diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-10-14 12:31:14 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-10-14 12:31:14 -0700 |
commit | 8acd3a60bcca17c6d89c73cee3ad6057eb83ba1e (patch) | |
tree | d610c8d39246c33c499ee9d92d302d3ca9e89ae3 /fs/lockd/grace.c | |
parent | c269bc00fcb876ae3b85f178f1e34601185c8ccc (diff) | |
parent | 107e0008dfb8bd6366bc8827f5bbbc0c1f795d2d (diff) |
Merge branch 'for-2.6.28' of git://linux-nfs.org/~bfields/linux
* 'for-2.6.28' of git://linux-nfs.org/~bfields/linux: (59 commits)
svcrdma: Fix IRD/ORD polarity
svcrdma: Update svc_rdma_send_error to use DMA LKEY
svcrdma: Modify the RPC reply path to use FRMR when available
svcrdma: Modify the RPC recv path to use FRMR when available
svcrdma: Add support to svc_rdma_send to handle chained WR
svcrdma: Modify post recv path to use local dma key
svcrdma: Add a service to register a Fast Reg MR with the device
svcrdma: Query device for Fast Reg support during connection setup
svcrdma: Add FRMR get/put services
NLM: Remove unused argument from svc_addsock() function
NLM: Remove "proto" argument from lockd_up()
NLM: Always start both UDP and TCP listeners
lockd: Remove unused fields in the nlm_reboot structure
lockd: Add helper to sanity check incoming NOTIFY requests
lockd: change nlmclnt_grant() to take a "struct sockaddr *"
lockd: Adjust nlmsvc_lookup_host() to accomodate AF_INET6 addresses
lockd: Adjust nlmclnt_lookup_host() signature to accomodate non-AF_INET
lockd: Support non-AF_INET addresses in nlm_lookup_host()
NLM: Convert nlm_lookup_host() to use a single argument
svcrdma: Add Fast Reg MR Data Types
...
Diffstat (limited to 'fs/lockd/grace.c')
-rw-r--r-- | fs/lockd/grace.c | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/fs/lockd/grace.c b/fs/lockd/grace.c new file mode 100644 index 000000000000..183cc1f0af1c --- /dev/null +++ b/fs/lockd/grace.c @@ -0,0 +1,59 @@ +/* + * Common code for control of lockd and nfsv4 grace periods. + */ + +#include <linux/module.h> +#include <linux/lockd/bind.h> + +static LIST_HEAD(grace_list); +static DEFINE_SPINLOCK(grace_lock); + +/** + * locks_start_grace + * @lm: who this grace period is for + * + * A grace period is a period during which locks should not be given + * out. Currently grace periods are only enforced by the two lock + * managers (lockd and nfsd), using the locks_in_grace() function to + * check when they are in a grace period. + * + * This function is called to start a grace period. + */ +void locks_start_grace(struct lock_manager *lm) +{ + spin_lock(&grace_lock); + list_add(&lm->list, &grace_list); + spin_unlock(&grace_lock); +} +EXPORT_SYMBOL_GPL(locks_start_grace); + +/** + * locks_end_grace + * @lm: who this grace period is for + * + * Call this function to state that the given lock manager is ready to + * resume regular locking. The grace period will not end until all lock + * managers that called locks_start_grace() also call locks_end_grace(). + * Note that callers count on it being safe to call this more than once, + * and the second call should be a no-op. + */ +void locks_end_grace(struct lock_manager *lm) +{ + spin_lock(&grace_lock); + list_del_init(&lm->list); + spin_unlock(&grace_lock); +} +EXPORT_SYMBOL_GPL(locks_end_grace); + +/** + * locks_in_grace + * + * Lock managers call this function to determine when it is OK for them + * to answer ordinary lock requests, and when they should accept only + * lock reclaims. + */ +int locks_in_grace(void) +{ + return !list_empty(&grace_list); +} +EXPORT_SYMBOL_GPL(locks_in_grace); |