To prevent scattered pin block generation, don't allow non-section aligned
truncation
to smaller or equal size on pinned file. But for truncation to larger size,
after
commit 3fdd89b452c2("f2fs: prevent writing without fallocate() for pinned
files"),
we only support overwrite IO to pinned file, so we don't need to consider
attr->ia_size > i_size case.
In addition, xfstests #494 assumes truncation on active swapfile(pinned) will
return
ETXTBSY by setattr_prepare() -> inode_newsize_ok(), so we relocate this check
after
setattr_prepare().
Signed-off-by: wangzijie <wangzij...@honor.com>
---
v5:
- fix xfstests #494 fail
---
fs/f2fs/file.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 78368b793..d4feea44b 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1070,6 +1070,23 @@ int f2fs_setattr(struct mnt_idmap *idmap, struct dentry
*dentry,
if (err)
return err;
+ /*
+ * To prevent scattered pin block generation, we don't allow
+ * smaller/equal size unaligned truncation for pinned file.
+ * We only support overwrite IO to pinned file, so don't
+ * care about larger size truncation.
+ * We need to check this after setattr_prepare() because xfstests
+ * #494 assumes truncation on active swapfile(pinned) will
+ * return ETXTBSY by setattr_prepare() -> inode_newsize_ok().
+ */
+ if (attr->ia_valid & ATTR_SIZE) {
+ if (f2fs_is_pinned_file(inode) &&
+ attr->ia_size <= i_size_read(inode) &&
+ !IS_ALIGNED(attr->ia_size,
+ F2FS_BLK_TO_BYTES(CAP_BLKS_PER_SEC(sbi))))
+ return -EINVAL;
+ }
+
err = fscrypt_prepare_setattr(dentry, attr);
if (err)
return err;
--
2.25.1
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