5557a069f3
When we find a conflicting inode (an inode that had the same name and parent directory as the inode we are logging now) that was deleted in the current transaction, we always end up logging its parent directory. This is to deal with the case where the conflicting inode corresponds to a deleted subvolume/snapshot or a directory that had subvolumes/snapshots (or some subdirectory inside it had subvolumes/snapshots, etc), because we can't deal with dropping subvolumes/snapshots during log replay. So if we log the parent directory, and if we are dealing with these special cases, then we fallback to a transaction commit when logging the parent, because its last_unlink_trans will match the current transaction (which gets set and propagated when a subvolume/snapshot is deleted). This change skips the logging of the parent directory when the conflicting inode is not a directory (or a subvolume/snapshot). This is ok because in this case logging the current inode is enough to trigger an unlink of the conflicting inode during log replay. So for a case like this: $ mkdir /mnt/dir $ echo -n "first foo data" > /mnt/dir/foo $ sync $ rm -f /mnt/dir/foo $ echo -n "second foo data" > /mnt/dir/foo $ xfs_io -c "fsync" /mnt/dir/foo We avoid logging parent directory "dir" when logging the new file "foo". In other cases it avoids falling back to a transaction commit, when the parent directory has a last_unlink_trans value that matches the current transaction, due to moving a file from it to some other directory. This is a case that happens frequently with dbench for example, where a new file that has the name/parent of another file that was deleted in the current transaction, is fsynced. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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.