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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: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
hifive-unleashed-5.1
Christoph Hellwig 2015-01-14 10:42:31 +01:00 committed by Jens Axboe
parent a7a2c680a2
commit 97b713ba3e
5 changed files with 18 additions and 46 deletions
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13
include/linux/backing-dev.h
View File

@ -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();

17
mm/madvise.c
View File

@ -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
force_shm_swapin_readahead(vma, start, end,
file->f_mapping);
force_swapin_readahead(vma, start, end);
return 0;
}
#endif
if (shmem_mapping(file->f_mapping)) {
*prev = vma;
force_shm_swapin_readahead(vma, start, end,
file->f_mapping);
return 0;
}
#else
if (!file)
return -EBADF;
#endif
if (file->f_mapping->a_ops->get_xip_mem) {
/* no bad return value, but ignore advice */

25
mm/shmem.c
View File

@ -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 @@ out1:
out2:
shmem_destroy_inodecache();
out3:
bdi_destroy(&shmem_backing_dev_info);
out4:
shm_mnt = ERR_PTR(error);
return error;
}

2
mm/swap.c
View File

@ -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);

7
mm/swap_state.c
View File

@ -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,
}
};