[PATCH v4 10/17] vfs: fix symlinkat to retry on ESTALE errors
From: Jeff Layton <hidden>
Date: 2012-07-26 11:55:13
Also in:
linux-fsdevel, lkml
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
Signed-off-by: Jeff Layton <redacted> --- fs/namei.c | 43 ++++++++++++++++++++++++++----------------- 1 file changed, 26 insertions(+), 17 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c
index 4bec3f4..5a81c48 100644
--- a/fs/namei.c
+++ b/fs/namei.c@@ -3340,33 +3340,42 @@ SYSCALL_DEFINE3(symlinkat, const char __user *, oldname, int, newdfd, const char __user *, newname) { int error; - char *from; + char *from, *to; struct dentry *dentry; struct path path; + unsigned int try = 0; from = getname(oldname); if (IS_ERR(from)) return PTR_ERR(from); - dentry = user_path_create(newdfd, newname, &path, 0); - error = PTR_ERR(dentry); - if (IS_ERR(dentry)) - goto out_putname; + to = getname(newname); + if (IS_ERR(to)) { + putname(from); + return PTR_ERR(to); + } - error = mnt_want_write(path.mnt); - if (error) - goto out_dput; - error = security_path_symlink(&path, dentry, from); - if (error) - goto out_drop_write; - error = vfs_symlink(path.dentry->d_inode, dentry, from); + do { + dentry = kern_path_create(newdfd, to, &path, 0, try); + error = PTR_ERR(dentry); + if (IS_ERR(dentry)) + break; + + error = mnt_want_write(path.mnt); + if (error) + goto out_dput; + error = security_path_symlink(&path, dentry, from); + if (error) + goto out_drop_write; + error = vfs_symlink(path.dentry->d_inode, dentry, from); out_drop_write: - mnt_drop_write(path.mnt); + mnt_drop_write(path.mnt); out_dput: - dput(dentry); - mutex_unlock(&path.dentry->d_inode->i_mutex); - path_put(&path); -out_putname: + dput(dentry); + mutex_unlock(&path.dentry->d_inode->i_mutex); + path_put(&path); + } while (retry_estale(error, try++)); + putname(to); putname(from); return error; }
--
1.7.11.2