From d26c2ddd33569667e3eeb577c4c1d966ca9192e2 Mon Sep 17 00:00:00 2001 From: Steve French Date: Thu, 6 Feb 2020 06:00:14 -0600 Subject: cifs: add SMB3 change notification support A commonly used SMB3 feature is change notification, allowing an app to be notified about changes to a directory. The SMB3 Notify request blocks until the server detects a change to that directory or its contents that matches the completion flags that were passed in and the "watch_tree" flag (which indicates whether subdirectories under this directory should be also included). See MS-SMB2 2.2.35 for additional detail. To use this simply pass in the following structure to ioctl: struct __attribute__((__packed__)) smb3_notify { uint32_t completion_filter; bool watch_tree; } __packed; using CIFS_IOC_NOTIFY 0x4005cf09 or equivalently _IOW(CIFS_IOCTL_MAGIC, 9, struct smb3_notify) SMB3 change notification is supported by all major servers. The ioctl will block until the server detects a change to that directory or its subdirectories (if watch_tree is set). Signed-off-by: Steve French Reviewed-by: Aurelien Aptel Acked-by: Paulo Alcantara (SUSE) --- fs/cifs/smb2ops.c | 62 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) (limited to 'fs/cifs/smb2ops.c') diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index ac6628e28b12..baa825f4cec0 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -2045,6 +2045,66 @@ smb3_enum_snapshots(const unsigned int xid, struct cifs_tcon *tcon, return rc; } + + +static int +smb3_notify(const unsigned int xid, struct file *pfile, + void __user *ioc_buf) +{ + struct smb3_notify notify; + struct dentry *dentry = pfile->f_path.dentry; + struct inode *inode = file_inode(pfile); + struct cifs_sb_info *cifs_sb; + struct cifs_open_parms oparms; + struct cifs_fid fid; + struct cifs_tcon *tcon; + unsigned char *path = NULL; + __le16 *utf16_path = NULL; + u8 oplock = SMB2_OPLOCK_LEVEL_NONE; + int rc = 0; + + path = build_path_from_dentry(dentry); + if (path == NULL) + return -ENOMEM; + + cifs_sb = CIFS_SB(inode->i_sb); + + utf16_path = cifs_convert_path_to_utf16(path + 1, cifs_sb); + if (utf16_path == NULL) { + rc = -ENOMEM; + goto notify_exit; + } + + if (copy_from_user(¬ify, ioc_buf, sizeof(struct smb3_notify))) { + rc = -EFAULT; + goto notify_exit; + } + + tcon = cifs_sb_master_tcon(cifs_sb); + oparms.tcon = tcon; + oparms.desired_access = FILE_READ_ATTRIBUTES; + oparms.disposition = FILE_OPEN; + oparms.create_options = cifs_create_options(cifs_sb, 0); + oparms.fid = &fid; + oparms.reconnect = false; + + rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL, NULL); + if (rc) + goto notify_exit; + + rc = SMB2_change_notify(xid, tcon, fid.persistent_fid, fid.volatile_fid, + notify.watch_tree, notify.completion_filter); + + SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid); + + cifs_dbg(FYI, "change notify for path %s rc %d\n", path, rc); + +notify_exit: + kfree(path); + kfree(utf16_path); + return rc; +} + static int smb2_query_dir_first(const unsigned int xid, struct cifs_tcon *tcon, const char *path, struct cifs_sb_info *cifs_sb, @@ -4841,6 +4901,7 @@ struct smb_version_operations smb30_operations = { .dir_needs_close = smb2_dir_needs_close, .fallocate = smb3_fallocate, .enum_snapshots = smb3_enum_snapshots, + .notify = smb3_notify, .init_transform_rq = smb3_init_transform_rq, .is_transform_hdr = smb3_is_transform_hdr, .receive_transform = smb3_receive_transform, @@ -4951,6 +5012,7 @@ struct smb_version_operations smb311_operations = { .dir_needs_close = smb2_dir_needs_close, .fallocate = smb3_fallocate, .enum_snapshots = smb3_enum_snapshots, + .notify = smb3_notify, .init_transform_rq = smb3_init_transform_rq, .is_transform_hdr = smb3_is_transform_hdr, .receive_transform = smb3_receive_transform, -- cgit v1.2.3