edbb35cc6b
Currently inode_init_always() doesn't initialize i_ino to 0. This is unexpected because unlike the other inode fields that aren't initialized by inode_init_always(), i_ino isn't guaranteed to end up back at its initial value after the inode is freed. Only one filesystem (XFS) actually sets set i_ino back to 0 when freeing its inodes. So, callers of new_inode() see some random previous i_ino. Normally that's fine, since normally i_ino isn't accessed before being set. There can be edge cases where that isn't necessarily true, though. The one I've run into is that on ext4, when creating an encrypted file, the new file's encryption key has to be set up prior to the jbd2 transaction, and thus prior to i_ino being set. If something goes wrong, fs/crypto/ may log warning or error messages, which normally include i_ino. So it needs to know whether it is valid to include i_ino yet or not. Also, on some files i_ino needs to be hashed for use in the crypto, so fs/crypto/ needs to know whether that can be done yet or not. There are ways this could be worked around, either in fs/crypto/ or in fs/ext4/. But, it seems there's no reason not to just fix inode_init_always() to do the expected thing and initialize i_ino to 0. So, do that, and also remove the initialization in jfs_fill_super() that becomes redundant. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.