diff options
| -rw-r--r-- | fs/namei.c | 37 | ||||
| -rw-r--r-- | include/linux/errno.h | 1 |
2 files changed, 36 insertions, 2 deletions
diff --git a/fs/namei.c b/fs/namei.c index 998d5316921..7d694194024 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2202,6 +2202,8 @@ static struct file *do_last(struct nameidata *nd, struct path *path, struct file *filp; struct inode *inode; int symlink_ok = 0; + struct path save_parent = { .dentry = NULL, .mnt = NULL }; + bool retried = false; int error; nd->flags &= ~LOOKUP_PARENT; @@ -2267,6 +2269,7 @@ static struct file *do_last(struct nameidata *nd, struct path *path, if (nd->last.name[nd->last.len]) goto exit; +retry_lookup: mutex_lock(&dir->d_inode->i_mutex); dentry = lookup_hash(nd); @@ -2349,12 +2352,21 @@ finish_lookup: return NULL; } - path_to_nameidata(path, nd); + if ((nd->flags & LOOKUP_RCU) || nd->path.mnt != path->mnt) { + path_to_nameidata(path, nd); + } else { + save_parent.dentry = nd->path.dentry; + save_parent.mnt = mntget(path->mnt); + nd->path.dentry = path->dentry; + + } nd->inode = inode; /* Why this, you ask? _Now_ we might have grown LOOKUP_JUMPED... */ error = complete_walk(nd); - if (error) + if (error) { + path_put(&save_parent); return ERR_PTR(error); + } error = -EISDIR; if ((open_flag & O_CREAT) && S_ISDIR(nd->inode->i_mode)) goto exit; @@ -2377,6 +2389,20 @@ common: if (error) goto exit; filp = nameidata_to_filp(nd); + if (filp == ERR_PTR(-EOPENSTALE) && save_parent.dentry && !retried) { + BUG_ON(save_parent.dentry != dir); + path_put(&nd->path); + nd->path = save_parent; + nd->inode = dir->d_inode; + save_parent.mnt = NULL; + save_parent.dentry = NULL; + if (want_write) { + mnt_drop_write(nd->path.mnt); + want_write = 0; + } + retried = true; + goto retry_lookup; + } if (!IS_ERR(filp)) { error = ima_file_check(filp, op->acc_mode); if (error) { @@ -2396,6 +2422,7 @@ common: out: if (want_write) mnt_drop_write(nd->path.mnt); + path_put(&save_parent); terminate_walk(nd); return filp; @@ -2459,6 +2486,12 @@ out: if (base) fput(base); release_open_intent(nd); + if (filp == ERR_PTR(-EOPENSTALE)) { + if (flags & LOOKUP_RCU) + filp = ERR_PTR(-ECHILD); + else + filp = ERR_PTR(-ESTALE); + } return filp; out_filp: diff --git a/include/linux/errno.h b/include/linux/errno.h index 2d09bfa5c26..e0de516374d 100644 --- a/include/linux/errno.h +++ b/include/linux/errno.h @@ -17,6 +17,7 @@ #define ENOIOCTLCMD 515 /* No ioctl command */ #define ERESTART_RESTARTBLOCK 516 /* restart by calling sys_restart_syscall */ #define EPROBE_DEFER 517 /* Driver requests probe retry */ +#define EOPENSTALE 518 /* open found a stale dentry */ /* Defined for the NFSv3 protocol */ #define EBADHANDLE 521 /* Illegal NFS file handle */ |