[RFC PATCH v4 3/8] iomap: pass blocksize to iomap_truncate_page()

From: Zhang Yi
Date: Tue May 28 2024 - 21:59:54 EST


From: Zhang Yi <yi.zhang@xxxxxxxxxx>

iomap_truncate_page() always assumes the block size of the truncating
inode is i_blocksize(), this is not always true for some filesystems,
e.g. XFS does extent size alignment for realtime inodes. Drop this
assumption and pass the block size for zeroing into
iomap_truncate_page(), allow filesystems to indicate the correct block
size.

Suggested-by: Dave Chinner <david@xxxxxxxxxxxxx>
Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx>
---
fs/iomap/buffered-io.c | 8 ++++----
fs/xfs/xfs_iomap.c | 3 ++-
include/linux/iomap.h | 4 ++--
3 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index a3a5d4eb7289..30b49d6e9d48 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -17,6 +17,7 @@
#include <linux/bio.h>
#include <linux/sched/signal.h>
#include <linux/migrate.h>
+#include <linux/math64.h>
#include "trace.h"

#include "../internal.h"
@@ -1483,11 +1484,10 @@ iomap_zero_range(struct inode *inode, loff_t pos, loff_t len, bool *did_zero,
EXPORT_SYMBOL_GPL(iomap_zero_range);

int
-iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero,
- const struct iomap_ops *ops)
+iomap_truncate_page(struct inode *inode, loff_t pos, unsigned int blocksize,
+ bool *did_zero, const struct iomap_ops *ops)
{
- unsigned int blocksize = i_blocksize(inode);
- unsigned int off = pos & (blocksize - 1);
+ unsigned int off = rem_u64(pos, blocksize);

/* Block boundary? Nothing to do */
if (!off)
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index 378342673925..32306804b01b 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -1471,10 +1471,11 @@ xfs_truncate_page(
bool *did_zero)
{
struct inode *inode = VFS_I(ip);
+ unsigned int blocksize = i_blocksize(inode);

if (IS_DAX(inode))
return dax_truncate_page(inode, pos, did_zero,
&xfs_dax_write_iomap_ops);
- return iomap_truncate_page(inode, pos, did_zero,
+ return iomap_truncate_page(inode, pos, blocksize, did_zero,
&xfs_buffered_write_iomap_ops);
}
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 6fc1c858013d..d67bf86ec582 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -273,8 +273,8 @@ int iomap_file_unshare(struct inode *inode, loff_t pos, loff_t len,
const struct iomap_ops *ops);
int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len,
bool *did_zero, const struct iomap_ops *ops);
-int iomap_truncate_page(struct inode *inode, loff_t pos, bool *did_zero,
- const struct iomap_ops *ops);
+int iomap_truncate_page(struct inode *inode, loff_t pos, unsigned int blocksize,
+ bool *did_zero, const struct iomap_ops *ops);
vm_fault_t iomap_page_mkwrite(struct vm_fault *vmf,
const struct iomap_ops *ops);
int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
--
2.39.2