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authorChristoph Hellwig <hch@lst.de>2023-04-11 19:14:43 +0200
committerAndrew Morton <akpm@linux-foundation.org>2023-04-18 16:29:56 -0700
commita70aae12502b130b0c30dda44dff09e575c1aaeb (patch)
treebc115f0d687524aac8099d0352106edb3f2bfd01 /drivers/block/zram
parent3b7939c8e5345fb84309f2605a4b6f7ac8dd7fce (diff)
zram: always compile read_from_bdev_sync
Patch series "zram I/O path cleanups and fixups", v3. This series cleans up the zram I/O path, and fixes the handling of synchronous I/O to the underlying device in the writeback_store function or for > 4K PAGE_SIZE systems. The fixes are at the end, as I could not fully reason about them being safe before untangling the callchain. This patch (of 17): read_from_bdev_sync is currently only compiled for non-4k PAGE_SIZE, which means it won't be built with the most common configurations. Replace the ifdef with a check for the PAGE_SIZE in an if instead. The check uses an extra symbol and IS_ENABLED to allow the compiler to eliminate the dead code, leading to the same generated code size: text data bss dec hex filename 16709 1428 12 18149 46e5 drivers/block/zram/zram_drv.o.old 16709 1428 12 18149 46e5 drivers/block/zram/zram_drv.o.new Link: https://lkml.kernel.org/r/20230411171459.567614-1-hch@lst.de Link: https://lkml.kernel.org/r/20230411171459.567614-2-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'drivers/block/zram')
-rw-r--r--drivers/block/zram/zram_drv.c18
1 files changed, 6 insertions, 12 deletions
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index aa490da3cef2..57787cbdf1f7 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -148,6 +148,7 @@ static inline bool is_partial_io(struct bio_vec *bvec)
{
return bvec->bv_len != PAGE_SIZE;
}
+#define ZRAM_PARTIAL_IO 1
#else
static inline bool is_partial_io(struct bio_vec *bvec)
{
@@ -833,7 +834,6 @@ struct zram_work {
struct bio_vec bvec;
};
-#if PAGE_SIZE != 4096
static void zram_sync_read(struct work_struct *work)
{
struct zram_work *zw = container_of(work, struct zram_work, work);
@@ -866,23 +866,17 @@ static int read_from_bdev_sync(struct zram *zram, struct bio_vec *bvec,
return 1;
}
-#else
-static int read_from_bdev_sync(struct zram *zram, struct bio_vec *bvec,
- unsigned long entry, struct bio *bio)
-{
- WARN_ON(1);
- return -EIO;
-}
-#endif
static int read_from_bdev(struct zram *zram, struct bio_vec *bvec,
unsigned long entry, struct bio *parent, bool sync)
{
atomic64_inc(&zram->stats.bd_reads);
- if (sync)
+ if (sync) {
+ if (WARN_ON_ONCE(!IS_ENABLED(ZRAM_PARTIAL_IO)))
+ return -EIO;
return read_from_bdev_sync(zram, bvec, entry, parent);
- else
- return read_from_bdev_async(zram, bvec, entry, parent);
+ }
+ return read_from_bdev_async(zram, bvec, entry, parent);
}
#else
static inline void reset_bdev(struct zram *zram) {};