Hi Gu > -----Original Message----- > From: Gu Zheng [mailto:guz.fnst@xxxxxxxxxxxxxx] > Sent: Monday, September 16, 2013 10:09 AM > To: Chao Yu > Cc: Kim Jaegeuk; linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx; > linux-fsdevel@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; 谭姝 > Subject: Re: [f2fs-dev][PATCH RESEND] f2fs: avoid allocating failure in bio_alloc > > Hi Chao, > > On 09/13/2013 09:27 PM, Chao Yu wrote: > > > This patch add macro MAX_BIO_BLOCKS to limit value of npages in > > f2fs_bio_alloc, it can avoid allocating failure in bio_alloc caused by > > npages is larger than UIO_MAXIOV. > > As I know bio_alloc is based of *fs_bio_set* pool, without the limitation of > UIO_MAXIOV, am I missing something? Here is the code in bio.c, fs_bio_set is as the actual parameter pass to bs without being inited. So it may have opportunity to return NULL in this function. --- Bio.c struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs) { ...... if (!bs) { if (nr_iovecs > UIO_MAXIOV) return NULL; --- I did the abnormal test: modify the max_sectors_kb in /sys/block/sdx/queue to 32767 for a disk with f2fs format, and I got a segfualt in f2fs_bio_alloc after the img mounted. Is there anyting I missed? > > Thanks, > Gu > > > > > Signed-off-by: Yu Chao <chao2.yu@xxxxxxxxxxx> > > --- > > fs/f2fs/segment.c | 4 +++- > > fs/f2fs/segment.h | 3 +++ > > 2 files changed, 6 insertions(+), 1 deletion(-) > > > > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index > > 09af9c7..bd79bbe 100644 > > --- a/fs/f2fs/segment.c > > +++ b/fs/f2fs/segment.c > > @@ -657,6 +657,7 @@ static void submit_write_page(struct f2fs_sb_info > > *sbi, struct page *page, > > block_t blk_addr, enum page_type > type) > > { > > struct block_device *bdev = sbi->sb->s_bdev; > > + int bio_blocks; > > > > verify_block_addr(sbi, blk_addr); > > > > @@ -676,7 +677,8 @@ retry: > > goto retry; > > } > > > > - sbi->bio[type] = f2fs_bio_alloc(bdev, max_hw_blocks(sbi)); > > + bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi)); > > + sbi->bio[type] = f2fs_bio_alloc(bdev, bio_blocks); > > sbi->bio[type]->bi_sector = SECTOR_FROM_BLOCK(sbi, > > blk_addr); > > sbi->bio[type]->bi_private = priv; > > /* > > diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h index > > bdd10ea..6352af1 100644 > > --- a/fs/f2fs/segment.h > > +++ b/fs/f2fs/segment.h > > @@ -9,6 +9,7 @@ > > * published by the Free Software Foundation. > > */ > > #include <linux/blkdev.h> > > +#include <linux/uio.h> > > > > /* constant macro */ > > #define NULL_SEGNO ((unsigned int)(~0)) > > @@ -90,6 +91,8 @@ > > (blk_addr << ((sbi)->log_blocksize - F2FS_LOG_SECTOR_SIZE)) > > #define SECTOR_TO_BLOCK(sbi, sectors) > \ > > (sectors >> ((sbi)->log_blocksize - F2FS_LOG_SECTOR_SIZE)) > > +#define MAX_BIO_BLOCKS(max_hw_blocks) > \ > > + (min((int)max_hw_blocks, UIO_MAXIOV)) > > > > /* during checkpoint, bio_private is used to synchronize the last bio > > */ struct bio_private { > > --- > > > > -- > > To unsubscribe from this list: send the line "unsubscribe > > linux-kernel" in the body of a message to majordomo@xxxxxxxxxxxxxxx > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > Please read the FAQ at http://www.tux.org/lkml/ > > -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
