Since we only enforce an upper bound, not a lower bound, a "negative"
length can get through here.
The symptom seen was a warning when we attempt to a kmalloc with an
excessive size.
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Cc: stable@kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
vfs_writev() updates the offset argument - but the code then passes the
offset to vfs_fsync_range(). Since offset now points to the offset after
what was just written, this is probably not what was intended
Introduced by face15025f "nfsd: use
vfs_fsync_range(), not O_SYNC, for stable writes".
Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: stable@vger.kernel.org
Reviewed-by: Zach Brown <zab@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
If we end up doing "goto out_nomem" in this function, we'll call
nfsd_reply_cache_shutdown. That will attempt to walk the LRU list and
free entries, but that list may not be initialized yet if the server is
starting up for the first time. It's also possible for the shrinker to
kick in before we've initialized the LRU list.
Rearrange the initialization so that the LRU list_head and cache size
are initialized before doing any of the allocations that might fail.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
It's not safe to call hlist_del() on a newly initialized hlist_node.
That leads to a NULL pointer dereference. Only do that if the entry
is hashed.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
idr_get_new*() and friends are about to be deprecated. Convert to the
new idr_alloc() interface.
Only compile-tested.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: J. Bruce Fields <bfields@redhat.com>
Tested-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
get_new_stid() is no longer used since commit 3abdb60712 ("nfsd4:
simplify idr allocation"). Remove it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
Pull nfsd changes from J Bruce Fields:
"Miscellaneous bugfixes, plus:
- An overhaul of the DRC cache by Jeff Layton. The main effect is
just to make it larger. This decreases the chances of intermittent
errors especially in the UDP case. But we'll need to watch for any
reports of performance regressions.
- Containerized nfsd: with some limitations, we now support
per-container nfs-service, thanks to extensive work from Stanislav
Kinsbursky over the last year."
Some notes about conflicts, since there were *two* non-data semantic
conflicts here:
- idr_remove_all() had been added by a memory leak fix, but has since
become deprecated since idr_destroy() does it for us now.
- xs_local_connect() had been added by this branch to make AF_LOCAL
connections be synchronous, but in the meantime Trond had changed the
calling convention in order to avoid a RCU dereference.
There were a couple of more obvious actual source-level conflicts due to
the hlist traversal changes and one just due to code changes next to
each other, but those were trivial.
* 'for-3.9' of git://linux-nfs.org/~bfields/linux: (49 commits)
SUNRPC: make AF_LOCAL connect synchronous
nfsd: fix compiler warning about ambiguous types in nfsd_cache_csum
svcrpc: fix rpc server shutdown races
svcrpc: make svc_age_temp_xprts enqueue under sv_lock
lockd: nlmclnt_reclaim(): avoid stack overflow
nfsd: enable NFSv4 state in containers
nfsd: disable usermode helper client tracker in container
nfsd: use proper net while reading "exports" file
nfsd: containerize NFSd filesystem
nfsd: fix comments on nfsd_cache_lookup
SUNRPC: move cache_detail->cache_request callback call to cache_read()
SUNRPC: remove "cache_request" argument in sunrpc_cache_pipe_upcall() function
SUNRPC: rework cache upcall logic
SUNRPC: introduce cache_detail->cache_request callback
NFS: simplify and clean cache library
NFS: use SUNRPC cache creation and destruction helper for DNS cache
nfsd4: free_stid can be static
nfsd: keep a checksum of the first 256 bytes of request
sunrpc: trim off trailing checksum before returning decrypted or integrity authenticated buffer
sunrpc: fix comment in struct xdr_buf definition
...
I'm not sure why, but the hlist for each entry iterators were conceived
list_for_each_entry(pos, head, member)
The hlist ones were greedy and wanted an extra parameter:
hlist_for_each_entry(tpos, pos, head, member)
Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.
Besides the semantic patch, there was some manual work required:
- Fix up the actual hlist iterators in linux/list.h
- Fix up the declaration of other iterators based on the hlist ones.
- A very small amount of places were using the 'node' parameter, this
was modified to use 'obj->member' instead.
- Coccinelle didn't handle the hlist_for_each_entry_safe iterator
properly, so those had to be fixed up manually.
The semantic patch which is mostly the work of Peter Senna Tschudin is here:
@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;
type T;
expression a,c,d,e;
identifier b;
statement S;
@@
-T b;
<+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
...+>
[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull vfs pile (part one) from Al Viro:
"Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent
locking violations, etc.
The most visible changes here are death of FS_REVAL_DOT (replaced with
"has ->d_weak_revalidate()") and a new helper getting from struct file
to inode. Some bits of preparation to xattr method interface changes.
Misc patches by various people sent this cycle *and* ocfs2 fixes from
several cycles ago that should've been upstream right then.
PS: the next vfs pile will be xattr stuff."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits)
saner proc_get_inode() calling conventions
proc: avoid extra pde_put() in proc_fill_super()
fs: change return values from -EACCES to -EPERM
fs/exec.c: make bprm_mm_init() static
ocfs2/dlm: use GFP_ATOMIC inside a spin_lock
ocfs2: fix possible use-after-free with AIO
ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path
get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero
target: writev() on single-element vector is pointless
export kernel_write(), convert open-coded instances
fs: encode_fh: return FILEID_INVALID if invalid fid_type
kill f_vfsmnt
vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op
nfsd: handle vfs_getattr errors in acl protocol
switch vfs_getattr() to struct path
default SET_PERSONALITY() in linux/elf.h
ceph: prepopulate inodes only when request is aborted
d_hash_and_lookup(): export, switch open-coded instances
9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate()
9p: split dropping the acls from v9fs_set_create_acl()
...
We're currently ignoring errors from vfs_getattr.
The correct thing to do is to do the stat in the main service procedure
not in the response encoding.
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull user namespace and namespace infrastructure changes from Eric W Biederman:
"This set of changes starts with a few small enhnacements to the user
namespace. reboot support, allowing more arbitrary mappings, and
support for mounting devpts, ramfs, tmpfs, and mqueuefs as just the
user namespace root.
I do my best to document that if you care about limiting your
unprivileged users that when you have the user namespace support
enabled you will need to enable memory control groups.
There is a minor bug fix to prevent overflowing the stack if someone
creates way too many user namespaces.
The bulk of the changes are a continuation of the kuid/kgid push down
work through the filesystems. These changes make using uids and gids
typesafe which ensures that these filesystems are safe to use when
multiple user namespaces are in use. The filesystems converted for
3.9 are ceph, 9p, afs, ocfs2, gfs2, ncpfs, nfs, nfsd, and cifs. The
changes for these filesystems were a little more involved so I split
the changes into smaller hopefully obviously correct changes.
XFS is the only filesystem that remains. I was hoping I could get
that in this release so that user namespace support would be enabled
with an allyesconfig or an allmodconfig but it looks like the xfs
changes need another couple of days before it they are ready."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (93 commits)
cifs: Enable building with user namespaces enabled.
cifs: Convert struct cifs_ses to use a kuid_t and a kgid_t
cifs: Convert struct cifs_sb_info to use kuids and kgids
cifs: Modify struct smb_vol to use kuids and kgids
cifs: Convert struct cifsFileInfo to use a kuid
cifs: Convert struct cifs_fattr to use kuid and kgids
cifs: Convert struct tcon_link to use a kuid.
cifs: Modify struct cifs_unix_set_info_args to hold a kuid_t and a kgid_t
cifs: Convert from a kuid before printing current_fsuid
cifs: Use kuids and kgids SID to uid/gid mapping
cifs: Pass GLOBAL_ROOT_UID and GLOBAL_ROOT_GID to keyring_alloc
cifs: Use BUILD_BUG_ON to validate uids and gids are the same size
cifs: Override unmappable incoming uids and gids
nfsd: Enable building with user namespaces enabled.
nfsd: Properly compare and initialize kuids and kgids
nfsd: Store ex_anon_uid and ex_anon_gid as kuids and kgids
nfsd: Modify nfsd4_cb_sec to use kuids and kgids
nfsd: Handle kuids and kgids in the nfs4acl to posix_acl conversion
nfsd: Convert nfsxdr to use kuids and kgids
nfsd: Convert nfs3xdr to use kuids and kgids
...
The three variables are calculated from nr_free_buffer_pages so change
their types to unsigned long in case of overflow.
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, NFSd is ready to operate in network namespace based containers.
So let's drop check for "init_net" and make it able to fly.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This tracker uses khelper kthread to execute binaries.
Execution itself is done from kthread context - i.e. global root is used.
This is not suitable for containers with own root.
So, disable this tracker for a while.
Note: one of possible solutions can be pass "init" callback to khelper, which
will swap root to desired one.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Functuon "exports_open" is used for both "/proc/fs/nfs/exports" and
"/proc/fs/nfsd/exports" files.
Now NFSd filesystem is containerised, so proper net can be taken from
superblock for "/proc/fs/nfsd/exports" reader.
But for "/proc/fs/nfsd/exports" only current->nsproxy->net_ns can be used.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This patch makes NFSD file system superblock to be created per net.
This makes possible to get proper network namespace from superblock instead of
using hard-coded "init_net".
Note: NFSd fs super-block holds network namespace. This garantees, that
network namespace won't disappear from underneath of it.
This, obviously, means, that in case of kill of a container's "init" (which is not a mount
namespace, but network namespace creator) netowrk namespace won't be
destroyed.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
For most of SUNRPC caches (except NFS DNS cache) cache_detail->cache_upcall is
redundant since all that it's implementations are doing is calling
sunrpc_cache_pipe_upcall() with proper function address argument.
Cache request function address is now stored on cache_detail structure and
thus all the code can be simplified.
Now, for those cache details, which doesn't have cache_upcall callback (the
only one, which still has is nfs_dns_resolve_template)
sunrpc_cache_pipe_upcall will be called instead.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This callback will allow to simplify upcalls in further patches in this
series.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Use uid_eq(uid, GLOBAL_ROOT_UID) instead of !uid.
Use gid_eq(gid, GLOBAL_ROOT_GID) instead of !gid.
Use uid_eq(uid, INVALID_UID) instead of uid == -1
Use gid_eq(uid, INVALID_GID) instead of gid == -1
Use uid = GLOBAL_ROOT_UID instead of uid = 0;
Use gid = GLOBAL_ROOT_GID instead of gid = 0;
Use !uid_eq(uid1, uid2) instead of uid1 != uid2.
Use !gid_eq(gid1, gid2) instead of gid1 != gid2.
Use uid_eq(uid1, uid2) instead of uid1 == uid2.
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Change uid and gid in struct nfsd4_cb_sec to be of type kuid_t and
kgid_t.
In nfsd4_decode_cb_sec when reading uids and gids off the wire convert
them to kuids and kgids, and if they don't convert to valid kuids or
valid kuids ignore RPC_AUTH_UNIX and don't fill in any of the fields.
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
In struct nfs4_ace remove the member who and replace it with an
anonymous union holding who_uid and who_gid. Allowing typesafe
storage uids and gids.
Add a helper pace_gt for sorting posix_acl_entries.
In struct posix_user_ace_state to replace uid with a union
of kuid_t uid and kgid_t gid.
Remove all initializations of the deprecated posic_acl_entry
e_id field. Which is not present when user namespaces are enabled.
Split find_uid into two functions find_uid and find_gid that work
in a typesafe manner.
In nfs4xdr update nfsd4_encode_fattr to deal with the changes
in struct nfs4_ace.
Rewrite nfsd4_encode_name to take a kuid_t and a kgid_t instead
of a generic id and flag if it is a group or a uid. Replace
the group flag with a test for a valid gid.
Modify nfsd4_encode_user to take a kuid_t and call the modifed
nfsd4_encode_name.
Modify nfsd4_encode_group to take a kgid_t and call the modified
nfsd4_encode_name.
Modify nfsd4_encode_aclname to take an ace instead of taking the
fields of an ace broken out. This allows it to detect if the ace is
for a user or a group and to pass the appropriate value while still
being typesafe.
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
When reading uids and gids off the wire convert them to
kuids and kgids. If the conversion results in an invalid
result don't set the ATTR_UID or ATTR_GID.
When putting kuids and kgids onto the wire first convert
them to uids and gids the other side will understand.
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
When reading uids and gids off the wire convert them to kuids and
kgids.
When putting kuids and kgids onto the wire first convert them to uids
and gids the other side will understand.
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
These trivial macros that don't currently do anything are the last
vestiages of an old attempt at uid mapping that was removed from the
kernel in September of 2002. Remove them to make it clear what the
code is currently doing.
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Convert nfsd_map_name_to_uid to return a kuid_t value.
Convert nfsd_map_name_to_gid to return a kgid_t value.
Convert nfsd_map_uid_to_name to take a kuid_t parameter.
Convert nfsd_map_gid_to_name to take a kgid_t paramater.
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
u32 and uid_t have the same size and semantics so this change
should have no operational effect. This just removes the WTF
factor when looking at variables that hold both uids and gids
whos type is uid_t.
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Now that we're allowing more DRC entries, it becomes a lot easier to hit
problems with XID collisions. In order to mitigate those, calculate a
checksum of up to the first 256 bytes of each request coming in and store
that in the cache entry, along with the total length of the request.
This initially used crc32, but Chuck Lever and Jim Rees pointed out that
crc32 is probably more heavyweight than we really need for generating
these checksums, and recommended looking at using the same routines that
are used to generate checksums for IP packets.
On an x86_64 KVM guest measurements with ftrace showed ~800ns to use
csum_partial vs ~1750ns for crc32. The difference probably isn't
terribly significant, but for now we may as well use csum_partial.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Stones-thrown-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
These routines are used by server and client code, so having them in a
separate header would be best.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
We don't really need to preallocate at all; just allocate and initialize
everything at once, but leave the sc_type field initially 0 to prevent
finding the stateid till it's fully initialized.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
When free nfs-client, it must free the ->cl_stateids.
Cc: stable@kernel.org
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Since we dynamically allocate them now, allow the system to call us up
to release them if it gets low on memory. Since these entries aren't
replaceable, only free ones that are expired or that are over the cap.
The the seeks value is set to '1' however to indicate that freeing the
these entries is low-cost.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
It's not sufficient to only clean the cache when requests come in. What
if we have a flurry of activity and then the server goes idle? Add a
workqueue job that will clean the cache every RC_EXPIRE period.
Care is taken to only run this when we expect to have entries expiring.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
There's no need to keep entries around that we're declaring RC_NOCACHE.
Ditto if there's a problem with the entry.
With this change too, there's no need to test for RC_UNUSED in the
search function. If the entry's in the hash table then it's either
INPROG or DONE.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
With the change to dynamically allocate entries, the cache is never
disabled on the fly. Remove this flag.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The existing code keeps a fixed-size cache of 1024 entries. This is much
too small for a busy server, and wastes memory on an idle one. This
patch changes the code to dynamically allocate and free these cache
entries.
A cap on the number of entries is retained, but it's much larger than
the existing value and now scales with the amount of low memory in the
machine.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
...otherwise, we end up with the list ordering wrong. Currently, it's
not a problem since we skip RC_INPROG entries, but keeping the ordering
strict will be necessary for a later patch that adds a cache cleaner.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Later, we'll need more than one call site for this, so break it out
into a new function.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Add a preprocessor constant for the expiry time of cache entries, and
move the test for an expired entry into a function. Note that the current
code does not test for RC_INPROG. It just assumes that it won't take more
than 2 minutes to fill out an in-progress entry.
I'm not sure how valid that assumption is though, so let's just ensure
that we never consider an RC_INPROG entry to be expired.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Entries can only get a c_type of RC_REPLBUFF iff they are
RC_DONE. Therefore the test for RC_DONE isn't necessary here.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
J. Bruce Fields
Kent Overstreet
Jeff Layton
Tejun Heo
Eric W. Biederman
Linus Torvalds
Sasha Levin
J. Bruce Fields
Al Viro
Zhang Yanfei
Stanislav Kinsbursky
Fengguang Wu
majianpeng