Messages in this thread Patch in this message | | | Date | Sun, 25 Mar 2001 00:40:13 +0000 | From | "Stephen C. Tweedie" <> | Subject | [PATCH] 2.4.2-ac24 buffer.c oops on highmem |
| |
Hi,
We've just seen a buffer.c oops in:
>>EIP; c013ae4b <__block_prepare_write+2bb/300> <===== Trace; c013b732 <block_prepare_write+22/70> Trace; c015dbba <ext2_get_block+a/4e0> Trace; c012a67e <generic_file_write+3ee/710> Trace; c015dbba <ext2_get_block+a/4e0> Trace; c01281c0 <file_read_actor+0/f0> Trace; c01384a6 <sys_write+96/d0> Trace; c010910b <system_call+33/38>
__block_prepare_write()'s "out:" error handler tries to do a
memset(bh->b_data, 0, bh->b_size);
even if the buffer's page has already been kmapped for highmem. Highmem pages will obviously have b_data being NULL. Patch below.
I had a quick look through the rest of buffer.c and apart from the initialisation of bh->b_data in set_bh_page(), there are no other references left to b_data once we fix this.
Cheers, Stephen
--- fs/buffer.c.~1~ Sat Mar 24 17:30:13 2001 +++ fs/buffer.c Sat Mar 24 18:16:55 2001 @@ -1629,12 +1629,14 @@ return 0; out: bh = head; + block_start = 0; do { if (buffer_new(bh) && !buffer_uptodate(bh)) { - memset(bh->b_data, 0, bh->b_size); + memset(kaddr+block_start, 0, bh->b_size); set_bit(BH_Uptodate, &bh->b_state); mark_buffer_dirty(bh); } + block_start += bh->b_size; bh = bh->b_this_page; } while (bh != head); return err; | |