[PATCH 08/23] vfs: Teach readdir to use file_hotplug_lock

Eric W. Biederman
2009-06-03T18:17:43Z

From: Eric W. Biederman <ebiederm@maxwell.arastra.com>

Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
---
fs/readdir.c | 20 +++++++++++++++-----
1 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/fs/readdir.c b/fs/readdir.c
index 7723401..2e147cf 100644
--- a/fs/readdir.c
+++ b/fs/readdir.c
@@ -21,18 +21,26 @@

int vfs_readdir(struct file *file, filldir_t filler, void *buf)
{
- struct inode *inode = file->f_path.dentry->d_inode;
- int res = -ENOTDIR;
- if (!file->f_op || !file->f_op->readdir)
+ struct inode *inode;
+ int res;
+
+ res = -EIO;
+ if (!file_hotplug_read_trylock(file))
goto out;

+ inode = file->f_path.dentry->d_inode;
+
+ res = -ENOTDIR;
+ if (!file->f_op || !file->f_op->readdir)
+ goto out_unlock;
+
res = security_file_permission(file, MAY_READ);
if (res)
- goto out;
+ goto out_unlock;

res = mutex_lock_killable(&inode->i_mutex);
if (res)
- goto out;
+ goto out_unlock;

res = -ENOENT;
if (!IS_DEADDIR(inode)) {
@@ -40,6 +48,8 @@ int vfs_readdir(struct file *file, filldir_t filler, void *buf)
file_accessed(file);
}
mutex_unlock(&inode->i_mutex);
+out_unlock:
+ file_hotplug_read_unlock(file);
out:
return res;
}
--
1.6.3.1.54.g99dd.dirty