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author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-05-07 00:11:19 +0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-05-07 00:11:19 +0400 |
commit | 91f8575685e35f3bd021286bc82d26397458f5a9 (patch) | |
tree | 09de8d889758a12071adb9427ed741e27c907aa6 /net/ceph/snapshot.c | |
parent | 2e378f3eebd28feefbb1f9953834a5a19482f053 (diff) | |
parent | b5b09be30cf99f9c699e825629f02e3bce555d44 (diff) | |
download | linux-91f8575685e35f3bd021286bc82d26397458f5a9.tar.xz |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
Pull Ceph changes from Alex Elder:
"This is a big pull.
Most of it is culmination of Alex's work to implement RBD image
layering, which is now complete (yay!).
There is also some work from Yan to fix i_mutex behavior surrounding
writes in cephfs, a sync write fix, a fix for RBD images that get
resized while they are mapped, and a few patches from me that resolve
annoying auth warnings and fix several bugs in the ceph auth code."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (254 commits)
rbd: fix image request leak on parent read
libceph: use slab cache for osd client requests
libceph: allocate ceph message data with a slab allocator
libceph: allocate ceph messages with a slab allocator
rbd: allocate image object names with a slab allocator
rbd: allocate object requests with a slab allocator
rbd: allocate name separate from obj_request
rbd: allocate image requests with a slab allocator
rbd: use binary search for snapshot lookup
rbd: clear EXISTS flag if mapped snapshot disappears
rbd: kill off the snapshot list
rbd: define rbd_snap_size() and rbd_snap_features()
rbd: use snap_id not index to look up snap info
rbd: look up snapshot name in names buffer
rbd: drop obj_request->version
rbd: drop rbd_obj_method_sync() version parameter
rbd: more version parameter removal
rbd: get rid of some version parameters
rbd: stop tracking header object version
rbd: snap names are pointer to constant data
...
Diffstat (limited to 'net/ceph/snapshot.c')
-rw-r--r-- | net/ceph/snapshot.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/net/ceph/snapshot.c b/net/ceph/snapshot.c new file mode 100644 index 000000000000..154683f5f14c --- /dev/null +++ b/net/ceph/snapshot.c @@ -0,0 +1,78 @@ +/* + * snapshot.c Ceph snapshot context utility routines (part of libceph) + * + * Copyright (C) 2013 Inktank Storage, Inc. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +#include <stddef.h> + +#include <linux/types.h> +#include <linux/export.h> +#include <linux/ceph/libceph.h> + +/* + * Ceph snapshot contexts are reference counted objects, and the + * returned structure holds a single reference. Acquire additional + * references with ceph_get_snap_context(), and release them with + * ceph_put_snap_context(). When the reference count reaches zero + * the entire structure is freed. + */ + +/* + * Create a new ceph snapshot context large enough to hold the + * indicated number of snapshot ids (which can be 0). Caller has + * to fill in snapc->seq and snapc->snaps[0..snap_count-1]. + * + * Returns a null pointer if an error occurs. + */ +struct ceph_snap_context *ceph_create_snap_context(u32 snap_count, + gfp_t gfp_flags) +{ + struct ceph_snap_context *snapc; + size_t size; + + size = sizeof (struct ceph_snap_context); + size += snap_count * sizeof (snapc->snaps[0]); + snapc = kzalloc(size, gfp_flags); + if (!snapc) + return NULL; + + atomic_set(&snapc->nref, 1); + snapc->num_snaps = snap_count; + + return snapc; +} +EXPORT_SYMBOL(ceph_create_snap_context); + +struct ceph_snap_context *ceph_get_snap_context(struct ceph_snap_context *sc) +{ + if (sc) + atomic_inc(&sc->nref); + return sc; +} +EXPORT_SYMBOL(ceph_get_snap_context); + +void ceph_put_snap_context(struct ceph_snap_context *sc) +{ + if (!sc) + return; + if (atomic_dec_and_test(&sc->nref)) { + /*printk(" deleting snap_context %p\n", sc);*/ + kfree(sc); + } +} +EXPORT_SYMBOL(ceph_put_snap_context); |