[PATCH 2/4] block: bio_check_eod() needs to consider partition

Jiufei Xue
2018-02-27T12:11:12Z

bio_check_eod() should check partiton size not the whole
disk if bio->bi_partno is not zero.

Fixes: 74d46992e0d9 ("block: replace bi_bdev with a gendisk pointer and partitions index")
Signed-off-by: Jiufei Xue <jiufei.xue@linux.alibaba.com>
---
block/blk-core.c | 79 ++++++++++++++++++++++++++++++--------------------------
1 file changed, 43 insertions(+), 36 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 6d82c4f..5fb5278 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -2023,7 +2023,7 @@ static blk_qc_t blk_queue_bio(struct request_queue *q, struct bio *bio)
return BLK_QC_T_NONE;
}

-static void handle_bad_sector(struct bio *bio)
+static void handle_bad_sector(struct bio *bio, sector_t maxsector)
{
char b[BDEVNAME_SIZE];

@@ -2031,7 +2031,7 @@ static void handle_bad_sector(struct bio *bio)
printk(KERN_INFO "%s: rw=%d, want=%Lu, limit=%Lu\n",
bio_devname(bio, b), bio->bi_opf,
(unsigned long long)bio_end_sector(bio),
- (long long)get_capacity(bio->bi_disk));
+ (long long)maxsector);
}

#ifdef CONFIG_FAIL_MAKE_REQUEST
@@ -2093,11 +2093,45 @@ static noinline int should_fail_bio(struct bio *bio)
ALLOW_ERROR_INJECTION(should_fail_bio, ERRNO);

/*
+ * Check whether this bio extends beyond the end of the device.
+ */
+static inline int bio_check_eod(struct bio *bio, unsigned int nr_sectors,
+ struct hd_struct *part)
+{
+ sector_t maxsector;
+
+ if (!nr_sectors)
+ return 0;
+
+ /* Test device or partition size, when known. */
+ if (part->partno)
+ maxsector = part_nr_sects_read(part);
+ else
+ maxsector = get_capacity(bio->bi_disk);
+ if (maxsector) {
+ sector_t sector = bio->bi_iter.bi_sector;
+
+ if (maxsector < nr_sectors || maxsector - nr_sectors < sector) {
+ /*
+ * This may well happen - the kernel calls bread()
+ * without checking the size of the device, e.g., when
+ * mounting a device.
+ */
+ handle_bad_sector(bio, maxsector);
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+/*
* Remap block n of partition p to block n+start(p) of the disk.
*/
static inline int blk_partition_remap(struct bio *bio)
{
struct hd_struct *p;
+ int nr_sectors = bio_sectors(bio);
int ret = 0;

rcu_read_lock();
@@ -2108,11 +2142,16 @@ static inline int blk_partition_remap(struct bio *bio)
goto out;
}

+ if (bio_check_eod(bio, nr_sectors, p)) {
+ ret = -EIO;
+ goto out;
+ }
+
/*
* Zone reset does not include bi_size so bio_sectors() is always 0.
* Include a test for the reset op code and perform the remap if needed.
*/
- if (!bio_sectors(bio) && bio_op(bio) != REQ_OP_ZONE_RESET)
+ if (!nr_sectors && bio_op(bio) != REQ_OP_ZONE_RESET)
goto out;

bio->bi_iter.bi_sector += p->start_sect;
@@ -2125,35 +2164,6 @@ static inline int blk_partition_remap(struct bio *bio)
return ret;
}

-/*
- * Check whether this bio extends beyond the end of the device.
- */
-static inline int bio_check_eod(struct bio *bio, unsigned int nr_sectors)
-{
- sector_t maxsector;
-
- if (!nr_sectors)
- return 0;
-
- /* Test device or partition size, when known. */
- maxsector = get_capacity(bio->bi_disk);
- if (maxsector) {
- sector_t sector = bio->bi_iter.bi_sector;
-
- if (maxsector < nr_sectors || maxsector - nr_sectors < sector) {
- /*
- * This may well happen - the kernel calls bread()
- * without checking the size of the device, e.g., when
- * mounting a device.
- */
- handle_bad_sector(bio);
- return 1;
- }
- }
-
- return 0;
-}
-
static noinline_for_stack bool
generic_make_request_checks(struct bio *bio)
{
@@ -2164,9 +2174,6 @@ static inline int bio_check_eod(struct bio *bio, unsigned int nr_sectors)

might_sleep();

- if (bio_check_eod(bio, nr_sectors))
- goto end_io;
-
q = bio->bi_disk->queue;
if (unlikely(!q)) {
printk(KERN_ERR
@@ -2194,7 +2201,7 @@ static inline int bio_check_eod(struct bio *bio, unsigned int nr_sectors)
goto end_io;
}

- if (bio_check_eod(bio, nr_sectors))
+ if (bio_check_eod(bio, nr_sectors, &bio->bi_disk->part0))
goto end_io;

/*
--
1.9.4