This is the same function to read from pageache. XFS will also need
this, so move this to core fsverity.

Reviewed-by: Darrick J. Wong <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Andrey Albershteyn <[email protected]>
---
 fs/ext4/verity.c         | 32 +++-----------------------------
 fs/f2fs/verity.c         | 30 +-----------------------------
 fs/verity/pagecache.c    | 33 +++++++++++++++++++++++++++++++++
 include/linux/fsverity.h |  2 ++
 4 files changed, 39 insertions(+), 58 deletions(-)

diff --git a/fs/ext4/verity.c b/fs/ext4/verity.c
index 347945ac23a4..ac5c133f5529 100644
--- a/fs/ext4/verity.c
+++ b/fs/ext4/verity.c
@@ -34,32 +34,6 @@ static inline loff_t ext4_verity_metadata_pos(const struct 
inode *inode)
        return round_up(inode->i_size, 65536);
 }
 
-/*
- * Read some verity metadata from the inode.  __vfs_read() can't be used 
because
- * we need to read beyond i_size.
- */
-static int pagecache_read(struct inode *inode, void *buf, size_t count,
-                         loff_t pos)
-{
-       while (count) {
-               struct folio *folio;
-               size_t n;
-
-               folio = read_mapping_folio(inode->i_mapping, pos >> PAGE_SHIFT,
-                                        NULL);
-               if (IS_ERR(folio))
-                       return PTR_ERR(folio);
-
-               n = memcpy_from_file_folio(buf, folio, pos, count);
-               folio_put(folio);
-
-               buf += n;
-               pos += n;
-               count -= n;
-       }
-       return 0;
-}
-
 /*
  * Write some verity metadata to the inode for FS_IOC_ENABLE_VERITY.
  * kernel_write() can't be used because the file descriptor is readonly.
@@ -311,8 +285,8 @@ static int ext4_get_verity_descriptor_location(struct inode 
*inode,
                goto bad;
        desc_size_pos -= sizeof(desc_size_disk);
 
-       err = pagecache_read(inode, &desc_size_disk, sizeof(desc_size_disk),
-                            desc_size_pos);
+       err = fsverity_pagecache_read(inode, &desc_size_disk,
+                                     sizeof(desc_size_disk), desc_size_pos);
        if (err)
                return err;
        desc_size = le32_to_cpu(desc_size_disk);
@@ -352,7 +326,7 @@ static int ext4_get_verity_descriptor(struct inode *inode, 
void *buf,
        if (buf_size) {
                if (desc_size > buf_size)
                        return -ERANGE;
-               err = pagecache_read(inode, buf, desc_size, desc_pos);
+               err = fsverity_pagecache_read(inode, buf, desc_size, desc_pos);
                if (err)
                        return err;
        }
diff --git a/fs/f2fs/verity.c b/fs/f2fs/verity.c
index b3b3e71604ac..5ea0a9b40443 100644
--- a/fs/f2fs/verity.c
+++ b/fs/f2fs/verity.c
@@ -36,34 +36,6 @@ static inline loff_t f2fs_verity_metadata_pos(const struct 
inode *inode)
        return round_up(inode->i_size, 65536);
 }
 
-/*
- * Read some verity metadata from the inode.  __vfs_read() can't be used 
because
- * we need to read beyond i_size.
- */
-static int pagecache_read(struct inode *inode, void *buf, size_t count,
-                         loff_t pos)
-{
-       while (count) {
-               size_t n = min_t(size_t, count,
-                                PAGE_SIZE - offset_in_page(pos));
-               struct page *page;
-
-               page = read_mapping_page(inode->i_mapping, pos >> PAGE_SHIFT,
-                                        NULL);
-               if (IS_ERR(page))
-                       return PTR_ERR(page);
-
-               memcpy_from_page(buf, page, offset_in_page(pos), n);
-
-               put_page(page);
-
-               buf += n;
-               pos += n;
-               count -= n;
-       }
-       return 0;
-}
-
 /*
  * Write some verity metadata to the inode for FS_IOC_ENABLE_VERITY.
  * kernel_write() can't be used because the file descriptor is readonly.
@@ -248,7 +220,7 @@ static int f2fs_get_verity_descriptor(struct inode *inode, 
void *buf,
        if (buf_size) {
                if (size > buf_size)
                        return -ERANGE;
-               res = pagecache_read(inode, buf, size, pos);
+               res = fsverity_pagecache_read(inode, buf, size, pos);
                if (res)
                        return res;
        }
diff --git a/fs/verity/pagecache.c b/fs/verity/pagecache.c
index c338dfa3eb18..da8606d58637 100644
--- a/fs/verity/pagecache.c
+++ b/fs/verity/pagecache.c
@@ -78,3 +78,36 @@ void fsverity_fill_zerohash(struct folio *folio, size_t 
poff, size_t plen,
                                vi->tree_params.digest_size);
 }
 EXPORT_SYMBOL_GPL(fsverity_fill_zerohash);
+
+/**
+ * fsverity_pagecache_read() - read page and copy data to buffer
+ * @inode:     copy from this inode's address space
+ * @buf:       buffer to copy to
+ * @count:     number of bytes to copy
+ * @pos:       position of the folio to copy from
+ *
+ * Read some verity metadata from the inode.  __vfs_read() can't be used 
because
+ * we need to read beyond i_size.
+ */
+int fsverity_pagecache_read(struct inode *inode, void *buf, size_t count,
+                         loff_t pos)
+{
+       while (count) {
+               struct folio *folio;
+               size_t n;
+
+               folio = read_mapping_folio(inode->i_mapping, pos >> PAGE_SHIFT,
+                                        NULL);
+               if (IS_ERR(folio))
+                       return PTR_ERR(folio);
+
+               n = memcpy_from_file_folio(buf, folio, pos, count);
+               folio_put(folio);
+
+               buf += n;
+               pos += n;
+               count -= n;
+       }
+       return 0;
+}
+EXPORT_SYMBOL_GPL(fsverity_pagecache_read);
diff --git a/include/linux/fsverity.h b/include/linux/fsverity.h
index 881db75f1cba..9a2f9c055a49 100644
--- a/include/linux/fsverity.h
+++ b/include/linux/fsverity.h
@@ -339,5 +339,7 @@ void fsverity_cleanup_inode(struct inode *inode);
 struct page *generic_read_merkle_tree_page(struct inode *inode, pgoff_t index);
 void generic_readahead_merkle_tree(struct inode *inode, pgoff_t index,
                                   unsigned long nr_pages);
+int fsverity_pagecache_read(struct inode *inode, void *buf, size_t count,
+                           loff_t pos);
 
 #endif /* _LINUX_FSVERITY_H */
-- 
2.51.2



_______________________________________________
Linux-f2fs-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

Reply via email to