vfs: guard end of device for mpage interface (4db96b71) · Commits · 戴 / test

Add guard_bio_eod() check for mpage code in order to allow us to do IO even on the odd last sectors of a device, even if the block size is some multiple of the physical sector size. Using mpage_readpages() for block device requires this guard check. Signed-off-by:

Akinobu Mita <akinobu.mita@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jeff Moyer <jmoyer@redhat.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

fs/buffer.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -2966,7 +2966,7 @@ static void end_bio_bh_io_sync(struct bio *bio, int err)
		* errors, this only handles the "we need to be able to
		* do IO at the final sector" case.
		*/
		static void guard_bio_eod(int rw, struct bio *bio)
		void guard_bio_eod(int rw, struct bio *bio)
		{
		sector_t maxsector;
		struct bio_vec *bvec = &bio->bi_io_vec[bio->bi_vcnt - 1];

fs/internal.h

+5 −0

Original line number	Diff line number	Diff line
		@@ -34,6 +34,11 @@ static inline int __sync_blockdev(struct block_device *bdev, int wait)
		}
		#endif

		/*
		* buffer.c
		*/
		extern void guard_bio_eod(int rw, struct bio *bio);

		/*
		* char_dev.c
		*/

fs/mpage.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -28,6 +28,7 @@
		#include <linux/backing-dev.h>
		#include <linux/pagevec.h>
		#include <linux/cleancache.h>
		#include "internal.h"

		/*
		* I/O completion handler for multipage BIOs.
		@@ -57,6 +58,7 @@ static void mpage_end_io(struct bio *bio, int err)
		static struct bio mpage_bio_submit(int rw, struct bio bio)
		{
		bio->bi_end_io = mpage_end_io;
		guard_bio_eod(rw, bio);
		submit_bio(rw, bio);
		return NULL;
		}

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