[PATCH V2 0/4] Squashfs: fix BIO migration regression and add sanity checks

[Phillip Lougher]

Hi all,

Patch [1/4] fixes a regression introduced by the "migrate from ll_rw_block
usage to BIO" patch, which has produced a number of Sysbot/Syzkaller reports.

Patches [2/4], [3/4], and [4/4] fix a number of filesystem corruption
issues which have produced Sysbot reports in the id, inode and xattr
lookup code.

Each patch has been tested against the Sysbot reproducers using the given
kernel configuration.  They have the appropriate "Reported-by:" lines
added.

Additionally, all of the reproducer filesystems are indirectly fixed by
patch [4/4] due to the fact they all have xattr corruption which is now
detected there.

Additional testing with other configurations and architectures (32bit,
big endian), and normal filesystems has also been done to trap any inadvertent
regressions caused by the additional sanity checks.

V2: Fix two checkpatch.pl errors.

Phillip