fs: guard_bio_eod() needs to consider partitions

commit 67f2519fe2903c4041c0e94394d14d372fe51399 upstream.

guard_bio_eod() needs to look at the partition capacity, not just the
capacity of the whole device, when determining if truncation is
necessary.

[   60.268688] attempt to access beyond end of device
[   60.268690] unknown-block(9,1): rw=0, want=67103509, limit=67103506
[   60.268693] buffer_io_error: 2 callbacks suppressed
[   60.268696] Buffer I/O error on dev md1p7, logical block 4524305, async page read

Fixes: 74d46992e0d9 ("block: replace bi_bdev with a gendisk pointer and partitions index")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Edwards <gedwards@ddn.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/buffer.c b/fs/buffer.c
index 170df856bdb99715b126b2d129ff19ea95d46ad8..b96f3b98a6ef9f8fc9a3ac22d1e60996eabf4d50 100644 (file)
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -3055,8 +3055,16 @@ void guard_bio_eod(int op, struct bio *bio)
        sector_t maxsector;
        struct bio_vec *bvec = &bio->bi_io_vec[bio->bi_vcnt - 1];
        unsigned truncated_bytes;
+       struct hd_struct *part;
+
+       rcu_read_lock();
+       part = __disk_get_part(bio->bi_disk, bio->bi_partno);
+       if (part)
+               maxsector = part_nr_sects_read(part);
+       else
+               maxsector = get_capacity(bio->bi_disk);
+       rcu_read_unlock();
 
-       maxsector = get_capacity(bio->bi_disk);
        if (!maxsector)
                return;
 

diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 44790523057f0380b1254458a20ca658f17a3305..5ade8f2a698764986b2d8fb3757ae812a2b1b310 100644 (file)
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -243,6 +243,7 @@ static inline dev_t part_devt(struct hd_struct *part)
        return part_to_dev(part)->devt;
 }
 
+extern struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
 extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
 
 static inline void disk_put_part(struct hd_struct *part)