github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-11-07 06:17:02 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

fsverity: hoist pagecache_read from f2fs/ext4 to fsverity

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

Note that f2fs and ext4 functions diverged a bit, as ext4 operated over
folios and f2fs operated over pages. The common one will operate over
folios.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Andrey Albershteyn <aalbersh@kernel.org>
Link: https://patch.msgid.link/20261002223705.2175542-5-aalbersh@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
This commit is contained in:
Andrey Albershteyn 2026-10-03 00:36:45 +02:00 committed by Eric Biggers
parent ad7be74b38
commit 9e74c01463
4 changed files with 39 additions and 58 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
fs/ext4/verity.c
View File

@ -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;
}

30
fs/f2fs/verity.c
View File

@ -37,34 +37,6 @@ 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.
@ -250,7 +222,7 @@ 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;
}

33
fs/verity/pagecache.c
View File

@ -78,3 +78,36 @@ void fsverity_fill_zerohash(struct folio *folio, size_t offset, size_t len,
vi->tree_params.digest_size);
}
EXPORT_SYMBOL_GPL(fsverity_fill_zerohash);
/**
* fsverity_pagecache_read() - read verity metadata via the pagecache
* @inode: copy from this inode's address space
* @buf: buffer to copy to
* @count: number of bytes to copy
* @pos: byte offset in the file 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);

2
include/linux/fsverity.h
View File

@ -328,5 +328,7 @@ 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 */