commit 946e51f2 upstream.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.2:
 - Apply name changes in all the different places we use d_alias and d_child
 - Move the WARN_ON() in __d_free() to d_free() as we don't have dentry_free()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
[lizf: Backported to 3.4:
 - adjust context
 - need one more name change in debugfs]

Lockdep was reporting a possible circular lock dependency in
dentry_lease_is_valid().  That function needs to sample the
session's s_cap_gen and and s_cap_ttl fields coherently, but needs
to do so while holding a dentry lock.  The s_cap_lock field was
being used to protect the two fields, but that can't be taken while
holding a lock on a dentry within the session.

In most cases, the s_cap_gen and s_cap_ttl fields only get operated
on separately.  But in three cases they need to be updated together.
Implement a new lock to protect the spots updating both fields
atomically is required.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Reviewed-by: Sage Weil <sage@newdream.net>

Enable/disable use of the dentry dir 'complete' flag via a mount option.
This lets the admin control whether ceph uses the dcache to satisfy
negative lookups or readdir when it has the entire directory contents in
its cache.

This is purely a performance optimization; correctness is guaranteed
whether it is enabled or not.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sage Weil <sage@newdream.net>

ceph_mdsc_put_request() can call iput(), which can sleep.  Don't do that.

Fixes: #1812
Signed-off-by: Sage Weil <sage@newdream.net>

We now set d_fsdata unconditionally on all dentries prior to setting up
the d_ops, so all of these checks are unnecessary.
Signed-off-by: Sage Weil <sage@newdream.net>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

vfs_create() ignores everything outside of 16bit subset of its
mode argument; switching it to umode_t is obviously equivalent
and it's the only caller of the method
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

vfs_mkdir() gets int, but immediately drops everything that might not
fit into umode_t and that's the only caller of ->mkdir()...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Ceph attempts to use the dcache to satisfy negative lookups and readdir
when the entire directory contents are in cache.  Disable this behavior
until lingering bugs in this code are shaken out; we'll re-enable these
hooks once things are fully stable.
Signed-off-by: Sage Weil <sage@newdream.net>

We have been using i_lock to protect all kinds of data structures in the
ceph_inode_info struct, including lists of inodes that we need to iterate
over while avoiding races with inode destruction.  That requires grabbing
a reference to the inode with the list lock protected, but igrab() now
takes i_lock to check the inode flags.

Changing the list lock ordering would be a painful process.

However, using a ceph-specific i_ceph_lock in the ceph inode instead of
i_lock is a simple mechanical change and avoids the ordering constraints
imposed by igrab().
Reported-by: Amon Ott <a.ott@m-privacy.de>
Signed-off-by: Sage Weil <sage@newdream.net>

Set up d_fsdata on the root dentry.  This fixes a NULL pointer dereference
in ceph_d_prune on umount.  It also means we can eventually strip out all
of the conditional checks on d_fsdata because it is now set unconditionally
(prior to setting up the d_ops).

Fix the ceph_d_prune debug print while we're here.
Signed-off-by: Sage Weil <sage@newdream.net>

We used to use a flag on the directory inode to track whether the dcache
contents for a directory were a complete cached copy.  Switch to a dentry
flag CEPH_D_COMPLETE that is safely updated by ->d_prune().
Signed-off-by: Sage Weil <sage@newdream.net>

When the VFS prunes a dentry from the cache, clear the D_COMPLETE flag
on the parent dentry.  Do this for the live and snapshotted namespaces. Do
not bother for the .snap dir contents, since we do not cache that.
Signed-off-by: Sage Weil <sage@newdream.net>

For the most part we don't care about racing with rename when directing
MDS requests; either the old or new parent is fine.  Document that, and
do some minor cleanup.
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>

We carry a pin on the parent directory for the rename source and dest
dentries.  For the source it's r_locked_dir; we need to explicitly
reference the old_dentry parent as well, since the dentry's d_parent may
change between when the request was created and pinned and when it is
freed.
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>

Have caller pass in a safely-obtained reference to the parent directory
for calculating a dentry's hash valud.

While we're here, simpify the flow through ceph_encode_fh() so that there
is a single exit point and cleanup.

Also fix a bug with the dentry hash calculation: calculate the hash for the
dentry we were given, not its parent.
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>

Protect d_parent with d_lock.  Carry a reference.  Simplify the flow so
that there is a single exit point and cleanup.
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>

d_parent is protected by d_lock: use it when looking up a dentry's parent
directory inode.  Also take a reference and drop it in the caller to avoid
a use-after-free.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>

The ->lookup() and prepopulate_readdir() callers are working with unhashed
dentries, so we don't have to worry.  The export.c callers, though, need
to initialize something they got back from d_obtain_alias() and are
potentially racing with other callers.  Make sure we don't return unless
the dentry is properly initialized (by us or someone else).
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>

We weren't properly calling lookup_instantiate_filp when setting up the
lookup intent, which could lead to file leakage on errors.  So:

 - use separate helper for the hidden snapdir translation, immediately
   following the mds request
 - use ceph_finish_lookup for the final dentry/return value dance in the
   exit path
 - lookup_instantiate_filp on success
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>

This saves us a word of memory per file.
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>

Btrfs needs to be able to control how filemap_write_and_wait_range() is called
in fsync to make it less of a painful operation, so push down taking i_mutex and
the calling of filemap_write_and_wait() down into the ->fsync() handlers.  Some
file systems can drop taking the i_mutex altogether it seems, like ext3 and
ocfs2.  For correctness sake I just pushed everything down in all cases to make
sure that we keep the current behavior the same for everybody, and then each
individual fs maintainer can make up their mind about what to do from there.
Thanks,
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

This converts everybody to handle SEEK_HOLE/SEEK_DATA properly.  In some cases
we just return -EINVAL, in others we do the normal generic thing, and in others
we're simply making sure that the properly due-dilligence is done.  For example
in NFS/CIFS we need to make sure the file size is update properly for the
SEEK_HOLE and SEEK_DATA case, but since it calls the generic llseek stuff itself
that is all we have to do.  Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

We should use ihold whenever we already have a stable inode ref, even
when we aren't holding i_lock.  This avoids adding new and unnecessary
locking dependencies.
Signed-off-by: Sage Weil <sage@newdream.net>

Ceph does not need these, and they screw up our use of the dcache as a
consistent cache.
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Only a few file systems need this.  Start by pushing it down into each
rename method (except gfs2 and xfs) so that it can be dealt with on a
per-fs basis.
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Only a few file systems need this.  Start by pushing it down into each
fs rmdir method (except gfs2 and xfs) so it can be dealt with on a per-fs
basis.

This does not change behavior for any in-tree file systems.
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Both off and fi->offset are unsigned, so the difference is always >= 0.
Compare them directly instead of the sign of the difference.
Signed-off-by: Sage Weil <sage@newdream.net>

We allocate a buffer for rstats if the dirstat option is enabled.  Use
snprintf.
Signed-off-by: Sage Weil <sage@newdream.net>

Just for consistency's sake.  Fix obsolete comment too.
Signed-off-by: Sage Weil <sage@newdream.net>

The ino32 mount option forces the ceph fs to report 32 bit
ino values.  This is useful for 64 bit kernels with 32 bit userspace.
Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>

can't blindly check nd->flags in ->d_revalidate()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Otherwise you can do things like

# mkdir .snap/foo
# cd .snap/foo/.snap
# ls
<badness>
Signed-off-by: Sage Weil <sage@newdream.net>

First, this was racy anyway: d_release isn't called until well after the
dentry is unhashed.  Second, this runs afoul of the recent dcache change
that clears d_parent prior to calling d_release (949854d0), causing a NULL
pointer dereference.
Signed-off-by: Sage Weil <sage@newdream.net>

Do not set the I_COMPLETE flag on directories until we resolve races with
dcache pruning.
Signed-off-by: Sage Weil <sage@newdream.net>

This reverts commit 97d79b40.

This fails to account for d_parent changes due to rename or disconnected
dentries due to submounts or NFS reexports.
Signed-off-by: Sage Weil <sage@newdream.net>

When creating a new dentry we now hold a reference to the parent
inode in the ceph_dentry.  This is required due to the new RCU
changes from 949854d0, which set dentry->d_parent to NULL in d_kill before
calling the ->release() callback.  If/when that behavior is changed, we can
revert this hack.
Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>