This patch makes dm_bufio_prefetch return 1 on success and 0 on failure.
A prefetch failure may happen in case of temporary memory shortage.
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
---
drivers/md/dm-bufio.c | 8 ++++++--
drivers/md/dm-bufio.h | 4 ++--
2 files changed, 8 insertions(+), 4 deletions(-)
Index: linux-3.13-rc7/drivers/md/dm-bufio.c
===================================================================
--- linux-3.13-rc7.orig/drivers/md/dm-bufio.c 2014-01-09 16:11:31.000000000 +0100
+++ linux-3.13-rc7/drivers/md/dm-bufio.c 2014-01-09 16:16:43.000000000 +0100
@@ -1068,10 +1068,11 @@ void *dm_bufio_new(struct dm_bufio_clien
}
EXPORT_SYMBOL_GPL(dm_bufio_new);
-void dm_bufio_prefetch(struct dm_bufio_client *c,
+int dm_bufio_prefetch(struct dm_bufio_client *c,
sector_t block, unsigned n_blocks)
{
struct blk_plug plug;
+ int success = 1;
LIST_HEAD(write_list);
@@ -1104,13 +1105,16 @@ void dm_bufio_prefetch(struct dm_bufio_c
if (!n_blocks)
goto flush_plug;
dm_bufio_lock(c);
- }
+ } else
+ success = 0;
}
dm_bufio_unlock(c);
flush_plug:
blk_finish_plug(&plug);
+
+ return success;
}
EXPORT_SYMBOL_GPL(dm_bufio_prefetch);
Index: linux-3.13-rc7/drivers/md/dm-bufio.h
===================================================================
--- linux-3.13-rc7.orig/drivers/md/dm-bufio.h 2014-01-09 16:15:47.000000000 +0100
+++ linux-3.13-rc7/drivers/md/dm-bufio.h 2014-01-09 16:15:55.000000000 +0100
@@ -67,8 +67,8 @@ void *dm_bufio_new(struct dm_bufio_clien
* The function starts to read the blocks and returns without waiting for
* I/O to finish.
*/
-void dm_bufio_prefetch(struct dm_bufio_client *c,
- sector_t block, unsigned n_blocks);
+int dm_bufio_prefetch(struct dm_bufio_client *c,
+ sector_t block, unsigned n_blocks);
/*
* Release a reference obtained with dm_bufio_{read,get,new}. The data
--
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