v9fs_writeback_fid(dentry); if (IS_ERR(inode_fid)) { err = PTR_ERR(inode_fid); + mutex_unlock(&v9inode->v_mutex); goto error; } v9inode->writeback_fid = (void *) inode_fid; } + mutex_unlock(&v9inode->v_mutex); /* Since we are opening a file, assign the open fid to the file */ filp = lookup_instantiate_filp(nd, dentry, generic_file_open); if (IS_ERR(filp)) { |