SMB311: Add support for query info using posix extensions (level 100)

Adds support for better query info on dentry revalidation (using
the SMB3.1.1 POSIX extensions level 100).  Followon patch will
add support for translating the UID/GID from the SID and also
will add support for using the posix query info on lookup.

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>

1 files changed, 175 insertions, 1 deletions

diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 5072bcaf4be1..c367195bdb08 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -32,6 +32,7 @@
 #include "cifspdu.h"
 #include "cifsglob.h"
 #include "cifsproto.h"
+#include "smb2proto.h"
 #include "cifs_debug.h"
 #include "cifs_fs_sb.h"
 #include "cifs_unicode.h"
@@ -595,6 +596,62 @@ static int cifs_sfu_mode(struct cifs_fattr *fattr, const unsigned char *path,
 #endif
 }
 
+/* Fill a cifs_fattr struct with info from POSIX info struct */
+static void
+smb311_posix_info_to_fattr(struct cifs_fattr *fattr, struct smb311_posix_qinfo *info,
+			   struct super_block *sb, bool adjust_tz, bool symlink)
+{
+	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
+	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
+
+	memset(fattr, 0, sizeof(*fattr));
+
+	/* no fattr->flags to set */
+	fattr->cf_cifsattrs = le32_to_cpu(info->DosAttributes);
+	fattr->cf_uniqueid = le64_to_cpu(info->Inode);
+
+	if (info->LastAccessTime)
+		fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
+	else
+		ktime_get_coarse_real_ts64(&fattr->cf_atime);
+
+	fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);
+	fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
+
+	if (adjust_tz) {
+		fattr->cf_ctime.tv_sec += tcon->ses->server->timeAdj;
+		fattr->cf_mtime.tv_sec += tcon->ses->server->timeAdj;
+	}
+
+	fattr->cf_eof = le64_to_cpu(info->EndOfFile);
+	fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
+	fattr->cf_createtime = le64_to_cpu(info->CreationTime);
+
+	fattr->cf_nlink = le32_to_cpu(info->HardLinks);
+	fattr->cf_mode = (umode_t) le32_to_cpu(info->Mode);
+	/* The srv fs device id is overridden on network mount so setting rdev isn't needed here */
+	/* fattr->cf_rdev = le32_to_cpu(info->DeviceId); */
+
+	if (symlink) {
+		fattr->cf_mode |= S_IFLNK;
+		fattr->cf_dtype = DT_LNK;
+	} else if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
+		fattr->cf_mode |= S_IFDIR;
+		fattr->cf_dtype = DT_DIR;
+	} else { /* file */
+		fattr->cf_mode |= S_IFREG;
+		fattr->cf_dtype = DT_REG;
+	}
+	/* else if reparse point ... TODO: add support for FIFO and blk dev; special file types */
+
+	fattr->cf_uid = cifs_sb->mnt_uid; /* TODO: map uid and gid from SID */
+	fattr->cf_gid = cifs_sb->mnt_gid;
+
+	cifs_dbg(FYI, "POSIX query info: mode 0x%x uniqueid 0x%llx nlink %d\n",
+		fattr->cf_mode, fattr->cf_uniqueid, fattr->cf_nlink);
+}
+
+
 /* Fill a cifs_fattr struct with info from FILE_ALL_INFO */
 static void
 cifs_all_info_to_fattr(struct cifs_fattr *fattr, FILE_ALL_INFO *info,
@@ -1023,6 +1080,121 @@ out:
 	return rc;
 }
 
+int
+smb311_posix_get_inode_info(struct inode **inode,
+		    const char *full_path,
+		    struct super_block *sb, unsigned int xid)
+{
+	struct cifs_tcon *tcon;
+	struct TCP_Server_Info *server;
+	struct tcon_link *tlink;
+	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
+	bool adjust_tz = false;
+	struct cifs_fattr fattr = {0};
+	bool symlink = false;
+	struct smb311_posix_qinfo *data = NULL;
+	int rc = 0;
+	int tmprc = 0;
+
+	tlink = cifs_sb_tlink(cifs_sb);
+	if (IS_ERR(tlink))
+		return PTR_ERR(tlink);
+	tcon = tlink_tcon(tlink);
+	server = tcon->ses->server;
+
+	/*
+	 * 1. Fetch file metadata
+	 */
+
+	if (is_inode_cache_good(*inode)) {
+		cifs_dbg(FYI, "No need to revalidate cached inode sizes\n");
+		goto out;
+	}
+	data = kmalloc(sizeof(struct smb311_posix_qinfo), GFP_KERNEL);
+	if (!data) {
+		rc = -ENOMEM;
+		goto out;
+	}
+
+	rc = smb311_posix_query_path_info(xid, tcon, cifs_sb,
+						  full_path, data,
+						  &adjust_tz, &symlink);
+
+	/*
+	 * 2. Convert it to internal cifs metadata (fattr)
+	 */
+
+	switch (rc) {
+	case 0:
+		smb311_posix_info_to_fattr(&fattr, data, sb, adjust_tz, symlink);
+		break;
+	case -EREMOTE:
+		/* DFS link, no metadata available on this server */
+		cifs_create_dfs_fattr(&fattr, sb);
+		rc = 0;
+		break;
+	case -EACCES:
+		/*
+		 * For SMB2 and later the backup intent flag
+		 * is already sent if needed on open and there
+		 * is no path based FindFirst operation to use
+		 * to retry with so nothing we can do, bail out
+		 */
+		goto out;
+	default:
+		cifs_dbg(FYI, "%s: unhandled err rc %d\n", __func__, rc);
+		goto out;
+	}
+
+
+	/*
+	 * 4. Tweak fattr based on mount options
+	 */
+
+	/* check for Minshall+French symlinks */
+	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) {
+		tmprc = check_mf_symlink(xid, tcon, cifs_sb, &fattr,
+					 full_path);
+		if (tmprc)
+			cifs_dbg(FYI, "check_mf_symlink: %d\n", tmprc);
+	}
+
+	/*
+	 * 5. Update inode with final fattr data
+	 */
+
+	if (!*inode) {
+		*inode = cifs_iget(sb, &fattr);
+		if (!*inode)
+			rc = -ENOMEM;
+	} else {
+		/* we already have inode, update it */
+
+		/* if uniqueid is different, return error */
+		if (unlikely(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM &&
+		    CIFS_I(*inode)->uniqueid != fattr.cf_uniqueid)) {
+			CIFS_I(*inode)->time = 0; /* force reval */
+			rc = -ESTALE;
+			goto out;
+		}
+
+		/* if filetype is different, return error */
+		if (unlikely(((*inode)->i_mode & S_IFMT) !=
+		    (fattr.cf_mode & S_IFMT))) {
+			CIFS_I(*inode)->time = 0; /* force reval */
+			rc = -ESTALE;
+			goto out;
+		}
+
+		cifs_fattr_to_inode(*inode, &fattr);
+	}
+out:
+	cifs_put_tlink(tlink);
+	kfree(data);
+	return rc;
+}
+
+
 static const struct inode_operations cifs_ipc_inode_ops = {
 	.lookup = cifs_lookup,
 };
@@ -2114,7 +2286,9 @@ int cifs_revalidate_dentry_attr(struct dentry *dentry)
 		 dentry, cifs_get_time(dentry), jiffies);
 
 again:
-	if (cifs_sb_master_tcon(CIFS_SB(sb))->unix_ext)
+	if (cifs_sb_master_tcon(CIFS_SB(sb))->posix_extensions)
+		rc = smb311_posix_get_inode_info(&inode, full_path, sb, xid);
+	else if (cifs_sb_master_tcon(CIFS_SB(sb))->unix_ext)
 		rc = cifs_get_inode_info_unix(&inode, full_path, sb, xid);
 	else
 		rc = cifs_get_inode_info(&inode, full_path, NULL, sb,