[v2,12/17] locks: update Documentation/filesystems with new setlease semantics

Commit Message

Jeff Layton Sept. 4, 2014, 12:38 p.m. UTC

Signed-off-by: Jeff Layton <[e-mail]>
---
 Documentation/filesystems/Locking | 11 ++++++-----
 Documentation/filesystems/vfs.txt |  7 ++++---
 2 files changed, 10 insertions(+), 8 deletions(-)

Comments

Christoph Hellwig Sept. 4, 2014, 5:50 p.m. UTC | #1

Looks good, but I'd rather merge it into the patch that changes the
semantics.

Reviewed-by: Christoph Hellwig <[e-mail]>
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Jeff Layton Sept. 5, 2014, 2:02 p.m. UTC | #2

On Thu, 4 Sep 2014 10:50:43 -0700
Christoph Hellwig <[e-mail]> wrote:

> Looks good, but I'd rather merge it into the patch that changes the
> semantics.
> 
> Reviewed-by: Christoph Hellwig <[e-mail]>

Fair enough. I'll merge the changes to the Documentation in with the
patches that change them.

Patch

diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index f1997e9da61f..94d93b1f8b53 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -464,15 +464,12 @@  prototypes:
 			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 **);
+	int (*setlease)(struct file *, long, struct file_lock **, void **);
 	long (*fallocate)(struct file *, int, loff_t, loff_t);
 };
 
 locking rules:
-	All may block except for ->setlease.
-	No VFS locks held on entry except for ->setlease.
-
-->setlease has the file_list_lock held and must not sleep.
+	All may block.
 
 ->llseek() locking has moved from llseek to the individual llseek
 implementations.  If your fs is not using generic_file_llseek, you
@@ -496,6 +493,10 @@  components. And there are other reasons why the current interface is a mess...
 ->read on directories probably must go away - we should just enforce -EISDIR
 in sys_read() and friends.
 
+->setlease operations should call generic_setlease() before or after setting
+the lease within the individual filesystem to record the result of the
+operation
+
 --------------------------- dquot_operations -------------------------------
 prototypes:
 	int (*write_dquot) (struct dquot *);
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index 61d65cc65c54..af9441f32a62 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -826,7 +826,7 @@  struct file_operations {
 	int (*flock) (struct file *, int, struct file_lock *);
 	ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, size_t, unsigned int);
 	ssize_t (*splice_read)(struct file *, struct pipe_inode_info *, size_t, unsigned int);
-	int (*setlease)(struct file *, long arg, struct file_lock **);
+	int (*setlease)(struct file *, long arg, struct file_lock **, void **);
 	long (*fallocate)(struct file *, int mode, loff_t offset, loff_t len);
 	int (*show_fdinfo)(struct seq_file *m, struct file *f);
 };
@@ -895,8 +895,9 @@  otherwise noted.
   splice_read: called by the VFS to splice data from file to a pipe. This
 	       method is used by the splice(2) system call
 
-  setlease: called by the VFS to set or release a file lock lease.
-	    setlease has the file_lock_lock held and must not sleep.
+  setlease: called by the VFS to set or release a file lock lease. setlease
+	    implementations should call generic_setlease to record or remove
+	    the lease in the inode after setting it
 
   fallocate: called by the VFS to preallocate blocks or punch a hole.