Force decode of encrypted files even if the integrity check fails, instead of
failing with an IO error. Warning messages are still printed to syslog if corrupted
files are encountered.
It can be useful to recover files from disks with bad sectors or other corrupted
media.
Closes https://github.com/rfjakob/gocryptfs/pull/102 .
The volatile inode numbers that we used before cause "find" to complain and error out.
Virtual inode numbers are derived from their parent file inode number by adding 10^19,
which is hopefully large enough no never cause problems in practice.
If the backing directory contains inode numbers higher than that, stat() on these files
will return EOVERFLOW.
Example directory lising after this change:
$ ls -i
926473 gocryptfs.conf
1000000000000926466 gocryptfs.diriv
944878 gocryptfs.longname.hmZojMqC6ns47eyVxLlH2ailKjN9bxfosi3C-FR8mjA
1000000000000944878 gocryptfs.longname.hmZojMqC6ns47eyVxLlH2ailKjN9bxfosi3C-FR8mjA.name
934408 Tdfbf02CKsTaGVYnAsSypA
Due to kernel readahead, we usually get multiple read requests
at the same time. These get submitted to the backing storage in
random order, which is a problem if seeking is very expensive.
Details: https://github.com/rfjakob/gocryptfs/issues/92
...but keep it disabled by default for new filesystems.
We are still missing an example filesystem and CLI arguments
to explicitely enable and disable it.
There are two independent backends, one for name encryption,
the other one, AEAD, for file content.
"BackendTypeEnum" only applies to AEAD (file content), so make that
clear in the name.
Preallocation is very slow on hdds that run btrfs. Give the
user the option to disable it. This greatly speeds up small file
operations but reduces the robustness against out-of-space errors.
Also add the option to the man page.
More info: https://github.com/rfjakob/gocryptfs/issues/63
