The implementation of these two functions in fscache mode is almost the
same. Extract the same part as a generic helper to remove the code
duplication.
Signed-off-by: Jingbo Xu <jefflexu@xxxxxxxxxxxxxxxxx>
Reviewed-by: Jia Zhu <zhujia.zj@xxxxxxxxxxxxx>
---
changes since v1:
- update the commit subject to stress it's in fscache mode
- rename erofs_fscache_read() to erofs_fscache_data_read()
- add more comment on the return value of erofs_fscache_data_read() to
avoid misunderstanding
- add Reviewed-by tag
---
fs/erofs/fscache.c | 213 ++++++++++++++++++---------------------------
1 file changed, 83 insertions(+), 130 deletions(-)
diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c
index b5fd9d71e67f..508b1a4df15e 100644
--- a/fs/erofs/fscache.c
+++ b/fs/erofs/fscache.c
@@ -234,113 +234,111 @@ static int erofs_fscache_meta_read_folio(struct file *data, struct folio *folio)
return ret;
}
-static int erofs_fscache_read_folio_inline(struct folio *folio,
- struct erofs_map_blocks *map)
-{
- struct super_block *sb = folio_mapping(folio)->host->i_sb;
- struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
- erofs_blk_t blknr;
- size_t offset, len;
- void *src, *dst;
-
- /* For tail packing layout, the offset may be non-zero. */
- offset = erofs_blkoff(map->m_pa);
- blknr = erofs_blknr(map->m_pa);
- len = map->m_llen;
-
- src = erofs_read_metabuf(&buf, sb, blknr, EROFS_KMAP);
- if (IS_ERR(src))
- return PTR_ERR(src);
-
- dst = kmap_local_folio(folio, 0);
- memcpy(dst, src + offset, len);
- memset(dst + len, 0, PAGE_SIZE - len);
- kunmap_local(dst);
-
- erofs_put_metabuf(&buf);
- return 0;
-}
-
-static int erofs_fscache_read_folio(struct file *file, struct folio *folio)
+/*
+ * Read into page cache in the range described by (@pos, @len).
+ *
+ * On return, the caller is responsible for page unlocking if the output @unlock
+ * is true, or the callee will take this responsibility through netfs_io_request
+ * interface.
+ *
+ * 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 netfs_io_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)
{
- struct inode *inode = folio_mapping(folio)->host;
+ struct inode *inode = mapping->host;
struct super_block *sb = inode->i_sb;
+ struct netfs_io_request *rreq;
struct erofs_map_blocks map;
struct erofs_map_dev mdev;
- struct netfs_io_request *rreq;
- erofs_off_t pos;
- loff_t pstart;
+ struct iov_iter iter;
+ size_t count;
int ret;
- DBG_BUGON(folio_size(folio) != EROFS_BLKSIZ);
+ *unlock = true;
- pos = folio_pos(folio);
map.m_la = pos;
-
ret = erofs_map_blocks(inode, &map, EROFS_GET_BLOCKS_RAW);
if (ret)
- goto out_unlock;
+ return ret;
- if (!(map.m_flags & EROFS_MAP_MAPPED)) {
- folio_zero_range(folio, 0, folio_size(folio));
- goto out_uptodate;
+ if (map.m_flags & EROFS_MAP_META) {
+ struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
+ erofs_blk_t blknr;
+ size_t offset, size;
+ 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;
+
+ 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)
+ return -EFAULT;
+ iov_iter_zero(PAGE_SIZE - size, &iter);
+ erofs_put_metabuf(&buf);
+ return PAGE_SIZE;
}
- if (map.m_flags & EROFS_MAP_META) {
- ret = erofs_fscache_read_folio_inline(folio, &map);
- goto out_uptodate;
+ count = min_t(size_t, map.m_llen - (pos - map.m_la), len);
+ DBG_BUGON(!count || count % PAGE_SIZE);
+
+ if (!(map.m_flags & EROFS_MAP_MAPPED)) {
+ iov_iter_xarray(&iter, READ, &mapping->i_pages, pos, count);
+ iov_iter_zero(count, &iter);
+ return count;
}
mdev = (struct erofs_map_dev) {
.m_deviceid = map.m_deviceid,
.m_pa = map.m_pa,
};
-
ret = erofs_map_dev(sb, &mdev);
if (ret)
- goto out_unlock;
-
-
- rreq = erofs_fscache_alloc_request(folio_mapping(folio),
- folio_pos(folio), folio_size(folio));
- if (IS_ERR(rreq)) {
- ret = PTR_ERR(rreq);
- goto out_unlock;
- }
+ return ret;
- pstart = mdev.m_pa + (pos - map.m_la);
- return erofs_fscache_read_folios_async(mdev.m_fscache->cookie,
- rreq, pstart);
+ rreq = erofs_fscache_alloc_request(mapping, pos, count);
+ if (IS_ERR(rreq))
+ return PTR_ERR(rreq);
-out_uptodate:
- if (!ret)
- folio_mark_uptodate(folio);
-out_unlock:
- folio_unlock(folio);
- return ret;
+ *unlock = false;
+ erofs_fscache_read_folios_async(mdev.m_fscache->cookie,
+ rreq, mdev.m_pa + (pos - map.m_la));
+ return count;
}
-static void erofs_fscache_advance_folios(struct readahead_control *rac,
- size_t len, bool unlock)
+static int erofs_fscache_read_folio(struct file *file, struct folio *folio)
{
- while (len) {
- struct folio *folio = readahead_folio(rac);
- len -= folio_size(folio);
- if (unlock) {
+ bool unlock;
+ 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);
- folio_unlock(folio);
- }
+ folio_unlock(folio);
}
+ return ret < 0 ? ret : 0;
}
static void erofs_fscache_readahead(struct readahead_control *rac)
{
- struct inode *inode = rac->mapping->host;
- struct super_block *sb = inode->i_sb;
- size_t len, count, done = 0;
- erofs_off_t pos;
- loff_t start, offset;
- int ret;
+ struct folio *folio;
+ size_t len, done = 0;
+ loff_t start, pos;
+ bool unlock;
+ int ret, size;
if (!readahead_count(rac))
return;
@@ -349,67 +347,22 @@ static void erofs_fscache_readahead(struct readahead_control *rac)
len = readahead_length(rac);
do {
- struct erofs_map_blocks map;
- struct erofs_map_dev mdev;
- struct netfs_io_request *rreq;
-
pos = start + done;
- map.m_la = pos;
-
- ret = erofs_map_blocks(inode, &map, EROFS_GET_BLOCKS_RAW);
- if (ret)
+ ret = erofs_fscache_data_read(rac->mapping, pos,
+ len - done, &unlock);
+ if (ret <= 0)
return;
- offset = start + done;
- count = min_t(size_t, map.m_llen - (pos - map.m_la),
- len - done);
-
- if (!(map.m_flags & EROFS_MAP_MAPPED)) {
- struct iov_iter iter;
-
- iov_iter_xarray(&iter, READ, &rac->mapping->i_pages,
- offset, count);
- iov_iter_zero(count, &iter);
-
- erofs_fscache_advance_folios(rac, count, true);
- ret = count;
- continue;
- }
-
- if (map.m_flags & EROFS_MAP_META) {
- struct folio *folio = readahead_folio(rac);
-
- ret = erofs_fscache_read_folio_inline(folio, &map);
- if (!ret) {
+ size = ret;
+ while (size) {
+ folio = readahead_folio(rac);
+ size -= folio_size(folio);
+ if (unlock) {
folio_mark_uptodate(folio);
- ret = folio_size(folio);
+ folio_unlock(folio);
}
-
- folio_unlock(folio);
- continue;
}
-
- mdev = (struct erofs_map_dev) {
- .m_deviceid = map.m_deviceid,
- .m_pa = map.m_pa,
- };
- ret = erofs_map_dev(sb, &mdev);
- if (ret)
- return;
-
- rreq = erofs_fscache_alloc_request(rac->mapping, offset, count);
- if (IS_ERR(rreq))
- return;
- /*
- * Drop the ref of folios here. Unlock them in
- * rreq_unlock_folios() when rreq complete.
- */
- erofs_fscache_advance_folios(rac, count, false);
- ret = erofs_fscache_read_folios_async(mdev.m_fscache->cookie,
- rreq, mdev.m_pa + (pos - map.m_la));
- if (!ret)
- ret = count;
- } while (ret > 0 && ((done += ret) < len));
+ } while ((done += ret) < len);
}
static const struct address_space_operations erofs_fscache_meta_aops = {
--
2.24.4
