Merge tag 'erofs-for-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs

Pull erofs updates from Gao Xiang:
 "The most noticeable feature for this cycle is per-CPU kthread
  decompression since Android use cases need low-latency I/O handling in
  order to ensure the app runtime performance, currently unbounded
  workqueue latencies are not quite good for production on many aarch64
  hardwares and thus we need to introduce a deterministic expectation
  for these. Decompression is CPU-intensive and it is sleepable for
  EROFS, so other alternatives like decompression under softirq contexts
  are not considered. More details are in the corresponding commit
  message.

  Others are random cleanups around the whole codebase and we will
  continue to clean up further in the next few months.

  Due to Lunar New Year holidays, some other new features were not
  completely reviewed and solidified as expected and we may delay them
  into the next version.

  Summary:

   - Add per-cpu kthreads for low-latency decompression for Android use
     cases

   - Get rid of tagged pointer helpers since they are rarely used now

   - Several code cleanups to reduce codebase

   - Documentation and MAINTAINERS updates"

* tag 'erofs-for-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs: (21 commits)
  erofs: fix an error code in z_erofs_init_zip_subsystem()
  erofs: unify anonymous inodes for blob
  erofs: relinquish volume with mutex held
  erofs: maintain cookies of share domain in self-contained list
  erofs: remove unused device mapping in meta routine
  MAINTAINERS: erofs: Add Documentation/ABI/testing/sysfs-fs-erofs
  Documentation/ABI: sysfs-fs-erofs: update supported features
  erofs: remove unused EROFS_GET_BLOCKS_RAW flag
  erofs: update print symbols for various flags in trace
  erofs: make kobj_type structures constant
  erofs: add per-cpu threads for decompression as an option
  erofs: tidy up internal.h
  erofs: get rid of z_erofs_do_map_blocks() forward declaration
  erofs: move zdata.h into zdata.c
  erofs: remove tagged pointer helpers
  erofs: avoid tagged pointers to mark sync decompression
  erofs: get rid of erofs_inode_datablocks()
  erofs: simplify iloc()
  erofs: get rid of debug_one_dentry()
  erofs: remove linux/buffer_head.h dependency
  ...

1 files changed, 22 insertions, 20 deletions

diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index a194e8ee5861..4be7dda3cd24 100644
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -14,7 +14,7 @@ static void *erofs_read_inode(struct erofs_buf *buf,
 	struct super_block *sb = inode->i_sb;
 	struct erofs_sb_info *sbi = EROFS_SB(sb);
 	struct erofs_inode *vi = EROFS_I(inode);
-	const erofs_off_t inode_loc = iloc(sbi, vi->nid);
+	const erofs_off_t inode_loc = erofs_iloc(inode);
 
 	erofs_blk_t blkaddr, nblks = 0;
 	void *kaddr;
@@ -308,47 +308,49 @@ out_unlock:
 }
 
 /*
- * erofs nid is 64bits, but i_ino is 'unsigned long', therefore
- * we should do more for 32-bit platform to find the right inode.
+ * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
+ * so that it will fit.
  */
-static int erofs_ilookup_test_actor(struct inode *inode, void *opaque)
+static ino_t erofs_squash_ino(erofs_nid_t nid)
 {
-	const erofs_nid_t nid = *(erofs_nid_t *)opaque;
+	ino_t ino = (ino_t)nid;
+
+	if (sizeof(ino_t) < sizeof(erofs_nid_t))
+		ino ^= nid >> (sizeof(erofs_nid_t) - sizeof(ino_t)) * 8;
+	return ino;
+}
 
-	return EROFS_I(inode)->nid == nid;
+static int erofs_iget5_eq(struct inode *inode, void *opaque)
+{
+	return EROFS_I(inode)->nid == *(erofs_nid_t *)opaque;
 }
 
-static int erofs_iget_set_actor(struct inode *inode, void *opaque)
+static int erofs_iget5_set(struct inode *inode, void *opaque)
 {
 	const erofs_nid_t nid = *(erofs_nid_t *)opaque;
 
-	inode->i_ino = erofs_inode_hash(nid);
+	inode->i_ino = erofs_squash_ino(nid);
+	EROFS_I(inode)->nid = nid;
 	return 0;
 }
 
 struct inode *erofs_iget(struct super_block *sb, erofs_nid_t nid)
 {
-	const unsigned long hashval = erofs_inode_hash(nid);
 	struct inode *inode;
 
-	inode = iget5_locked(sb, hashval, erofs_ilookup_test_actor,
-		erofs_iget_set_actor, &nid);
+	inode = iget5_locked(sb, erofs_squash_ino(nid), erofs_iget5_eq,
+			     erofs_iget5_set, &nid);
 	if (!inode)
 		return ERR_PTR(-ENOMEM);
 
 	if (inode->i_state & I_NEW) {
-		int err;
-		struct erofs_inode *vi = EROFS_I(inode);
-
-		vi->nid = nid;
+		int err = erofs_fill_inode(inode);
 
-		err = erofs_fill_inode(inode);
-		if (!err) {
-			unlock_new_inode(inode);
-		} else {
+		if (err) {
 			iget_failed(inode);
-			inode = ERR_PTR(err);
+			return ERR_PTR(err);
 		}
+		unlock_new_inode(inode);
 	}
 	return inode;
 }