block: read i_size with i_size_read()
Convert direct reads of an inode's i_size to using i_size_read().
i_size_{read,write} use a seqcount to protect reads from accessing
incomple writes. Concurrent i_size_write()s require mutual exclussion
to protect the seqcount that is used by i_size_{read,write}. But
i_size_read() callers do not need to use additional locking.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: NeilBrown <neilb@suse.de>
Acked-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/block/compat_ioctl.c b/block/compat_ioctl.c
index 119f07b..58c6ee5b 100644
--- a/block/compat_ioctl.c
+++ b/block/compat_ioctl.c
@@ -744,13 +744,13 @@
bdi->ra_pages = (arg * 512) / PAGE_CACHE_SIZE;
return 0;
case BLKGETSIZE:
- size = bdev->bd_inode->i_size;
+ size = i_size_read(bdev->bd_inode);
if ((size >> 9) > ~0UL)
return -EFBIG;
return compat_put_ulong(arg, size >> 9);
case BLKGETSIZE64_32:
- return compat_put_u64(arg, bdev->bd_inode->i_size);
+ return compat_put_u64(arg, i_size_read(bdev->bd_inode));
case BLKTRACESETUP32:
case BLKTRACESTART: /* compatible */