Gitweb:
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=f9ffed26d6f3e6ac9988947242821579d615fda7
Commit: f9ffed26d6f3e6ac9988947242821579d615fda7
Parent: a9933cea7a1d80dd9efae9f1acd857f5dce742b9
Author: J. Bruce Fields <[EMAIL PROTECTED]>
AuthorDate: Tue Nov 14 15:51:40 2006 -0500
Committer: J. Bruce Fields <[EMAIL PROTECTED]>
CommitDate: Wed Jul 18 19:14:47 2007 -0400
locks: provide a file lease method enabling cluster-coherent leases
Currently leases are only kept locally, so there's no way for a distributed
filesystem to enforce them against multiple clients. We're particularly
interested in the case of nfsd exporting a cluster filesystem, in which
case nfsd needs cluster-coherent leases in order to implement delegations
correctly.
Also add some documentation.
Signed-off-by: J. Bruce Fields <[EMAIL PROTECTED]>
---
fs/locks.c | 24 ++++++++++++++++++++++--
include/linux/fs.h | 1 +
2 files changed, 23 insertions(+), 2 deletions(-)
diff --git a/fs/locks.c b/fs/locks.c
index a65d85c..94f5d80 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1429,7 +1429,24 @@ out:
* @lease: file_lock to use
*
* Call this to establish a lease on the file.
- * The fl_lmops fl_break function is required by break_lease
+ * The (*lease)->fl_lmops->fl_break operation must be set; if not,
+ * break_lease will oops!
+ *
+ * This will call the filesystem's setlease file method, if
+ * defined. Note that there is no getlease method; instead, the
+ * filesystem setlease method should call back to setlease() to
+ * add a lease to the inode's lease list, where fcntl_getlease() can
+ * find it. Since fcntl_getlease() only reports whether the current
+ * task holds a lease, a cluster filesystem need only do this for
+ * leases held by processes on this node.
+ *
+ * There is also no break_lease method; filesystems that
+ * handle their own leases shoud break leases themselves from the
+ * filesystem's open, create, and (on truncate) setattr methods.
+ *
+ * Warning: the only current setlease methods exist only to disable
+ * leases in certain cases. More vfs changes may be required to
+ * allow a full filesystem lease implementation.
*/
int vfs_setlease(struct file *filp, long arg, struct file_lock **lease)
@@ -1437,7 +1454,10 @@ int vfs_setlease(struct file *filp, long arg, struct
file_lock **lease)
int error;
lock_kernel();
- error = setlease(filp, arg, lease);
+ if (filp->f_op && filp->f_op->setlease)
+ error = filp->f_op->setlease(filp, arg, lease);
+ else
+ error = setlease(filp, arg, lease);
unlock_kernel();
return error;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index a24f029..c8ddf34 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1122,6 +1122,7 @@ struct file_operations {
int (*flock) (struct file *, int, struct file_lock *);
ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t
*, size_t, unsigned int);
ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info
*, size_t, unsigned int);
+ int (*setlease)(struct file *, long, struct file_lock **);
};
struct inode_operations {
-
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