---
fs/erofs/fscache.c | 116 +++++++++++++++++++--------------------------
1 file changed, 48 insertions(+), 68 deletions(-)
diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c
index 3cfe1af7a46e..0643b205c7eb 100644
--- a/fs/erofs/fscache.c
+++ b/fs/erofs/fscache.c
@@ -167,32 +167,18 @@ static int erofs_fscache_meta_read_folio(struct file
*data, struct folio *folio)
return ret;
}
-/*
- * Read into page cache in the range described by (@pos, @len).
- *
- * On return, if the output @unlock is true, the caller is responsible for page
- * unlocking; otherwise the callee will take this responsibility through
request
- * completion.
- *
- * The return value is the number of bytes successfully handled, or negative
- * error code on failure. The only exception is that, the length of the range
- * instead of the error code is returned on failure after request is allocated,
- * so that .readahead() could advance rac accordingly.
- */
-static int erofs_fscache_data_read(struct address_space *mapping,
- loff_t pos, size_t len, bool *unlock)
+static int erofs_fscache_data_read_slice(struct erofs_fscache_request *req)
{
+ struct address_space *mapping = req->mapping;
struct inode *inode = mapping->host;
struct super_block *sb = inode->i_sb;
- struct erofs_fscache_request *req;
+ loff_t pos = req->start + req->submitted;
struct erofs_map_blocks map;
struct erofs_map_dev mdev;
struct iov_iter iter;
size_t count;
int ret;
- *unlock = true;
-
map.m_la = pos;
ret = erofs_map_blocks(inode, &map, EROFS_GET_BLOCKS_RAW);
if (ret)
@@ -201,36 +187,37 @@ static int erofs_fscache_data_read(struct address_space
*mapping,
if (map.m_flags & EROFS_MAP_META) {
struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
erofs_blk_t blknr;
- size_t offset, size;
+ size_t offset;
void *src;
/* For tail packing layout, the offset may be non-zero. */
offset = erofs_blkoff(map.m_pa);
blknr = erofs_blknr(map.m_pa);
- size = map.m_llen;
+ count = map.m_llen;
src = erofs_read_metabuf(&buf, sb, blknr, EROFS_KMAP);
if (IS_ERR(src))
return PTR_ERR(src);
- iov_iter_xarray(&iter, READ, &mapping->i_pages, pos, PAGE_SIZE);
- if (copy_to_iter(src + offset, size, &iter) != size) {
+ iov_iter_xarray(&iter, READ, &mapping->i_pages, pos, count);
+ if (copy_to_iter(src + offset, count, &iter) != count) {
erofs_put_metabuf(&buf);
return -EFAULT;
}
- iov_iter_zero(PAGE_SIZE - size, &iter);
erofs_put_metabuf(&buf);
- return PAGE_SIZE;
+ req->submitted += count;
+ return 0;
}
+ count = req->len - req->submitted;
if (!(map.m_flags & EROFS_MAP_MAPPED)) {
- count = len;
iov_iter_xarray(&iter, READ, &mapping->i_pages, pos, count);
iov_iter_zero(count, &iter);
- return count;
+ req->submitted += count;
+ return 0;
}
- count = min_t(size_t, map.m_llen - (pos - map.m_la), len);
+ count = min_t(size_t, map.m_llen - (pos - map.m_la), count);
DBG_BUGON(!count || count % PAGE_SIZE);
mdev = (struct erofs_map_dev) {
@@ -241,68 +228,61 @@ static int erofs_fscache_data_read(struct address_space
*mapping,
if (ret)
return ret;
- req = erofs_fscache_req_alloc(mapping, pos, count);
- if (IS_ERR(req))
- return PTR_ERR(req);
-
- *unlock = false;
- ret = erofs_fscache_read_folios_async(mdev.m_fscache->cookie,
+ return erofs_fscache_read_folios_async(mdev.m_fscache->cookie,
req, mdev.m_pa + (pos - map.m_la), count);
- if (ret)
- req->error = ret;
+}
- erofs_fscache_req_put(req);
- return count;
+/*
+ * Read into page cache in the range described by (req->start, req->len).
+ */
+static int erofs_fscache_data_read(struct erofs_fscache_request *req)
+{
+ int ret;
+
+ do {
+ ret = erofs_fscache_data_read_slice(req);
+ if (ret)
+ req->error = ret;
+ } while (!ret && req->submitted < req->len);
+
+ return ret;
}
static int erofs_fscache_read_folio(struct file *file, struct folio *folio)
{
- bool unlock;
+ struct erofs_fscache_request *req;
int ret;
- DBG_BUGON(folio_size(folio) != EROFS_BLKSIZ);
-
- ret = erofs_fscache_data_read(folio_mapping(folio), folio_pos(folio),
- folio_size(folio), &unlock);
- if (unlock) {
- if (ret > 0)
- folio_mark_uptodate(folio);
+ req = erofs_fscache_req_alloc(folio_mapping(folio),
+ folio_pos(folio), folio_size(folio));
+ if (IS_ERR(req)) {
folio_unlock(folio);
+ return PTR_ERR(req);
}
- return ret < 0 ? ret : 0;
+
+ ret = erofs_fscache_data_read(req);
+ erofs_fscache_req_put(req);
+ return ret;
}
static void erofs_fscache_readahead(struct readahead_control *rac)
{
- struct folio *folio;
- size_t len, done = 0;
- loff_t start, pos;
- bool unlock;
- int ret, size;
+ struct erofs_fscache_request *req;
if (!readahead_count(rac))
return;
- start = readahead_pos(rac);
- len = readahead_length(rac);
+ req = erofs_fscache_req_alloc(rac->mapping,
+ readahead_pos(rac), readahead_length(rac));
+ if (IS_ERR(req))
+ return;
- do {
- pos = start + done;
- ret = erofs_fscache_data_read(rac->mapping, pos,
- len - done, &unlock);
- if (ret <= 0)
- return;
+ /* The request completion will drop refs on the folios. */
+ while (readahead_folio(rac))
+ ;
- size = ret;
- while (size) {
- folio = readahead_folio(rac);
- size -= folio_size(folio);
- if (unlock) {
- folio_mark_uptodate(folio);
- folio_unlock(folio);
- }
- }
- } while ((done += ret) < len);
+ erofs_fscache_data_read(req);
+ erofs_fscache_req_put(req);
}
static const struct address_space_operations erofs_fscache_meta_aops = {
