linux.git/fs/ceph/super.c, branch v3.17 Linux kernel source tree dcache: d_obtain_alias callers don't all want DISCONNECTED 2014-08-07T18:40:10+00:00 J. Bruce Fields bfields@redhat.com 2014-02-14T22:35:37+00:00 1a0a397e41cb1bf70cfe45fd0eeff08c7c501ec0 There are a few d_obtain_alias callers that are using it to get the root of a filesystem which may already have an alias somewhere else. This is not the same as the filehandle-lookup case, and none of them actually need DCACHE_DISCONNECTED set. It isn't really a serious problem, but it would really be clearer if we reserved DCACHE_DISCONNECTED for those cases where it's actually needed. In the btrfs case this was causing a spurious printk from nfsd/nfsfh.c:fh_verify when it found an unexpected DCACHE_DISCONNECTED dentry. Josef worked around this by unsetting DCACHE_DISCONNECTED manually in 3a0dfa6a12e "Btrfs: unset DCACHE_DISCONNECTED when mounting default subvol", and this replaces that workaround. Cc: Josef Bacik <jbacik@fb.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> 
There are a few d_obtain_alias callers that are using it to get the
root of a filesystem which may already have an alias somewhere else.

This is not the same as the filehandle-lookup case, and none of them
actually need DCACHE_DISCONNECTED set.

It isn't really a serious problem, but it would really be clearer if we
reserved DCACHE_DISCONNECTED for those cases where it's actually needed.

In the btrfs case this was causing a spurious printk from
nfsd/nfsfh.c:fh_verify when it found an unexpected DCACHE_DISCONNECTED
dentry.  Josef worked around this by unsetting DCACHE_DISCONNECTED
manually in 3a0dfa6a12e "Btrfs: unset DCACHE_DISCONNECTED when mounting
default subvol", and this replaces that workaround.

Cc: Josef Bacik <jbacik@fb.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
ceph: use fl->fl_file as owner identifier of flock and posix lock 2014-04-05T04:07:11+00:00 Yan, Zheng zheng.z.yan@intel.com 2014-03-09T15:16:40+00:00 eb13e832f823f6c110ea53e3067bafe22b87de63 flock and posix lock should use fl->fl_file instead of process ID as owner identifier. (posix lock uses fl->fl_owner. fl->fl_owner is usually equal to fl->fl_file, but it also can be a customized value). The process ID of who holds the lock is just for F_GETLK fcntl(2). The fix is rename the 'pid' fields of struct ceph_mds_request_args and struct ceph_filelock to 'owner', rename 'pid_namespace' fields to 'pid'. Assign fl->fl_file to the 'owner' field of lock messages. We also set the most significant bit of the 'owner' field. MDS can use that bit to distinguish between old and new clients. The MDS counterpart of this patch modifies the flock code to not take the 'pid_namespace' into consideration when checking conflict locks. Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com> Reviewed-by: Sage Weil <sage@inktank.com> 
flock and posix lock should use fl->fl_file instead of process ID
as owner identifier. (posix lock uses fl->fl_owner. fl->fl_owner
is usually equal to fl->fl_file, but it also can be a customized
value). The process ID of who holds the lock is just for F_GETLK
fcntl(2).

The fix is rename the 'pid' fields of struct ceph_mds_request_args
and struct ceph_filelock to 'owner', rename 'pid_namespace' fields
to 'pid'. Assign fl->fl_file to the 'owner' field of lock messages.
We also set the most significant bit of the 'owner' field. MDS can
use that bit to distinguish between old and new clients.

The MDS counterpart of this patch modifies the flock code to not
take the 'pid_namespace' into consideration when checking conflict
locks.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
ceph: add acl, noacl options for cephfs mount 2014-02-17T20:37:12+00:00 Sage Weil sage@inktank.com 2014-02-16T18:05:29+00:00 45195e42c78ea91135108207dbcaf75e5556a309 Make the 'acl' option dependent on having ACL support compiled in. Make the 'noacl' option work even without it so that one can always ask it to be off and not error out on mount when it is not supported. Signed-off-by: Guangliang Zhao <lucienchao@gmail.com> Signed-off-by: Sage Weil <sage@inktank.com> 
Make the 'acl' option dependent on having ACL support compiled in.  Make
the 'noacl' option work even without it so that one can always ask it to
be off and not error out on mount when it is not supported.

Signed-off-by: Guangliang Zhao <lucienchao@gmail.com>
Signed-off-by: Sage Weil <sage@inktank.com>
libceph: all features fields must be u64 2013-12-31T18:32:08+00:00 Ilya Dryomov ilya.dryomov@inktank.com 2013-12-24T19:19:23+00:00 12b4629a9fb80fecaebadc217b13b8776ed8dbef In preparation for ceph_features.h update, change all features fields from unsigned int/u32 to u64. (ceph.git has ~40 feature bits at this point.) Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com> Reviewed-by: Sage Weil <sage@inktank.com> 
In preparation for ceph_features.h update, change all features fields
from unsigned int/u32 to u64.  (ceph.git has ~40 feature bits at this
point.)

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
ceph: add acl for cephfs 2013-12-31T18:32:01+00:00 Guangliang Zhao lucienchao@gmail.com 2013-11-11T07:18:03+00:00 7221fe4c2ed72804b28633c8e0217d65abb0023f Signed-off-by: Guangliang Zhao <lucienchao@gmail.com> Reviewed-by: Li Wang <li.wang@ubuntykylin.com> Reviewed-by: Zheng Yan <zheng.z.yan@intel.com> 
Signed-off-by: Guangliang Zhao <lucienchao@gmail.com>
Reviewed-by: Li Wang <li.wang@ubuntykylin.com>
Reviewed-by: Zheng Yan <zheng.z.yan@intel.com>
ceph: drop unconnected inodes 2013-12-13T17:13:16+00:00 Yan, Zheng zheng.z.yan@intel.com 2013-09-20T11:55:31+00:00 9f12bd119e408388233e7aeb1152f372a8b5dcad Positve dentry and corresponding inode are always accompanied in MDS reply. So no need to keep inode in the cache after dropping all its aliases. Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com> Reviewed-by: Sage Weil <sage@inktank.com> 
Positve dentry and corresponding inode are always accompanied in MDS reply.
So no need to keep inode in the cache after dropping all its aliases.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
ceph: use fscache as a local presisent cache 2013-09-06T16:50:11+00:00 Milosz Tanski milosz@adfin.com 2013-08-21T21:29:54+00:00 99ccbd229cf7453206bc858e795ec1f0345ff258 Adding support for fscache to the Ceph filesystem. This would bring it to on par with some of the other network filesystems in Linux (like NFS, AFS, etc...) In order to mount the filesystem with fscache the 'fsc' mount option must be passed. Signed-off-by: Milosz Tanski <milosz@adfin.com> Signed-off-by: Sage Weil <sage@inktank.com> 
Adding support for fscache to the Ceph filesystem. This would bring it to on
par with some of the other network filesystems in Linux (like NFS, AFS, etc...)

In order to mount the filesystem with fscache the 'fsc' mount option must be
passed.

Signed-off-by: Milosz Tanski <milosz@adfin.com>
Signed-off-by: Sage Weil <sage@inktank.com>
ceph: avoid accessing invalid memory 2013-07-03T22:32:55+00:00 Sasha Levin sasha.levin@oracle.com 2013-07-01T22:33:39+00:00 5446429630257f4723829409337a26c076907d5d when mounting ceph with a dev name that starts with a slash, ceph would attempt to access the character before that slash. Since we don't actually own that byte of memory, we would trigger an invalid access: [ 43.499934] BUG: unable to handle kernel paging request at ffff880fa3a97fff [ 43.500984] IP: [<ffffffff818f3884>] parse_mount_options+0x1a4/0x300 [ 43.501491] PGD 743b067 PUD 10283c4067 PMD 10282a6067 PTE 8000000fa3a97060 [ 43.502301] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC [ 43.503006] Dumping ftrace buffer: [ 43.503596] (ftrace buffer empty) [ 43.504046] CPU: 0 PID: 10879 Comm: mount Tainted: G W 3.10.0-sasha #1129 [ 43.504851] task: ffff880fa625b000 ti: ffff880fa3412000 task.ti: ffff880fa3412000 [ 43.505608] RIP: 0010:[<ffffffff818f3884>] [<ffffffff818f3884>] parse_mount_options$ [ 43.506552] RSP: 0018:ffff880fa3413d08 EFLAGS: 00010286 [ 43.507133] RAX: ffff880fa3a98000 RBX: ffff880fa3a98000 RCX: 0000000000000000 [ 43.507893] RDX: ffff880fa3a98001 RSI: 000000000000002f RDI: ffff880fa3a98000 [ 43.508610] RBP: ffff880fa3413d58 R08: 0000000000001f99 R09: ffff880fa3fe64c0 [ 43.509426] R10: ffff880fa3413d98 R11: ffff880fa38710d8 R12: ffff880fa3413da0 [ 43.509792] R13: ffff880fa3a97fff R14: 0000000000000000 R15: ffff880fa3413d90 [ 43.509792] FS: 00007fa9c48757e0(0000) GS:ffff880fd2600000(0000) knlGS:000000000000$ [ 43.509792] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 43.509792] CR2: ffff880fa3a97fff CR3: 0000000fa3bb9000 CR4: 00000000000006b0 [ 43.509792] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 43.509792] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 43.509792] Stack: [ 43.509792] 0000e5180000000e ffffffff85ca1900 ffff880fa38710d8 ffff880fa3413d98 [ 43.509792] 0000000000000120 0000000000000000 ffff880fa3a98000 0000000000000000 [ 43.509792] ffffffff85cf32a0 0000000000000000 ffff880fa3413dc8 ffffffff818f3c72 [ 43.509792] Call Trace: [ 43.509792] [<ffffffff818f3c72>] ceph_mount+0xa2/0x390 [ 43.509792] [<ffffffff81226314>] ? pcpu_alloc+0x334/0x3c0 [ 43.509792] [<ffffffff81282f8d>] mount_fs+0x8d/0x1a0 [ 43.509792] [<ffffffff812263d0>] ? __alloc_percpu+0x10/0x20 [ 43.509792] [<ffffffff8129f799>] vfs_kern_mount+0x79/0x100 [ 43.509792] [<ffffffff812a224d>] do_new_mount+0xcd/0x1c0 [ 43.509792] [<ffffffff812a2e8d>] do_mount+0x15d/0x210 [ 43.509792] [<ffffffff81220e55>] ? strndup_user+0x45/0x60 [ 43.509792] [<ffffffff812a2fdd>] SyS_mount+0x9d/0xe0 [ 43.509792] [<ffffffff83fd816c>] tracesys+0xdd/0xe2 [ 43.509792] Code: 4c 8b 5d c0 74 0a 48 8d 50 01 49 89 14 24 eb 17 31 c0 48 83 c9 ff $ [ 43.509792] RIP [<ffffffff818f3884>] parse_mount_options+0x1a4/0x300 [ 43.509792] RSP <ffff880fa3413d08> [ 43.509792] CR2: ffff880fa3a97fff [ 43.509792] ---[ end trace 22469cd81e93af51 ]--- Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Reviewed-by: Sage Weil <sage@inktan.com> 
when mounting ceph with a dev name that starts with a slash, ceph
would attempt to access the character before that slash. Since we
don't actually own that byte of memory, we would trigger an
invalid access:

[   43.499934] BUG: unable to handle kernel paging request at ffff880fa3a97fff
[   43.500984] IP: [<ffffffff818f3884>] parse_mount_options+0x1a4/0x300
[   43.501491] PGD 743b067 PUD 10283c4067 PMD 10282a6067 PTE 8000000fa3a97060
[   43.502301] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[   43.503006] Dumping ftrace buffer:
[   43.503596]    (ftrace buffer empty)
[   43.504046] CPU: 0 PID: 10879 Comm: mount Tainted: G        W    3.10.0-sasha #1129
[   43.504851] task: ffff880fa625b000 ti: ffff880fa3412000 task.ti: ffff880fa3412000
[   43.505608] RIP: 0010:[<ffffffff818f3884>]  [<ffffffff818f3884>] parse_mount_options$
[   43.506552] RSP: 0018:ffff880fa3413d08  EFLAGS: 00010286
[   43.507133] RAX: ffff880fa3a98000 RBX: ffff880fa3a98000 RCX: 0000000000000000
[   43.507893] RDX: ffff880fa3a98001 RSI: 000000000000002f RDI: ffff880fa3a98000
[   43.508610] RBP: ffff880fa3413d58 R08: 0000000000001f99 R09: ffff880fa3fe64c0
[   43.509426] R10: ffff880fa3413d98 R11: ffff880fa38710d8 R12: ffff880fa3413da0
[   43.509792] R13: ffff880fa3a97fff R14: 0000000000000000 R15: ffff880fa3413d90
[   43.509792] FS:  00007fa9c48757e0(0000) GS:ffff880fd2600000(0000) knlGS:000000000000$
[   43.509792] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[   43.509792] CR2: ffff880fa3a97fff CR3: 0000000fa3bb9000 CR4: 00000000000006b0
[   43.509792] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   43.509792] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[   43.509792] Stack:
[   43.509792]  0000e5180000000e ffffffff85ca1900 ffff880fa38710d8 ffff880fa3413d98
[   43.509792]  0000000000000120 0000000000000000 ffff880fa3a98000 0000000000000000
[   43.509792]  ffffffff85cf32a0 0000000000000000 ffff880fa3413dc8 ffffffff818f3c72
[   43.509792] Call Trace:
[   43.509792]  [<ffffffff818f3c72>] ceph_mount+0xa2/0x390
[   43.509792]  [<ffffffff81226314>] ? pcpu_alloc+0x334/0x3c0
[   43.509792]  [<ffffffff81282f8d>] mount_fs+0x8d/0x1a0
[   43.509792]  [<ffffffff812263d0>] ? __alloc_percpu+0x10/0x20
[   43.509792]  [<ffffffff8129f799>] vfs_kern_mount+0x79/0x100
[   43.509792]  [<ffffffff812a224d>] do_new_mount+0xcd/0x1c0
[   43.509792]  [<ffffffff812a2e8d>] do_mount+0x15d/0x210
[   43.509792]  [<ffffffff81220e55>] ? strndup_user+0x45/0x60
[   43.509792]  [<ffffffff812a2fdd>] SyS_mount+0x9d/0xe0
[   43.509792]  [<ffffffff83fd816c>] tracesys+0xdd/0xe2
[   43.509792] Code: 4c 8b 5d c0 74 0a 48 8d 50 01 49 89 14 24 eb 17 31 c0 48 83 c9 ff $
[   43.509792] RIP  [<ffffffff818f3884>] parse_mount_options+0x1a4/0x300
[   43.509792]  RSP <ffff880fa3413d08>
[   43.509792] CR2: ffff880fa3a97fff
[   43.509792] ---[ end trace 22469cd81e93af51 ]---

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Reviewed-by: Sage Weil <sage@inktan.com>
ceph: set up page array mempool with correct size 2013-05-02T04:17:50+00:00 Alex Elder elder@inktank.com 2013-04-01T15:48:40+00:00 3bf53337af27a3ccc6e0f433b081063cdf0a2bf6 In create_fs_client() a memory pool is set up be used for arrays of pages that might be needed in ceph_writepages_start() if memory is tight. There are two problems with the way it's initialized: - The size provided is the number of pages we want in the array, but it should be the number of bytes required for that many page pointers. - The number of pages computed can end up being 0, while we will always need at least one page. This patch fixes both of these problems. This resolves the two simple problems defined in: http://tracker.ceph.com/issues/4603 Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com> 
In create_fs_client() a memory pool is set up be used for arrays of
pages that might be needed in ceph_writepages_start() if memory is
tight.  There are two problems with the way it's initialized:
    - The size provided is the number of pages we want in the
      array, but it should be the number of bytes required for
      that many page pointers.
    - The number of pages computed can end up being 0, while we
      will always need at least one page.

This patch fixes both of these problems.

This resolves the two simple problems defined in:
    http://tracker.ceph.com/issues/4603

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
fs: Limit sys_mount to only request filesystem modules. 2013-03-04T03:36:31+00:00 Eric W. Biederman ebiederm@xmission.com 2013-03-03T03:39:14+00:00 7f78e0351394052e1a6293e175825eb5c7869507 Modify the request_module to prefix the file system type with "fs-" and add aliases to all of the filesystems that can be built as modules to match. A common practice is to build all of the kernel code and leave code that is not commonly needed as modules, with the result that many users are exposed to any bug anywhere in the kernel. Looking for filesystems with a fs- prefix limits the pool of possible modules that can be loaded by mount to just filesystems trivially making things safer with no real cost. Using aliases means user space can control the policy of which filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf with blacklist and alias directives. Allowing simple, safe, well understood work-arounds to known problematic software. This also addresses a rare but unfortunate problem where the filesystem name is not the same as it's module name and module auto-loading would not work. While writing this patch I saw a handful of such cases. The most significant being autofs that lives in the module autofs4. This is relevant to user namespaces because we can reach the request module in get_fs_type() without having any special permissions, and people get uncomfortable when a user specified string (in this case the filesystem type) goes all of the way to request_module. After having looked at this issue I don't think there is any particular reason to perform any filtering or permission checks beyond making it clear in the module request that we want a filesystem module. The common pattern in the kernel is to call request_module() without regards to the users permissions. In general all a filesystem module does once loaded is call register_filesystem() and go to sleep. Which means there is not much attack surface exposed by loading a filesytem module unless the filesystem is mounted. In a user namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT, which most filesystems do not set today. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Reported-by: Kees Cook <keescook@google.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> 
Modify the request_module to prefix the file system type with "fs-"
and add aliases to all of the filesystems that can be built as modules
to match.

A common practice is to build all of the kernel code and leave code
that is not commonly needed as modules, with the result that many
users are exposed to any bug anywhere in the kernel.

Looking for filesystems with a fs- prefix limits the pool of possible
modules that can be loaded by mount to just filesystems trivially
making things safer with no real cost.

Using aliases means user space can control the policy of which
filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
with blacklist and alias directives.  Allowing simple, safe,
well understood work-arounds to known problematic software.

This also addresses a rare but unfortunate problem where the filesystem
name is not the same as it's module name and module auto-loading
would not work.  While writing this patch I saw a handful of such
cases.  The most significant being autofs that lives in the module
autofs4.

This is relevant to user namespaces because we can reach the request
module in get_fs_type() without having any special permissions, and
people get uncomfortable when a user specified string (in this case
the filesystem type) goes all of the way to request_module.

After having looked at this issue I don't think there is any
particular reason to perform any filtering or permission checks beyond
making it clear in the module request that we want a filesystem
module.  The common pattern in the kernel is to call request_module()
without regards to the users permissions.  In general all a filesystem
module does once loaded is call register_filesystem() and go to sleep.
Which means there is not much attack surface exposed by loading a
filesytem module unless the filesystem is mounted.  In a user
namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
which most filesystems do not set today.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reported-by: Kees Cook <keescook@google.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>