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authorSteve French <stfrench@microsoft.com>2022-10-15 08:43:22 +0300
committerSteve French <stfrench@microsoft.com>2022-10-15 18:05:53 +0300
commite3e9463414f610e91528f2b920b8cb655f4bae33 (patch)
tree68cad4efa13223def4aa3d32b138eb7a94e3aedb /fs/cifs/ioctl.c
parent2bff0659338e58a3a24698a35e7dcb2b62199ba4 (diff)
downloadlinux-e3e9463414f610e91528f2b920b8cb655f4bae33.tar.xz
smb3: improve SMB3 change notification support
Change notification is a commonly supported feature by most servers, but the current ioctl to request notification when a directory is changed does not return the information about what changed (even though it is returned by the server in the SMB3 change notify response), it simply returns when there is a change. This ioctl improves upon CIFS_IOC_NOTIFY by returning the notify information structure which includes the name of the file(s) that changed and why. See MS-SMB2 2.2.35 for details on the individual filter flags and the file_notify_information structure returned. To use this simply pass in the following (with enough space to fit at least one file_notify_information structure) struct __attribute__((__packed__)) smb3_notify { uint32_t completion_filter; bool watch_tree; uint32_t data_len; uint8_t data[]; } __packed; using CIFS_IOC_NOTIFY_INFO 0xc009cf0b or equivalently _IOWR(CIFS_IOCTL_MAGIC, 11, struct smb3_notify_info) The ioctl will block until the server detects a change to that directory or its subdirectories (if watch_tree is set). Acked-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Acked-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs/cifs/ioctl.c')
-rw-r--r--fs/cifs/ioctl.c25
1 files changed, 24 insertions, 1 deletions
diff --git a/fs/cifs/ioctl.c b/fs/cifs/ioctl.c
index b6e6e5d6c8dd..89d5fa887364 100644
--- a/fs/cifs/ioctl.c
+++ b/fs/cifs/ioctl.c
@@ -484,12 +484,35 @@ long cifs_ioctl(struct file *filep, unsigned int command, unsigned long arg)
tcon = tlink_tcon(tlink);
if (tcon && tcon->ses->server->ops->notify) {
rc = tcon->ses->server->ops->notify(xid,
- filep, (void __user *)arg);
+ filep, (void __user *)arg,
+ false /* no ret data */);
cifs_dbg(FYI, "ioctl notify rc %d\n", rc);
} else
rc = -EOPNOTSUPP;
cifs_put_tlink(tlink);
break;
+ case CIFS_IOC_NOTIFY_INFO:
+ if (!S_ISDIR(inode->i_mode)) {
+ /* Notify can only be done on directories */
+ rc = -EOPNOTSUPP;
+ break;
+ }
+ cifs_sb = CIFS_SB(inode->i_sb);
+ tlink = cifs_sb_tlink(cifs_sb);
+ if (IS_ERR(tlink)) {
+ rc = PTR_ERR(tlink);
+ break;
+ }
+ tcon = tlink_tcon(tlink);
+ if (tcon && tcon->ses->server->ops->notify) {
+ rc = tcon->ses->server->ops->notify(xid,
+ filep, (void __user *)arg,
+ true /* return details */);
+ cifs_dbg(FYI, "ioctl notify info rc %d\n", rc);
+ } else
+ rc = -EOPNOTSUPP;
+ cifs_put_tlink(tlink);
+ break;
case CIFS_IOC_SHUTDOWN:
rc = cifs_shutdown(inode->i_sb, arg);
break;