[Devel] [PATCH RHEL8 COMMIT] fuse: add support for fallocate(FL_ZERO_RANGE)

[Konstantin Khorenko]

The commit is pushed to "branch-rh8-4.18.0-240.1.1.vz8.5.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh8-4.18.0-240.1.1.vz8.5.19
------>
commit 6d0c2f07c01b77b62feb6fab975d53daf6f033b8
Author: Maxim Patlasov <mpatlasov at virtuozzo.com>
Date:   Fri Apr 23 11:54:55 2021 +0300

    fuse: add support for fallocate(FL_ZERO_RANGE)
    
    The patch is required to do FALLOC_FL_ZERO_RANGE.
    
    Authored-by: Alexey Kuznetsov <kuznet at virtuozzo.com>
    Signed-off-by: Maxim Patlasov <mpatlasov at virtuozzo.com>
---
 fs/fuse/file.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index c9112c1e15d1..02f6a6eb2f29 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -3657,9 +3657,10 @@ static long fuse_file_fallocate(struct file *file, int mode, loff_t offset,
 	};
 	int err;
 	bool lock_inode = !(mode & FALLOC_FL_KEEP_SIZE) ||
-			   (mode & FALLOC_FL_PUNCH_HOLE);
+			   (mode & (FALLOC_FL_PUNCH_HOLE|FALLOC_FL_ZERO_RANGE));
 
-	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
+	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
+		     FALLOC_FL_ZERO_RANGE))
 		return -EOPNOTSUPP;
 
 	if (fc->no_fallocate)
@@ -3667,7 +3668,7 @@ static long fuse_file_fallocate(struct file *file, int mode, loff_t offset,
 
 	if (lock_inode) {
 		inode_lock(inode);
-		if (mode & FALLOC_FL_PUNCH_HOLE) {
+		if (mode & (FALLOC_FL_PUNCH_HOLE|FALLOC_FL_ZERO_RANGE)) {
 			loff_t endbyte = offset + length - 1;
 
 			err = fuse_writeback_range(inode, offset, endbyte);
@@ -3708,7 +3709,7 @@ static long fuse_file_fallocate(struct file *file, int mode, loff_t offset,
 			file_update_time(file);
 	}
 
-	if (mode & FALLOC_FL_PUNCH_HOLE)
+	if (mode & (FALLOC_FL_PUNCH_HOLE|FALLOC_FL_ZERO_RANGE))
 		truncate_pagecache_range(inode, offset, offset + length - 1);
 
 	fuse_invalidate_attr(inode);