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authorNick Piggin <npiggin@kernel.dk>2011-01-07 17:49:57 +1100
committerNick Piggin <npiggin@kernel.dk>2011-01-07 17:50:29 +1100
commit34286d6662308d82aed891852d04c7c3a2649b16 (patch)
treec4b7311404d302e7cb94df7a4690298e1059910a /fs
parent44a7d7a878c9cbb74f236ea755b25b6b2e26a9a9 (diff)
fs: rcu-walk aware d_revalidate method
Require filesystems be aware of .d_revalidate being called in rcu-walk mode (nd->flags & LOOKUP_RCU). For now do a simple push down, returning -ECHILD from all implementations. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Diffstat (limited to 'fs')
-rw-r--r--fs/afs/dir.c4
-rw-r--r--fs/autofs4/root.c13
-rw-r--r--fs/ceph/dir.c7
-rw-r--r--fs/cifs/dir.c3
-rw-r--r--fs/coda/dir.c7
-rw-r--r--fs/ecryptfs/dentry.c9
-rw-r--r--fs/fat/namei_vfat.c6
-rw-r--r--fs/fuse/dir.c6
-rw-r--r--fs/gfs2/dentry.c17
-rw-r--r--fs/hfs/sysdep.c7
-rw-r--r--fs/jfs/namei.c2
-rw-r--r--fs/namei.c54
-rw-r--r--fs/ncpfs/dir.c4
-rw-r--r--fs/ncpfs/inode.c1
-rw-r--r--fs/nfs/dir.c8
-rw-r--r--fs/ocfs2/dcache.c10
-rw-r--r--fs/proc/base.c33
-rw-r--r--fs/proc/proc_sysctl.c3
-rw-r--r--fs/reiserfs/xattr.c2
-rw-r--r--fs/sysfs/dir.c6
20 files changed, 159 insertions, 43 deletions
diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index b8bb7e7148d..34a3263d60a 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -13,6 +13,7 @@
#include <linux/module.h>
#include <linux/init.h>
#include <linux/fs.h>
+#include <linux/namei.h>
#include <linux/pagemap.h>
#include <linux/ctype.h>
#include <linux/sched.h>
@@ -607,6 +608,9 @@ static int afs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
void *dir_version;
int ret;
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
vnode = AFS_FS_I(dentry->d_inode);
if (dentry->d_inode)
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index bfe3f2eb684..651e4ef563b 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -315,12 +315,19 @@ out_error:
*/
static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
{
- struct inode *dir = dentry->d_parent->d_inode;
- struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
- int oz_mode = autofs4_oz_mode(sbi);
+ struct inode *dir;
+ struct autofs_sb_info *sbi;
+ int oz_mode;
int flags = nd ? nd->flags : 0;
int status = 1;
+ if (flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ dir = dentry->d_parent->d_inode;
+ sbi = autofs4_sbi(dir->i_sb);
+ oz_mode = autofs4_oz_mode(sbi);
+
/* Pending dentry */
spin_lock(&sbi->fs_lock);
if (autofs4_ispending(dentry)) {
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index cc01cf82676..fa7ca04ee81 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -990,7 +990,12 @@ static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry)
*/
static int ceph_d_revalidate(struct dentry *dentry, struct nameidata *nd)
{
- struct inode *dir = dentry->d_parent->d_inode;
+ struct inode *dir;
+
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ dir = dentry->d_parent->d_inode;
dout("d_revalidate %p '%.*s' inode %p offset %lld\n", dentry,
dentry->d_name.len, dentry->d_name.name, dentry->d_inode,
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index e3b10ca6d45..db2a58c00f7 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -656,6 +656,9 @@ lookup_out:
static int
cifs_d_revalidate(struct dentry *direntry, struct nameidata *nd)
{
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
if (direntry->d_inode) {
if (cifs_revalidate_dentry(direntry))
return 0;
diff --git a/fs/coda/dir.c b/fs/coda/dir.c
index aa40c811f8d..619a8303766 100644
--- a/fs/coda/dir.c
+++ b/fs/coda/dir.c
@@ -18,6 +18,7 @@
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/spinlock.h>
+#include <linux/namei.h>
#include <asm/uaccess.h>
@@ -541,9 +542,13 @@ out:
/* called when a cache lookup succeeds */
static int coda_dentry_revalidate(struct dentry *de, struct nameidata *nd)
{
- struct inode *inode = de->d_inode;
+ struct inode *inode;
struct coda_inode_info *cii;
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ inode = de->d_inode;
if (!inode || coda_isroot(inode))
goto out;
if (is_bad_inode(inode))
diff --git a/fs/ecryptfs/dentry.c b/fs/ecryptfs/dentry.c
index 906e803f7f7..6fc4f319b55 100644
--- a/fs/ecryptfs/dentry.c
+++ b/fs/ecryptfs/dentry.c
@@ -44,12 +44,17 @@
*/
static int ecryptfs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
{
- struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
- struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
+ struct dentry *lower_dentry;
+ struct vfsmount *lower_mnt;
struct dentry *dentry_save;
struct vfsmount *vfsmount_save;
int rc = 1;
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ lower_dentry = ecryptfs_dentry_to_lower(dentry);
+ lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
if (!lower_dentry->d_op || !lower_dentry->d_op->d_revalidate)
goto out;
dentry_save = nd->path.dentry;
diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
index 3be5ed7d859..e3ffc5e1233 100644
--- a/fs/fat/namei_vfat.c
+++ b/fs/fat/namei_vfat.c
@@ -43,6 +43,9 @@ static int vfat_revalidate_shortname(struct dentry *dentry)
static int vfat_revalidate(struct dentry *dentry, struct nameidata *nd)
{
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
/* This is not negative dentry. Always valid. */
if (dentry->d_inode)
return 1;
@@ -51,6 +54,9 @@ static int vfat_revalidate(struct dentry *dentry, struct nameidata *nd)
static int vfat_revalidate_ci(struct dentry *dentry, struct nameidata *nd)
{
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
/*
* This is not negative dentry. Always valid.
*
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index c9a8a426a39..07f4b5e675f 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -156,8 +156,12 @@ u64 fuse_get_attr_version(struct fuse_conn *fc)
*/
static int fuse_dentry_revalidate(struct dentry *entry, struct nameidata *nd)
{
- struct inode *inode = entry->d_inode;
+ struct inode *inode;
+
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+ inode = entry->d_inode;
if (inode && is_bad_inode(inode))
return 0;
else if (fuse_dentry_time(entry) < get_jiffies_64()) {
diff --git a/fs/gfs2/dentry.c b/fs/gfs2/dentry.c
index 50497f65763..4a456338b87 100644
--- a/fs/gfs2/dentry.c
+++ b/fs/gfs2/dentry.c
@@ -11,6 +11,7 @@
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/gfs2_ondisk.h>
+#include <linux/namei.h>
#include <linux/crc32.h>
#include "gfs2.h"
@@ -34,15 +35,23 @@
static int gfs2_drevalidate(struct dentry *dentry, struct nameidata *nd)
{
- struct dentry *parent = dget_parent(dentry);
- struct gfs2_sbd *sdp = GFS2_SB(parent->d_inode);
- struct gfs2_inode *dip = GFS2_I(parent->d_inode);
- struct inode *inode = dentry->d_inode;
+ struct dentry *parent;
+ struct gfs2_sbd *sdp;
+ struct gfs2_inode *dip;
+ struct inode *inode;
struct gfs2_holder d_gh;
struct gfs2_inode *ip = NULL;
int error;
int had_lock = 0;
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ parent = dget_parent(dentry);
+ sdp = GFS2_SB(parent->d_inode);
+ dip = GFS2_I(parent->d_inode);
+ inode = dentry->d_inode;
+
if (inode) {
if (is_bad_inode(inode))
goto invalid;
diff --git a/fs/hfs/sysdep.c b/fs/hfs/sysdep.c
index 7478f5c219a..19cf291eb91 100644
--- a/fs/hfs/sysdep.c
+++ b/fs/hfs/sysdep.c
@@ -8,15 +8,20 @@
* This file contains the code to do various system dependent things.
*/
+#include <linux/namei.h>
#include "hfs_fs.h"
/* dentry case-handling: just lowercase everything */
static int hfs_revalidate_dentry(struct dentry *dentry, struct nameidata *nd)
{
- struct inode *inode = dentry->d_inode;
+ struct inode *inode;
int diff;
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ inode = dentry->d_inode;
if(!inode)
return 1;
diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index a151cbdec62..4414e3a4226 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -1608,6 +1608,8 @@ out:
static int jfs_ci_revalidate(struct dentry *dentry, struct nameidata *nd)
{
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
/*
* This is not negative dentry. Always valid.
*
diff --git a/fs/namei.c b/fs/namei.c
index 90bd2873e11..6e275363e89 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -563,10 +563,26 @@ void release_open_intent(struct nameidata *nd)
fput(nd->intent.open.file);
}
+static int d_revalidate(struct dentry *dentry, struct nameidata *nd)
+{
+ int status;
+
+ status = dentry->d_op->d_revalidate(dentry, nd);
+ if (status == -ECHILD) {
+ if (nameidata_dentry_drop_rcu(nd, dentry))
+ return status;
+ status = dentry->d_op->d_revalidate(dentry, nd);
+ }
+
+ return status;
+}
+
static inline struct dentry *
do_revalidate(struct dentry *dentry, struct nameidata *nd)
{
- int status = dentry->d_op->d_revalidate(dentry, nd);
+ int status;
+
+ status = d_revalidate(dentry, nd);
if (unlikely(status <= 0)) {
/*
* The dentry failed validation.
@@ -574,14 +590,20 @@ do_revalidate(struct dentry *dentry, struct nameidata *nd)
* the dentry otherwise d_revalidate is asking us
* to return a fail status.
*/
- if (!status) {
+ if (status < 0) {
+ /* If we're in rcu-walk, we don't have a ref */
+ if (!(nd->flags & LOOKUP_RCU))
+ dput(dentry);
+ dentry = ERR_PTR(status);
+
+ } else {
+ /* Don't d_invalidate in rcu-walk mode */
+ if (nameidata_dentry_drop_rcu_maybe(nd, dentry))
+ return ERR_PTR(-ECHILD);
if (!d_invalidate(dentry)) {
dput(dentry);
dentry = NULL;
}
- } else {
- dput(dentry);
- dentry = ERR_PTR(status);
}
}
return dentry;
@@ -626,7 +648,7 @@ force_reval_path(struct path *path, struct nameidata *nd)
if (!need_reval_dot(dentry))
return 0;
- status = dentry->d_op->d_revalidate(dentry, nd);
+ status = d_revalidate(dentry, nd);
if (status > 0)
return 0;
@@ -1039,12 +1061,8 @@ static int do_lookup(struct nameidata *nd, struct qstr *name,
return -ECHILD;
nd->seq = seq;
- if (dentry->d_flags & DCACHE_OP_REVALIDATE) {
- /* We commonly drop rcu-walk here */
- if (nameidata_dentry_drop_rcu(nd, dentry))
- return -ECHILD;
+ if (dentry->d_flags & DCACHE_OP_REVALIDATE)
goto need_revalidate;
- }
path->mnt = mnt;
path->dentry = dentry;
__follow_mount_rcu(nd, path, inode);
@@ -1292,12 +1310,11 @@ return_reval:
* We may need to check the cached dentry for staleness.
*/
if (need_reval_dot(nd->path.dentry)) {
- if (nameidata_drop_rcu_maybe(nd))
- return -ECHILD;
- err = -ESTALE;
/* Note: we do not d_invalidate() */
- if (!nd->path.dentry->d_op->d_revalidate(
- nd->path.dentry, nd))
+ err = d_revalidate(nd->path.dentry, nd);
+ if (!err)
+ err = -ESTALE;
+ if (err < 0)
break;
}
return_base:
@@ -2080,10 +2097,11 @@ static struct file *do_last(struct nameidata *nd, struct path *path,
dir = nd->path.dentry;
case LAST_DOT:
if (need_reval_dot(dir)) {
- if (!dir->d_op->d_revalidate(dir, nd)) {
+ error = d_revalidate(nd->path.dentry, nd);
+ if (!error)
error = -ESTALE;
+ if (error < 0)
goto exit;
- }
}
/* fallthrough */
case LAST_ROOT:
diff --git a/fs/ncpfs/dir.c b/fs/ncpfs/dir.c
index 4b9cbb28d7f..28f136d4aae 100644
--- a/fs/ncpfs/dir.c
+++ b/fs/ncpfs/dir.c
@@ -17,6 +17,7 @@
#include <linux/kernel.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
+#include <linux/namei.h>
#include <asm/uaccess.h>
#include <asm/byteorder.h>
@@ -308,6 +309,9 @@ ncp_lookup_validate(struct dentry *dentry, struct nameidata *nd)
int res, val = 0, len;
__u8 __name[NCP_MAXPATHLEN + 1];
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
parent = dget_parent(dentry);
dir = parent->d_inode;
diff --git a/fs/ncpfs/inode.c b/fs/ncpfs/inode.c
index 0c75a5f3caf..9531c052d7a 100644
--- a/fs/ncpfs/inode.c
+++ b/fs/ncpfs/inode.c
@@ -29,6 +29,7 @@
#include <linux/vfs.h>
#include <linux/mount.h>
#include <linux/seq_file.h>
+#include <linux/namei.h>
#include <linux/ncp_fs.h>
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index 37e0a8bb077..58beace14b1 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -938,7 +938,8 @@ static int nfs_check_verifier(struct inode *dir, struct dentry *dentry)
* component of the path.
* We check for this using LOOKUP_CONTINUE and LOOKUP_PARENT.
*/
-static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd, unsigned int mask)
+static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd,
+ unsigned int mask)
{
if (nd->flags & (LOOKUP_CONTINUE|LOOKUP_PARENT))
return 0;
@@ -1018,7 +1019,7 @@ int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry,
* If the parent directory is seen to have changed, we throw out the
* cached dentry and do a new lookup.
*/
-static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd)
+static int nfs_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
{
struct inode *dir;
struct inode *inode;
@@ -1027,6 +1028,9 @@ static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd)
struct nfs_fattr *fattr = NULL;
int error;
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
parent = dget_parent(dentry);
dir = parent->d_inode;
nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
diff --git a/fs/ocfs2/dcache.c b/fs/ocfs2/dcache.c
index 4d54c60ceee..0310b16a723 100644
--- a/fs/ocfs2/dcache.c
+++ b/fs/ocfs2/dcache.c
@@ -52,9 +52,15 @@ void ocfs2_dentry_attach_gen(struct dentry *dentry)
static int ocfs2_dentry_revalidate(struct dentry *dentry,
struct nameidata *nd)
{
- struct inode *inode = dentry->d_inode;
+ struct inode *inode;
int ret = 0; /* if all else fails, just return false */
- struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
+ struct ocfs2_super *osb;
+
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ inode = dentry->d_inode;
+ osb = OCFS2_SB(dentry->d_sb);
mlog_entry("(0x%p, '%.*s')\n", dentry,
dentry->d_name.len, dentry->d_name.name);
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 85f0a80912a..dc5b2fcadc3 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1719,10 +1719,16 @@ static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat
*/
static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
{
- struct inode *inode = dentry->d_inode;
- struct task_struct *task = get_proc_task(inode);
+ struct inode *inode;
+ struct task_struct *task;
const struct cred *cred;
+ if (nd && nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ inode = dentry->d_inode;
+ task = get_proc_task(inode);
+
if (task) {
if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
task_dumpable(task)) {
@@ -1888,12 +1894,19 @@ static int proc_fd_link(struct inode *inode, struct path *path)
static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
{
- struct inode *inode = dentry->d_inode;
- struct task_struct *task = get_proc_task(inode);
- int fd = proc_fd(inode);
+ struct inode *inode;
+ struct task_struct *task;
+ int fd;
struct files_struct *files;
const struct cred *cred;
+ if (nd && nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ inode = dentry->d_inode;
+ task = get_proc_task(inode);
+ fd = proc_fd(inode);
+
if (task) {
files = get_files_struct(task);
if (files) {
@@ -2563,8 +2576,14 @@ static const struct pid_entry proc_base_stuff[] = {
*/
static int proc_base_revalidate(struct dentry *dentry, struct nameidata *nd)
{
- struct inode *inode = dentry->d_inode;
- struct task_struct *task = get_proc_task(inode);
+ struct inode *inode;
+ struct task_struct *task;
+
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ inode = dentry->d_inode;
+ task = get_proc_task(inode);
if (task) {
put_task_struct(task);
return 1;
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 35efd85a4d3..c9097f43b42 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -5,6 +5,7 @@
#include <linux/sysctl.h>
#include <linux/proc_fs.h>
#include <linux/security.h>
+#include <linux/namei.h>
#include "internal.h"
static const struct dentry_operations proc_sys_dentry_operations;
@@ -389,6 +390,8 @@ static const struct inode_operations proc_sys_dir_operations = {
static int proc_sys_revalidate(struct dentry *dentry, struct nameidata *nd)
{
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
return !PROC_I(dentry->d_inode)->sysctl->unregistering;
}
diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c
index e0f0d7ea10a..9ea22a56cdf 100644
--- a/fs/reiserfs/xattr.c
+++ b/fs/reiserfs/xattr.c
@@ -972,6 +972,8 @@ int reiserfs_permission(struct inode *inode, int mask)
static int xattr_hide_revalidate(struct dentry *dentry, struct nameidata *nd)
{
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
return -EPERM;
}
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 3e076caa8da..ea9120a830d 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -239,9 +239,13 @@ static int sysfs_dentry_delete(const struct dentry *dentry)
static int sysfs_dentry_revalidate(struct dentry *dentry, struct nameidata *nd)
{
- struct sysfs_dirent *sd = dentry->d_fsdata;
+ struct sysfs_dirent *sd;
int is_dir;
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ sd = dentry->d_fsdata;
mutex_lock(&sysfs_mutex);
/* The sysfs dirent has been deleted */