diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2014-10-23 22:56:05 -0400 |
|---|---|---|
| committer | Alex Shi <alex.shi@linaro.org> | 2015-04-17 15:51:03 +0800 |
| commit | a5613f10c5230eb50a863caf596774c50ec8f3e9 (patch) | |
| tree | 8f2278551db0c95ef9c998a535a03412beb6911e /fs | |
| parent | 8f963c31b87794a5c16a6ea155f8001cdd1d93c7 (diff) | |
overlayfs: don't hold ->i_mutex over opening the real directory
just use it to serialize the assignment
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
(cherry picked from commit 3d268c9b136f51385f9d041f3f2424501b257388)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/overlayfs/readdir.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c index c6787f84ece9..b7d9fb098840 100644 --- a/fs/overlayfs/readdir.c +++ b/fs/overlayfs/readdir.c @@ -458,20 +458,27 @@ static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end, if (!od->is_upper && ovl_path_type(dentry) == OVL_PATH_MERGE) { struct inode *inode = file_inode(file); - mutex_lock(&inode->i_mutex); realfile = od->upperfile; if (!realfile) { struct path upperpath; ovl_path_upper(dentry, &upperpath); realfile = ovl_path_open(&upperpath, O_RDONLY); - if (IS_ERR(realfile)) { - mutex_unlock(&inode->i_mutex); - return PTR_ERR(realfile); + mutex_lock(&inode->i_mutex); + if (!od->upperfile) { + if (IS_ERR(realfile)) { + mutex_unlock(&inode->i_mutex); + return PTR_ERR(realfile); + } + od->upperfile = realfile; + } else { + /* somebody has beaten us to it */ + if (!IS_ERR(realfile)) + fput(realfile); + realfile = od->upperfile; } - od->upperfile = realfile; + mutex_unlock(&inode->i_mutex); } - mutex_unlock(&inode->i_mutex); } return vfs_fsync_range(realfile, start, end, datasync); |