From: Chris Mason <mason@suse.com>
In order for filesystems to detect asynchronous ordered write failures for
buffers sent via submit_bh, they need a bit they can test for in the buffer
head. This adds BH_Eopnotsupp and the related buffer operations
end_buffer_write_sync is changed to avoid a printk for BH_Eoptnotsupp
related failures, since the FS is responsible for a retry.
sync_dirty_buffer is changed to test for BH_Eopnotsupp and return
-EOPNOTSUPP to the caller
Some of this came from Jens Axboe
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/fs/buffer.c | 10 ++++++++--
25-akpm/include/linux/buffer_head.h | 2 ++
2 files changed, 10 insertions(+), 2 deletions(-)
diff -puN fs/buffer.c~add-bh_eopnotsupp-for-testing fs/buffer.c
--- 25/fs/buffer.c~add-bh_eopnotsupp-for-testing 2004-07-11 14:26:06.849610544 -0700
+++ 25-akpm/fs/buffer.c 2004-07-11 14:26:06.856609480 -0700
@@ -213,7 +213,7 @@ void end_buffer_write_sync(struct buffer
if (uptodate) {
set_buffer_uptodate(bh);
} else {
- if (printk_ratelimit()) {
+ if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
buffer_io_error(bh);
printk(KERN_WARNING "lost page write due to "
"I/O error on %s\n",
@@ -2756,8 +2756,10 @@ static int end_bio_bh_io_sync(struct bio
if (bio->bi_size)
return 1;
- if (err == -EOPNOTSUPP)
+ if (err == -EOPNOTSUPP) {
set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
+ set_bit(BH_Eopnotsupp, &bh->b_state);
+ }
bh->b_end_io(bh, test_bit(BIO_UPTODATE, &bio->bi_flags));
bio_put(bio);
@@ -2882,6 +2884,10 @@ int sync_dirty_buffer(struct buffer_head
bh->b_end_io = end_buffer_write_sync;
ret = submit_bh(WRITE, bh);
wait_on_buffer(bh);
+ if (buffer_eopnotsupp(bh)) {
+ clear_buffer_eopnotsupp(bh);
+ ret = -EOPNOTSUPP;
+ }
if (!ret && !buffer_uptodate(bh))
ret = -EIO;
} else {
diff -puN include/linux/buffer_head.h~add-bh_eopnotsupp-for-testing include/linux/buffer_head.h
--- 25/include/linux/buffer_head.h~add-bh_eopnotsupp-for-testing 2004-07-11 14:26:06.850610392 -0700
+++ 25-akpm/include/linux/buffer_head.h 2004-07-11 14:26:06.856609480 -0700
@@ -27,6 +27,7 @@ enum bh_state_bits {
BH_Boundary, /* Block is followed by a discontiguity */
BH_Write_EIO, /* I/O error on write */
BH_Ordered, /* ordered write */
+ BH_Eopnotsupp, /* operation not supported (barrier) */
BH_PrivateStart,/* not a state bit, but the first bit available
* for private allocation by other entities
@@ -113,6 +114,7 @@ BUFFER_FNS(Delay, delay)
BUFFER_FNS(Boundary, boundary)
BUFFER_FNS(Write_EIO, write_io_error)
BUFFER_FNS(Ordered, ordered)
+BUFFER_FNS(Eopnotsupp, eopnotsupp)
#define bh_offset(bh) ((unsigned long)(bh)->b_data & ~PAGE_MASK)
#define touch_buffer(bh) mark_page_accessed(bh->b_page)
_