提交 b4df6ed8 编写于 作者: M Mark Fasheh

[PATCH] ocfs2: fix orphan recovery deadlock

Orphan dir recovery can deadlock with another process in
ocfs2_delete_inode() in some corner cases. Fix this by tracking recovery
state more closely and allowing it to handle inode wipes which might
deadlock.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>
上级 895928b8
......@@ -67,6 +67,7 @@ void ocfs2_init_node_maps(struct ocfs2_super *osb)
ocfs2_node_map_init(&osb->mounted_map);
ocfs2_node_map_init(&osb->recovery_map);
ocfs2_node_map_init(&osb->umount_map);
ocfs2_node_map_init(&osb->osb_recovering_orphan_dirs);
}
static void ocfs2_do_node_down(int node_num,
......
......@@ -41,6 +41,7 @@
#include "dlmglue.h"
#include "extent_map.h"
#include "file.h"
#include "heartbeat.h"
#include "inode.h"
#include "journal.h"
#include "namei.h"
......@@ -544,6 +545,42 @@ static int ocfs2_remove_inode(struct inode *inode,
return status;
}
/*
* Serialize with orphan dir recovery. If the process doing
* recovery on this orphan dir does an iget() with the dir
* i_mutex held, we'll deadlock here. Instead we detect this
* and exit early - recovery will wipe this inode for us.
*/
static int ocfs2_check_orphan_recovery_state(struct ocfs2_super *osb,
int slot)
{
int ret = 0;
spin_lock(&osb->osb_lock);
if (ocfs2_node_map_test_bit(osb, &osb->osb_recovering_orphan_dirs, slot)) {
mlog(0, "Recovery is happening on orphan dir %d, will skip "
"this inode\n", slot);
ret = -EDEADLK;
goto out;
}
/* This signals to the orphan recovery process that it should
* wait for us to handle the wipe. */
osb->osb_orphan_wipes[slot]++;
out:
spin_unlock(&osb->osb_lock);
return ret;
}
static void ocfs2_signal_wipe_completion(struct ocfs2_super *osb,
int slot)
{
spin_lock(&osb->osb_lock);
osb->osb_orphan_wipes[slot]--;
spin_unlock(&osb->osb_lock);
wake_up(&osb->osb_wipe_event);
}
static int ocfs2_wipe_inode(struct inode *inode,
struct buffer_head *di_bh)
{
......@@ -555,6 +592,11 @@ static int ocfs2_wipe_inode(struct inode *inode,
/* We've already voted on this so it should be readonly - no
* spinlock needed. */
orphaned_slot = OCFS2_I(inode)->ip_orphaned_slot;
status = ocfs2_check_orphan_recovery_state(osb, orphaned_slot);
if (status)
return status;
orphan_dir_inode = ocfs2_get_system_file_inode(osb,
ORPHAN_DIR_SYSTEM_INODE,
orphaned_slot);
......@@ -597,6 +639,7 @@ static int ocfs2_wipe_inode(struct inode *inode,
brelse(orphan_dir_bh);
bail:
iput(orphan_dir_inode);
ocfs2_signal_wipe_completion(osb, orphaned_slot);
return status;
}
......@@ -822,7 +865,8 @@ void ocfs2_delete_inode(struct inode *inode)
status = ocfs2_wipe_inode(inode, di_bh);
if (status < 0) {
mlog_errno(status);
if (status != -EDEADLK)
mlog_errno(status);
goto bail_unlock_inode;
}
......
......@@ -1408,21 +1408,17 @@ int ocfs2_mark_dead_nodes(struct ocfs2_super *osb)
return status;
}
static int ocfs2_recover_orphans(struct ocfs2_super *osb,
int slot)
static int ocfs2_queue_orphans(struct ocfs2_super *osb,
int slot,
struct inode **head)
{
int status = 0;
int have_disk_lock = 0;
struct inode *inode = NULL;
struct inode *iter;
int status;
struct inode *orphan_dir_inode = NULL;
struct inode *iter;
unsigned long offset, blk, local;
struct buffer_head *bh = NULL;
struct ocfs2_dir_entry *de;
struct super_block *sb = osb->sb;
struct ocfs2_inode_info *oi;
mlog(0, "Recover inodes from orphan dir in slot %d\n", slot);
orphan_dir_inode = ocfs2_get_system_file_inode(osb,
ORPHAN_DIR_SYSTEM_INODE,
......@@ -1430,17 +1426,15 @@ static int ocfs2_recover_orphans(struct ocfs2_super *osb,
if (!orphan_dir_inode) {
status = -ENOENT;
mlog_errno(status);
goto out;
}
return status;
}
mutex_lock(&orphan_dir_inode->i_mutex);
status = ocfs2_meta_lock(orphan_dir_inode, NULL, NULL, 0);
if (status < 0) {
mutex_unlock(&orphan_dir_inode->i_mutex);
mlog_errno(status);
goto out;
}
have_disk_lock = 1;
offset = 0;
iter = NULL;
......@@ -1451,11 +1445,10 @@ static int ocfs2_recover_orphans(struct ocfs2_super *osb,
if (!bh)
status = -EINVAL;
if (status < 0) {
mutex_unlock(&orphan_dir_inode->i_mutex);
if (bh)
brelse(bh);
mlog_errno(status);
goto out;
goto out_unlock;
}
local = 0;
......@@ -1465,11 +1458,10 @@ static int ocfs2_recover_orphans(struct ocfs2_super *osb,
if (!ocfs2_check_dir_entry(orphan_dir_inode,
de, bh, local)) {
mutex_unlock(&orphan_dir_inode->i_mutex);
status = -EINVAL;
mlog_errno(status);
brelse(bh);
goto out;
goto out_unlock;
}
local += le16_to_cpu(de->rec_len);
......@@ -1504,18 +1496,95 @@ static int ocfs2_recover_orphans(struct ocfs2_super *osb,
mlog(0, "queue orphan %"MLFu64"\n",
OCFS2_I(iter)->ip_blkno);
OCFS2_I(iter)->ip_next_orphan = inode;
inode = iter;
/* No locking is required for the next_orphan
* queue as there is only ever a single
* process doing orphan recovery. */
OCFS2_I(iter)->ip_next_orphan = *head;
*head = iter;
}
brelse(bh);
}
mutex_unlock(&orphan_dir_inode->i_mutex);
out_unlock:
ocfs2_meta_unlock(orphan_dir_inode, 0);
have_disk_lock = 0;
out:
mutex_unlock(&orphan_dir_inode->i_mutex);
iput(orphan_dir_inode);
orphan_dir_inode = NULL;
return status;
}
static int ocfs2_orphan_recovery_can_continue(struct ocfs2_super *osb,
int slot)
{
int ret;
spin_lock(&osb->osb_lock);
ret = !osb->osb_orphan_wipes[slot];
spin_unlock(&osb->osb_lock);
return ret;
}
static void ocfs2_mark_recovering_orphan_dir(struct ocfs2_super *osb,
int slot)
{
spin_lock(&osb->osb_lock);
/* Mark ourselves such that new processes in delete_inode()
* know to quit early. */
ocfs2_node_map_set_bit(osb, &osb->osb_recovering_orphan_dirs, slot);
while (osb->osb_orphan_wipes[slot]) {
/* If any processes are already in the middle of an
* orphan wipe on this dir, then we need to wait for
* them. */
spin_unlock(&osb->osb_lock);
wait_event_interruptible(osb->osb_wipe_event,
ocfs2_orphan_recovery_can_continue(osb, slot));
spin_lock(&osb->osb_lock);
}
spin_unlock(&osb->osb_lock);
}
static void ocfs2_clear_recovering_orphan_dir(struct ocfs2_super *osb,
int slot)
{
ocfs2_node_map_clear_bit(osb, &osb->osb_recovering_orphan_dirs, slot);
}
/*
* Orphan recovery. Each mounted node has it's own orphan dir which we
* must run during recovery. Our strategy here is to build a list of
* the inodes in the orphan dir and iget/iput them. The VFS does
* (most) of the rest of the work.
*
* Orphan recovery can happen at any time, not just mount so we have a
* couple of extra considerations.
*
* - We grab as many inodes as we can under the orphan dir lock -
* doing iget() outside the orphan dir risks getting a reference on
* an invalid inode.
* - We must be sure not to deadlock with other processes on the
* system wanting to run delete_inode(). This can happen when they go
* to lock the orphan dir and the orphan recovery process attempts to
* iget() inside the orphan dir lock. This can be avoided by
* advertising our state to ocfs2_delete_inode().
*/
static int ocfs2_recover_orphans(struct ocfs2_super *osb,
int slot)
{
int ret = 0;
struct inode *inode = NULL;
struct inode *iter;
struct ocfs2_inode_info *oi;
mlog(0, "Recover inodes from orphan dir in slot %d\n", slot);
ocfs2_mark_recovering_orphan_dir(osb, slot);
ret = ocfs2_queue_orphans(osb, slot, &inode);
ocfs2_clear_recovering_orphan_dir(osb, slot);
/* Error here should be noted, but we want to continue with as
* many queued inodes as we've got. */
if (ret)
mlog_errno(ret);
while (inode) {
oi = OCFS2_I(inode);
......@@ -1541,14 +1610,7 @@ static int ocfs2_recover_orphans(struct ocfs2_super *osb,
inode = iter;
}
out:
if (have_disk_lock)
ocfs2_meta_unlock(orphan_dir_inode, 0);
if (orphan_dir_inode)
iput(orphan_dir_inode);
return status;
return ret;
}
static int ocfs2_wait_on_mount(struct ocfs2_super *osb)
......
......@@ -287,6 +287,10 @@ struct ocfs2_super
struct inode *osb_tl_inode;
struct buffer_head *osb_tl_bh;
struct work_struct osb_truncate_log_wq;
struct ocfs2_node_map osb_recovering_orphan_dirs;
unsigned int *osb_orphan_wipes;
wait_queue_head_t osb_wipe_event;
};
#define OCFS2_SB(sb) ((struct ocfs2_super *)(sb)->s_fs_info)
......
......@@ -1325,6 +1325,16 @@ static int ocfs2_initialize_super(struct super_block *sb,
}
mlog(ML_NOTICE, "max_slots for this device: %u\n", osb->max_slots);
init_waitqueue_head(&osb->osb_wipe_event);
osb->osb_orphan_wipes = kcalloc(osb->max_slots,
sizeof(*osb->osb_orphan_wipes),
GFP_KERNEL);
if (!osb->osb_orphan_wipes) {
status = -ENOMEM;
mlog_errno(status);
goto bail;
}
osb->s_feature_compat =
le32_to_cpu(OCFS2_RAW_SB(di)->s_feature_compat);
osb->s_feature_ro_compat =
......@@ -1638,6 +1648,7 @@ static void ocfs2_delete_osb(struct ocfs2_super *osb)
if (osb->slot_info)
ocfs2_free_slot_info(osb->slot_info);
kfree(osb->osb_orphan_wipes);
/* FIXME
* This belongs in journal shutdown, but because we have to
* allocate osb->journal at the start of ocfs2_initalize_osb(),
......
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