Merge tag 'erofs-for-6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang...

Pull erofs updates from Gao Xiang:
 "In this cycle, we add file-backed mount support, which has has been a
  strong requirement for years. It is especially useful when there are
  thousands of images running on the same host for containers and other
  sandbox use cases, unlike OS image use cases.

  Without file-backed mounts, it's hard for container runtimes to manage
  and isolate so many unnecessary virtual block devices safely and
  efficiently, therefore file-backed mounts are highly preferred. For
  EROFS users, ComposeFS [1], containerd, and Android APEXes [2] will
  directly benefit from it, and I've seen no risk in implementing it as
  a completely immutable filesystem.

  The previous experimental feature "EROFS over fscache" is now marked
  as deprecated because:

   - Fscache is no longer an independent subsystem and has been merged
     into netfs, which was somewhat unexpected when it was proposed.

   - New HSM "fanotify pre-content hooks" [3] will be landed upstream.
     These hooks will replace "EROFS over fscache" in a simpler way, as
     EROFS won't be bother with kernel caching anymore. Userspace
     programs can also manage their own caching hierarchy more flexibly.

  Once the HSM "fanotify pre-content hooks" is landed, I will remove the
  fscache backend entirely as an internal dependency cleanup. More
  backgrounds are listed in the original patchset [4].

  In addition to that, there are bugfixes and cleanups as usual.

  Summary:

   - Support file-backed mounts for containers and sandboxes

   - Mark the experimental fscache backend as deprecated

   - Handle overlapped pclusters caused by crafted images properly

   - Fix a failure path which could cause infinite loops in
     z_erofs_init_decompressor()

   - Get rid of unnecessary NOFAILs

   - Harmless on-disk hardening & minor cleanups"

* tag 'erofs-for-6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
  erofs: reject inodes with negative i_size
  erofs: restrict pcluster size limitations
  erofs: allocate more short-lived pages from reserved pool first
  erofs: sunset unneeded NOFAILs
  erofs: simplify erofs_map_blocks_flatmode()
  erofs: refactor read_inode calling convention
  erofs: use kmemdup_nul in erofs_fill_symlink
  erofs: mark experimental fscache backend deprecated
  erofs: support compressed inodes for fileio
  erofs: support unencoded inodes for fileio
  erofs: add file-backed mount support
  erofs: handle overlapped pclusters out of crafted images properly
  erofs: fix error handling in z_erofs_init_decompressor
  erofs: clean up erofs_register_sysfs()
  erofs: fix incorrect symlink detection in fast symlink