[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
Trace; c015dbba
Trace; c012a67e
Trace; c015dbba
Trace; c01281c0
Trace; c01384a6
Trace; c010910b
__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, >b_state);
mark_buffer_dirty(bh);
}
+ block_start += bh->b_size;
bh = bh->b_this_page;
} while (bh != head);
return err;
[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;
