erofs: enable sub-page compressed block support

Let's just disable cached decompression and inplace I/Os for partial
pages as the first step in order to enable sub-page block initial
support.  In other words, currently it works primarily based on
temporary short-lived pages.  Don't expect too much in terms of
performance.

Reviewed-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20231206091057.87027-6-hsiangkao@linux.alibaba.com

diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index 14a79d3226abf4d6ce49c27123bba14394bf5f29..3d616dea55dc3dbccbac495988f865947b0d2a96 100644 (file)
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -259,8 +259,10 @@ static int erofs_fill_inode(struct inode *inode)
 
        if (erofs_inode_is_data_compressed(vi->datalayout)) {
 #ifdef CONFIG_EROFS_FS_ZIP
-               if (!erofs_is_fscache_mode(inode->i_sb) &&
-                   inode->i_sb->s_blocksize_bits == PAGE_SHIFT) {
+               if (!erofs_is_fscache_mode(inode->i_sb)) {
+                       DO_ONCE_LITE_IF(inode->i_sb->s_blocksize != PAGE_SIZE,
+                                 erofs_info, inode->i_sb,
+                                 "EXPERIMENTAL EROFS subpage compressed block support in use. Use at your own risk!");
                        inode->i_mapping->a_ops = &z_erofs_aops;
                        err = 0;
                        goto out_unlock;

diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 5d564017341208a6e7ffbc6a831965151c0f0dc8..8264936b86123d61a3d08ef464eb8752fc1eaadb 100644 (file)
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -563,6 +563,8 @@ static void z_erofs_bind_cache(struct z_erofs_decompress_frontend *fe)
                        __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN;
        unsigned int i;
 
+       if (i_blocksize(fe->inode) != PAGE_SIZE)
+               return;
        if (fe->mode < Z_EROFS_PCLUSTER_FOLLOWED)
                return;
 
@@ -967,12 +969,12 @@ static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
        struct inode *const inode = fe->inode;
        struct erofs_map_blocks *const map = &fe->map;
        const loff_t offset = page_offset(page);
+       const unsigned int bs = i_blocksize(inode);
        bool tight = true, exclusive;
        unsigned int cur, end, len, split;
        int err = 0;
 
        z_erofs_onlinepage_init(page);
-
        split = 0;
        end = PAGE_SIZE;
 repeat:
@@ -1021,7 +1023,7 @@ repeat:
         * for inplace I/O or bvpage (should be processed in a strict order.)
         */
        tight &= (fe->mode > Z_EROFS_PCLUSTER_FOLLOWED_NOINPLACE);
-       exclusive = (!cur && ((split <= 1) || tight));
+       exclusive = (!cur && ((split <= 1) || (tight && bs == PAGE_SIZE)));
        if (cur)
                tight &= (fe->mode >= Z_EROFS_PCLUSTER_FOLLOWED);