erofs: simplify erofs_read_inode()

After commit 1c7f49a76773 ("erofs: tidy up EROFS on-disk naming"),
there is a unique `union erofs_inode_i_u` so that we could parse
the union directly.

Besides, it also replaces `inode->i_sb` with `sb` for simplicity.

Signed-off-by: Ferry Meng <mengferry@linux.alibaba.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20231109111822.17944-1-mengferry@linux.alibaba.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index b8ad05b..14a79d3 100644 (file)
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -15,11 +15,11 @@ static void *erofs_read_inode(struct erofs_buf *buf,
        struct erofs_sb_info *sbi = EROFS_SB(sb);
        struct erofs_inode *vi = EROFS_I(inode);
        const erofs_off_t inode_loc = erofs_iloc(inode);
-
        erofs_blk_t blkaddr, nblks = 0;
        void *kaddr;
        struct erofs_inode_compact *dic;
        struct erofs_inode_extended *die, *copied = NULL;
+       union erofs_inode_i_u iu;
        unsigned int ifmt;
        int err;
 
@@ -35,9 +35,8 @@ static void *erofs_read_inode(struct erofs_buf *buf,
 
        dic = kaddr + *ofs;
        ifmt = le16_to_cpu(dic->i_format);
-
        if (ifmt & ~EROFS_I_ALL) {
-               erofs_err(inode->i_sb, "unsupported i_format %u of nid %llu",
+               erofs_err(sb, "unsupported i_format %u of nid %llu",
                          ifmt, vi->nid);
                err = -EOPNOTSUPP;
                goto err_out;
@@ -45,7 +44,7 @@ static void *erofs_read_inode(struct erofs_buf *buf,
 
        vi->datalayout = erofs_inode_datalayout(ifmt);
        if (vi->datalayout >= EROFS_INODE_DATALAYOUT_MAX) {
-               erofs_err(inode->i_sb, "unsupported datalayout %u of nid %llu",
+               erofs_err(sb, "unsupported datalayout %u of nid %llu",
                          vi->datalayout, vi->nid);
                err = -EOPNOTSUPP;
                goto err_out;
@@ -82,40 +81,15 @@ static void *erofs_read_inode(struct erofs_buf *buf,
                vi->xattr_isize = erofs_xattr_ibody_size(die->i_xattr_icount);
 
                inode->i_mode = le16_to_cpu(die->i_mode);
-               switch (inode->i_mode & S_IFMT) {
-               case S_IFREG:
-               case S_IFDIR:
-               case S_IFLNK:
-                       vi->raw_blkaddr = le32_to_cpu(die->i_u.raw_blkaddr);
-                       break;
-               case S_IFCHR:
-               case S_IFBLK:
-                       inode->i_rdev =
-                               new_decode_dev(le32_to_cpu(die->i_u.rdev));
-                       break;
-               case S_IFIFO:
-               case S_IFSOCK:
-                       inode->i_rdev = 0;
-                       break;
-               default:
-                       goto bogusimode;
-               }
+               iu = die->i_u;
                i_uid_write(inode, le32_to_cpu(die->i_uid));
                i_gid_write(inode, le32_to_cpu(die->i_gid));
                set_nlink(inode, le32_to_cpu(die->i_nlink));
-
-               /* extended inode has its own timestamp */
+               /* each extended inode has its own timestamp */
                inode_set_ctime(inode, le64_to_cpu(die->i_mtime),
                                le32_to_cpu(die->i_mtime_nsec));
 
                inode->i_size = le64_to_cpu(die->i_size);
-
-               /* total blocks for compressed files */
-               if (erofs_inode_is_data_compressed(vi->datalayout))
-                       nblks = le32_to_cpu(die->i_u.compressed_blocks);
-               else if (vi->datalayout == EROFS_INODE_CHUNK_BASED)
-                       /* fill chunked inode summary info */
-                       vi->chunkformat = le16_to_cpu(die->i_u.c.format);
                kfree(copied);
                copied = NULL;
                break;
@@ -125,49 +99,51 @@ static void *erofs_read_inode(struct erofs_buf *buf,
                vi->xattr_isize = erofs_xattr_ibody_size(dic->i_xattr_icount);
 
                inode->i_mode = le16_to_cpu(dic->i_mode);
-               switch (inode->i_mode & S_IFMT) {
-               case S_IFREG:
-               case S_IFDIR:
-               case S_IFLNK:
-                       vi->raw_blkaddr = le32_to_cpu(dic->i_u.raw_blkaddr);
-                       break;
-               case S_IFCHR:
-               case S_IFBLK:
-                       inode->i_rdev =
-                               new_decode_dev(le32_to_cpu(dic->i_u.rdev));
-                       break;
-               case S_IFIFO:
-               case S_IFSOCK:
-                       inode->i_rdev = 0;
-                       break;
-               default:
-                       goto bogusimode;
-               }
+               iu = dic->i_u;
                i_uid_write(inode, le16_to_cpu(dic->i_uid));
                i_gid_write(inode, le16_to_cpu(dic->i_gid));
                set_nlink(inode, le16_to_cpu(dic->i_nlink));
-
                /* use build time for compact inodes */
                inode_set_ctime(inode, sbi->build_time, sbi->build_time_nsec);
 
                inode->i_size = le32_to_cpu(dic->i_size);
-               if (erofs_inode_is_data_compressed(vi->datalayout))
-                       nblks = le32_to_cpu(dic->i_u.compressed_blocks);
-               else if (vi->datalayout == EROFS_INODE_CHUNK_BASED)
-                       vi->chunkformat = le16_to_cpu(dic->i_u.c.format);
                break;
        default:
-               erofs_err(inode->i_sb,
-                         "unsupported on-disk inode version %u of nid %llu",
+               erofs_err(sb, "unsupported on-disk inode version %u of nid %llu",
                          erofs_inode_version(ifmt), vi->nid);
                err = -EOPNOTSUPP;
                goto err_out;
        }
 
-       if (vi->datalayout == EROFS_INODE_CHUNK_BASED) {
+       switch (inode->i_mode & S_IFMT) {
+       case S_IFREG:
+       case S_IFDIR:
+       case S_IFLNK:
+               vi->raw_blkaddr = le32_to_cpu(iu.raw_blkaddr);
+               break;
+       case S_IFCHR:
+       case S_IFBLK:
+               inode->i_rdev = new_decode_dev(le32_to_cpu(iu.rdev));
+               break;
+       case S_IFIFO:
+       case S_IFSOCK:
+               inode->i_rdev = 0;
+               break;
+       default:
+               erofs_err(sb, "bogus i_mode (%o) @ nid %llu", inode->i_mode,
+                         vi->nid);
+               err = -EFSCORRUPTED;
+               goto err_out;
+       }
+
+       /* total blocks for compressed files */
+       if (erofs_inode_is_data_compressed(vi->datalayout)) {
+               nblks = le32_to_cpu(iu.compressed_blocks);
+       } else if (vi->datalayout == EROFS_INODE_CHUNK_BASED) {
+               /* fill chunked inode summary info */
+               vi->chunkformat = le16_to_cpu(iu.c.format);
                if (vi->chunkformat & ~EROFS_CHUNK_FORMAT_ALL) {
-                       erofs_err(inode->i_sb,
-                                 "unsupported chunk format %x of nid %llu",
+                       erofs_err(sb, "unsupported chunk format %x of nid %llu",
                                  vi->chunkformat, vi->nid);
                        err = -EOPNOTSUPP;
                        goto err_out;
@@ -191,10 +167,6 @@ static void *erofs_read_inode(struct erofs_buf *buf,
                inode->i_blocks = nblks << (sb->s_blocksize_bits - 9);
        return kaddr;
 
-bogusimode:
-       erofs_err(inode->i_sb, "bogus i_mode (%o) @ nid %llu",
-                 inode->i_mode, vi->nid);
-       err = -EFSCORRUPTED;
 err_out:
        DBG_BUGON(1);
        kfree(copied);