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mm: migrate: move migrate_page_lock_buffers()

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buffer_migrate_page() is the only caller of migrate_page_lock_buffers()
move it close to it and also drop the now unused stub for !CONFIG_BLOCK.

Link: http://lkml.kernel.org/r/20181211172143.7358-4-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jan Kara 2018-12-28 00:39:09 -08:00 committed by Linus Torvalds
parent cc4f11e69f
commit 84ade7c15c
1 changed files with 42 additions and 50 deletions
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92
mm/migrate.c
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@ -374,56 +374,6 @@ unlock:
}
#endif
#ifdef CONFIG_BLOCK
/* Returns true if all buffers are successfully locked */
static bool buffer_migrate_lock_buffers(struct buffer_head *head,
enum migrate_mode mode)
{
struct buffer_head *bh = head;
/* Simple case, sync compaction */
if (mode != MIGRATE_ASYNC) {
do {
get_bh(bh);
lock_buffer(bh);
bh = bh->b_this_page;
} while (bh != head);
return true;
}
/* async case, we cannot block on lock_buffer so use trylock_buffer */
do {
get_bh(bh);
if (!trylock_buffer(bh)) {
/*
* We failed to lock the buffer and cannot stall in
* async migration. Release the taken locks
*/
struct buffer_head *failed_bh = bh;
put_bh(failed_bh);
bh = head;
while (bh != failed_bh) {
unlock_buffer(bh);
put_bh(bh);
bh = bh->b_this_page;
}
return false;
}
bh = bh->b_this_page;
} while (bh != head);
return true;
}
#else
static inline bool buffer_migrate_lock_buffers(struct buffer_head *head,
enum migrate_mode mode)
{
return true;
}
#endif /* CONFIG_BLOCK */
static int expected_page_refs(struct page *page)
{
int expected_count = 1;
@ -751,6 +701,48 @@ int migrate_page(struct address_space *mapping,
EXPORT_SYMBOL(migrate_page);
#ifdef CONFIG_BLOCK
/* Returns true if all buffers are successfully locked */
static bool buffer_migrate_lock_buffers(struct buffer_head *head,
enum migrate_mode mode)
{
struct buffer_head *bh = head;
/* Simple case, sync compaction */
if (mode != MIGRATE_ASYNC) {
do {
get_bh(bh);
lock_buffer(bh);
bh = bh->b_this_page;
} while (bh != head);
return true;
}
/* async case, we cannot block on lock_buffer so use trylock_buffer */
do {
get_bh(bh);
if (!trylock_buffer(bh)) {
/*
* We failed to lock the buffer and cannot stall in
* async migration. Release the taken locks
*/
struct buffer_head *failed_bh = bh;
put_bh(failed_bh);
bh = head;
while (bh != failed_bh) {
unlock_buffer(bh);
put_bh(bh);
bh = bh->b_this_page;
}
return false;
}
bh = bh->b_this_page;
} while (bh != head);
return true;
}
/*
* Migration function for pages with buffers. This function can only be used
* if the underlying filesystem guarantees that no other references to "page"