s3 oplocks: Make the level2 oplock contention API more granular

This replaces release_level2_oplocks_on_change with
contend_level2_oplock_begin/end in order to contend level2 oplocks
throughout an operation rather than just at the begining.  This is
necessary for some kernel oplock implementations, and also lays the
groundwork for better correctness in Samba's standard level2 oplock
handling.  The next step for non-kernel oplocks is to add additional
state to the share mode lock struct that prevents any new opens from
granting oplocks while a contending operation is in progress.

All operations that contend level 2 oplocks are now correctly spanned
except for aio and synchronous writes.  The two write paths both have
non-trivial error paths that need extra care to get right.

RAW-OPLOCK and the rest of 'make test' are still passing with this
change.

1 files changed, 14 insertions, 0 deletions

diff --git a/source3/include/smb.h b/source3/include/smb.h
index 96cd3b7d85..557489f211 100644
--- a/source3/include/smb.h
+++ b/source3/include/smb.h
@@ -1695,6 +1695,16 @@ struct kernel_oplocks {
 	void *private_data;
 };
 
+enum level2_contention_type {
+	LEVEL2_CONTEND_ALLOC_SHRINK,
+	LEVEL2_CONTEND_ALLOC_GROW,
+	LEVEL2_CONTEND_SET_FILE_LEN,
+	LEVEL2_CONTEND_FILL_SPARSE,
+	LEVEL2_CONTEND_WRITE,
+	LEVEL2_CONTEND_WINDOWS_BRL,
+	LEVEL2_CONTEND_POSIX_BRL
+};
+
 /* if a kernel does support oplocks then a structure of the following
    typee is used to describe how to interact with the kernel */
 struct kernel_oplocks_ops {
@@ -1702,6 +1712,10 @@ struct kernel_oplocks_ops {
 			   files_struct *fsp, int oplock_type);
 	void (*release_oplock)(struct kernel_oplocks *ctx,
 			       files_struct *fsp, int oplock_type);
+	void (*contend_level2_oplocks_begin)(files_struct *fsp,
+					     enum level2_contention_type type);
+	void (*contend_level2_oplocks_end)(files_struct *fsp,
+					   enum level2_contention_type type);
 };
 
 #include "smb_macros.h"