The comment above jfs_quota_read() is stale; sb_bread() will use the
page cache, so we may as well use the page cache directly and avoid
using jfs_get_block().
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
fs/jfs/super.c | 54 ++++++++++++++++++++------------------------------
1 file changed, 21 insertions(+), 33 deletions(-)
diff --git a/fs/jfs/super.c b/fs/jfs/super.c
index 85d4f44f2ac4..1e7d117b555d 100644
--- a/fs/jfs/super.c
+++ b/fs/jfs/super.c
@@ -721,51 +721,39 @@ static int jfs_show_options(struct seq_file *seq, struct dentry *root)
}
#ifdef CONFIG_QUOTA
-
-/* Read data from quotafile - avoid pagecache and such because we cannot afford
- * acquiring the locks... As quota files are never truncated and quota code
- * itself serializes the operations (and no one else should touch the files)
- * we don't have to be afraid of races */
static ssize_t jfs_quota_read(struct super_block *sb, int type, char *data,
- size_t len, loff_t off)
+ size_t len, loff_t pos)
{
struct inode *inode = sb_dqopt(sb)->files[type];
- sector_t blk = off >> sb->s_blocksize_bits;
- int err = 0;
- int offset = off & (sb->s_blocksize - 1);
- int tocopy;
+ struct address_space *mapping = inode->i_mapping;
size_t toread;
- struct buffer_head tmp_bh;
- struct buffer_head *bh;
+ pgoff_t index;
loff_t i_size = i_size_read(inode);
- if (off > i_size)
+ if (pos > i_size)
return 0;
- if (off+len > i_size)
- len = i_size-off;
+ if (pos + len > i_size)
+ len = i_size - pos;
toread = len;
+ index = pos / PAGE_SIZE;
+
while (toread > 0) {
- tocopy = sb->s_blocksize - offset < toread ?
- sb->s_blocksize - offset : toread;
+ struct folio *folio = read_mapping_folio(mapping, index, NULL);
+ size_t tocopy = PAGE_SIZE - offset_in_page(pos);
+ void *src;
+
+ if (IS_ERR(folio))
+ return PTR_ERR(folio);
+
+ src = kmap_local_folio(folio, offset_in_folio(folio, pos));
+ memcpy(data, src, tocopy);
+ kunmap_local(src);
+ folio_put(folio);
- tmp_bh.b_state = 0;
- tmp_bh.b_size = i_blocksize(inode);
- err = jfs_get_block(inode, blk, &tmp_bh, 0);
- if (err)
- return err;
- if (!buffer_mapped(&tmp_bh)) /* A hole? */
- memset(data, 0, tocopy);
- else {
- bh = sb_bread(sb, tmp_bh.b_blocknr);
- if (!bh)
- return -EIO;
- memcpy(data, bh->b_data+offset, tocopy);
- brelse(bh);
- }
- offset = 0;
toread -= tocopy;
data += tocopy;
- blk++;
+ pos += tocopy;
+ index++;
}
return len;
}
--
2.34.1
