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authorChristoph Hellwig <hch@lst.de>2015-01-14 10:42:31 +0100
committerJens Axboe <axboe@fb.com>2015-01-20 14:02:56 -0700
commit97b713ba3ebaa6c8d84c2c720f5468a7c6a6eb4e (patch)
treea2a430b22f8c220e719114786905b18aa605f9ec /mm/shmem.c
parenta7a2c680a2ad81b3181a335ee76e23d5195007ee (diff)
downloadlwn-97b713ba3ebaa6c8d84c2c720f5468a7c6a6eb4e.tar.gz
lwn-97b713ba3ebaa6c8d84c2c720f5468a7c6a6eb4e.zip
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>
Diffstat (limited to 'mm/shmem.c')
-rw-r--r--mm/shmem.c25
1 files changed, 7 insertions, 18 deletions
diff --git a/mm/shmem.c b/mm/shmem.c
index 73ba1df7c8ba..1b77eaf589fd 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -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;
}