* FAILED: patch "[PATCH] ext4: don't set EXT4_GET_BLOCKS_CONVERT when splitting before" failed to apply to 6.1-stable tree
@ 2026-02-24 21:43 gregkh
2026-02-25 2:57 ` [PATCH 6.1.y] ext4: don't set EXT4_GET_BLOCKS_CONVERT when splitting before submitting I/O Sasha Levin
0 siblings, 1 reply; 3+ messages in thread
From: gregkh @ 2026-02-24 21:43 UTC (permalink / raw)
To: yi.zhang, libaokun1, ojaswin, tytso; +Cc: stable
The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x feaf2a80e78f89ee8a3464126077ba8683b62791
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026022422-humorous-scam-a54d@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From feaf2a80e78f89ee8a3464126077ba8683b62791 Mon Sep 17 00:00:00 2001
From: Zhang Yi <yi.zhang@huawei.com>
Date: Sat, 29 Nov 2025 18:32:35 +0800
Subject: [PATCH] ext4: don't set EXT4_GET_BLOCKS_CONVERT when splitting before
submitting I/O
When allocating blocks during within-EOF DIO and writeback with
dioread_nolock enabled, EXT4_GET_BLOCKS_PRE_IO was set to split an
existing large unwritten extent. However, EXT4_GET_BLOCKS_CONVERT was
set when calling ext4_split_convert_extents(), which may potentially
result in stale data issues.
Assume we have an unwritten extent, and then DIO writes the second half.
[UUUUUUUUUUUUUUUU] on-disk extent U: unwritten extent
[UUUUUUUUUUUUUUUU] extent status tree
|<- ->| ----> dio write this range
First, ext4_iomap_alloc() call ext4_map_blocks() with
EXT4_GET_BLOCKS_PRE_IO, EXT4_GET_BLOCKS_UNWRIT_EXT and
EXT4_GET_BLOCKS_CREATE flags set. ext4_map_blocks() find this extent and
call ext4_split_convert_extents() with EXT4_GET_BLOCKS_CONVERT and the
above flags set.
Then, ext4_split_convert_extents() calls ext4_split_extent() with
EXT4_EXT_MAY_ZEROOUT, EXT4_EXT_MARK_UNWRIT2 and EXT4_EXT_DATA_VALID2
flags set, and it calls ext4_split_extent_at() to split the second half
with EXT4_EXT_DATA_VALID2, EXT4_EXT_MARK_UNWRIT1, EXT4_EXT_MAY_ZEROOUT
and EXT4_EXT_MARK_UNWRIT2 flags set. However, ext4_split_extent_at()
failed to insert extent since a temporary lack -ENOSPC. It zeroes out
the first half but convert the entire on-disk extent to written since
the EXT4_EXT_DATA_VALID2 flag set, but left the second half as unwritten
in the extent status tree.
[0000000000SSSSSS] data S: stale data, 0: zeroed
[WWWWWWWWWWWWWWWW] on-disk extent W: written extent
[WWWWWWWWWWUUUUUU] extent status tree
Finally, if the DIO failed to write data to the disk, the stale data in
the second half will be exposed once the cached extent entry is gone.
Fix this issue by not passing EXT4_GET_BLOCKS_CONVERT when splitting
an unwritten extent before submitting I/O, and make
ext4_split_convert_extents() to zero out the entire extent range
to zero for this case, and also mark the extent in the extent status
tree for consistency.
Fixes: b8a8684502a0 ("ext4: Introduce FALLOC_FL_ZERO_RANGE flag for fallocate")
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Cc: stable@kernel.org
Message-ID: <20251129103247.686136-4-yi.zhang@huaweicloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 1fee84ea20af..91b56de60c90 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3746,15 +3746,19 @@ static struct ext4_ext_path *ext4_split_convert_extents(handle_t *handle,
/* Convert to unwritten */
if (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN) {
split_flag |= EXT4_EXT_DATA_ENTIRE_VALID1;
- /* Convert to initialized */
- } else if (flags & EXT4_GET_BLOCKS_CONVERT) {
+ /* Split the existing unwritten extent */
+ } else if (flags & (EXT4_GET_BLOCKS_UNWRIT_EXT |
+ EXT4_GET_BLOCKS_CONVERT)) {
/*
* It is safe to convert extent to initialized via explicit
* zeroout only if extent is fully inside i_size or new_size.
*/
split_flag |= ee_block + ee_len <= eof_block ?
EXT4_EXT_MAY_ZEROOUT : 0;
- split_flag |= (EXT4_EXT_MARK_UNWRIT2 | EXT4_EXT_DATA_VALID2);
+ split_flag |= EXT4_EXT_MARK_UNWRIT2;
+ /* Convert to initialized */
+ if (flags & EXT4_GET_BLOCKS_CONVERT)
+ split_flag |= EXT4_EXT_DATA_VALID2;
}
flags |= EXT4_GET_BLOCKS_SPLIT_NOMERGE;
return ext4_split_extent(handle, inode, path, map, split_flag, flags,
@@ -3930,7 +3934,7 @@ ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode,
/* get_block() before submitting IO, split the extent */
if (flags & EXT4_GET_BLOCKS_SPLIT_NOMERGE) {
path = ext4_split_convert_extents(handle, inode, map, path,
- flags | EXT4_GET_BLOCKS_CONVERT, allocated);
+ flags, allocated);
if (IS_ERR(path))
return path;
/*
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH 6.1.y] ext4: don't set EXT4_GET_BLOCKS_CONVERT when splitting before submitting I/O
2026-02-24 21:43 FAILED: patch "[PATCH] ext4: don't set EXT4_GET_BLOCKS_CONVERT when splitting before" failed to apply to 6.1-stable tree gregkh
@ 2026-02-25 2:57 ` Sasha Levin
2026-03-21 14:39 ` Greg KH
0 siblings, 1 reply; 3+ messages in thread
From: Sasha Levin @ 2026-02-25 2:57 UTC (permalink / raw)
To: stable
Cc: Zhang Yi, Ojaswin Mujoo, Baokun Li, stable, Theodore Ts'o,
Sasha Levin
From: Zhang Yi <yi.zhang@huawei.com>
[ Upstream commit feaf2a80e78f89ee8a3464126077ba8683b62791 ]
When allocating blocks during within-EOF DIO and writeback with
dioread_nolock enabled, EXT4_GET_BLOCKS_PRE_IO was set to split an
existing large unwritten extent. However, EXT4_GET_BLOCKS_CONVERT was
set when calling ext4_split_convert_extents(), which may potentially
result in stale data issues.
Assume we have an unwritten extent, and then DIO writes the second half.
[UUUUUUUUUUUUUUUU] on-disk extent U: unwritten extent
[UUUUUUUUUUUUUUUU] extent status tree
|<- ->| ----> dio write this range
First, ext4_iomap_alloc() call ext4_map_blocks() with
EXT4_GET_BLOCKS_PRE_IO, EXT4_GET_BLOCKS_UNWRIT_EXT and
EXT4_GET_BLOCKS_CREATE flags set. ext4_map_blocks() find this extent and
call ext4_split_convert_extents() with EXT4_GET_BLOCKS_CONVERT and the
above flags set.
Then, ext4_split_convert_extents() calls ext4_split_extent() with
EXT4_EXT_MAY_ZEROOUT, EXT4_EXT_MARK_UNWRIT2 and EXT4_EXT_DATA_VALID2
flags set, and it calls ext4_split_extent_at() to split the second half
with EXT4_EXT_DATA_VALID2, EXT4_EXT_MARK_UNWRIT1, EXT4_EXT_MAY_ZEROOUT
and EXT4_EXT_MARK_UNWRIT2 flags set. However, ext4_split_extent_at()
failed to insert extent since a temporary lack -ENOSPC. It zeroes out
the first half but convert the entire on-disk extent to written since
the EXT4_EXT_DATA_VALID2 flag set, but left the second half as unwritten
in the extent status tree.
[0000000000SSSSSS] data S: stale data, 0: zeroed
[WWWWWWWWWWWWWWWW] on-disk extent W: written extent
[WWWWWWWWWWUUUUUU] extent status tree
Finally, if the DIO failed to write data to the disk, the stale data in
the second half will be exposed once the cached extent entry is gone.
Fix this issue by not passing EXT4_GET_BLOCKS_CONVERT when splitting
an unwritten extent before submitting I/O, and make
ext4_split_convert_extents() to zero out the entire extent range
to zero for this case, and also mark the extent in the extent status
tree for consistency.
Fixes: b8a8684502a0 ("ext4: Introduce FALLOC_FL_ZERO_RANGE flag for fallocate")
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Cc: stable@kernel.org
Message-ID: <20251129103247.686136-4-yi.zhang@huaweicloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
[ different function signatures ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/ext4/extents.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 1aad4ae0e7ae4..dfc365b021094 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3705,11 +3705,15 @@ static int ext4_split_convert_extents(handle_t *handle,
/* Convert to unwritten */
if (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN) {
split_flag |= EXT4_EXT_DATA_VALID1;
- /* Convert to initialized */
- } else if (flags & EXT4_GET_BLOCKS_CONVERT) {
+ /* Split the existing unwritten extent */
+ } else if (flags & (EXT4_GET_BLOCKS_UNWRIT_EXT |
+ EXT4_GET_BLOCKS_CONVERT)) {
split_flag |= ee_block + ee_len <= eof_block ?
EXT4_EXT_MAY_ZEROOUT : 0;
- split_flag |= (EXT4_EXT_MARK_UNWRIT2 | EXT4_EXT_DATA_VALID2);
+ split_flag |= EXT4_EXT_MARK_UNWRIT2;
+ /* Convert to initialized */
+ if (flags & EXT4_GET_BLOCKS_CONVERT)
+ split_flag |= EXT4_EXT_DATA_VALID2;
}
flags |= EXT4_GET_BLOCKS_PRE_IO;
return ext4_split_extent(handle, inode, ppath, map, split_flag, flags);
@@ -3874,7 +3878,7 @@ ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode,
/* get_block() before submitting IO, split the extent */
if (flags & EXT4_GET_BLOCKS_PRE_IO) {
ret = ext4_split_convert_extents(handle, inode, map, ppath,
- flags | EXT4_GET_BLOCKS_CONVERT);
+ flags);
if (ret < 0) {
err = ret;
goto out2;
--
2.51.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH 6.1.y] ext4: don't set EXT4_GET_BLOCKS_CONVERT when splitting before submitting I/O
2026-02-25 2:57 ` [PATCH 6.1.y] ext4: don't set EXT4_GET_BLOCKS_CONVERT when splitting before submitting I/O Sasha Levin
@ 2026-03-21 14:39 ` Greg KH
0 siblings, 0 replies; 3+ messages in thread
From: Greg KH @ 2026-03-21 14:39 UTC (permalink / raw)
To: Sasha Levin
Cc: stable, Zhang Yi, Ojaswin Mujoo, Baokun Li, stable,
Theodore Ts'o
On Tue, Feb 24, 2026 at 09:57:32PM -0500, Sasha Levin wrote:
> From: Zhang Yi <yi.zhang@huawei.com>
>
> [ Upstream commit feaf2a80e78f89ee8a3464126077ba8683b62791 ]
>
> When allocating blocks during within-EOF DIO and writeback with
> dioread_nolock enabled, EXT4_GET_BLOCKS_PRE_IO was set to split an
> existing large unwritten extent. However, EXT4_GET_BLOCKS_CONVERT was
> set when calling ext4_split_convert_extents(), which may potentially
> result in stale data issues.
>
> Assume we have an unwritten extent, and then DIO writes the second half.
>
> [UUUUUUUUUUUUUUUU] on-disk extent U: unwritten extent
> [UUUUUUUUUUUUUUUU] extent status tree
> |<- ->| ----> dio write this range
>
> First, ext4_iomap_alloc() call ext4_map_blocks() with
> EXT4_GET_BLOCKS_PRE_IO, EXT4_GET_BLOCKS_UNWRIT_EXT and
> EXT4_GET_BLOCKS_CREATE flags set. ext4_map_blocks() find this extent and
> call ext4_split_convert_extents() with EXT4_GET_BLOCKS_CONVERT and the
> above flags set.
>
> Then, ext4_split_convert_extents() calls ext4_split_extent() with
> EXT4_EXT_MAY_ZEROOUT, EXT4_EXT_MARK_UNWRIT2 and EXT4_EXT_DATA_VALID2
> flags set, and it calls ext4_split_extent_at() to split the second half
> with EXT4_EXT_DATA_VALID2, EXT4_EXT_MARK_UNWRIT1, EXT4_EXT_MAY_ZEROOUT
> and EXT4_EXT_MARK_UNWRIT2 flags set. However, ext4_split_extent_at()
> failed to insert extent since a temporary lack -ENOSPC. It zeroes out
> the first half but convert the entire on-disk extent to written since
> the EXT4_EXT_DATA_VALID2 flag set, but left the second half as unwritten
> in the extent status tree.
>
> [0000000000SSSSSS] data S: stale data, 0: zeroed
> [WWWWWWWWWWWWWWWW] on-disk extent W: written extent
> [WWWWWWWWWWUUUUUU] extent status tree
>
> Finally, if the DIO failed to write data to the disk, the stale data in
> the second half will be exposed once the cached extent entry is gone.
>
> Fix this issue by not passing EXT4_GET_BLOCKS_CONVERT when splitting
> an unwritten extent before submitting I/O, and make
> ext4_split_convert_extents() to zero out the entire extent range
> to zero for this case, and also mark the extent in the extent status
> tree for consistency.
>
> Fixes: b8a8684502a0 ("ext4: Introduce FALLOC_FL_ZERO_RANGE flag for fallocate")
> Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
> Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
> Reviewed-by: Baokun Li <libaokun1@huawei.com>
> Cc: stable@kernel.org
> Message-ID: <20251129103247.686136-4-yi.zhang@huaweicloud.com>
> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
> [ different function signatures ]
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
> fs/ext4/extents.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
> index 1aad4ae0e7ae4..dfc365b021094 100644
> --- a/fs/ext4/extents.c
> +++ b/fs/ext4/extents.c
> @@ -3705,11 +3705,15 @@ static int ext4_split_convert_extents(handle_t *handle,
> /* Convert to unwritten */
> if (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN) {
> split_flag |= EXT4_EXT_DATA_VALID1;
> - /* Convert to initialized */
> - } else if (flags & EXT4_GET_BLOCKS_CONVERT) {
> + /* Split the existing unwritten extent */
> + } else if (flags & (EXT4_GET_BLOCKS_UNWRIT_EXT |
> + EXT4_GET_BLOCKS_CONVERT)) {
> split_flag |= ee_block + ee_len <= eof_block ?
> EXT4_EXT_MAY_ZEROOUT : 0;
> - split_flag |= (EXT4_EXT_MARK_UNWRIT2 | EXT4_EXT_DATA_VALID2);
> + split_flag |= EXT4_EXT_MARK_UNWRIT2;
> + /* Convert to initialized */
> + if (flags & EXT4_GET_BLOCKS_CONVERT)
> + split_flag |= EXT4_EXT_DATA_VALID2;
> }
> flags |= EXT4_GET_BLOCKS_PRE_IO;
> return ext4_split_extent(handle, inode, ppath, map, split_flag, flags);
> @@ -3874,7 +3878,7 @@ ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode,
> /* get_block() before submitting IO, split the extent */
> if (flags & EXT4_GET_BLOCKS_PRE_IO) {
> ret = ext4_split_convert_extents(handle, inode, map, ppath,
> - flags | EXT4_GET_BLOCKS_CONVERT);
> + flags);
> if (ret < 0) {
> err = ret;
> goto out2;
> --
> 2.51.0
>
>
Does not apply :(
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2026-03-21 14:41 UTC | newest]
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2026-02-24 21:43 FAILED: patch "[PATCH] ext4: don't set EXT4_GET_BLOCKS_CONVERT when splitting before" failed to apply to 6.1-stable tree gregkh
2026-02-25 2:57 ` [PATCH 6.1.y] ext4: don't set EXT4_GET_BLOCKS_CONVERT when splitting before submitting I/O Sasha Levin
2026-03-21 14:39 ` Greg KH
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