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Commit b4df6ed8 authored by Mark Fasheh's avatar Mark Fasheh
Browse files

[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: default avatarMark Fasheh <mark.fasheh@oracle.com>
parent 895928b8

fs/ocfs2/heartbeat.c

+1 −0
Original line number Diff line number Diff line
@@ -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,

fs/ocfs2/inode.c

+45 −1
Original line number Diff line number Diff line
@@ -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 @@ bail: 
	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 @@ bail_unlock_dir: 
	brelse(orphan_dir_bh);

bail:

	iput(orphan_dir_inode);

	ocfs2_signal_wipe_completion(osb, orphaned_slot);



	return status;

}
@@ -822,6 +865,7 @@ void ocfs2_delete_inode(struct inode *inode) 


	status = ocfs2_wipe_inode(inode, di_bh);

	if (status < 0) {

		if (status != -EDEADLK)

			mlog_errno(status);

		goto bail_unlock_inode;

	}

fs/ocfs2/journal.c

+93 −31
Original line number Diff line number Diff line
@@ -1408,21 +1408,17 @@ bail: 
	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)

fs/ocfs2/ocfs2.h

+4 −0
Original line number Diff line number Diff line
@@ -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)

fs/ocfs2/super.c

+11 −0
Original line number Diff line number Diff line
@@ -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(),