From 86e332447d726127e042b28f7c65ca3784443794 Mon Sep 17 00:00:00 2001
From: Pankaj Raghav
Date: Mon, 6 Jul 2026 10:41:16 +0200
Subject: [PATCH] xfs: add an allocation mode to xfs_alloc_file_space()
xfs_alloc_file_space() hardcodes XFS_BMAPI_PREALLOC to preallocate
unwritten extents across a range.
In preparation for FALLOC_FL_WRITE_ZEROES, add an explicit allocation
mode argument, enum xfs_alloc_file_space_mode, and derive the xfs_bmapi
flags from it. The only mode for now is XFS_ALLOC_FILE_SPACE_PREALLOC,
which preallocates unwritten extents and marks the inode as preallocated
exactly as before, so there is no functional change.
Reviewed-by: Christoph Hellwig
Reviewed-by: "Darrick J. Wong"
Signed-off-by: Pankaj Raghav
Signed-off-by: Carlos Maiolino
---
fs/xfs/xfs_bmap_util.c | 25 +++++++++++++++++++++----
fs/xfs/xfs_bmap_util.h | 6 +++++-
fs/xfs/xfs_file.c | 9 ++++++---
3 files changed, 32 insertions(+), 8 deletions(-)
diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index c88b9ade7389..48db310b118c 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -642,11 +642,19 @@ xfs_free_eofblocks(
return error;
}
+/*
+ * Allocate space for a file according to @mode:
+ *
+ * XFS_ALLOC_FILE_SPACE_PREALLOC:
+ * Preallocate unwritten extents over holes across the range and mark the inode
+ * as preallocated.
+ */
int
xfs_alloc_file_space(
struct xfs_inode *ip,
xfs_off_t offset,
- xfs_off_t len)
+ xfs_off_t len,
+ enum xfs_alloc_file_space_mode mode)
{
xfs_mount_t *mp = ip->i_mount;
xfs_off_t count;
@@ -657,6 +665,7 @@ xfs_alloc_file_space(
int rt;
xfs_trans_t *tp;
xfs_bmbt_irec_t imaps[1], *imapp;
+ uint32_t bmapi_flags, nr_exts;
int error;
if (xfs_is_always_cow_inode(ip))
@@ -674,6 +683,15 @@ xfs_alloc_file_space(
if (len <= 0)
return -EINVAL;
+ switch (mode) {
+ case XFS_ALLOC_FILE_SPACE_PREALLOC:
+ bmapi_flags = XFS_BMAPI_PREALLOC;
+ nr_exts = XFS_IEXT_ADD_NOSPLIT_CNT;
+ break;
+ default:
+ return -EINVAL;
+ }
+
rt = XFS_IS_REALTIME_INODE(ip);
extsz = xfs_get_extsz_hint(ip);
@@ -733,8 +751,7 @@ xfs_alloc_file_space(
if (error)
break;
- error = xfs_iext_count_extend(tp, ip, XFS_DATA_FORK,
- XFS_IEXT_ADD_NOSPLIT_CNT);
+ error = xfs_iext_count_extend(tp, ip, XFS_DATA_FORK, nr_exts);
if (error)
goto error;
@@ -748,7 +765,7 @@ xfs_alloc_file_space(
* will eventually reach the requested range.
*/
error = xfs_bmapi_write(tp, ip, startoffset_fsb,
- allocatesize_fsb, XFS_BMAPI_PREALLOC, 0, imapp,
+ allocatesize_fsb, bmapi_flags, 0, imapp,
&nimaps);
if (error) {
if (error != -ENOSR)
diff --git a/fs/xfs/xfs_bmap_util.h b/fs/xfs/xfs_bmap_util.h
index eaaf094154b9..929b39d9d88a 100644
--- a/fs/xfs/xfs_bmap_util.h
+++ b/fs/xfs/xfs_bmap_util.h
@@ -55,8 +55,12 @@ int xfs_bmap_last_extent(struct xfs_trans *tp, struct xfs_inode *ip,
int *is_empty);
/* preallocation and hole punch interface */
+enum xfs_alloc_file_space_mode {
+ XFS_ALLOC_FILE_SPACE_PREALLOC,
+};
+
int xfs_alloc_file_space(struct xfs_inode *ip, xfs_off_t offset,
- xfs_off_t len);
+ xfs_off_t len, enum xfs_alloc_file_space_mode mode);
int xfs_free_file_space(struct xfs_inode *ip, xfs_off_t offset,
xfs_off_t len, struct xfs_zone_alloc_ctx *ac);
int xfs_collapse_file_space(struct xfs_inode *, xfs_off_t offset,
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 845a97c9b063..e90ea6ebdc8e 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1406,7 +1406,8 @@ xfs_falloc_zero_range(
len = round_up(offset + len, blksize) -
round_down(offset, blksize);
offset = round_down(offset, blksize);
- error = xfs_alloc_file_space(ip, offset, len);
+ error = xfs_alloc_file_space(ip, offset, len,
+ XFS_ALLOC_FILE_SPACE_PREALLOC);
}
if (error)
return error;
@@ -1432,7 +1433,8 @@ xfs_falloc_unshare_range(
if (error)
return error;
- error = xfs_alloc_file_space(XFS_I(inode), offset, len);
+ error = xfs_alloc_file_space(XFS_I(inode), offset, len,
+ XFS_ALLOC_FILE_SPACE_PREALLOC);
if (error)
return error;
return xfs_falloc_setsize(file, new_size);
@@ -1460,7 +1462,8 @@ xfs_falloc_allocate_range(
if (error)
return error;
- error = xfs_alloc_file_space(XFS_I(inode), offset, len);
+ error = xfs_alloc_file_space(XFS_I(inode), offset, len,
+ XFS_ALLOC_FILE_SPACE_PREALLOC);
if (error)
return error;
return xfs_falloc_setsize(file, new_size);