Redfs-6.8 with dlm_lock opcode for fuse

fs/fuse/Makefile

@@ -10,7 +10,7 @@ obj-$(CONFIG_FUSE_FS) += fuse.o
 obj-$(CONFIG_CUSE) += cuse.o
 obj-$(CONFIG_VIRTIO_FS) += virtiofs.o
 
-fuse-y := dev.o dir.o file.o inode.o control.o xattr.o acl.o readdir.o ioctl.o
+fuse-y := dev.o dir.o file.o inode.o control.o xattr.o acl.o readdir.o ioctl.o fuse_dlm_cache.o
 fuse-y += iomode.o
 fuse-$(CONFIG_FUSE_DAX) += dax.o
 fuse-$(CONFIG_FUSE_IO_URING) += dev_uring.o

fs/fuse/dir.c

@@ -6,6 +6,7 @@
   See the file COPYING.
 */
 
+#include "fuse_dlm_cache.h"
 #include "fuse_i.h"
 
 #include <linux/pagemap.h>
@@ -1924,6 +1925,8 @@ int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
 			 * truncation has already been done by OPEN.  But still
 			 * need to truncate page cache.
 			 */
+			if (fc->dlm && fc->writeback_cache)
+				fuse_dlm_cache_release_locks(fi);
 			i_size_write(inode, 0);
 			truncate_pagecache(inode, 0);
 			goto out;
@@ -2029,6 +2032,9 @@ int fuse_do_setattr(struct dentry *dentry, struct iattr *attr,
 	 */
 	if ((is_truncate || !is_wb) &&
 	    S_ISREG(inode->i_mode) && oldsize != outarg.attr.size) {
+		if (fc->dlm && fc->writeback_cache)
+			fuse_dlm_unlock_range(fi, outarg.attr.size & PAGE_MASK, -1);
+
 		truncate_pagecache(inode, outarg.attr.size);
 		invalidate_inode_pages2(mapping);
 	}

fs/fuse/file.c

@@ -7,6 +7,7 @@
 */
 
 #include "fuse_i.h"
+#include "fuse_dlm_cache.h"
 
 #include <linux/pagemap.h>
 #include <linux/slab.h>
@@ -1423,6 +1424,17 @@ static ssize_t fuse_cache_write_iter(struct kiocb *iocb, struct iov_iter *from)
 			goto writethrough;
 		}
 
+		/* if we have dlm support acquire the lock for the area
+		 * we are writing into */
+		if (fc->dlm) {
+			/* note that a file opened with O_APPEND will have relative values
+			 * in ki_pos. This code is here for convenience and for libfuse overlay test.
+			 * Filesystems should handle O_APPEND with 'direct io' to additionally
+			 * get the performance benefits of 'parallel direct writes'. */
+			loff_t pos = file->f_flags & O_APPEND ? i_size_read(inode) + iocb->ki_pos : iocb->ki_pos;
+			size_t length = iov_iter_count(from);
+			fuse_get_dlm_write_lock(file, pos, length);
+		}
 		return generic_file_write_iter(iocb, from);
 	}
 
@@ -3336,6 +3348,7 @@ void fuse_init_file_inode(struct inode *inode, unsigned int flags)
 
 	INIT_LIST_HEAD(&fi->write_files);
 	INIT_LIST_HEAD(&fi->queued_writes);
+	fuse_dlm_cache_init(fi);
 	fi->writectr = 0;
 	fi->iocachectr = 0;
 	init_waitqueue_head(&fi->page_waitq);