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 Reviewed-by: Christoph Hellwig Signed-off-by: Andrey Albershteyn --- 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