[Devel] [PATCH RHEL7 COMMIT] fs/fuse kio: add warning about jumbo chunks

[Konstantin Khorenko]

The commit is pushed to "branch-rh7-3.10.0-957.1.3.vz7.83.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-957.1.3.vz7.83.11
------>
commit c68caad88815dfb45bb831a0dd438fa092e435db
Author: Pavel Butsykin <pbutsykin at virtuozzo.com>
Date:   Thu Feb 14 17:33:12 2019 +0300

    fs/fuse kio: add warning about jumbo chunks
    
    KIO doesn't support jumbo chunks yet, so all requests to jumbo chunks are
    silently redirected to user-space. It will be useful to see a message about
    this until support has been added to KIO.
    
    https://pmc.acronis.com/browse/VSTOR-20372
    
    Signed-off-by: Pavel Butsykin <pbutsykin at virtuozzo.com>
---
 fs/fuse/kio/pcs/pcs_fuse_kdirect.c | 3 +++
 fs/fuse/kio/pcs/pcs_mds_prot.h     | 2 ++
 2 files changed, 5 insertions(+)

diff --git a/fs/fuse/kio/pcs/pcs_fuse_kdirect.c b/fs/fuse/kio/pcs/pcs_fuse_kdirect.c
index 55a11a3a925a..b908337f0e11 100644
--- a/fs/fuse/kio/pcs/pcs_fuse_kdirect.c
+++ b/fs/fuse/kio/pcs/pcs_fuse_kdirect.c
@@ -323,6 +323,9 @@ static int kpcs_do_file_open(struct fuse_conn *fc, struct file *file, struct ino
 
 	if (info.sys.map_type != PCS_MAP_PLAIN) {
 		TRACE("Unsupported map_type:%x, ignore\n", info.sys.map_type);
+
+		if (info.sys.map_type & PCS_JUMBO_CHUNK_FLAG)
+			pr_warn_once("kio: fpath doesn't support jumbo chunks\n");
 		return 0;
 	}
 
diff --git a/fs/fuse/kio/pcs/pcs_mds_prot.h b/fs/fuse/kio/pcs/pcs_mds_prot.h
index 80c20fde1537..1dc1724fa94d 100644
--- a/fs/fuse/kio/pcs/pcs_mds_prot.h
+++ b/fs/fuse/kio/pcs/pcs_mds_prot.h
@@ -259,6 +259,8 @@ enum
 	PCS_MAP_LS = PCS_MAP_COMBINED, /* Log structured storage */
 };
 
+#define PCS_JUMBO_CHUNK_FLAG (1 << 28) /* Chunks size > 4G */
+
 /* Max inline file size */
 #define PCS_MAX_INLINE_SIZE 0x100000 /* 1Mb */