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Commit 97b713ba authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

fs: kill BDI_CAP_SWAP_BACKED 



This bdi flag isn't too useful - we can determine that a vma is backed by
either swap or shmem trivially in the caller.

This also allows removing the backing_dev_info instaces for swap and shmem
in favor of noop_backing_dev_info.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarTejun Heo <tj@kernel.org>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent a7a2c680

include/linux/backing-dev.h

+0 −13
Original line number Diff line number Diff line
@@ -238,8 +238,6 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); 
 * BDI_CAP_WRITE_MAP:      Can be mapped for writing

 * BDI_CAP_EXEC_MAP:       Can be mapped for execution

 *

 * BDI_CAP_SWAP_BACKED:    Count shmem/tmpfs objects as swap-backed.

 *

 * BDI_CAP_STRICTLIMIT:    Keep number of dirty pages below bdi threshold.

 */

#define BDI_CAP_NO_ACCT_DIRTY	0x00000001
@@ -250,7 +248,6 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); 
#define BDI_CAP_WRITE_MAP	0x00000020

#define BDI_CAP_EXEC_MAP	0x00000040

#define BDI_CAP_NO_ACCT_WB	0x00000080

#define BDI_CAP_SWAP_BACKED	0x00000100

#define BDI_CAP_STABLE_WRITES	0x00000200

#define BDI_CAP_STRICTLIMIT	0x00000400
@@ -329,11 +326,6 @@ static inline bool bdi_cap_account_writeback(struct backing_dev_info *bdi) 
				      BDI_CAP_NO_WRITEBACK));

}



static inline bool bdi_cap_swap_backed(struct backing_dev_info *bdi)

{

	return bdi->capabilities & BDI_CAP_SWAP_BACKED;

}



static inline bool mapping_cap_writeback_dirty(struct address_space *mapping)

{

	return bdi_cap_writeback_dirty(mapping->backing_dev_info);
@@ -344,11 +336,6 @@ static inline bool mapping_cap_account_dirty(struct address_space *mapping) 
	return bdi_cap_account_dirty(mapping->backing_dev_info);

}



static inline bool mapping_cap_swap_backed(struct address_space *mapping)

{

	return bdi_cap_swap_backed(mapping->backing_dev_info);

}



static inline int bdi_sched_wait(void *word)

{

	schedule();

mm/madvise.c

+10 −7
Original line number Diff line number Diff line
@@ -222,19 +222,22 @@ static long madvise_willneed(struct vm_area_struct *vma, 
	struct file *file = vma->vm_file;



#ifdef CONFIG_SWAP

	if (!file || mapping_cap_swap_backed(file->f_mapping)) {

	if (!file) {

		*prev = vma;

		if (!file)

		force_swapin_readahead(vma, start, end);

		else

		return 0;

	}



	if (shmem_mapping(file->f_mapping)) {

		*prev = vma;

		force_shm_swapin_readahead(vma, start, end,

					file->f_mapping);

		return 0;

	}

#endif



#else

	if (!file)

		return -EBADF;

#endif



	if (file->f_mapping->a_ops->get_xip_mem) {

		/* no bad return value, but ignore advice */

mm/shmem.c

+7 −18
Original line number Diff line number Diff line
@@ -191,11 +191,6 @@ static const struct inode_operations shmem_dir_inode_operations; 
static const struct inode_operations shmem_special_inode_operations;

static const struct vm_operations_struct shmem_vm_ops;



static struct backing_dev_info shmem_backing_dev_info  __read_mostly = {

	.ra_pages	= 0,	/* No readahead */

	.capabilities	= BDI_CAP_NO_ACCT_AND_WRITEBACK | BDI_CAP_SWAP_BACKED,

};



static LIST_HEAD(shmem_swaplist);

static DEFINE_MUTEX(shmem_swaplist_mutex);
@@ -765,11 +760,11 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc) 
		goto redirty;



	/*

	 * shmem_backing_dev_info's capabilities prevent regular writeback or

	 * sync from ever calling shmem_writepage; but a stacking filesystem

	 * might use ->writepage of its underlying filesystem, in which case

	 * tmpfs should write out to swap only in response to memory pressure,

	 * and not for the writeback threads or sync.

	 * Our capabilities prevent regular writeback or sync from ever calling

	 * shmem_writepage; but a stacking filesystem might use ->writepage of

	 * its underlying filesystem, in which case tmpfs should write out to

	 * swap only in response to memory pressure, and not for the writeback

	 * threads or sync.

	 */

	if (!wbc->for_reclaim) {

		WARN_ON_ONCE(1);	/* Still happens? Tell us about it! */
@@ -1415,7 +1410,7 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode 
		inode->i_ino = get_next_ino();

		inode_init_owner(inode, dir, mode);

		inode->i_blocks = 0;

		inode->i_mapping->backing_dev_info = &shmem_backing_dev_info;

		inode->i_mapping->backing_dev_info = &noop_backing_dev_info;

		inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;

		inode->i_generation = get_seconds();

		info = SHMEM_I(inode);
@@ -1461,7 +1456,7 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode 


bool shmem_mapping(struct address_space *mapping)

{

	return mapping->backing_dev_info == &shmem_backing_dev_info;

	return mapping->host->i_sb->s_op == &shmem_ops;

}



#ifdef CONFIG_TMPFS
@@ -3226,10 +3221,6 @@ int __init shmem_init(void) 
	if (shmem_inode_cachep)

		return 0;



	error = bdi_init(&shmem_backing_dev_info);

	if (error)

		goto out4;



	error = shmem_init_inodecache();

	if (error)

		goto out3;
@@ -3253,8 +3244,6 @@ int __init shmem_init(void) 
out2:

	shmem_destroy_inodecache();

out3:

	bdi_destroy(&shmem_backing_dev_info);

out4:

	shm_mnt = ERR_PTR(error);

	return error;

}

mm/swap.c

+0 −2
Original line number Diff line number Diff line
@@ -1138,8 +1138,6 @@ void __init swap_setup(void) 
#ifdef CONFIG_SWAP

	int i;



	if (bdi_init(swapper_spaces[0].backing_dev_info))

		panic("Failed to init swap bdi");

	for (i = 0; i < MAX_SWAPFILES; i++) {

		spin_lock_init(&swapper_spaces[i].tree_lock);

		INIT_LIST_HEAD(&swapper_spaces[i].i_mmap_nonlinear);

mm/swap_state.c

+1 −6
Original line number Diff line number Diff line
@@ -32,17 +32,12 @@ static const struct address_space_operations swap_aops = { 
#endif

};



static struct backing_dev_info swap_backing_dev_info = {

	.name		= "swap",

	.capabilities	= BDI_CAP_NO_ACCT_AND_WRITEBACK | BDI_CAP_SWAP_BACKED,

};



struct address_space swapper_spaces[MAX_SWAPFILES] = {

	[0 ... MAX_SWAPFILES - 1] = {

		.page_tree	= RADIX_TREE_INIT(GFP_ATOMIC|__GFP_NOWARN),

		.i_mmap_writable = ATOMIC_INIT(0),

		.a_ops		= &swap_aops,

		.backing_dev_info = &swap_backing_dev_info,

		.backing_dev_info = &noop_backing_dev_info,

	}

};