"Richard W.M. Jones" <rjones@xxxxxxxxxx> writes: > On Mon, Jun 18, 2012 at 07:59:30AM +0200, Torsten Hilbrich wrote: >> Hello, >> >> a software that tries to mount each existing partition as ext3 file system started to fail when updating from v3.3.7 to v3.3.8. >> >> The applications then hangs-up in the mount syscall, here is a snapshot of its stack at this moment: > > We just ran into what we think is the same problem. > > Note that ext4 fails like this for any 1024 byte sized filesystem (of > zeroes) that you try to mount. It's really nothing to do with > extended partitions. > > Here is a very simple reproducer + stack trace: > > https://bugzilla.redhat.com/show_bug.cgi?id=835019#c4 > > I will try out the patch suggested later on in this thread. Please try the attached patch instead. The patch I had originally posted for this allowed marking the first buffer beyond EOD as uptodate. This isn't correct. The patch I've attached below fixes the infinite loop in __getblk_slow. Cheers, Jeff diff --git a/fs/buffer.c b/fs/buffer.c index 838a9cf..c7062c8 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1036,6 +1036,9 @@ grow_buffers(struct block_device *bdev, sector_t block, int size) static struct buffer_head * __getblk_slow(struct block_device *bdev, sector_t block, int size) { + int ret; + struct buffer_head *bh; + /* Size must be multiple of hard sectorsize */ if (unlikely(size & (bdev_logical_block_size(bdev)-1) || (size < 512 || size > PAGE_SIZE))) { @@ -1048,20 +1051,21 @@ __getblk_slow(struct block_device *bdev, sector_t block, int size) return NULL; } - for (;;) { - struct buffer_head * bh; - int ret; +retry: + bh = __find_get_block(bdev, block, size); + if (bh) + return bh; + ret = grow_buffers(bdev, block, size); + if (ret == 0) { + free_more_memory(); + goto retry; + } else if (ret > 0) { bh = __find_get_block(bdev, block, size); if (bh) return bh; - - ret = grow_buffers(bdev, block, size); - if (ret < 0) - return NULL; - if (ret == 0) - free_more_memory(); } + return NULL; } /* -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
