RCU free the struct inode. This will allow:
- Subsequent store-free path walking patch. The inode must be consulted for
permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
to take i_lock no longer need to take sb_inode_list_lock to walk the list in
the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
page lock to follow page->mapping.
The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.
In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.
The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.
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>
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>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
ceph: fix readdir EOVERFLOW on 32-bit archs
ceph: fix frag offset for non-leftmost frags
ceph: fix dangling pointer
ceph: explicitly specify page alignment in network messages
ceph: make page alignment explicit in osd interface
ceph: fix comment, remove extraneous args
ceph: fix update of ctime from MDS
ceph: fix version check on racing inode updates
ceph: fix uid/gid on resent mds requests
ceph: fix rdcache_gen usage and invalidate
ceph: re-request max_size if cap auth changes
ceph: only let auth caps update max_size
ceph: fix open for write on clustered mds
ceph: fix bad pointer dereference in ceph_fill_trace
ceph: fix small seq message skipping
Revert "ceph: update issue_seq on cap grant"
The big kernel lock has been removed from all these files at some point,
leaving only the #include.
Remove this too as a cleanup.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We used to infer alignment of IOs within a page based on the file offset,
which assumed they matched. This broke with direct IO that was not aligned
to pages (e.g., 512-byte aligned IO). We were also trusting the alignment
specified in the OSD reply, which could have been adjusted by the server.
Explicitly specify the page alignment when setting up OSD IO requests.
Signed-off-by: Sage Weil <sage@newdream.net>
The client can have a newer ctime than the MDS due to AUTH_EXCL and
XATTR_EXCL caps as well; update the check in ceph_fill_file_time
appropriately.
This fixes cases where ctime/mtime goes backward under the right sequence
of local updates (e.g. chmod) and mds replies (e.g. subsequent stat that
goes to the MDS).
Signed-off-by: Sage Weil <sage@newdream.net>
We may get updates on the same inode from multiple MDSs; generally we only
pay attention if the update is newer than what we already have. The
exception is when an MDS sense unstable information, in which case we
always update.
The old > check got this wrong when our version was odd (e.g. 3) and the
reply version was even (e.g. 2): the older stale (v2) info would be
applied. Fixed and clarified the comment.
Signed-off-by: Sage Weil <sage@newdream.net>
We used to use rdcache_gen to indicate whether we "might" have cached
pages. Now we just look at the mapping to determine that. However, some
old behavior remains from that transition.
First, rdcache_gen == 0 no longer means we have no pages. That can happen
at any time (presumably when we carry FILE_CACHE). We should not reset it
to zero, and we should not check that it is zero.
That means that the only purpose for rdcache_revoking is to resolve races
between new issues of FILE_CACHE and an async invalidate. If they are
equal, we should invalidate. On success, we decrement rdcache_revoking,
so that it is no longer equal to rdcache_gen. Similarly, if we success
in doing a sync invalidate, set revoking = gen - 1. (This is a small
optimization to avoid doing unnecessary invalidate work and does not
affect correctness.)
Signed-off-by: Sage Weil <sage@newdream.net>
Only the auth MDS has a meaningful max_size value for us, so only update it
in fill_inode if we're being issued an auth cap. Otherwise, a random
stat result from a non-auth MDS can clobber a meaningful max_size, get
the client<->mds cap state out of sync, and make writes hang.
Specifically, even if the client re-requests a larger max_size (which it
will), the MDS won't respond because as far as it knows we already have a
sufficiently large value.
Signed-off-by: Sage Weil <sage@newdream.net>
We dereference *in a few lines down, but only set it on rename. It is
apparently pretty rare for this to trigger, but I have been hitting it
with a clustered MDSs.
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 adding the readdir results to the cache, ceph_set_dentry_offset was
clobbered our just-set offset. This can cause the readdir result offsets
to get out of sync with the server. Add an argument to the helper so
that it does not.
This bug was introduced by 1cd3935bed.
Signed-off-by: Sage Weil <sage@newdream.net>
ceph_get_inode() returns an ERR_PTR and it doesn't return a NULL.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Sage Weil <sage@newdream.net>
If we hold the EXCL cap, we cannot trust the dir stats from the MDS (num
files, subdirs) and must not incorrectly conclude that the directory is
empty. If we do, we get can bad results from lookup (bad ENOENT) and
bad readdir results.
Signed-off-by: Sage Weil <sage@newdream.net>
If the file mode is marked as "lazy," perform cached/buffered reads when
the caps permit it. Adjust the rdcache_gen and invalidation logic
accordingly so that we manage our cache based on the FILE_CACHE -or-
FILE_LAZYIO cap bits.
Signed-off-by: Sage Weil <sage@newdream.net>
This fixes an issue triggered by running concurrent syncs. One of the syncs
would go through while the other would just hang indefinitely. In any case, we
never actually want to wake a single waiter, so the *_all functions should
be used.
Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
Handle a splice_dentry failure (due to a d_materialize_unique error)
without crashing. (Also, report the error code.)
Signed-off-by: Sage Weil <sage@newdream.net>
We misused list_move_tail() to order the dentry in d_subdirs.
This will screw up the d_subdirs order.
This bug can be reliably reproduced by:
1. mount ceph fs.
2. on ceph fs, git clone git://ceph.newdream.net/git/ceph.git
3. Run autogen.sh in ceph directory.
(Note: Errors only occur at the first time you run autogen.sh.)
Signed-off-by: Henry C Chang <henry_c_chang@tcloudcomputing.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Use ERR_CAST(x) rather than ERR_PTR(PTR_ERR(x)). The former makes more
clear what is the purpose of the operation, which otherwise looks like a
no-op.
In the case of fs/ceph/inode.c, ERR_CAST is not needed, because the type of
the returned value is the same as the type of the enclosing function.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
type T;
T x;
identifier f;
@@
T f (...) { <+...
- ERR_PTR(PTR_ERR(x))
+ x
...+> }
@@
expression x;
@@
- ERR_PTR(PTR_ERR(x))
+ ERR_CAST(x)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Sage Weil <sage@newdream.net>
We invalidate I_COMPLETE and dentry leases in two places: on aborted mds
request and on request replay. Use common helper to avoid duplicate code.
Signed-off-by: Sage Weil <sage@newdream.net>
We want to assign an offset when the dentry goes from null to linked, which
is always done by splice_dentry(). Notably, we should NOT assign an
offset when a dentry is first created and is still null.
BUG if we try to splice a non-null dentry (we shouldn't).
Signed-off-by: Sage Weil <sage@newdream.net>
If we use the xattr_blob, clear the pointer so we don't release the memory
at the bottom of the fuction.
Reported-by: Henry C Chang <henry_c_chang@tcloudcomputing.com>
Signed-off-by: Sage Weil <sage@newdream.net>
ceph_sb_to_client and ceph_client are really identical, we need to dump
one; while function ceph_client is confusing with "struct ceph_client",
ceph_sb_to_client's definition is more clear; so we'd better switch all
call to ceph_sb_to_client.
-static inline struct ceph_client *ceph_client(struct super_block *sb)
-{
- return sb->s_fs_info;
-}
Signed-off-by: Cheng Renquan <crquan@gmail.com>
Signed-off-by: Sage Weil <sage@newdream.net>
If we abort a request, we return to caller, but the request may still
complete. And if we hold the dir FILE_EXCL bit, we may not release a
lease when sending a request. A simple un-tar, control-c, un-tar again
will reproduce the bug (manifested as a 'Cannot open: File exists').
Ensure we invalidate affected dentry leases (as well dir I_COMPLETE) so
we don't have valid (but incorrect) leases. Do the same, consistently, at
other sites where I_COMPLETE is similarly cleared.
Signed-off-by: Sage Weil <sage@newdream.net>
It's possible the MDS will not issue caps on a snapped inode, in which case
an open request may not __ceph_get_fmode(), botching the open file
counting. (This is actually a server bug, but the client shouldn't BUG out
in this case.)
Signed-off-by: Sage Weil <sage@newdream.net>
d_move() reorders the d_subdirs list, breaking the readdir result caching.
Unless/until d_move preserves that ordering, clear CEPH_I_COMPLETE on
rename.
Signed-off-by: Sage Weil <sage@newdream.net>
If a lookup fails on the magic .snap directory, we bind it to a magic
snap directory inode in ceph_lookup_finish(). That code assumes the dentry
is unhashed, but a recent server-side change started returning NULL leases
on lookup failure, causing the .snap dentry to be hashed and NULL by
ceph_fill_trace().
This causes dentry hash chain corruption, or a dies when d_rehash()
includes
BUG_ON(!d_unhashed(entry));
So, avoid processing the NULL dentry lease if it the dentry matches the
snapdir name in ceph_fill_trace(). That allows the lookup completion to
properly bind it to the snapdir inode. BUG there if dentry is hashed to
be sure.
Signed-off-by: Sage Weil <sage@newdream.net>
When an inode was dropped while being migrated between two MDSs,
i_cap_exporting_issued was non-zero such that issue caps were non-zero and
__ceph_is_any_caps(ci) was true. This prevented the inode from being
removed from the snap realm, even as it was dropped from the cache.
Fix this by dropping any residual i_snap_realm ref in destroy_inode.
Signed-off-by: Sage Weil <sage@newdream.net>
Instead of truncating the whole range of pages, we skip those
pages that are dirty or in the middle of writeback. Those pages
will be cleared later when the writeback completes.
Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
A truncation should occur when either we have the
specified caps for the file, or (in cases where we are
not the only ones referencing the file) when it is mapped
or when it is opened. The latter two cases were not
handled.
Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
We never truncate to a smaller size without contacting the MDS.
Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
Previously, if the MDS request was interrupted, we would unregister the
request and ignore any reply. This could cause the caps or other cache
state to become out of sync. (For instance, aborting dbench and doing
rm -r on clients would complain about a non-empty directory because the
client didn't realize it's aborted file create request completed.)
Even we don't unregister, we still can't process the reply normally because
we are no longer holding the caller's locks (like the dir i_mutex).
So, mark aborted operations with r_aborted, and in the reply handler, be
sure to process all the caps. Do not process the namespace changes,
though, since we no longer will hold the dir i_mutex. The dentry lease
state can also be ignored as it's more forgiving.
Signed-off-by: Sage Weil <sage@newdream.net>
This fixes a bug, where we had the parent list have dentries with
offsets that are not monotonically increasing, which caused the ceph
dcache_readdir to skip entries.
Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
This works around a bug in vfs_rename_dir() that rehashes the target
dentry. Ensure such dentries always fail revalidation by timing out the
dentry lease and kicking it out of the current directory lease gen.
This can be reverted when the vfs bug is fixed.
Signed-off-by: Sage Weil <sage@newdream.net>
We never allocate the ceph_buffer and buffer separtely, so use a single
constructor.
Disallow put on NULL buffer; make the caller check.
Signed-off-by: Sage Weil <sage@newdream.net>
We can't fill i_size with rbytes at the fill_file_size stage without
adding additional checks for directories. Notably, we want st_blocks
to remain 0 on directories so that 'du' still works.
Fill in i_blocks, i_size specially in ceph_getattr instead.
Signed-off-by: Sage Weil <sage@newdream.net>
Inode cache and inode operations. We also include routines to
incorporate metadata structures returned by the MDS into the client
cache, and some helpers to deal with file capabilities and metadata
leases. The bulk of that work is done by fill_inode() and
fill_trace().
Signed-off-by: Sage Weil <sage@newdream.net>
