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authorJiri Kosina <jkosina@suse.cz>2013-04-22 15:40:15 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-04-25 21:23:48 -0700
commitbb5489176fda28aff304b59e0405f7d7d4906224 (patch)
tree26ccc319459a55b26e05a9ec4d345bf2540569a6
parent0236d37edc0522f37b83eba35432815cd98789ff (diff)
downloadlinux-linaro-stable-bb5489176fda28aff304b59e0405f7d7d4906224.tar.gz
Revert "sysfs: fix race between readdir and lseek"
This reverts commit 991f76f837bf22c5bb07261cfd86525a0a96650c in Linus' tree which is f366c8f271888f48e15cc7c0ab70f184c220c8a4 in linux-stable.git It depends on ef3d0fd27e90f ("vfs: do (nearly) lockless generic_file_llseek") which is available only in 3.2+. When applied on 3.0 codebase, it causes A-A deadlock, whenever anyone does seek() on sysfs, as both generic_file_llseek() and sysfs_dir_llseek() obtain i_mutex. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/sysfs/dir.c14
1 files changed, 1 insertions, 13 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 7cbc585..3ab78b8 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -959,21 +959,9 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
return 0;
}
-static loff_t sysfs_dir_llseek(struct file *file, loff_t offset, int whence)
-{
- struct inode *inode = file->f_path.dentry->d_inode;
- loff_t ret;
-
- mutex_lock(&inode->i_mutex);
- ret = generic_file_llseek(file, offset, whence);
- mutex_unlock(&inode->i_mutex);
-
- return ret;
-}
-
const struct file_operations sysfs_dir_operations = {
.read = generic_read_dir,
.readdir = sysfs_readdir,
.release = sysfs_dir_release,
- .llseek = sysfs_dir_llseek,
+ .llseek = generic_file_llseek,
};