[PATCH v2] erofs: simplify erofs_read_inode()

From: Ferry Meng
Date: Thu Nov 09 2023 - 06:18:38 EST


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@xxxxxxxxxxxxxxxxx>
---
fs/erofs/inode.c | 98 +++++++++++++++++-------------------------------
1 file changed, 35 insertions(+), 63 deletions(-)

diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index edc8ec7581b8..7f63e7c01ffc 100644
--- 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;
@@ -190,10 +166,6 @@ 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);
--
2.19.1.6.gb485710b