[PATCH v2] libxfs/quota: utilize FS_IOC_FSSETXATTRAT to set prjid on special files

[Andrey Albershteyn <aalbersh@redhat.com>]

Utilize new FS_IOC_FS[SET|GET]XATTRAT ioctl to set project ID on
special files. Previously, special files were skipped due to lack of
the way to call FS_IOC_SETFSXATTR on them. The quota accounting was
therefore missing a few inodes (special files created before project
setup).

Signed-off-by: Andrey Albershteyn <aalbersh@redhat.com>
---
 include/linux.h |  14 +++++
 quota/project.c | 158 ++++++++++++++++++++++++++++++++----------------
 2 files changed, 120 insertions(+), 52 deletions(-)

diff --git a/include/linux.h b/include/linux.h
index 95a0deee2594..baae28727030 100644
--- a/include/linux.h
+++ b/include/linux.h
@@ -249,6 +249,20 @@ struct fsxattr {
 #define FS_XFLAG_COWEXTSIZE	0x00010000	/* CoW extent size allocator hint */
 #endif
 
+#ifndef FS_IOC_FSGETXATTRAT
+/*
+ * Structure passed to FS_IOC_FSGETXATTRAT/FS_IOC_FSSETXATTRAT
+ */
+struct fsxattrat {
+	struct fsxattr	fsx;		/* XATTR to get/set */
+	__u32		dfd;		/* parent dir */
+	const char	*path;
+};
+
+#define FS_IOC_FSGETXATTRAT   _IOR ('X', 33, struct fsxattrat)
+#define FS_IOC_FSSETXATTRAT   _IOW ('X', 34, struct fsxattrat)
+#endif
+
 /*
  * Reminder: anything added to this file will be compiled into downstream
  * userspace projects!
diff --git a/quota/project.c b/quota/project.c
index adb26945fa57..438dd925c884 100644
--- a/quota/project.c
+++ b/quota/project.c
@@ -12,6 +12,8 @@
 static cmdinfo_t project_cmd;
 static prid_t prid;
 static int recurse_depth = -1;
+static int dfd;
+static int dlen;
 
 enum {
 	CHECK_PROJECT	= 0x1,
@@ -19,7 +21,7 @@ enum {
 	CLEAR_PROJECT	= 0x4,
 };
 
-#define EXCLUDED_FILE_TYPES(x) \
+#define SPECIAL_FILE(x) \
 	   (S_ISCHR((x)) \
 	|| S_ISBLK((x)) \
 	|| S_ISFIFO((x)) \
@@ -78,6 +80,71 @@ project_help(void)
 "\n"));
 }
 
+static int
+get_fsxattr(
+	const char		*path,
+	const struct stat	*stat,
+	struct FTW		*data,
+	struct fsxattr		*fsx)
+{
+	int			error;
+	int			fd;
+	struct fsxattrat	xreq = {
+		.fsx = { 0 },
+		.dfd = dfd,
+		.path = path + (data->level ? dlen + 1 : 0),
+	};
+
+	if (SPECIAL_FILE(stat->st_mode)) {
+		error = ioctl(dfd, FS_IOC_FSGETXATTRAT, &xreq);
+		if (error)
+			return error;
+
+		memcpy(fsx, &xreq.fsx, sizeof(struct fsxattr));
+		return error;
+	}
+
+	fd = open(path, O_RDONLY|O_NOCTTY);
+	if (fd == -1)
+		return errno;
+
+	error = ioctl(fd, FS_IOC_FSGETXATTR, fsx);
+	close(fd);
+
+	return error;
+}
+
+static int
+set_fsxattr(
+	const char		*path,
+	const struct stat	*stat,
+	struct FTW		*data,
+	struct fsxattr		*fsx)
+{
+	int			error;
+	int			fd;
+	struct fsxattrat	xreq = {
+		.fsx = { 0 },
+		.dfd = dfd,
+		.path = path + (data->level ? dlen + 1 : 0),
+	};
+
+	if (SPECIAL_FILE(stat->st_mode)) {
+		memcpy(&xreq.fsx, fsx, sizeof(struct fsxattr));
+		error = ioctl(dfd, FS_IOC_FSSETXATTRAT, &xreq);
+		return error;
+	}
+
+	fd = open(path, O_RDONLY|O_NOCTTY);
+	if (fd == -1)
+		return errno;
+
+	error = ioctl(fd, FS_IOC_FSSETXATTR, fsx);
+	close(fd);
+
+	return error;
+}
+
 static int
 check_project(
 	const char		*path,
@@ -85,8 +152,8 @@ check_project(
 	int			flag,
 	struct FTW		*data)
 {
-	struct fsxattr		fsx;
-	int			fd;
+	int			error;
+	struct fsxattr		fsx = { 0 };
 
 	if (recurse_depth >= 0 && data->level > recurse_depth)
 		return 0;
@@ -96,30 +163,23 @@ check_project(
 		fprintf(stderr, _("%s: cannot stat file %s\n"), progname, path);
 		return 0;
 	}
-	if (EXCLUDED_FILE_TYPES(stat->st_mode)) {
-		fprintf(stderr, _("%s: skipping special file %s\n"), progname, path);
-		return 0;
-	}
 
-	if ((fd = open(path, O_RDONLY|O_NOCTTY)) == -1) {
-		exitcode = 1;
-		fprintf(stderr, _("%s: cannot open %s: %s\n"),
-			progname, path, strerror(errno));
-	} else if ((xfsctl(path, fd, FS_IOC_FSGETXATTR, &fsx)) < 0) {
+	error = get_fsxattr(path, stat, data, &fsx);
+	if (error) {
 		exitcode = 1;
 		fprintf(stderr, _("%s: cannot get flags on %s: %s\n"),
 			progname, path, strerror(errno));
-	} else {
-		if (fsx.fsx_projid != prid)
-			printf(_("%s - project identifier is not set"
-				 " (inode=%u, tree=%u)\n"),
-				path, fsx.fsx_projid, (unsigned int)prid);
-		if (!(fsx.fsx_xflags & FS_XFLAG_PROJINHERIT) && S_ISDIR(stat->st_mode))
-			printf(_("%s - project inheritance flag is not set\n"),
-				path);
+		return 0;
 	}
-	if (fd != -1)
-		close(fd);
+
+	if (fsx.fsx_projid != prid)
+		printf(_("%s - project identifier is not set"
+				" (inode=%u, tree=%u)\n"),
+			path, fsx.fsx_projid, (unsigned int)prid);
+	if (!(fsx.fsx_xflags & FS_XFLAG_PROJINHERIT) && S_ISDIR(stat->st_mode))
+		printf(_("%s - project inheritance flag is not set\n"),
+			path);
+
 	return 0;
 }
 
@@ -130,8 +190,8 @@ clear_project(
 	int			flag,
 	struct FTW		*data)
 {
+	int			error;
 	struct fsxattr		fsx;
-	int			fd;
 
 	if (recurse_depth >= 0 && data->level > recurse_depth)
 		return 0;
@@ -141,32 +201,24 @@ clear_project(
 		fprintf(stderr, _("%s: cannot stat file %s\n"), progname, path);
 		return 0;
 	}
-	if (EXCLUDED_FILE_TYPES(stat->st_mode)) {
-		fprintf(stderr, _("%s: skipping special file %s\n"), progname, path);
-		return 0;
-	}
 
-	if ((fd = open(path, O_RDONLY|O_NOCTTY)) == -1) {
-		exitcode = 1;
-		fprintf(stderr, _("%s: cannot open %s: %s\n"),
-			progname, path, strerror(errno));
-		return 0;
-	} else if (xfsctl(path, fd, FS_IOC_FSGETXATTR, &fsx) < 0) {
+	error = get_fsxattr(path, stat, data, &fsx);
+	if (error) {
 		exitcode = 1;
 		fprintf(stderr, _("%s: cannot get flags on %s: %s\n"),
-			progname, path, strerror(errno));
-		close(fd);
+				progname, path, strerror(errno));
 		return 0;
 	}
 
 	fsx.fsx_projid = 0;
 	fsx.fsx_xflags &= ~FS_XFLAG_PROJINHERIT;
-	if (xfsctl(path, fd, FS_IOC_FSSETXATTR, &fsx) < 0) {
+
+	error = set_fsxattr(path, stat, data, &fsx);
+	if (error) {
 		exitcode = 1;
 		fprintf(stderr, _("%s: cannot clear project on %s: %s\n"),
 			progname, path, strerror(errno));
 	}
-	close(fd);
 	return 0;
 }
 
@@ -178,7 +230,7 @@ setup_project(
 	struct FTW		*data)
 {
 	struct fsxattr		fsx;
-	int			fd;
+	int			error;
 
 	if (recurse_depth >= 0 && data->level > recurse_depth)
 		return 0;
@@ -188,32 +240,24 @@ setup_project(
 		fprintf(stderr, _("%s: cannot stat file %s\n"), progname, path);
 		return 0;
 	}
-	if (EXCLUDED_FILE_TYPES(stat->st_mode)) {
-		fprintf(stderr, _("%s: skipping special file %s\n"), progname, path);
-		return 0;
-	}
 
-	if ((fd = open(path, O_RDONLY|O_NOCTTY)) == -1) {
-		exitcode = 1;
-		fprintf(stderr, _("%s: cannot open %s: %s\n"),
-			progname, path, strerror(errno));
-		return 0;
-	} else if (xfsctl(path, fd, FS_IOC_FSGETXATTR, &fsx) < 0) {
+	error = get_fsxattr(path, stat, data, &fsx);
+	if (error) {
 		exitcode = 1;
 		fprintf(stderr, _("%s: cannot get flags on %s: %s\n"),
-			progname, path, strerror(errno));
-		close(fd);
+				progname, path, strerror(errno));
 		return 0;
 	}
 
 	fsx.fsx_projid = prid;
 	fsx.fsx_xflags |= FS_XFLAG_PROJINHERIT;
-	if (xfsctl(path, fd, FS_IOC_FSSETXATTR, &fsx) < 0) {
+
+	error = set_fsxattr(path, stat, data, &fsx);
+	if (error) {
 		exitcode = 1;
 		fprintf(stderr, _("%s: cannot set project on %s: %s\n"),
 			progname, path, strerror(errno));
 	}
-	close(fd);
 	return 0;
 }
 
@@ -223,6 +267,14 @@ project_operations(
 	char		*dir,
 	int		type)
 {
+	dfd = open(dir, O_RDONLY|O_NOCTTY);
+	if (dfd < -1) {
+		printf(_("Error opening dir %s for project %s...\n"), dir,
+				project);
+		return;
+	}
+	dlen = strlen(dir);
+
 	switch (type) {
 	case CHECK_PROJECT:
 		printf(_("Checking project %s (path %s)...\n"), project, dir);
@@ -237,6 +289,8 @@ project_operations(
 		nftw(dir, clear_project, 100, FTW_PHYS|FTW_MOUNT);
 		break;
 	}
+
+	close(dfd);
 }
 
 static void
-- 
2.42.0