[PATCH 10/15] ubifs: Convert do_readpage() to take a folio

Matthew Wilcox (Oracle)
2024-01-20T23:08:47Z

All the callers now have a folio, so pass it in, and convert do_readpage()
to us folios directly. Includes unifying the exit paths from this
function and using kmap_local instead of plain kmap. This function
should now work with large folios, but this is not tested.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
fs/ubifs/file.c | 64 +++++++++++++++++++++++--------------------------
1 file changed, 30 insertions(+), 34 deletions(-)

diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index 52027b4feebf..cc450afdcc47 100644
--- a/fs/ubifs/file.c
+++ b/fs/ubifs/file.c
@@ -96,36 +96,36 @@ static int read_block(struct inode *inode, void *addr, unsigned int block,
return -EINVAL;
}

-static int do_readpage(struct page *page)
+static int do_readpage(struct folio *folio)
{
void *addr;
int err = 0, i;
unsigned int block, beyond;
- struct ubifs_data_node *dn;
- struct inode *inode = page->mapping->host;
+ struct ubifs_data_node *dn = NULL;
+ struct inode *inode = folio->mapping->host;
struct ubifs_info *c = inode->i_sb->s_fs_info;
loff_t i_size = i_size_read(inode);

dbg_gen("ino %lu, pg %lu, i_size %lld, flags %#lx",
- inode->i_ino, page->index, i_size, page->flags);
- ubifs_assert(c, !PageChecked(page));
- ubifs_assert(c, !PagePrivate(page));
+ inode->i_ino, folio->index, i_size, folio->flags);
+ ubifs_assert(c, !folio_test_checked(folio));
+ ubifs_assert(c, !folio->private);

- addr = kmap(page);
+ addr = kmap_local_folio(folio, 0);

- block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT;
+ block = folio->index << UBIFS_BLOCKS_PER_PAGE_SHIFT;
beyond = (i_size + UBIFS_BLOCK_SIZE - 1) >> UBIFS_BLOCK_SHIFT;
if (block >= beyond) {
/* Reading beyond inode */
- SetPageChecked(page);
- memset(addr, 0, PAGE_SIZE);
+ folio_set_checked(folio);
+ addr = folio_zero_tail(folio, 0, addr);
goto out;
}

dn = kmalloc(UBIFS_MAX_DATA_NODE_SZ, GFP_NOFS);
if (!dn) {
err = -ENOMEM;
- goto error;
+ goto out;
}

i = 0;
@@ -150,39 +150,35 @@ static int do_readpage(struct page *page)
memset(addr + ilen, 0, dlen - ilen);
}
}
- if (++i >= UBIFS_BLOCKS_PER_PAGE)
+ if (++i >= (UBIFS_BLOCKS_PER_PAGE << folio_order(folio)))
break;
block += 1;
addr += UBIFS_BLOCK_SIZE;
+ if (folio_test_highmem(folio) && (offset_in_page(addr) == 0)) {
+ kunmap_local(addr - UBIFS_BLOCK_SIZE);
+ addr = kmap_local_folio(folio, i * UBIFS_BLOCK_SIZE);
+ }
}
+
if (err) {
struct ubifs_info *c = inode->i_sb->s_fs_info;
if (err == -ENOENT) {
/* Not found, so it must be a hole */
- SetPageChecked(page);
+ folio_set_checked(folio);
dbg_gen("hole");
- goto out_free;
+ err = 0;
+ } else {
+ ubifs_err(c, "cannot read page %lu of inode %lu, error %d",
+ folio->index, inode->i_ino, err);
}
- ubifs_err(c, "cannot read page %lu of inode %lu, error %d",
- page->index, inode->i_ino, err);
- goto error;
}

-out_free:
- kfree(dn);
out:
- SetPageUptodate(page);
- ClearPageError(page);
- flush_dcache_page(page);
- kunmap(page);
- return 0;
-
-error:
kfree(dn);
- ClearPageUptodate(page);
- SetPageError(page);
- flush_dcache_page(page);
- kunmap(page);
+ if (!err)
+ folio_mark_uptodate(folio);
+ flush_dcache_folio(folio);
+ kunmap_local(addr);
return err;
}

@@ -254,7 +250,7 @@ static int write_begin_slow(struct address_space *mapping,
if (pos == folio_pos(folio) && len >= folio_size(folio))
folio_set_checked(folio);
else {
- err = do_readpage(&folio->page);
+ err = do_readpage(folio);
if (err) {
folio_unlock(folio);
folio_put(folio);
@@ -457,7 +453,7 @@ static int ubifs_write_begin(struct file *file, struct address_space *mapping,
folio_set_checked(folio);
skipped_read = 1;
} else {
- err = do_readpage(&folio->page);
+ err = do_readpage(folio);
if (err) {
folio_unlock(folio);
folio_put(folio);
@@ -561,7 +557,7 @@ static int ubifs_write_end(struct file *file, struct address_space *mapping,
* Return 0 to force VFS to repeat the whole operation, or the
* error code if 'do_readpage()' fails.
*/
- copied = do_readpage(&folio->page);
+ copied = do_readpage(folio);
goto out;
}

@@ -897,7 +893,7 @@ static int ubifs_read_folio(struct file *file, struct folio *folio)

if (ubifs_bulk_read(page))
return 0;
- do_readpage(page);
+ do_readpage(folio);
folio_unlock(folio);
return 0;
}
--
2.43.0