Commit 08b005f1 authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

xfs: remove kmem_zalloc_greedy 

The sole remaining caller of kmem_zalloc_greedy is bulkstat, which uses
it to grab 1-4 pages for staging of inobt records.  The infinite loop in
the greedy allocation function is causing hangs[1] in generic/269, so
just get rid of the greedy allocator in favor of kmem_zalloc_large.
This makes bulkstat somewhat more likely to ENOMEM if there's really no
pages to spare, but eliminates a source of hangs.

[1] http://lkml.kernel.org/r/20170301044634.rgidgdqqiiwsmfpj%40XZHOUW.usersys.redhat.com



Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
---
v2: remove single-page fallback
parent d5825712

fs/xfs/kmem.c

+0 −18
Original line number Original line Diff line number Diff line
@@ -25,24 +25,6 @@ 
#include "kmem.h"

#include "kmem.h"

#include "xfs_message.h"

#include "xfs_message.h"





/*

 * Greedy allocation.  May fail and may return vmalloced memory.

 */

void *

kmem_zalloc_greedy(size_t *size, size_t minsize, size_t maxsize)

{

	void		*ptr;

	size_t		kmsize = maxsize;



	while (!(ptr = vzalloc(kmsize))) {

		if ((kmsize >>= 1) <= minsize)

			kmsize = minsize;

	}

	if (ptr)

		*size = kmsize;

	return ptr;

}



void *

void *

kmem_alloc(size_t size, xfs_km_flags_t flags)

kmem_alloc(size_t size, xfs_km_flags_t flags)

{

{

fs/xfs/kmem.h

+0 −2
Original line number Original line Diff line number Diff line
@@ -69,8 +69,6 @@ static inline void kmem_free(const void *ptr) 
}

}









extern void *kmem_zalloc_greedy(size_t *, size_t, size_t);



static inline void *

static inline void *

kmem_zalloc(size_t size, xfs_km_flags_t flags)

kmem_zalloc(size_t size, xfs_km_flags_t flags)

{

{

fs/xfs/xfs_itable.c

+2 −4
Original line number Original line Diff line number Diff line
@@ -361,7 +361,6 @@ xfs_bulkstat( 
	xfs_agino_t		agino;	/* inode # in allocation group */

	xfs_agino_t		agino;	/* inode # in allocation group */

	xfs_agnumber_t		agno;	/* allocation group number */

	xfs_agnumber_t		agno;	/* allocation group number */

	xfs_btree_cur_t		*cur;	/* btree cursor for ialloc btree */

	xfs_btree_cur_t		*cur;	/* btree cursor for ialloc btree */

	size_t			irbsize; /* size of irec buffer in bytes */

	xfs_inobt_rec_incore_t	*irbuf;	/* start of irec buffer */

	xfs_inobt_rec_incore_t	*irbuf;	/* start of irec buffer */

	int			nirbuf;	/* size of irbuf */

	int			nirbuf;	/* size of irbuf */

	int			ubcount; /* size of user's buffer */

	int			ubcount; /* size of user's buffer */
@@ -388,11 +387,10 @@ xfs_bulkstat( 
	*ubcountp = 0;

	*ubcountp = 0;

	*done = 0;

	*done = 0;





	irbuf = kmem_zalloc_greedy(&irbsize, PAGE_SIZE, PAGE_SIZE * 4);

	irbuf = kmem_zalloc_large(PAGE_SIZE * 4, KM_SLEEP);

	if (!irbuf)

	if (!irbuf)

		return -ENOMEM;

		return -ENOMEM;



	nirbuf = (PAGE_SIZE * 4) / sizeof(*irbuf);

	nirbuf = irbsize / sizeof(*irbuf);





	/*

	/*

	 * Loop over the allocation groups, starting from the last

	 * Loop over the allocation groups, starting from the last

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