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-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (23 commits)
ceph: document unlocked d_parent accesses
ceph: explicitly reference rename old_dentry parent dir in request
ceph: document locking for ceph_set_dentry_offset
ceph: avoid d_parent in ceph_dentry_hash; fix ceph_encode_fh() hashing bug
ceph: protect d_parent access in ceph_d_revalidate
ceph: protect access to d_parent
ceph: handle racing calls to ceph_init_dentry
ceph: set dir complete frag after adding capability
rbd: set blk_queue request sizes to object size
ceph: set up readahead size when rsize is not passed
rbd: cancel watch request when releasing the device
ceph: ignore lease mask
ceph: fix ceph_lookup_open intent usage
ceph: only link open operations to directory unsafe list if O_CREAT|O_TRUNC
ceph: fix bad parent_inode calc in ceph_lookup_open
ceph: avoid carrying Fw cap during write into page cache
libceph: don't time out osd requests that haven't been received
ceph: report f_bfree based on kb_avail rather than diffing.
ceph: only queue capsnap if caps are dirty
ceph: fix snap writeback when racing with writes
...
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>
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>
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>
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>
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>
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>
This reverts commit 97d79b403e.
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>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
rbd: fix cleanup when trying to mount inexistent image
net/ceph: make ceph_msgr_wq non-reentrant
ceph: fsc->*_wq's aren't used in memory reclaim path
ceph: Always free allocated memory in osdmap_decode()
ceph: Makefile: Remove unnessary code
ceph: associate requests with opening sessions
ceph: drop redundant r_mds field
ceph: implement DIRLAYOUTHASH feature to get dir layout from MDS
ceph: add dir_layout to inode
Add a ceph_dir_layout to the inode, and calculate dentry hash values based
on the parent directory's specified dir_hash function. This is needed
because the old default Linux dcache hash function is extremely week and
leads to a poor distribution of files among dir fragments.
Signed-off-by: Sage Weil <sage@newdream.net>
Require filesystems be aware of .d_revalidate being called in rcu-walk
mode (nd->flags & LOOKUP_RCU). For now do a simple push down, returning
-ECHILD from all implementations.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Reduce some branches and memory accesses in dcache lookup by adding dentry
flags to indicate common d_ops are set, rather than having to check them.
This saves a pointer memory access (dentry->d_op) in common path lookup
situations, and saves another pointer load and branch in cases where we
have d_op but not the particular operation.
Patched with:
git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Protect d_subdirs and d_child with d_lock, except in filesystems that aren't
using dcache_lock for these anyway (eg. using i_mutex).
Note: if we change the locking rule in future so that ->d_child protection is
provided only with ->d_parent->d_lock, it may allow us to reduce some locking.
But it would be an exception to an otherwise regular locking scheme, so we'd
have to see some good results. Probably not worthwhile.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Protect d_unhashed(dentry) condition with d_lock. This means keeping
DCACHE_UNHASHED bit in synch with hash manipulations.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Make d_count non-atomic and protect it with d_lock. This allows us to ensure a
0 refcount dentry remains 0 without dcache_lock. It is also fairly natural when
we start protecting many other dentry members with d_lock.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
The fh_to_dentry etc. methods use ceph_init_dentry(), which assumes that
d_parent is defined. It isn't for those callers, so check!
Signed-off-by: Sage Weil <sage@newdream.net>
last may be NULL, but we dereference it in the else branch without
checking. Normally it doesn't trigger because last == NULL when fpos == 2,
but it could happen on a newly opened dir if the user seeks forward.
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Sage Weil <sage@newdream.net>
One of the readdir filldir_t callers was passing the raw ceph 64-bit ino
instead of the hashed 32-bit one, producing an EOVERFLOW in the filler
callback. Fix this by calling the ceph_vino_to_ino() helper to do the
conversion.
Reported-by: Jan Smets <jan.smets@alcatel-lucent.com>
Tested-by: Jan Smets <jan.smets@alcatel-lucent.com>
Signed-off-by: Sage Weil <sage@newdream.net>
We start at offset 2 for the leftmost frag, and 0 for subsequent frags.
When we reach the end (rightmost), we go back to 2. This fixes readdir on
fragmented (large) directories.
Signed-off-by: Sage Weil <sage@newdream.net>
We were taking dcache_lock inside of i_lock, which introduces a dependency
not found elsewhere in the kernel, complicationg the vfs locking
scalability work. Since we don't actually need it here anyway, remove
it.
We only need i_lock to test for the I_COMPLETE flag, so be careful to do
so without dcache_lock held.
Signed-off-by: Sage Weil <sage@newdream.net>
This factors out protocol and low-level storage parts of ceph into a
separate libceph module living in net/ceph and include/linux/ceph. This
is mostly a matter of moving files around. However, a few key pieces
of the interface change as well:
- ceph_client becomes ceph_fs_client and ceph_client, where the latter
captures the mon and osd clients, and the fs_client gets the mds client
and file system specific pieces.
- Mount option parsing and debugfs setup is correspondingly broken into
two pieces.
- The mon client gets a generic handler callback for otherwise unknown
messages (mds map, in this case).
- The basic supported/required feature bits can be expanded (and are by
ceph_fs_client).
No functional change, aside from some subtle error handling cases that got
cleaned up in the refactoring process.
Signed-off-by: Sage Weil <sage@newdream.net>
When we release a root dentry, particularly after a splice, the parent
(actually our) inode was evaluating to NULL and was getting dereferenced
by ceph_snap(). This is reproduced by something as simple as
mount -t ceph monhost:/a/b mnt
mount -t ceph monhost:/a mnt2
ls mnt2
A splice_dentry() would kill the old 'b' inode's root dentry, and we'd
crash while releasing it.
Fix by checking for both the ROOT and NULL cases explicitly. We only need
to invalidate the parent dir when we have a correct parent to invalidate.
Signed-off-by: Sage Weil <sage@newdream.net>
Sage Weil