Commit 9e1a9ecd authored by Andreas Gruenbacher's avatar Andreas Gruenbacher Committed by Bob Peterson
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gfs2: Don't withdraw under a spin lock 



In two places, the gfs2_io_error_bh macro is called while holding the
sd_ail_lock spin lock.  This isn't allowed because gfs2_io_error_bh
withdraws the filesystem, which can sleep because it issues a uevent.
To fix that, add a gfs2_io_error_bh_wd macro that does withdraw the
filesystem and change gfs2_io_error_bh to not withdraw the filesystem.
In those places where the new gfs2_io_error_bh is used, withdraw the
filesystem after releasing sd_ail_lock.

Signed-off-by: default avatarAndreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: default avatarBob Peterson <rpeterso@redhat.com>
Reviewed-by: default avatarAndrew Price <anprice@redhat.com>
parent f85c10e2

fs/gfs2/log.c

+19 −7
Original line number Diff line number Diff line
@@ -92,7 +92,8 @@ static void gfs2_remove_from_ail(struct gfs2_bufdata *bd) 


static int gfs2_ail1_start_one(struct gfs2_sbd *sdp,

			       struct writeback_control *wbc,

			       struct gfs2_trans *tr)

			       struct gfs2_trans *tr,

			       bool *withdraw)

__releases(&sdp->sd_ail_lock)

__acquires(&sdp->sd_ail_lock)

{
@@ -107,8 +108,10 @@ __acquires(&sdp->sd_ail_lock) 
		gfs2_assert(sdp, bd->bd_tr == tr);



		if (!buffer_busy(bh)) {

			if (!buffer_uptodate(bh))

			if (!buffer_uptodate(bh)) {

				gfs2_io_error_bh(sdp, bh);

				*withdraw = true;

			}

			list_move(&bd->bd_ail_st_list, &tr->tr_ail2_list);

			continue;

		}
@@ -148,6 +151,7 @@ void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc) 
	struct list_head *head = &sdp->sd_ail1_list;

	struct gfs2_trans *tr;

	struct blk_plug plug;

	bool withdraw = false;



	trace_gfs2_ail_flush(sdp, wbc, 1);

	blk_start_plug(&plug);
@@ -156,11 +160,13 @@ restart: 
	list_for_each_entry_reverse(tr, head, tr_list) {

		if (wbc->nr_to_write <= 0)

			break;

		if (gfs2_ail1_start_one(sdp, wbc, tr))

		if (gfs2_ail1_start_one(sdp, wbc, tr, &withdraw))

			goto restart;

	}

	spin_unlock(&sdp->sd_ail_lock);

	blk_finish_plug(&plug);

	if (withdraw)

		gfs2_lm_withdraw(sdp, NULL);

	trace_gfs2_ail_flush(sdp, wbc, 0);

}
@@ -188,7 +194,8 @@ static void gfs2_ail1_start(struct gfs2_sbd *sdp) 
 *

 */



static void gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_trans *tr)

static void gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_trans *tr,

				bool *withdraw)

{

	struct gfs2_bufdata *bd, *s;

	struct buffer_head *bh;
@@ -199,11 +206,12 @@ static void gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_trans *tr) 
		gfs2_assert(sdp, bd->bd_tr == tr);

		if (buffer_busy(bh))

			continue;

		if (!buffer_uptodate(bh))

		if (!buffer_uptodate(bh)) {

			gfs2_io_error_bh(sdp, bh);

			*withdraw = true;

		}

		list_move(&bd->bd_ail_st_list, &tr->tr_ail2_list);

	}



}



/**
@@ -218,10 +226,11 @@ static int gfs2_ail1_empty(struct gfs2_sbd *sdp) 
	struct gfs2_trans *tr, *s;

	int oldest_tr = 1;

	int ret;

	bool withdraw = false;



	spin_lock(&sdp->sd_ail_lock);

	list_for_each_entry_safe_reverse(tr, s, &sdp->sd_ail1_list, tr_list) {

		gfs2_ail1_empty_one(sdp, tr);

		gfs2_ail1_empty_one(sdp, tr, &withdraw);

		if (list_empty(&tr->tr_ail1_list) && oldest_tr)

			list_move(&tr->tr_list, &sdp->sd_ail2_list);

		else
@@ -230,6 +239,9 @@ static int gfs2_ail1_empty(struct gfs2_sbd *sdp) 
	ret = list_empty(&sdp->sd_ail1_list);

	spin_unlock(&sdp->sd_ail_lock);



	if (withdraw)

		gfs2_lm_withdraw(sdp, "fatal: I/O error(s)\n");



	return ret;

}

fs/gfs2/lops.c

+1 −1
Original line number Diff line number Diff line
@@ -49,7 +49,7 @@ void gfs2_pin(struct gfs2_sbd *sdp, struct buffer_head *bh) 
	if (test_set_buffer_pinned(bh))

		gfs2_assert_withdraw(sdp, 0);

	if (!buffer_uptodate(bh))

		gfs2_io_error_bh(sdp, bh);

		gfs2_io_error_bh_wd(sdp, bh);

	bd = bh->b_private;

	/* If this buffer is in the AIL and it has already been written

	 * to in-place disk block, remove it from the AIL.

fs/gfs2/meta_io.c

+2 −2
Original line number Diff line number Diff line
@@ -293,7 +293,7 @@ int gfs2_meta_read(struct gfs2_glock *gl, u64 blkno, int flags, 
	if (unlikely(!buffer_uptodate(bh))) {

		struct gfs2_trans *tr = current->journal_info;

		if (tr && test_bit(TR_TOUCHED, &tr->tr_flags))

			gfs2_io_error_bh(sdp, bh);

			gfs2_io_error_bh_wd(sdp, bh);

		brelse(bh);

		*bhp = NULL;

		return -EIO;
@@ -320,7 +320,7 @@ int gfs2_meta_wait(struct gfs2_sbd *sdp, struct buffer_head *bh) 
	if (!buffer_uptodate(bh)) {

		struct gfs2_trans *tr = current->journal_info;

		if (tr && test_bit(TR_TOUCHED, &tr->tr_flags))

			gfs2_io_error_bh(sdp, bh);

			gfs2_io_error_bh_wd(sdp, bh);

		return -EIO;

	}

	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))

fs/gfs2/util.c

+20 −18
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ int gfs2_lm_withdraw(struct gfs2_sbd *sdp, const char *fmt, ...) 
	    test_and_set_bit(SDF_SHUTDOWN, &sdp->sd_flags))

		return 0;



	if (fmt) {

		va_start(args, fmt);



		vaf.fmt = fmt;
@@ -54,6 +55,7 @@ int gfs2_lm_withdraw(struct gfs2_sbd *sdp, const char *fmt, ...) 
		fs_err(sdp, "%pV", &vaf);



		va_end(args);

	}



	if (sdp->sd_args.ar_errors == GFS2_ERRORS_WITHDRAW) {

		fs_err(sdp, "about to withdraw this file system\n");
@@ -246,21 +248,21 @@ int gfs2_io_error_i(struct gfs2_sbd *sdp, const char *function, char *file, 
}



/**

 * gfs2_io_error_bh_i - Flag a buffer I/O error and withdraw

 * Returns: -1 if this call withdrew the machine,

 *          0 if it was already withdrawn

 * gfs2_io_error_bh_i - Flag a buffer I/O error

 * @withdraw: withdraw the filesystem

 */



int gfs2_io_error_bh_i(struct gfs2_sbd *sdp, struct buffer_head *bh,

		       const char *function, char *file, unsigned int line)

void gfs2_io_error_bh_i(struct gfs2_sbd *sdp, struct buffer_head *bh,

			const char *function, char *file, unsigned int line,

			bool withdraw)

{

	int rv;

	rv = gfs2_lm_withdraw(sdp,

	fs_err(sdp,

	       "fatal: I/O error\n"

	       "  block = %llu\n"

	       "  function = %s, file = %s, line = %u\n",

	       (unsigned long long)bh->b_blocknr,

	       function, file, line);

	return rv;

	if (withdraw)

		gfs2_lm_withdraw(sdp, NULL);

}

fs/gfs2/util.h

+7 −3
Original line number Diff line number Diff line
@@ -136,11 +136,15 @@ int gfs2_io_error_i(struct gfs2_sbd *sdp, const char *function, 
gfs2_io_error_i((sdp), __func__, __FILE__, __LINE__);





int gfs2_io_error_bh_i(struct gfs2_sbd *sdp, struct buffer_head *bh,

		       const char *function, char *file, unsigned int line);

void gfs2_io_error_bh_i(struct gfs2_sbd *sdp, struct buffer_head *bh,

			const char *function, char *file, unsigned int line,

			bool withdraw);



#define gfs2_io_error_bh_wd(sdp, bh) \

gfs2_io_error_bh_i((sdp), (bh), __func__, __FILE__, __LINE__, true);



#define gfs2_io_error_bh(sdp, bh) \

gfs2_io_error_bh_i((sdp), (bh), __func__, __FILE__, __LINE__);

gfs2_io_error_bh_i((sdp), (bh), __func__, __FILE__, __LINE__, false);





extern struct kmem_cache *gfs2_glock_cachep;

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