From: Jingbo Xu jefflexu@linux.alibaba.com
[ Upstream commit 1ae9470c3e14624b0f4d8741c22b5a94062c0e33 ]
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@linux.alibaba.com Reviewed-by: Jia Zhu zhujia.zj@bytedance.com Link: https://lore.kernel.org/r/20220922062414.20437-1-jefflexu@linux.alibaba.com Signed-off-by: Gao Xiang hsiangkao@linux.alibaba.com Stable-dep-of: e6d9f9ba111b ("erofs: get correct count for unmapped range in fscache mode") Signed-off-by: Sasha Levin sashal@kernel.org --- 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 = {