diff mbox series

[v3,1/7] ext4: Document an edge case for overwrites

Message ID 9f95d7e26f3421c5aa0b835b5aa1dd4f702fc380.1746734745.git.ritesh.list@gmail.com
State Superseded
Headers show
Series ext4: Add multi-fsblock atomic write support with bigalloc | expand

Commit Message

Ritesh Harjani (IBM) May 8, 2025, 8:50 p.m. UTC 
ext4_iomap_overwrite_begin() clears the flag for IOMAP_WRITE before
calling ext4_iomap_begin(). Document this above ext4_map_blocks() call
as it is easy to miss it when focusing on write paths alone.

Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
---
 fs/ext4/inode.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Ojaswin Mujoo May 9, 2025, 5:19 a.m. UTC | #1 
On Fri, May 09, 2025 at 02:20:31AM +0530, Ritesh Harjani (IBM) wrote:
> ext4_iomap_overwrite_begin() clears the flag for IOMAP_WRITE before
> calling ext4_iomap_begin(). Document this above ext4_map_blocks() call
> as it is easy to miss it when focusing on write paths alone.
> 
> Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
 
Looks good Ritesh. Feel free to add:

Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
> ---
>  fs/ext4/inode.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index 94c7d2d828a6..b10e5cd5bb5c 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -3436,6 +3436,10 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
>  		}
>  		ret = ext4_iomap_alloc(inode, &map, flags);
>  	} else {
> +		/*
> +		 * This can be called for overwrites path from
> +		 * ext4_iomap_overwrite_begin().
> +		 */
>  		ret = ext4_map_blocks(NULL, inode, &map, 0);
>  	}
>  
> -- 
> 2.49.0
>
Darrick J. Wong May 14, 2025, 4:23 p.m. UTC | #2 
On Fri, May 09, 2025 at 02:20:31AM +0530, Ritesh Harjani (IBM) wrote:
> ext4_iomap_overwrite_begin() clears the flag for IOMAP_WRITE before
> calling ext4_iomap_begin(). Document this above ext4_map_blocks() call
> as it is easy to miss it when focusing on write paths alone.
> 
> Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>

Weird but ok,
Acked-by: "Darrick J. Wong" <djwong@kernel.org>

--D

> ---
>  fs/ext4/inode.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index 94c7d2d828a6..b10e5cd5bb5c 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -3436,6 +3436,10 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
>  		}
>  		ret = ext4_iomap_alloc(inode, &map, flags);
>  	} else {
> +		/*
> +		 * This can be called for overwrites path from
> +		 * ext4_iomap_overwrite_begin().
> +		 */
>  		ret = ext4_map_blocks(NULL, inode, &map, 0);
>  	}
>  
> -- 
> 2.49.0
> 
>
diff mbox series

Patch

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 94c7d2d828a6..b10e5cd5bb5c 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3436,6 +3436,10 @@  static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
 		}
 		ret = ext4_iomap_alloc(inode, &map, flags);
 	} else {
+		/*
+		 * This can be called for overwrites path from
+		 * ext4_iomap_overwrite_begin().
+		 */
 		ret = ext4_map_blocks(NULL, inode, &map, 0);
 	}