Lots of Idiotic Silly Parentheses is -> that way... What that
condition checks is that there's exactly 32 bytes between the
end of name and the end of entire drectory record.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Note that lustre has its private mutex protecting directory pagecache;
if they ever remove it, they'll need to be careful with PageChecked()
use.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
use d_alloc_parallel() for sillyunlink/lookup exclusion and
explicit rwsem (nfs_rmdir() being a writer and nfs_call_unlink() -
a reader) for rmdir/sillyunlink one.
That ought to make lookup/readdir/!O_CREAT atomic_open really
parallel on NFS.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Payloads of NM entries are not supposed to contain NUL. When we run
into such, only the part prior to the first NUL goes into the
concatenation (i.e. the directory entry name being encoded by a bunch
of NM entries). We do stop when the amount collected so far + the
claimed amount in the current NM entry exceed 254. So far, so good,
but what we return as the total length is the sum of *claimed*
sizes, not the actual amount collected. And that can grow pretty
large - not unlimited, since you'd need to put CE entries in
between to be able to get more than the maximum that could be
contained in one isofs directory entry / continuation chunk and
we are stop once we'd encountered 32 CEs, but you can get about 8Kb
easily. And that's what will be passed to readdir callback as the
name length. 8Kb __copy_to_user() from a buffer allocated by
__get_free_page()
Cc: stable@vger.kernel.org # 0.98pl6+ (yes, really)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
First of all, trying to open them r/w is idiocy; it's guaranteed to fail.
Moreover, assigning ->f_pos and assuming that everything will work is
blatantly broken - try that with e.g. tmpfs as underlying layer and watch
the fireworks. There may be a non-trivial amount of state associated with
current IO position, well beyond the numeric offset. Using the single
struct file associated with underlying inode is really not a good idea;
we ought to open one for each ecryptfs directory struct file.
Additionally, file_operations both for directories and non-directories are
full of pointless methods; non-directories should *not* have ->iterate(),
directories should not have ->flush(), ->fasync() and ->splice_read().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
aside of the usual care about seeding dcache from readdir, we need
to be careful about the pagecache evictions here.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
It should never return positives; however, with Linux S&M crowd
involved, no bogosity is impossible. Results would be unpleasant...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
make it conditional on *opened & FILE_OPENED; in addition to getting
rid of exit_fput: thing, it simplifies atomic_open() cleanup on
may_open() failure.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Al Viro