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Use spa as key besides objsetid for snapentry

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objsetid is not unique across pool, so using it solely as key would cause
panic when automounting two snapshot on different pools with the same
objsetid. We fix this by adding spa pointer as additional key.

Signed-off-by: Chunwei Chen <david.chen@osnexus.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Issue #3948
Issue #3786
Issue #3887
This commit is contained in:
Chunwei Chen 2015-12-07 15:43:53 -08:00 committed by Brian Behlendorf
parent b58986eebf
commit 24ef51f660
3 changed files with 26 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
include/sys/zfs_ctldir.h
View File

@ -77,7 +77,8 @@ extern int zfsctl_snapdir_mkdir(struct inode *dip, char *dirname, vattr_t *vap,
extern void zfsctl_snapdir_inactive(struct inode *ip);
extern int zfsctl_snapshot_mount(struct path *path, int flags);
extern int zfsctl_snapshot_unmount(char *snapname, int flags);
extern int zfsctl_snapshot_unmount_delay(uint64_t objsetid, int delay);
extern int zfsctl_snapshot_unmount_delay(spa_t *spa, uint64_t objsetid,
int delay);
extern int zfsctl_lookup_objset(struct super_block *sb, uint64_t objsetid,
zfs_sb_t **zsb);

32
module/zfs/zfs_ctldir.c
View File

@ -81,6 +81,7 @@
#include <sys/zfs_vnops.h>
#include <sys/stat.h>
#include <sys/dmu.h>
#include <sys/dmu_objset.h>
#include <sys/dsl_destroy.h>
#include <sys/dsl_deleg.h>
#include <sys/mount.h>
@ -117,6 +118,7 @@ static taskq_t *zfs_expire_taskq;
typedef struct {
char *se_name; /* full snapshot name */
char *se_path; /* full mount path */
spa_t *se_spa; /* pool spa */
uint64_t se_objsetid; /* snapshot objset id */
struct dentry *se_root_dentry; /* snapshot root dentry */
taskqid_t se_taskqid; /* scheduled unmount taskqid */
@ -132,8 +134,8 @@ static void zfsctl_snapshot_unmount_delay_impl(zfs_snapentry_t *se, int delay);
* the snapshot name and provided mount point. No reference is taken.
*/
static zfs_snapentry_t *
zfsctl_snapshot_alloc(char *full_name, char *full_path, uint64_t objsetid,
struct dentry *root_dentry)
zfsctl_snapshot_alloc(char *full_name, char *full_path, spa_t *spa,
uint64_t objsetid, struct dentry *root_dentry)
{
zfs_snapentry_t *se;
@ -141,6 +143,7 @@ zfsctl_snapshot_alloc(char *full_name, char *full_path, uint64_t objsetid,
se->se_name = strdup(full_name);
se->se_path = strdup(full_path);
se->se_spa = spa;
se->se_objsetid = objsetid;
se->se_root_dentry = root_dentry;
se->se_taskqid = -1;
@ -242,6 +245,9 @@ snapentry_compare_by_objsetid(const void *a, const void *b)
const zfs_snapentry_t *se_a = a;
const zfs_snapentry_t *se_b = b;
if (se_a->se_spa != se_b->se_spa)
return ((ulong_t)se_a->se_spa < (ulong_t)se_b->se_spa ? -1 : 1);
if (se_a->se_objsetid < se_b->se_objsetid)
return (-1);
else if (se_a->se_objsetid > se_b->se_objsetid)
@ -278,12 +284,13 @@ zfsctl_snapshot_find_by_name(char *snapname)
* as zfsctl_snapshot_find_by_name().
*/
static zfs_snapentry_t *
zfsctl_snapshot_find_by_objsetid(uint64_t objsetid)
zfsctl_snapshot_find_by_objsetid(spa_t *spa, uint64_t objsetid)
{
zfs_snapentry_t *se, search;
ASSERT(MUTEX_HELD(&zfs_snapshot_lock));
search.se_spa = spa;
search.se_objsetid = objsetid;
se = avl_find(&zfs_snapshots_by_objsetid, &search, NULL);
if (se)
@ -323,6 +330,7 @@ static void
snapentry_expire(void *data)
{
zfs_snapentry_t *se = (zfs_snapentry_t *)data;
spa_t *spa = se->se_spa;
uint64_t objsetid = se->se_objsetid;
se->se_taskqid = -1;
@ -334,7 +342,7 @@ snapentry_expire(void *data)
* This can occur when the snapshot is busy.
*/
mutex_enter(&zfs_snapshot_lock);
if ((se = zfsctl_snapshot_find_by_objsetid(objsetid)) != NULL) {
if ((se = zfsctl_snapshot_find_by_objsetid(spa, objsetid)) != NULL) {
zfsctl_snapshot_unmount_delay_impl(se, zfs_expire_snapshot);
zfsctl_snapshot_rele(se);
}
@ -377,13 +385,13 @@ zfsctl_snapshot_unmount_delay_impl(zfs_snapentry_t *se, int delay)
* and held until the outstanding task is handled or cancelled.
*/
int
zfsctl_snapshot_unmount_delay(uint64_t objsetid, int delay)
zfsctl_snapshot_unmount_delay(spa_t *spa, uint64_t objsetid, int delay)
{
zfs_snapentry_t *se;
int error = ENOENT;
mutex_enter(&zfs_snapshot_lock);
if ((se = zfsctl_snapshot_find_by_objsetid(objsetid)) != NULL) {
if ((se = zfsctl_snapshot_find_by_objsetid(spa, objsetid)) != NULL) {
zfsctl_snapshot_unmount_cancel(se);
zfsctl_snapshot_unmount_delay_impl(se, delay);
zfsctl_snapshot_rele(se);
@ -560,10 +568,12 @@ zfsctl_destroy(zfs_sb_t *zsb)
{
if (zsb->z_issnap) {
zfs_snapentry_t *se;
spa_t *spa = zsb->z_os->os_spa;
uint64_t objsetid = dmu_objset_id(zsb->z_os);
mutex_enter(&zfs_snapshot_lock);
if ((se = zfsctl_snapshot_find_by_objsetid(objsetid)) != NULL) {
if ((se = zfsctl_snapshot_find_by_objsetid(spa, objsetid))
!= NULL) {
zfsctl_snapshot_unmount_cancel(se);
zfsctl_snapshot_remove(se);
zfsctl_snapshot_rele(se);
@ -1129,7 +1139,8 @@ zfsctl_snapshot_mount(struct path *path, int flags)
mutex_enter(&zfs_snapshot_lock);
se = zfsctl_snapshot_alloc(full_name, full_path,
dmu_objset_id(snap_zsb->z_os), dentry);
snap_zsb->z_os->os_spa, dmu_objset_id(snap_zsb->z_os),
dentry);
zfsctl_snapshot_add(se);
zfsctl_snapshot_unmount_delay_impl(se, zfs_expire_snapshot);
mutex_exit(&zfs_snapshot_lock);
@ -1152,6 +1163,7 @@ zfsctl_lookup_objset(struct super_block *sb, uint64_t objsetid, zfs_sb_t **zsbp)
{
zfs_snapentry_t *se;
int error;
spa_t *spa = ((zfs_sb_t *)(sb->s_fs_info))->z_os->os_spa;
/*
* Verify that the snapshot is mounted then lookup the mounted root
@ -1161,7 +1173,7 @@ zfsctl_lookup_objset(struct super_block *sb, uint64_t objsetid, zfs_sb_t **zsbp)
* because we hold the zfs_snapshot_lock to prevent the race.
*/
mutex_enter(&zfs_snapshot_lock);
if ((se = zfsctl_snapshot_find_by_objsetid(objsetid)) != NULL) {
if ((se = zfsctl_snapshot_find_by_objsetid(spa, objsetid)) != NULL) {
zfs_sb_t *zsb;
zsb = ITOZSB(se->se_root_dentry->d_inode);
@ -1170,7 +1182,7 @@ zfsctl_lookup_objset(struct super_block *sb, uint64_t objsetid, zfs_sb_t **zsbp)
if (time_after(jiffies, zsb->z_snap_defer_time +
MAX(zfs_expire_snapshot * HZ / 2, HZ))) {
zsb->z_snap_defer_time = jiffies;
zfsctl_snapshot_unmount_delay(objsetid,
zfsctl_snapshot_unmount_delay(spa, objsetid,
zfs_expire_snapshot);
}

3
module/zfs/zpl_inode.c
View File

@ -28,6 +28,7 @@
#include <sys/zfs_vfsops.h>
#include <sys/zfs_vnops.h>
#include <sys/zfs_znode.h>
#include <sys/dmu_objset.h>
#include <sys/vfs.h>
#include <sys/zpl.h>
@ -500,7 +501,7 @@ zpl_revalidate(struct dentry *dentry, unsigned int flags)
if (time_after(jiffies, zsb->z_snap_defer_time +
MAX(zfs_expire_snapshot * HZ / 2, HZ))) {
zsb->z_snap_defer_time = jiffies;
zfsctl_snapshot_unmount_delay(
zfsctl_snapshot_unmount_delay(zsb->z_os->os_spa,
dmu_objset_id(zsb->z_os), zfs_expire_snapshot);
}
}