Ext4 and F2FS store verity metadata in data extents (beyond
inode->i_size) associated with a file. But other filesystems might
choose alternative means to store verity metadata. Hence this commit
adds a callback function pointer to 'struct fsverity_operations' to help
in deciding if verity operation needs to performed against a page-cache
page holding file data.
Signed-off-by: Chandan Rajendra <chandan@xxxxxxxxxxxxx>
---
fs/ext4/super.c | 6 ++++++
fs/post_read_process.c | 4 +++-
include/linux/fsverity.h | 1 +
3 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index aba724f82cc3..63d73b360f1d 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1428,10 +1428,16 @@ static struct page *ext4_read_verity_metadata_page(struct inode *inode,
return read_mapping_page(inode->i_mapping, index, NULL);
}
+static bool ext4_verity_required(struct inode *inode, pgoff_t index)
+{
+ return index < (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
+}
+
static const struct fsverity_operations ext4_verityops = {
.set_verity = ext4_set_verity,
.get_metadata_end = ext4_get_verity_metadata_end,
.read_metadata_page = ext4_read_verity_metadata_page,
+ .verity_required = ext4_verity_required,
};
#endif /* CONFIG_FS_VERITY */
diff --git a/fs/post_read_process.c b/fs/post_read_process.c
index d203fc263091..c408184b671a 100644
--- a/fs/post_read_process.c
+++ b/fs/post_read_process.c
@@ -86,7 +86,9 @@ struct bio_post_read_ctx *get_bio_post_read_ctx(struct inode *inode,
post_read_steps |= 1 << STEP_DECRYPT;
#ifdef CONFIG_FS_VERITY
if (inode->i_verity_info != NULL &&
- (index < ((i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT)))
+ ((inode->i_sb->s_vop->verity_required
+ && inode->i_sb->s_vop->verity_required(inode, index))
+ || (inode->i_sb->s_vop->verity_required == NULL))
post_read_steps |= 1 << STEP_VERITY;
#endif
if (post_read_steps) {
diff --git a/include/linux/fsverity.h b/include/linux/fsverity.h
index 7c33b42abf1b..b83712d6c79a 100644
--- a/include/linux/fsverity.h
+++ b/include/linux/fsverity.h
@@ -18,6 +18,7 @@ struct fsverity_operations {
int (*set_verity)(struct inode *inode, loff_t data_i_size);
int (*get_metadata_end)(struct inode *inode, loff_t *metadata_end_ret);
struct page *(*read_metadata_page)(struct inode *inode, pgoff_t index);
+ bool (*verity_required)(struct inode *inode, pgoff_t index);
};
#ifdef CONFIG_FS_VERITY
--
2.19.1
