[PATCH 5.15 021/667] fs/ntfs3: Fix fiemap + fix shrink file size (to remove preallocated space)

From: Greg Kroah-Hartman
Date: Tue Jun 07 2022 - 14:18:25 EST


From: Konstantin Komarov <almaz.alexandrovich@xxxxxxxxxxxxxxxxxxxx>

commit 3880f2b816a7e4ca889b7e8a42e6c62c5706ed36 upstream.

Two problems:
1. ntfs3_setattr can't truncate preallocated space;
2. if allocated fragment "cross" valid size, then fragment splits into two parts:
- normal part;
- unwritten part (here we must return FIEMAP_EXTENT_LAST).
Before this commit we returned FIEMAP_EXTENT_LAST for whole fragment.
Fixes xfstest generic/092
Fixes: 4342306f0f0d ("fs/ntfs3: Add file operations and implementation")

Signed-off-by: Konstantin Komarov <almaz.alexandrovich@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ntfs3/file.c | 2 +-
fs/ntfs3/frecord.c | 10 +++++++---
2 files changed, 8 insertions(+), 4 deletions(-)

--- a/fs/ntfs3/file.c
+++ b/fs/ntfs3/file.c
@@ -761,7 +761,7 @@ int ntfs3_setattr(struct user_namespace
}
inode_dio_wait(inode);

- if (attr->ia_size < oldsize)
+ if (attr->ia_size <= oldsize)
err = ntfs_truncate(inode, attr->ia_size);
else if (attr->ia_size > oldsize)
err = ntfs_extend(inode, attr->ia_size, 0, NULL);
--- a/fs/ntfs3/frecord.c
+++ b/fs/ntfs3/frecord.c
@@ -1964,10 +1964,8 @@ int ni_fiemap(struct ntfs_inode *ni, str

vcn += clen;

- if (vbo + bytes >= end) {
+ if (vbo + bytes >= end)
bytes = end - vbo;
- flags |= FIEMAP_EXTENT_LAST;
- }

if (vbo + bytes <= valid) {
;
@@ -1977,6 +1975,9 @@ int ni_fiemap(struct ntfs_inode *ni, str
/* vbo < valid && valid < vbo + bytes */
u64 dlen = valid - vbo;

+ if (vbo + dlen >= end)
+ flags |= FIEMAP_EXTENT_LAST;
+
err = fiemap_fill_next_extent(fieinfo, vbo, lbo, dlen,
flags);
if (err < 0)
@@ -1995,6 +1996,9 @@ int ni_fiemap(struct ntfs_inode *ni, str
flags |= FIEMAP_EXTENT_UNWRITTEN;
}

+ if (vbo + bytes >= end)
+ flags |= FIEMAP_EXTENT_LAST;
+
err = fiemap_fill_next_extent(fieinfo, vbo, lbo, bytes, flags);
if (err < 0)
break;