diff options
Diffstat (limited to 'fs/dcache.c')
| -rw-r--r-- | fs/dcache.c | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index eb0978da1bd4..aafa2a146434 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -2887,24 +2887,28 @@ static int prepend_path(const struct path *path, struct vfsmount *vfsmnt = path->mnt; struct mount *mnt = real_mount(vfsmnt); int error = 0; - unsigned seq = 0; + unsigned seq, m_seq = 0; char *bptr; int blen; - br_read_lock(&vfsmount_lock); rcu_read_lock(); +restart_mnt: + read_seqbegin_or_lock(&mount_lock, &m_seq); + seq = 0; restart: bptr = *buffer; blen = *buflen; + error = 0; read_seqbegin_or_lock(&rename_lock, &seq); while (dentry != root->dentry || vfsmnt != root->mnt) { struct dentry * parent; if (dentry == vfsmnt->mnt_root || IS_ROOT(dentry)) { + struct mount *parent = ACCESS_ONCE(mnt->mnt_parent); /* Global root? */ - if (mnt_has_parent(mnt)) { - dentry = mnt->mnt_mountpoint; - mnt = mnt->mnt_parent; + if (mnt != parent) { + dentry = ACCESS_ONCE(mnt->mnt_mountpoint); + mnt = parent; vfsmnt = &mnt->mnt; continue; } @@ -2938,7 +2942,11 @@ restart: goto restart; } done_seqretry(&rename_lock, seq); - br_read_unlock(&vfsmount_lock); + if (need_seqretry(&mount_lock, m_seq)) { + m_seq = 1; + goto restart_mnt; + } + done_seqretry(&mount_lock, m_seq); if (error >= 0 && bptr == *buffer) { if (--blen < 0) |