FAILED: patch "[PATCH] ext4: don't zero the entire extent if" failed to apply to 6.1-stable tree

FAILED: patch "[PATCH] ext4: don't zero the entire extent if" failed to apply to 6.1-stable tree

[gregkh]

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 1bf6974822d1dba86cf11b5f05498581cf3488a2
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026022439-revered-giddily-d324@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 1bf6974822d1dba86cf11b5f05498581cf3488a2 Mon Sep 17 00:00:00 2001
From: Zhang Yi <yi.zhang@huawei.com>
Date: Sat, 29 Nov 2025 18:32:34 +0800
Subject: [PATCH] ext4: don't zero the entire extent if
 EXT4_EXT_DATA_PARTIAL_VALID1

When allocating initialized blocks from a large unwritten extent, or
when splitting an unwritten extent during end I/O and converting it to
initialized, there is currently a potential issue of stale data if the
extent needs to be split in the middle.

       0  A      B  N
       [UUUUUUUUUUUU]    U: unwritten extent
       [--DDDDDDDD--]    D: valid data
          |<-  ->| ----> this range needs to be initialized

ext4_split_extent() first try to split this extent at B with
EXT4_EXT_DATA_ENTIRE_VALID1 and EXT4_EXT_MAY_ZEROOUT flag set, but
ext4_split_extent_at() failed to split this extent due to temporary lack
of space. It zeroout B to N and mark the entire extent from 0 to N
as written.

       0  A      B  N
       [WWWWWWWWWWWW]    W: written extent
       [SSDDDDDDDDZZ]    Z: zeroed, S: stale data

ext4_split_extent() then try to split this extent at A with
EXT4_EXT_DATA_VALID2 flag set. This time, it split successfully and left
a stale written extent from 0 to A.

       0  A      B   N
       [WW|WWWWWWWWWW]
       [SS|DDDDDDDDZZ]

Fix this by pass EXT4_EXT_DATA_PARTIAL_VALID1 to ext4_split_extent_at()
when splitting at B, don't convert the entire extent to written and left
it as unwritten after zeroing out B to N. The remaining work is just
like the standard two-part split. ext4_split_extent() will pass the
EXT4_EXT_DATA_VALID2 flag when it calls ext4_split_extent_at() for the
second time, allowing it to properly handle the split. If the split is
successful, it will keep extent from 0 to A as unwritten.

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: <20251129103247.686136-3-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 8d5ca450aa5d..1fee84ea20af 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3310,6 +3310,15 @@ static struct ext4_ext_path *ext4_split_extent_at(handle_t *handle,
 		}
 
 		if (!err) {
+			/*
+			 * The first half contains partially valid data, the
+			 * splitting of this extent has not been completed, fix
+			 * extent length and ext4_split_extent() split will the
+			 * first half again.
+			 */
+			if (split_flag & EXT4_EXT_DATA_PARTIAL_VALID1)
+				goto fix_extent_len;
+
 			/* update the extent length and mark as initialized */
 			ex->ee_len = cpu_to_le16(ee_len);
 			ext4_ext_try_to_merge(handle, inode, path, ex);
@@ -3379,7 +3388,9 @@ static struct ext4_ext_path *ext4_split_extent(handle_t *handle,
 			split_flag1 |= EXT4_EXT_MARK_UNWRIT1 |
 				       EXT4_EXT_MARK_UNWRIT2;
 		if (split_flag & EXT4_EXT_DATA_VALID2)
-			split_flag1 |= EXT4_EXT_DATA_ENTIRE_VALID1;
+			split_flag1 |= map->m_lblk > ee_block ?
+				       EXT4_EXT_DATA_PARTIAL_VALID1 :
+				       EXT4_EXT_DATA_ENTIRE_VALID1;
 		path = ext4_split_extent_at(handle, inode, path,
 				map->m_lblk + map->m_len, split_flag1, flags1);
 		if (IS_ERR(path))

[PATCH 6.1.y 1/7] ext4: make ext4_es_remove_extent() return void

[Sasha Levin]

From: Baokun Li <libaokun1@huawei.com>

[ Upstream commit ed5d285b3f2a9a37ff778c5e440daf49351fcc4d ]

Now ext4_es_remove_extent() never fails, so make it return void.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230424033846.4732-10-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: 1bf6974822d1 ("ext4: don't zero the entire extent if EXT4_EXT_DATA_PARTIAL_VALID1")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext4/extents.c        | 34 ++++++----------------------------
 fs/ext4/extents_status.c | 12 ++++++------
 fs/ext4/extents_status.h |  4 ++--
 fs/ext4/inline.c         | 12 ++----------
 fs/ext4/inode.c          |  8 ++------
 5 files changed, 18 insertions(+), 52 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 1aad4ae0e7ae4..8100e20475f30 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4457,15 +4457,8 @@ int ext4_ext_truncate(handle_t *handle, struct inode *inode)
 
 	last_block = (inode->i_size + sb->s_blocksize - 1)
 			>> EXT4_BLOCK_SIZE_BITS(sb);
-retry:
-	err = ext4_es_remove_extent(inode, last_block,
-				    EXT_MAX_BLOCKS - last_block);
-	if (err == -ENOMEM) {
-		memalloc_retry_wait(GFP_ATOMIC);
-		goto retry;
-	}
-	if (err)
-		return err;
+	ext4_es_remove_extent(inode, last_block, EXT_MAX_BLOCKS - last_block);
+
 retry_remove_space:
 	err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
 	if (err == -ENOMEM) {
@@ -5412,13 +5405,7 @@ static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len)
 
 	down_write(&EXT4_I(inode)->i_data_sem);
 	ext4_discard_preallocations(inode, 0);
-
-	ret = ext4_es_remove_extent(inode, punch_start,
-				    EXT_MAX_BLOCKS - punch_start);
-	if (ret) {
-		up_write(&EXT4_I(inode)->i_data_sem);
-		goto out_stop;
-	}
+	ext4_es_remove_extent(inode, punch_start, EXT_MAX_BLOCKS - punch_start);
 
 	ret = ext4_ext_remove_space(inode, punch_start, punch_stop - 1);
 	if (ret) {
@@ -5604,12 +5591,7 @@ static int ext4_insert_range(struct file *file, loff_t offset, loff_t len)
 		ext4_free_ext_path(path);
 	}
 
-	ret = ext4_es_remove_extent(inode, offset_lblk,
-			EXT_MAX_BLOCKS - offset_lblk);
-	if (ret) {
-		up_write(&EXT4_I(inode)->i_data_sem);
-		goto out_stop;
-	}
+	ext4_es_remove_extent(inode, offset_lblk, EXT_MAX_BLOCKS - offset_lblk);
 
 	/*
 	 * if offset_lblk lies in a hole which is at start of file, use
@@ -5668,12 +5650,8 @@ ext4_swap_extents(handle_t *handle, struct inode *inode1,
 	BUG_ON(!inode_is_locked(inode1));
 	BUG_ON(!inode_is_locked(inode2));
 
-	*erp = ext4_es_remove_extent(inode1, lblk1, count);
-	if (unlikely(*erp))
-		return 0;
-	*erp = ext4_es_remove_extent(inode2, lblk2, count);
-	if (unlikely(*erp))
-		return 0;
+	ext4_es_remove_extent(inode1, lblk1, count);
+	ext4_es_remove_extent(inode2, lblk2, count);
 
 	while (count) {
 		struct ext4_extent *ex1, *ex2, tmp_ex;
diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index 592229027af72..862a8308cd9b0 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -1494,10 +1494,10 @@ static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
  * @len - number of blocks to remove
  *
  * Reduces block/cluster reservation count and for bigalloc cancels pending
- * reservations as needed. Returns 0 on success, error code on failure.
+ * reservations as needed.
  */
-int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
-			  ext4_lblk_t len)
+void ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
+			   ext4_lblk_t len)
 {
 	ext4_lblk_t end;
 	int err = 0;
@@ -1505,14 +1505,14 @@ int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
 	struct extent_status *es = NULL;
 
 	if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
-		return 0;
+		return;
 
 	trace_ext4_es_remove_extent(inode, lblk, len);
 	es_debug("remove [%u/%u) from extent status tree of inode %lu\n",
 		 lblk, len, inode->i_ino);
 
 	if (!len)
-		return err;
+		return;
 
 	end = lblk + len - 1;
 	BUG_ON(end < lblk);
@@ -1539,7 +1539,7 @@ int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
 
 	ext4_es_print_tree(inode);
 	ext4_da_release_space(inode, reserved);
-	return 0;
+	return;
 }
 
 static int __es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,
diff --git a/fs/ext4/extents_status.h b/fs/ext4/extents_status.h
index 481ec4381bee6..1d1247bbfd477 100644
--- a/fs/ext4/extents_status.h
+++ b/fs/ext4/extents_status.h
@@ -133,8 +133,8 @@ extern void ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
 extern void ext4_es_cache_extent(struct inode *inode, ext4_lblk_t lblk,
 				 ext4_lblk_t len, ext4_fsblk_t pblk,
 				 unsigned int status);
-extern int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
-				 ext4_lblk_t len);
+extern void ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
+				  ext4_lblk_t len);
 extern void ext4_es_find_extent_range(struct inode *inode,
 				      int (*match_fn)(struct extent_status *es),
 				      ext4_lblk_t lblk, ext4_lblk_t end,
diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index a1fb99d2b472b..c15ea7589945f 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -2004,16 +2004,8 @@ int ext4_inline_data_truncate(struct inode *inode, int *has_inline)
 		 * the extent status cache must be cleared to avoid leaving
 		 * behind stale delayed allocated extent entries
 		 */
-		if (!ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
-retry:
-			err = ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
-			if (err == -ENOMEM) {
-				memalloc_retry_wait(GFP_ATOMIC);
-				goto retry;
-			}
-			if (err)
-				goto out_error;
-		}
+		if (!ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA))
+			ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
 
 		/* Clear the content in the xattr space. */
 		if (inline_size > EXT4_MIN_INLINE_DATA_SIZE) {
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index bf1f8319e2d74..79619f3db984f 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4134,12 +4134,8 @@ int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
 		down_write(&EXT4_I(inode)->i_data_sem);
 		ext4_discard_preallocations(inode, 0);
 
-		ret = ext4_es_remove_extent(inode, first_block,
-					    stop_block - first_block);
-		if (ret) {
-			up_write(&EXT4_I(inode)->i_data_sem);
-			goto out_stop;
-		}
+		ext4_es_remove_extent(inode, first_block,
+				      stop_block - first_block);
 
 		if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
 			ret = ext4_ext_remove_space(inode, first_block,
-- 
2.51.0

[PATCH 6.1.y 2/7] ext4: get rid of ppath in ext4_find_extent()

[Sasha Levin]

From: Baokun Li <libaokun1@huawei.com>

[ Upstream commit 0be4c0c2f17bd10ae16c852f02d51a6a7b318aca ]

The use of path and ppath is now very confusing, so to make the code more
readable, pass path between functions uniformly, and get rid of ppath.

Getting rid of ppath in ext4_find_extent() requires its caller to update
ppath. These ppaths will also be dropped later. No functional changes.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Tested-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/20240822023545.1994557-12-libaokun@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: 1bf6974822d1 ("ext4: don't zero the entire extent if EXT4_EXT_DATA_PARTIAL_VALID1")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext4/ext4.h        |  2 +-
 fs/ext4/extents.c     | 55 +++++++++++++++++++++++--------------------
 fs/ext4/move_extent.c |  7 +++---
 3 files changed, 34 insertions(+), 30 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 27753291fb7ec..490496adf17cc 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -3723,7 +3723,7 @@ extern int ext4_ext_insert_extent(handle_t *, struct inode *,
 				  struct ext4_ext_path **,
 				  struct ext4_extent *, int);
 extern struct ext4_ext_path *ext4_find_extent(struct inode *, ext4_lblk_t,
-					      struct ext4_ext_path **,
+					      struct ext4_ext_path *,
 					      int flags);
 extern void ext4_free_ext_path(struct ext4_ext_path *);
 extern int ext4_ext_check_inode(struct inode *inode);
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 8100e20475f30..1285b8edd62fc 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -881,11 +881,10 @@ void ext4_ext_tree_init(handle_t *handle, struct inode *inode)
 
 struct ext4_ext_path *
 ext4_find_extent(struct inode *inode, ext4_lblk_t block,
-		 struct ext4_ext_path **orig_path, int flags)
+		 struct ext4_ext_path *path, int flags)
 {
 	struct ext4_extent_header *eh;
 	struct buffer_head *bh;
-	struct ext4_ext_path *path = orig_path ? *orig_path : NULL;
 	short int depth, i, ppos = 0;
 	int ret;
 	gfp_t gfp_flags = GFP_NOFS;
@@ -906,7 +905,7 @@ ext4_find_extent(struct inode *inode, ext4_lblk_t block,
 		ext4_ext_drop_refs(path);
 		if (depth > path[0].p_maxdepth) {
 			kfree(path);
-			*orig_path = path = NULL;
+			path = NULL;
 		}
 	}
 	if (!path) {
@@ -957,14 +956,10 @@ ext4_find_extent(struct inode *inode, ext4_lblk_t block,
 
 	ext4_ext_show_path(inode, path);
 
-	if (orig_path)
-		*orig_path = path;
 	return path;
 
 err:
 	ext4_free_ext_path(path);
-	if (orig_path)
-		*orig_path = NULL;
 	return ERR_PTR(ret);
 }
 
@@ -1429,7 +1424,7 @@ static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
 		/* refill path */
 		path = ext4_find_extent(inode,
 				    (ext4_lblk_t)le32_to_cpu(newext->ee_block),
-				    ppath, gb_flags);
+				    path, gb_flags);
 		if (IS_ERR(path))
 			err = PTR_ERR(path);
 	} else {
@@ -1441,7 +1436,7 @@ static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
 		/* refill path */
 		path = ext4_find_extent(inode,
 				   (ext4_lblk_t)le32_to_cpu(newext->ee_block),
-				    ppath, gb_flags);
+				    path, gb_flags);
 		if (IS_ERR(path)) {
 			err = PTR_ERR(path);
 			goto out;
@@ -1457,8 +1452,8 @@ static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
 			goto repeat;
 		}
 	}
-
 out:
+	*ppath = IS_ERR(path) ? NULL : path;
 	return err;
 }
 
@@ -3245,15 +3240,17 @@ static int ext4_split_extent_at(handle_t *handle,
 	 * WARN_ON may be triggered in ext4_da_update_reserve_space() due to
 	 * an incorrect ee_len causing the i_reserved_data_blocks exception.
 	 */
-	path = ext4_find_extent(inode, ee_block, ppath,
+	path = ext4_find_extent(inode, ee_block, *ppath,
 				flags | EXT4_EX_NOFAIL);
 	if (IS_ERR(path)) {
 		EXT4_ERROR_INODE(inode, "Failed split extent on %u, err %ld",
 				 split, PTR_ERR(path));
+		*ppath = NULL;
 		return PTR_ERR(path);
 	}
 	depth = ext_depth(inode);
 	ex = path[depth].p_ext;
+	*ppath = path;
 
 	if (EXT4_EXT_MAY_ZEROOUT & split_flag) {
 		if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
@@ -3363,9 +3360,12 @@ static int ext4_split_extent(handle_t *handle,
 	 * Update path is required because previous ext4_split_extent_at() may
 	 * result in split of original leaf or extent zeroout.
 	 */
-	path = ext4_find_extent(inode, map->m_lblk, ppath, flags);
-	if (IS_ERR(path))
+	path = ext4_find_extent(inode, map->m_lblk, *ppath, flags);
+	if (IS_ERR(path)) {
+		*ppath = NULL;
 		return PTR_ERR(path);
+	}
+	*ppath = path;
 	depth = ext_depth(inode);
 	ex = path[depth].p_ext;
 	if (!ex) {
@@ -3752,9 +3752,12 @@ static int ext4_convert_unwritten_extents_endio(handle_t *handle,
 						 EXT4_GET_BLOCKS_CONVERT);
 		if (err < 0)
 			return err;
-		path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
-		if (IS_ERR(path))
+		path = ext4_find_extent(inode, map->m_lblk, *ppath, 0);
+		if (IS_ERR(path)) {
+			*ppath = NULL;
 			return PTR_ERR(path);
+		}
+		*ppath = path;
 		depth = ext_depth(inode);
 		ex = path[depth].p_ext;
 	}
@@ -3810,9 +3813,12 @@ convert_initialized_extent(handle_t *handle, struct inode *inode,
 				EXT4_GET_BLOCKS_CONVERT_UNWRITTEN);
 		if (err < 0)
 			return err;
-		path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
-		if (IS_ERR(path))
+		path = ext4_find_extent(inode, map->m_lblk, *ppath, 0);
+		if (IS_ERR(path)) {
+			*ppath = NULL;
 			return PTR_ERR(path);
+		}
+		*ppath = path;
 		depth = ext_depth(inode);
 		ex = path[depth].p_ext;
 		if (!ex) {
@@ -5191,7 +5197,7 @@ ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
 	* won't be shifted beyond EXT_MAX_BLOCKS.
 	*/
 	if (SHIFT == SHIFT_LEFT) {
-		path = ext4_find_extent(inode, start - 1, &path,
+		path = ext4_find_extent(inode, start - 1, path,
 					EXT4_EX_NOCACHE);
 		if (IS_ERR(path))
 			return PTR_ERR(path);
@@ -5240,7 +5246,7 @@ ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
 	 * becomes NULL to indicate the end of the loop.
 	 */
 	while (iterator && start <= stop) {
-		path = ext4_find_extent(inode, *iterator, &path,
+		path = ext4_find_extent(inode, *iterator, path,
 					EXT4_EX_NOCACHE);
 		if (IS_ERR(path))
 			return PTR_ERR(path);
@@ -5837,11 +5843,8 @@ int ext4_clu_mapped(struct inode *inode, ext4_lblk_t lclu)
 
 	/* search for the extent closest to the first block in the cluster */
 	path = ext4_find_extent(inode, EXT4_C2B(sbi, lclu), NULL, 0);
-	if (IS_ERR(path)) {
-		err = PTR_ERR(path);
-		path = NULL;
-		goto out;
-	}
+	if (IS_ERR(path))
+		return PTR_ERR(path);
 
 	depth = ext_depth(inode);
 
@@ -5925,7 +5928,7 @@ int ext4_ext_replay_update_ex(struct inode *inode, ext4_lblk_t start,
 		if (ret)
 			goto out;
 
-		path = ext4_find_extent(inode, start, &path, 0);
+		path = ext4_find_extent(inode, start, path, 0);
 		if (IS_ERR(path))
 			return PTR_ERR(path);
 		ex = path[path->p_depth].p_ext;
@@ -5939,7 +5942,7 @@ int ext4_ext_replay_update_ex(struct inode *inode, ext4_lblk_t start,
 			if (ret)
 				goto out;
 
-			path = ext4_find_extent(inode, start, &path, 0);
+			path = ext4_find_extent(inode, start, path, 0);
 			if (IS_ERR(path))
 				return PTR_ERR(path);
 			ex = path[path->p_depth].p_ext;
diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index e01632462db9f..0aff07c570a46 100644
--- a/fs/ext4/move_extent.c
+++ b/fs/ext4/move_extent.c
@@ -26,16 +26,17 @@ static inline int
 get_ext_path(struct inode *inode, ext4_lblk_t lblock,
 		struct ext4_ext_path **ppath)
 {
-	struct ext4_ext_path *path;
+	struct ext4_ext_path *path = *ppath;
 
-	path = ext4_find_extent(inode, lblock, ppath, EXT4_EX_NOCACHE);
+	*ppath = NULL;
+	path = ext4_find_extent(inode, lblock, path, EXT4_EX_NOCACHE);
 	if (IS_ERR(path))
 		return PTR_ERR(path);
 	if (path[ext_depth(inode)].p_ext == NULL) {
 		ext4_free_ext_path(path);
-		*ppath = NULL;
 		return -ENODATA;
 	}
+	*ppath = path;
 	return 0;
 }
 
-- 
2.51.0

[PATCH 6.1.y 3/7] ext4: get rid of ppath in ext4_ext_create_new_leaf()

[Sasha Levin]

From: Baokun Li <libaokun1@huawei.com>

[ Upstream commit a000bc8678cc2bb10a5b80b4e991e77c7b4612fd ]

The use of path and ppath is now very confusing, so to make the code more
readable, pass path between functions uniformly, and get rid of ppath.

To get rid of the ppath in ext4_ext_create_new_leaf(), the following is
done here:

 * Free the extents path when an error is encountered.
 * Its caller needs to update ppath if it uses ppath.

No functional changes.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Tested-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/20240822023545.1994557-14-libaokun@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: 1bf6974822d1 ("ext4: don't zero the entire extent if EXT4_EXT_DATA_PARTIAL_VALID1")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext4/extents.c | 43 ++++++++++++++++++++++---------------------
 1 file changed, 22 insertions(+), 21 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 1285b8edd62fc..37113982a3329 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -1392,13 +1392,12 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
  * finds empty index and adds new leaf.
  * if no free index is found, then it requests in-depth growing.
  */
-static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
-				    unsigned int mb_flags,
-				    unsigned int gb_flags,
-				    struct ext4_ext_path **ppath,
-				    struct ext4_extent *newext)
+static struct ext4_ext_path *
+ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
+			 unsigned int mb_flags, unsigned int gb_flags,
+			 struct ext4_ext_path *path,
+			 struct ext4_extent *newext)
 {
-	struct ext4_ext_path *path = *ppath;
 	struct ext4_ext_path *curp;
 	int depth, i, err = 0;
 
@@ -1419,28 +1418,25 @@ static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
 		 * entry: create all needed subtree and add new leaf */
 		err = ext4_ext_split(handle, inode, mb_flags, path, newext, i);
 		if (err)
-			goto out;
+			goto errout;
 
 		/* refill path */
 		path = ext4_find_extent(inode,
 				    (ext4_lblk_t)le32_to_cpu(newext->ee_block),
 				    path, gb_flags);
-		if (IS_ERR(path))
-			err = PTR_ERR(path);
+		return path;
 	} else {
 		/* tree is full, time to grow in depth */
 		err = ext4_ext_grow_indepth(handle, inode, mb_flags);
 		if (err)
-			goto out;
+			goto errout;
 
 		/* refill path */
 		path = ext4_find_extent(inode,
 				   (ext4_lblk_t)le32_to_cpu(newext->ee_block),
 				    path, gb_flags);
-		if (IS_ERR(path)) {
-			err = PTR_ERR(path);
-			goto out;
-		}
+		if (IS_ERR(path))
+			return path;
 
 		/*
 		 * only first (depth 0 -> 1) produces free space;
@@ -1452,9 +1448,11 @@ static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
 			goto repeat;
 		}
 	}
-out:
-	*ppath = IS_ERR(path) ? NULL : path;
-	return err;
+	return path;
+
+errout:
+	ext4_free_ext_path(path);
+	return ERR_PTR(err);
 }
 
 /*
@@ -2097,11 +2095,14 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
 	 */
 	if (gb_flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
 		mb_flags |= EXT4_MB_USE_RESERVED;
-	err = ext4_ext_create_new_leaf(handle, inode, mb_flags, gb_flags,
-				       ppath, newext);
-	if (err)
+	path = ext4_ext_create_new_leaf(handle, inode, mb_flags, gb_flags,
+					path, newext);
+	if (IS_ERR(path)) {
+		*ppath = NULL;
+		err = PTR_ERR(path);
 		goto cleanup;
-	path = *ppath;
+	}
+	*ppath = path;
 	depth = ext_depth(inode);
 	eh = path[depth].p_hdr;
 
-- 
2.51.0

[PATCH 6.1.y 4/7] ext4: get rid of ppath in ext4_ext_insert_extent()

[Sasha Levin]

From: Baokun Li <libaokun1@huawei.com>

[ Upstream commit f7d1331f16a869c76a5102caebb58e840e1d509c ]

The use of path and ppath is now very confusing, so to make the code more
readable, pass path between functions uniformly, and get rid of ppath.

To get rid of the ppath in ext4_ext_insert_extent(), the following is done
here:

 * Free the extents path when an error is encountered.
 * Its caller needs to update ppath if it uses ppath.
 * Free path when npath is used, free npath when it is not used.
 * The got_allocated_blocks label in ext4_ext_map_blocks() does not
   update err now, so err is updated to 0 if the err returned by
   ext4_ext_search_right() is greater than 0 and is about to enter
   got_allocated_blocks.

No functional changes.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Tested-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/20240822023545.1994557-15-libaokun@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: 1bf6974822d1 ("ext4: don't zero the entire extent if EXT4_EXT_DATA_PARTIAL_VALID1")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext4/ext4.h        |  7 ++--
 fs/ext4/extents.c     | 88 ++++++++++++++++++++++++-------------------
 fs/ext4/fast_commit.c |  8 ++--
 fs/ext4/migrate.c     |  5 ++-
 4 files changed, 61 insertions(+), 47 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 490496adf17cc..7449777fabc36 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -3719,9 +3719,10 @@ extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
 extern int ext4_ext_calc_credits_for_single_extent(struct inode *inode,
 						   int num,
 						   struct ext4_ext_path *path);
-extern int ext4_ext_insert_extent(handle_t *, struct inode *,
-				  struct ext4_ext_path **,
-				  struct ext4_extent *, int);
+extern struct ext4_ext_path *ext4_ext_insert_extent(
+				handle_t *handle, struct inode *inode,
+				struct ext4_ext_path *path,
+				struct ext4_extent *newext, int gb_flags);
 extern struct ext4_ext_path *ext4_find_extent(struct inode *, ext4_lblk_t,
 					      struct ext4_ext_path *,
 					      int flags);
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 37113982a3329..8a5c1e1207ba7 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -1960,16 +1960,15 @@ static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi,
  * inserts requested extent as new one into the tree,
  * creating new leaf in the no-space case.
  */
-int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
-				struct ext4_ext_path **ppath,
-				struct ext4_extent *newext, int gb_flags)
+struct ext4_ext_path *
+ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
+		       struct ext4_ext_path *path,
+		       struct ext4_extent *newext, int gb_flags)
 {
-	struct ext4_ext_path *path = *ppath;
 	struct ext4_extent_header *eh;
 	struct ext4_extent *ex, *fex;
 	struct ext4_extent *nearex; /* nearest extent */
-	struct ext4_ext_path *npath = NULL;
-	int depth, len, err;
+	int depth, len, err = 0;
 	ext4_lblk_t next;
 	int mb_flags = 0, unwritten;
 
@@ -1977,14 +1976,16 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
 		mb_flags |= EXT4_MB_DELALLOC_RESERVED;
 	if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
 		EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
-		return -EFSCORRUPTED;
+		err = -EFSCORRUPTED;
+		goto errout;
 	}
 	depth = ext_depth(inode);
 	ex = path[depth].p_ext;
 	eh = path[depth].p_hdr;
 	if (unlikely(path[depth].p_hdr == NULL)) {
 		EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
-		return -EFSCORRUPTED;
+		err = -EFSCORRUPTED;
+		goto errout;
 	}
 
 	/* try to insert block into found extent and return */
@@ -2022,7 +2023,7 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
 			err = ext4_ext_get_access(handle, inode,
 						  path + depth);
 			if (err)
-				return err;
+				goto errout;
 			unwritten = ext4_ext_is_unwritten(ex);
 			ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
 					+ ext4_ext_get_actual_len(newext));
@@ -2047,7 +2048,7 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
 			err = ext4_ext_get_access(handle, inode,
 						  path + depth);
 			if (err)
-				return err;
+				goto errout;
 
 			unwritten = ext4_ext_is_unwritten(ex);
 			ex->ee_block = newext->ee_block;
@@ -2072,21 +2073,26 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
 	if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
 		next = ext4_ext_next_leaf_block(path);
 	if (next != EXT_MAX_BLOCKS) {
+		struct ext4_ext_path *npath;
+
 		ext_debug(inode, "next leaf block - %u\n", next);
-		BUG_ON(npath != NULL);
 		npath = ext4_find_extent(inode, next, NULL, gb_flags);
-		if (IS_ERR(npath))
-			return PTR_ERR(npath);
+		if (IS_ERR(npath)) {
+			err = PTR_ERR(npath);
+			goto errout;
+		}
 		BUG_ON(npath->p_depth != path->p_depth);
 		eh = npath[depth].p_hdr;
 		if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
 			ext_debug(inode, "next leaf isn't full(%d)\n",
 				  le16_to_cpu(eh->eh_entries));
+			ext4_free_ext_path(path);
 			path = npath;
 			goto has_space;
 		}
 		ext_debug(inode, "next leaf has no free space(%d,%d)\n",
 			  le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
+		ext4_free_ext_path(npath);
 	}
 
 	/*
@@ -2097,12 +2103,8 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
 		mb_flags |= EXT4_MB_USE_RESERVED;
 	path = ext4_ext_create_new_leaf(handle, inode, mb_flags, gb_flags,
 					path, newext);
-	if (IS_ERR(path)) {
-		*ppath = NULL;
-		err = PTR_ERR(path);
-		goto cleanup;
-	}
-	*ppath = path;
+	if (IS_ERR(path))
+		return path;
 	depth = ext_depth(inode);
 	eh = path[depth].p_hdr;
 
@@ -2111,7 +2113,7 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
 
 	err = ext4_ext_get_access(handle, inode, path + depth);
 	if (err)
-		goto cleanup;
+		goto errout;
 
 	if (!nearex) {
 		/* there is no extent in this leaf, create first one */
@@ -2169,17 +2171,20 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
 	if (!(gb_flags & EXT4_GET_BLOCKS_PRE_IO))
 		ext4_ext_try_to_merge(handle, inode, path, nearex);
 
-
 	/* time to correct all indexes above */
 	err = ext4_ext_correct_indexes(handle, inode, path);
 	if (err)
-		goto cleanup;
+		goto errout;
 
 	err = ext4_ext_dirty(handle, inode, path + path->p_depth);
+	if (err)
+		goto errout;
 
-cleanup:
-	ext4_free_ext_path(npath);
-	return err;
+	return path;
+
+errout:
+	ext4_free_ext_path(path);
+	return ERR_PTR(err);
 }
 
 static int ext4_fill_es_cache_info(struct inode *inode,
@@ -3229,24 +3234,29 @@ static int ext4_split_extent_at(handle_t *handle,
 	if (split_flag & EXT4_EXT_MARK_UNWRIT2)
 		ext4_ext_mark_unwritten(ex2);
 
-	err = ext4_ext_insert_extent(handle, inode, ppath, &newex, flags);
-	if (err != -ENOSPC && err != -EDQUOT && err != -ENOMEM)
+	path = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
+	if (!IS_ERR(path)) {
+		*ppath = path;
 		goto out;
+	}
+	*ppath = NULL;
+	err = PTR_ERR(path);
+	if (err != -ENOSPC && err != -EDQUOT && err != -ENOMEM)
+		return err;
 
 	/*
-	 * Update path is required because previous ext4_ext_insert_extent()
-	 * may have freed or reallocated the path. Using EXT4_EX_NOFAIL
-	 * guarantees that ext4_find_extent() will not return -ENOMEM,
-	 * otherwise -ENOMEM will cause a retry in do_writepages(), and a
-	 * WARN_ON may be triggered in ext4_da_update_reserve_space() due to
-	 * an incorrect ee_len causing the i_reserved_data_blocks exception.
+	 * Get a new path to try to zeroout or fix the extent length.
+	 * Using EXT4_EX_NOFAIL guarantees that ext4_find_extent()
+	 * will not return -ENOMEM, otherwise -ENOMEM will cause a
+	 * retry in do_writepages(), and a WARN_ON may be triggered
+	 * in ext4_da_update_reserve_space() due to an incorrect
+	 * ee_len causing the i_reserved_data_blocks exception.
 	 */
-	path = ext4_find_extent(inode, ee_block, *ppath,
+	path = ext4_find_extent(inode, ee_block, NULL,
 				flags | EXT4_EX_NOFAIL);
 	if (IS_ERR(path)) {
 		EXT4_ERROR_INODE(inode, "Failed split extent on %u, err %ld",
 				 split, PTR_ERR(path));
-		*ppath = NULL;
 		return PTR_ERR(path);
 	}
 	depth = ext_depth(inode);
@@ -3305,7 +3315,7 @@ static int ext4_split_extent_at(handle_t *handle,
 	ext4_ext_dirty(handle, inode, path + path->p_depth);
 	return err;
 out:
-	ext4_ext_show_leaf(inode, *ppath);
+	ext4_ext_show_leaf(inode, path);
 	return err;
 }
 
@@ -4293,6 +4303,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
 	    get_implied_cluster_alloc(inode->i_sb, map, &ex2, path)) {
 		ar.len = allocated = map->m_len;
 		newblock = map->m_pblk;
+		err = 0;
 		goto got_allocated_blocks;
 	}
 
@@ -4365,8 +4376,9 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
 		map->m_flags |= EXT4_MAP_UNWRITTEN;
 	}
 
-	err = ext4_ext_insert_extent(handle, inode, &path, &newex, flags);
-	if (err) {
+	path = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
+	if (IS_ERR(path)) {
+		err = PTR_ERR(path);
 		if (allocated_clusters) {
 			int fb_flags = 0;
 
diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
index 94f90032ca561..83a0a78a124a1 100644
--- a/fs/ext4/fast_commit.c
+++ b/fs/ext4/fast_commit.c
@@ -1828,12 +1828,12 @@ static int ext4_fc_replay_add_range(struct super_block *sb,
 			if (ext4_ext_is_unwritten(ex))
 				ext4_ext_mark_unwritten(&newex);
 			down_write(&EXT4_I(inode)->i_data_sem);
-			ret = ext4_ext_insert_extent(
-				NULL, inode, &path, &newex, 0);
+			path = ext4_ext_insert_extent(NULL, inode,
+						      path, &newex, 0);
 			up_write((&EXT4_I(inode)->i_data_sem));
-			ext4_free_ext_path(path);
-			if (ret)
+			if (IS_ERR(path))
 				goto out;
+			ext4_free_ext_path(path);
 			goto next;
 		}
 
diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c
index 0be0467ae6dd2..7a0e429507cf3 100644
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -37,7 +37,6 @@ static int finish_range(handle_t *handle, struct inode *inode,
 	path = ext4_find_extent(inode, lb->first_block, NULL, 0);
 	if (IS_ERR(path)) {
 		retval = PTR_ERR(path);
-		path = NULL;
 		goto err_out;
 	}
 
@@ -53,7 +52,9 @@ static int finish_range(handle_t *handle, struct inode *inode,
 	retval = ext4_datasem_ensure_credits(handle, inode, needed, needed, 0);
 	if (retval < 0)
 		goto err_out;
-	retval = ext4_ext_insert_extent(handle, inode, &path, &newext, 0);
+	path = ext4_ext_insert_extent(handle, inode, path, &newext, 0);
+	if (IS_ERR(path))
+		retval = PTR_ERR(path);
 err_out:
 	up_write((&EXT4_I(inode)->i_data_sem));
 	ext4_free_ext_path(path);
-- 
2.51.0

[PATCH 6.1.y 5/7] ext4: get rid of ppath in ext4_split_extent_at()

[Sasha Levin]

From: Baokun Li <libaokun1@huawei.com>

[ Upstream commit 1de82b1b60d4613753254bf3cbf622a4c02c945c ]

The use of path and ppath is now very confusing, so to make the code more
readable, pass path between functions uniformly, and get rid of ppath.

To get rid of the ppath in ext4_split_extent_at(), the following is done
here:

 * Free the extents path when an error is encountered.
 * Its caller needs to update ppath if it uses ppath.
 * Teach ext4_ext_show_leaf() to skip error pointer.

No functional changes.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Tested-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://patch.msgid.link/20240822023545.1994557-16-libaokun@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: 1bf6974822d1 ("ext4: don't zero the entire extent if EXT4_EXT_DATA_PARTIAL_VALID1")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext4/extents.c | 85 ++++++++++++++++++++++++++---------------------
 1 file changed, 47 insertions(+), 38 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 8a5c1e1207ba7..476fa4bc351a0 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -84,12 +84,11 @@ static void ext4_extent_block_csum_set(struct inode *inode,
 	et->et_checksum = ext4_extent_block_csum(inode, eh);
 }
 
-static int ext4_split_extent_at(handle_t *handle,
-			     struct inode *inode,
-			     struct ext4_ext_path **ppath,
-			     ext4_lblk_t split,
-			     int split_flag,
-			     int flags);
+static struct ext4_ext_path *ext4_split_extent_at(handle_t *handle,
+						  struct inode *inode,
+						  struct ext4_ext_path *path,
+						  ext4_lblk_t split,
+						  int split_flag, int flags);
 
 static int ext4_ext_trunc_restart_fn(struct inode *inode, int *dropped)
 {
@@ -335,9 +334,15 @@ ext4_force_split_extent_at(handle_t *handle, struct inode *inode,
 	if (nofail)
 		flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL | EXT4_EX_NOFAIL;
 
-	return ext4_split_extent_at(handle, inode, ppath, lblk, unwritten ?
+	path = ext4_split_extent_at(handle, inode, path, lblk, unwritten ?
 			EXT4_EXT_MARK_UNWRIT1|EXT4_EXT_MARK_UNWRIT2 : 0,
 			flags);
+	if (IS_ERR(path)) {
+		*ppath = NULL;
+		return PTR_ERR(path);
+	}
+	*ppath = path;
+	return 0;
 }
 
 static int
@@ -689,7 +694,7 @@ static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
 	struct ext4_extent *ex;
 	int i;
 
-	if (!path)
+	if (IS_ERR_OR_NULL(path))
 		return;
 
 	eh = path[depth].p_hdr;
@@ -3155,16 +3160,14 @@ static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
  *  a> the extent are splitted into two extent.
  *  b> split is not needed, and just mark the extent.
  *
- * return 0 on success.
+ * Return an extent path pointer on success, or an error pointer on failure.
  */
-static int ext4_split_extent_at(handle_t *handle,
-			     struct inode *inode,
-			     struct ext4_ext_path **ppath,
-			     ext4_lblk_t split,
-			     int split_flag,
-			     int flags)
+static struct ext4_ext_path *ext4_split_extent_at(handle_t *handle,
+						  struct inode *inode,
+						  struct ext4_ext_path *path,
+						  ext4_lblk_t split,
+						  int split_flag, int flags)
 {
-	struct ext4_ext_path *path = *ppath;
 	ext4_fsblk_t newblock;
 	ext4_lblk_t ee_block;
 	struct ext4_extent *ex, newex, orig_ex, zero_ex;
@@ -3235,14 +3238,12 @@ static int ext4_split_extent_at(handle_t *handle,
 		ext4_ext_mark_unwritten(ex2);
 
 	path = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
-	if (!IS_ERR(path)) {
-		*ppath = path;
+	if (!IS_ERR(path))
 		goto out;
-	}
-	*ppath = NULL;
+
 	err = PTR_ERR(path);
 	if (err != -ENOSPC && err != -EDQUOT && err != -ENOMEM)
-		return err;
+		return path;
 
 	/*
 	 * Get a new path to try to zeroout or fix the extent length.
@@ -3252,16 +3253,14 @@ static int ext4_split_extent_at(handle_t *handle,
 	 * in ext4_da_update_reserve_space() due to an incorrect
 	 * ee_len causing the i_reserved_data_blocks exception.
 	 */
-	path = ext4_find_extent(inode, ee_block, NULL,
-				flags | EXT4_EX_NOFAIL);
+	path = ext4_find_extent(inode, ee_block, NULL, flags | EXT4_EX_NOFAIL);
 	if (IS_ERR(path)) {
 		EXT4_ERROR_INODE(inode, "Failed split extent on %u, err %ld",
 				 split, PTR_ERR(path));
-		return PTR_ERR(path);
+		return path;
 	}
 	depth = ext_depth(inode);
 	ex = path[depth].p_ext;
-	*ppath = path;
 
 	if (EXT4_EXT_MAY_ZEROOUT & split_flag) {
 		if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
@@ -3313,10 +3312,13 @@ static int ext4_split_extent_at(handle_t *handle,
 	 * and err is a non-zero error code.
 	 */
 	ext4_ext_dirty(handle, inode, path + path->p_depth);
-	return err;
 out:
+	if (err) {
+		ext4_free_ext_path(path);
+		path = ERR_PTR(err);
+	}
 	ext4_ext_show_leaf(inode, path);
-	return err;
+	return path;
 }
 
 /*
@@ -3360,10 +3362,14 @@ static int ext4_split_extent(handle_t *handle,
 				       EXT4_EXT_MARK_UNWRIT2;
 		if (split_flag & EXT4_EXT_DATA_VALID2)
 			split_flag1 |= EXT4_EXT_DATA_VALID1;
-		err = ext4_split_extent_at(handle, inode, ppath,
+		path = ext4_split_extent_at(handle, inode, path,
 				map->m_lblk + map->m_len, split_flag1, flags1);
-		if (err)
+		if (IS_ERR(path)) {
+			err = PTR_ERR(path);
+			*ppath = NULL;
 			goto out;
+		}
+		*ppath = path;
 	} else {
 		allocated = ee_len - (map->m_lblk - ee_block);
 	}
@@ -3371,7 +3377,7 @@ static int ext4_split_extent(handle_t *handle,
 	 * Update path is required because previous ext4_split_extent_at() may
 	 * result in split of original leaf or extent zeroout.
 	 */
-	path = ext4_find_extent(inode, map->m_lblk, *ppath, flags);
+	path = ext4_find_extent(inode, map->m_lblk, path, flags);
 	if (IS_ERR(path)) {
 		*ppath = NULL;
 		return PTR_ERR(path);
@@ -3393,13 +3399,17 @@ static int ext4_split_extent(handle_t *handle,
 			split_flag1 |= split_flag & (EXT4_EXT_MAY_ZEROOUT |
 						     EXT4_EXT_MARK_UNWRIT2);
 		}
-		err = ext4_split_extent_at(handle, inode, ppath,
+		path = ext4_split_extent_at(handle, inode, path,
 				map->m_lblk, split_flag1, flags);
-		if (err)
+		if (IS_ERR(path)) {
+			err = PTR_ERR(path);
+			*ppath = NULL;
 			goto out;
+		}
+		*ppath = path;
 	}
 
-	ext4_ext_show_leaf(inode, *ppath);
+	ext4_ext_show_leaf(inode, path);
 out:
 	return err ? err : allocated;
 }
@@ -5594,22 +5604,21 @@ static int ext4_insert_range(struct file *file, loff_t offset, loff_t len)
 			if (ext4_ext_is_unwritten(extent))
 				split_flag = EXT4_EXT_MARK_UNWRIT1 |
 					EXT4_EXT_MARK_UNWRIT2;
-			ret = ext4_split_extent_at(handle, inode, &path,
+			path = ext4_split_extent_at(handle, inode, path,
 					offset_lblk, split_flag,
 					EXT4_EX_NOCACHE |
 					EXT4_GET_BLOCKS_PRE_IO |
 					EXT4_GET_BLOCKS_METADATA_NOFAIL);
 		}
 
-		ext4_free_ext_path(path);
-		if (ret < 0) {
+		if (IS_ERR(path)) {
 			up_write(&EXT4_I(inode)->i_data_sem);
+			ret = PTR_ERR(path);
 			goto out_stop;
 		}
-	} else {
-		ext4_free_ext_path(path);
 	}
 
+	ext4_free_ext_path(path);
 	ext4_es_remove_extent(inode, offset_lblk, EXT_MAX_BLOCKS - offset_lblk);
 
 	/*
-- 
2.51.0

[PATCH 6.1.y 6/7] ext4: subdivide EXT4_EXT_DATA_VALID1

[Sasha Levin]

From: Zhang Yi <yi.zhang@huawei.com>

[ Upstream commit 22784ca541c0f01c5ebad14e8228298dc0a390ed ]

When splitting an extent, if the EXT4_GET_BLOCKS_CONVERT flag is set and
it is necessary to split the target extent in the middle,
ext4_split_extent() first handles splitting the latter half of the
extent and passes the EXT4_EXT_DATA_VALID1 flag. This flag implies that
all blocks before the split point contain valid data; however, this
assumption is incorrect.

Therefore, subdivid EXT4_EXT_DATA_VALID1 into
EXT4_EXT_DATA_ENTIRE_VALID1 and EXT4_EXT_DATA_PARTIAL_VALID1, which
indicate that the first half of the extent is either entirely valid or
only partially valid, respectively. These two flags cannot be set
simultaneously.

This patch does not use EXT4_EXT_DATA_PARTIAL_VALID1, it only replaces
EXT4_EXT_DATA_VALID1 with EXT4_EXT_DATA_ENTIRE_VALID1 at the location
where it is set, no logical changes.

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: <20251129103247.686136-2-yi.zhang@huaweicloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Stable-dep-of: 1bf6974822d1 ("ext4: don't zero the entire extent if EXT4_EXT_DATA_PARTIAL_VALID1")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext4/extents.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 476fa4bc351a0..dac8b758b6837 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -43,8 +43,13 @@
 #define EXT4_EXT_MARK_UNWRIT1	0x2  /* mark first half unwritten */
 #define EXT4_EXT_MARK_UNWRIT2	0x4  /* mark second half unwritten */
 
-#define EXT4_EXT_DATA_VALID1	0x8  /* first half contains valid data */
-#define EXT4_EXT_DATA_VALID2	0x10 /* second half contains valid data */
+/* first half contains valid data */
+#define EXT4_EXT_DATA_ENTIRE_VALID1	0x8   /* has entirely valid data */
+#define EXT4_EXT_DATA_PARTIAL_VALID1	0x10  /* has partially valid data */
+#define EXT4_EXT_DATA_VALID1		(EXT4_EXT_DATA_ENTIRE_VALID1 | \
+					 EXT4_EXT_DATA_PARTIAL_VALID1)
+
+#define EXT4_EXT_DATA_VALID2	0x20 /* second half contains valid data */
 
 static __le32 ext4_extent_block_csum(struct inode *inode,
 				     struct ext4_extent_header *eh)
@@ -3175,8 +3180,9 @@ static struct ext4_ext_path *ext4_split_extent_at(handle_t *handle,
 	unsigned int ee_len, depth;
 	int err = 0;
 
-	BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) ==
-	       (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2));
+	BUG_ON((split_flag & EXT4_EXT_DATA_VALID1) == EXT4_EXT_DATA_VALID1);
+	BUG_ON((split_flag & EXT4_EXT_DATA_VALID1) &&
+	       (split_flag & EXT4_EXT_DATA_VALID2));
 
 	ext_debug(inode, "logical block %llu\n", (unsigned long long)split);
 
@@ -3361,7 +3367,7 @@ static int ext4_split_extent(handle_t *handle,
 			split_flag1 |= EXT4_EXT_MARK_UNWRIT1 |
 				       EXT4_EXT_MARK_UNWRIT2;
 		if (split_flag & EXT4_EXT_DATA_VALID2)
-			split_flag1 |= EXT4_EXT_DATA_VALID1;
+			split_flag1 |= EXT4_EXT_DATA_ENTIRE_VALID1;
 		path = ext4_split_extent_at(handle, inode, path,
 				map->m_lblk + map->m_len, split_flag1, flags1);
 		if (IS_ERR(path)) {
@@ -3725,7 +3731,7 @@ 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;
+		split_flag |= EXT4_EXT_DATA_ENTIRE_VALID1;
 	/* Convert to initialized */
 	} else if (flags & EXT4_GET_BLOCKS_CONVERT) {
 		split_flag |= ee_block + ee_len <= eof_block ?
-- 
2.51.0

[PATCH 6.1.y 7/7] ext4: don't zero the entire extent if EXT4_EXT_DATA_PARTIAL_VALID1

[Sasha Levin]

From: Zhang Yi <yi.zhang@huawei.com>

[ Upstream commit 1bf6974822d1dba86cf11b5f05498581cf3488a2 ]

When allocating initialized blocks from a large unwritten extent, or
when splitting an unwritten extent during end I/O and converting it to
initialized, there is currently a potential issue of stale data if the
extent needs to be split in the middle.

       0  A      B  N
       [UUUUUUUUUUUU]    U: unwritten extent
       [--DDDDDDDD--]    D: valid data
          |<-  ->| ----> this range needs to be initialized

ext4_split_extent() first try to split this extent at B with
EXT4_EXT_DATA_ENTIRE_VALID1 and EXT4_EXT_MAY_ZEROOUT flag set, but
ext4_split_extent_at() failed to split this extent due to temporary lack
of space. It zeroout B to N and mark the entire extent from 0 to N
as written.

       0  A      B  N
       [WWWWWWWWWWWW]    W: written extent
       [SSDDDDDDDDZZ]    Z: zeroed, S: stale data

ext4_split_extent() then try to split this extent at A with
EXT4_EXT_DATA_VALID2 flag set. This time, it split successfully and left
a stale written extent from 0 to A.

       0  A      B   N
       [WW|WWWWWWWWWW]
       [SS|DDDDDDDDZZ]

Fix this by pass EXT4_EXT_DATA_PARTIAL_VALID1 to ext4_split_extent_at()
when splitting at B, don't convert the entire extent to written and left
it as unwritten after zeroing out B to N. The remaining work is just
like the standard two-part split. ext4_split_extent() will pass the
EXT4_EXT_DATA_VALID2 flag when it calls ext4_split_extent_at() for the
second time, allowing it to properly handle the split. If the split is
successful, it will keep extent from 0 to A as unwritten.

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: <20251129103247.686136-3-yi.zhang@huaweicloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext4/extents.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index dac8b758b6837..1bdd30926024c 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3295,6 +3295,15 @@ static struct ext4_ext_path *ext4_split_extent_at(handle_t *handle,
 		}
 
 		if (!err) {
+			/*
+			 * The first half contains partially valid data, the
+			 * splitting of this extent has not been completed, fix
+			 * extent length and ext4_split_extent() split will the
+			 * first half again.
+			 */
+			if (split_flag & EXT4_EXT_DATA_PARTIAL_VALID1)
+				goto fix_extent_len;
+
 			/* update the extent length and mark as initialized */
 			ex->ee_len = cpu_to_le16(ee_len);
 			ext4_ext_try_to_merge(handle, inode, path, ex);
@@ -3367,7 +3376,9 @@ static int ext4_split_extent(handle_t *handle,
 			split_flag1 |= EXT4_EXT_MARK_UNWRIT1 |
 				       EXT4_EXT_MARK_UNWRIT2;
 		if (split_flag & EXT4_EXT_DATA_VALID2)
-			split_flag1 |= EXT4_EXT_DATA_ENTIRE_VALID1;
+			split_flag1 |= map->m_lblk > ee_block ?
+				       EXT4_EXT_DATA_PARTIAL_VALID1 :
+				       EXT4_EXT_DATA_ENTIRE_VALID1;
 		path = ext4_split_extent_at(handle, inode, path,
 				map->m_lblk + map->m_len, split_flag1, flags1);
 		if (IS_ERR(path)) {
-- 
2.51.0