coda: remove CODA_STORE/CODA_RELEASE upcalls

This is an variation on the patch sent by Christoph Hellwig which kills
file_count abuse by the Coda kernel module by moving the coda_flush
functionality into coda_release.  However part of reason we were using the
coda_flush callback was to allow Coda to pass errors that occur during
writeback from the userspace cache manager back to close().

As Al Viro explained on linux-fsdevel, it is impossible to guarantee that
such errors can in fact be returned back to the caller.  There are many
cases where the last reference to a file is not released by the close
system call and it is also impossible to pick some close as a 'last-close'
and delay it until all other references have been destroyed.

The CODA_STORE/CODA_RELEASE upcall combination is clearly a broken design,
and it is better to remove it completely.

Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@ftp.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jan Harkes 2007-07-21 04:37:26 -07:00 committed by Linus Torvalds
parent b50731732f
commit d3fec424b2
5 changed files with 7 additions and 112 deletions

View file

@ -36,7 +36,6 @@ extern const struct file_operations coda_ioctl_operations;
/* operations shared over more than one file */
int coda_open(struct inode *i, struct file *f);
int coda_flush(struct file *f, fl_owner_t id);
int coda_release(struct inode *i, struct file *f);
int coda_permission(struct inode *inode, int mask, struct nameidata *nd);
int coda_revalidate_inode(struct dentry *);