Merge branch 'work.adfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull adfs updates from Al Viro:
 "adfs stuff for this cycle"

* 'work.adfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (42 commits)
  fs/adfs: bigdir: Fix an error code in adfs_fplus_read()
  Documentation: update adfs filesystem documentation
  fs/adfs: mostly divorse inode number from indirect disc address
  fs/adfs: super: add support for E and E+ floppy image formats
  fs/adfs: super: extract filesystem block probe
  fs/adfs: dir: remove debug in adfs_dir_update()
  fs/adfs: super: fix inode dropping
  fs/adfs: bigdir: implement directory update support
  fs/adfs: bigdir: calculate and validate directory checkbyte
  fs/adfs: bigdir: directory validation strengthening
  fs/adfs: bigdir: extract directory validation
  fs/adfs: bigdir: factor out directory entry offset calculation
  fs/adfs: newdir: split out directory commit from update
  fs/adfs: newdir: clean up adfs_f_update()
  fs/adfs: newdir: merge adfs_dir_read() into adfs_f_read()
  fs/adfs: newdir: improve directory validation
  fs/adfs: newdir: factor out directory format validation
  fs/adfs: dir: use pointers to access directory head/tails
  fs/adfs: dir: add more efficient iterate() per-format method
  fs/adfs: dir: switch to iterate_shared method
  ...

Documentation/filesystems/adfs.txt

@@ -1,3 +1,27 @@
+Filesystems supported by ADFS
+-----------------------------
+
+The ADFS module supports the following Filecore formats which have:
+
+- new maps
+- new directories or big directories
+
+In terms of the named formats, this means we support:
+
+- E and E+, with or without boot block
+- F and F+
+
+We fully support reading files from these filesystems, and writing to
+existing files within their existing allocation.  Essentially, we do
+not support changing any of the filesystem metadata.
+
+This is intended to support loopback mounted Linux native filesystems
+on a RISC OS Filecore filesystem, but will allow the data within files
+to be changed.
+
+If write support (ADFS_FS_RW) is configured, we allow rudimentary
+directory updates, specifically updating the access mode and timestamp.
+
 Mount options for ADFS
 ----------------------