2023-01-26 20:24:37

by Matthew Wilcox

[permalink] [raw]
Subject: [PATCH 20/31] ext4: Convert __ext4_block_zero_page_range() to use a folio

Use folio APIs throughout. Saves many calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
---
fs/ext4/inode.c | 28 ++++++++++++++++------------
1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index b79e591b7c8e..727aa2e51a9d 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3812,23 +3812,26 @@ static int __ext4_block_zero_page_range(handle_t *handle,
ext4_lblk_t iblock;
struct inode *inode = mapping->host;
struct buffer_head *bh;
- struct page *page;
+ struct folio *folio;
int err = 0;

- page = find_or_create_page(mapping, from >> PAGE_SHIFT,
- mapping_gfp_constraint(mapping, ~__GFP_FS));
- if (!page)
+ folio = __filemap_get_folio(mapping, from >> PAGE_SHIFT,
+ FGP_LOCK | FGP_ACCESSED | FGP_CREAT,
+ mapping_gfp_constraint(mapping, ~__GFP_FS));
+ if (!folio)
return -ENOMEM;

blocksize = inode->i_sb->s_blocksize;

iblock = index << (PAGE_SHIFT - inode->i_sb->s_blocksize_bits);

- if (!page_has_buffers(page))
- create_empty_buffers(page, blocksize, 0);
+ bh = folio_buffers(folio);
+ if (!bh) {
+ create_empty_buffers(&folio->page, blocksize, 0);
+ bh = folio_buffers(folio);
+ }

/* Find the buffer that contains "offset" */
- bh = page_buffers(page);
pos = blocksize;
while (offset >= pos) {
bh = bh->b_this_page;
@@ -3850,7 +3853,7 @@ static int __ext4_block_zero_page_range(handle_t *handle,
}

/* Ok, it's mapped. Make sure it's up-to-date */
- if (PageUptodate(page))
+ if (folio_test_uptodate(folio))
set_buffer_uptodate(bh);

if (!buffer_uptodate(bh)) {
@@ -3860,7 +3863,8 @@ static int __ext4_block_zero_page_range(handle_t *handle,
if (fscrypt_inode_uses_fs_layer_crypto(inode)) {
/* We expect the key to be set. */
BUG_ON(!fscrypt_has_encryption_key(inode));
- err = fscrypt_decrypt_pagecache_blocks(page, blocksize,
+ err = fscrypt_decrypt_pagecache_blocks(&folio->page,
+ blocksize,
bh_offset(bh));
if (err) {
clear_buffer_uptodate(bh);
@@ -3875,7 +3879,7 @@ static int __ext4_block_zero_page_range(handle_t *handle,
if (err)
goto unlock;
}
- zero_user(page, offset, length);
+ folio_zero_range(folio, offset, length);
BUFFER_TRACE(bh, "zeroed end of block");

if (ext4_should_journal_data(inode)) {
@@ -3889,8 +3893,8 @@ static int __ext4_block_zero_page_range(handle_t *handle,
}

unlock:
- unlock_page(page);
- put_page(page);
+ folio_unlock(folio);
+ folio_put(folio);
return err;
}

--
2.35.1



2023-03-05 12:26:54

by Ritesh Harjani

[permalink] [raw]
Subject: Re: [PATCH 20/31] ext4: Convert __ext4_block_zero_page_range() to use a folio

"Matthew Wilcox (Oracle)" <[email protected]> writes:

> Use folio APIs throughout. Saves many calls to compound_head().

minor comment below.

>
> Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
> ---
> fs/ext4/inode.c | 28 ++++++++++++++++------------
> 1 file changed, 16 insertions(+), 12 deletions(-)
>
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index b79e591b7c8e..727aa2e51a9d 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -3812,23 +3812,26 @@ static int __ext4_block_zero_page_range(handle_t *handle,
> ext4_lblk_t iblock;
> struct inode *inode = mapping->host;
> struct buffer_head *bh;
> - struct page *page;
> + struct folio *folio;
> int err = 0;
>
> - page = find_or_create_page(mapping, from >> PAGE_SHIFT,
> - mapping_gfp_constraint(mapping, ~__GFP_FS));
> - if (!page)
> + folio = __filemap_get_folio(mapping, from >> PAGE_SHIFT,
> + FGP_LOCK | FGP_ACCESSED | FGP_CREAT,
> + mapping_gfp_constraint(mapping, ~__GFP_FS));
> + if (!folio)
> return -ENOMEM;
>
> blocksize = inode->i_sb->s_blocksize;
>
> iblock = index << (PAGE_SHIFT - inode->i_sb->s_blocksize_bits);
>
> - if (!page_has_buffers(page))
> - create_empty_buffers(page, blocksize, 0);
> + bh = folio_buffers(folio);
> + if (!bh) {
> + create_empty_buffers(&folio->page, blocksize, 0);
> + bh = folio_buffers(folio);
> + }
>
> /* Find the buffer that contains "offset" */
> - bh = page_buffers(page);
> pos = blocksize;
> while (offset >= pos) {
> bh = bh->b_this_page;
> @@ -3850,7 +3853,7 @@ static int __ext4_block_zero_page_range(handle_t *handle,
> }
>
> /* Ok, it's mapped. Make sure it's up-to-date */
> - if (PageUptodate(page))
> + if (folio_test_uptodate(folio))
> set_buffer_uptodate(bh);
>
> if (!buffer_uptodate(bh)) {
> @@ -3860,7 +3863,8 @@ static int __ext4_block_zero_page_range(handle_t *handle,
> if (fscrypt_inode_uses_fs_layer_crypto(inode)) {
> /* We expect the key to be set. */
> BUG_ON(!fscrypt_has_encryption_key(inode));
> - err = fscrypt_decrypt_pagecache_blocks(page, blocksize,
> + err = fscrypt_decrypt_pagecache_blocks(&folio->page,
> + blocksize,
> bh_offset(bh));

I think after this patch which added support for decrypting large folio,
fscrypt_descrypt_pagecache_blocks() takes folio as it's 1st argument.
Hence this patch will need a small change to pass folio instead of page.

Other than that the change looks good to me.

Please feel free to add -
Reviewed-by: Ritesh Harjani (IBM) <[email protected]>

51e4e3153ebc32d3280d5d17418ae6f1a44f1ec1
Author: Eric Biggers <[email protected]>
CommitDate: Sat Jan 28 15:10:12 2023 -0800

fscrypt: support decrypting data from large folios


-ritesh