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From: Christoph Hellwig <hch@lst.de>
To: Al Viro <viro@zeniv.linux.org.uk>,
	Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org,
	linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org
Subject: [PATCH 06/24] md: open code vfs_stat in md_setup_drive
Date: Tue, 21 Jul 2020 18:28:00 +0200	[thread overview]
Message-ID: <20200721162818.197315-7-hch@lst.de> (raw)
In-Reply-To: <20200721162818.197315-1-hch@lst.de>

Instead of passing a kernel pointer to vfs_stat by relying on the
implicit set_fs(KERNEL_DS) in md_setup_drive, just open code the
trivial getattr, and use the opportunity to move a little bit more
code from the caller into the new helper.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/md/md-autodetect.c | 29 ++++++++++++++++++++---------
 1 file changed, 20 insertions(+), 9 deletions(-)

diff --git a/drivers/md/md-autodetect.c b/drivers/md/md-autodetect.c
index 14b6e86814c061..1e8f1df257a112 100644
--- a/drivers/md/md-autodetect.c
+++ b/drivers/md/md-autodetect.c
@@ -8,6 +8,7 @@
 #include <linux/raid/detect.h>
 #include <linux/raid/md_u.h>
 #include <linux/raid/md_p.h>
+#include <linux/namei.h>
 #include "md.h"
 
 /*
@@ -119,6 +120,23 @@ static int __init md_setup(char *str)
 	return 1;
 }
 
+static void __init md_lookup_dev(const char *devname, dev_t *dev)
+{
+	struct kstat stat;
+	struct path path;
+	char filename[64];
+
+	if (strncmp(devname, "/dev/", 5) == 0)
+		devname += 5;
+	snprintf(filename, 63, "/dev/%s", devname);
+
+	if (!kern_path(filename, LOOKUP_FOLLOW, &path) &&
+	    !vfs_getattr(&path, &stat, STATX_BASIC_STATS, AT_NO_AUTOMOUNT) &&
+	    S_ISBLK(stat.mode))
+		*dev = new_decode_dev(stat.rdev);
+	path_put(&path);
+}
+
 static void __init md_setup_drive(struct md_setup_args *args)
 {
 	char *devname = args->device_names;
@@ -138,21 +156,14 @@ static void __init md_setup_drive(struct md_setup_args *args)
 	}
 
 	for (i = 0; i < MD_SB_DISKS && devname != NULL; i++) {
-		struct kstat stat;
-		char *p;
-		char comp_name[64];
 		dev_t dev;
+		char *p;
 
 		p = strchr(devname, ',');
 		if (p)
 			*p++ = 0;
-
 		dev = name_to_dev_t(devname);
-		if (strncmp(devname, "/dev/", 5) == 0)
-			devname += 5;
-		snprintf(comp_name, 63, "/dev/%s", devname);
-		if (vfs_stat(comp_name, &stat) == 0 && S_ISBLK(stat.mode))
-			dev = new_decode_dev(stat.rdev);
+		md_lookup_dev(devname, &dev);
 		if (!dev) {
 			pr_warn("md: Unknown device name: %s\n", devname);
 			break;
-- 
2.27.0


  parent reply	other threads:[~2020-07-21 16:30 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-21 16:27 add file system helpers that take kernel pointers for the init code v2 Christoph Hellwig
2020-07-21 16:27 ` [PATCH 01/24] fs: refactor do_mount Christoph Hellwig
2020-07-21 16:27 ` [PATCH 02/24] fs: refactor ksys_umount Christoph Hellwig
2020-07-21 16:27 ` [PATCH 03/24] fs: push the getname from do_rmdir into the callers Christoph Hellwig
2020-07-21 16:27 ` [PATCH 04/24] devtmpfs: open code do_mount Christoph Hellwig
2020-07-21 16:27 ` [PATCH 05/24] devtmpfs: open code ksys_chdir and ksys_chroot Christoph Hellwig
2020-07-21 16:49   ` Linus Torvalds
2020-07-21 17:16     ` Al Viro
2020-07-21 18:26       ` Christoph Hellwig
2020-07-21 16:28 ` Christoph Hellwig [this message]
2020-07-21 16:55   ` [PATCH 06/24] md: open code vfs_stat in md_setup_drive Al Viro
2020-07-21 18:27     ` Christoph Hellwig
2020-07-22  7:44       ` Al Viro
2020-07-22 14:05         ` Christoph Hellwig
2020-07-21 16:28 ` [PATCH 07/24] init: initialize ramdisk_execute_command at compile time Christoph Hellwig
2020-07-21 16:28 ` [PATCH 08/24] init: move the prepare_namespace prototype to init/do_mounts.h Christoph Hellwig
2020-07-21 16:28 ` [PATCH 09/24] init: mark create_dev as __init Christoph Hellwig
2020-07-21 16:28 ` [PATCH 10/24] init: open code ksys_umount in handle_initrd Christoph Hellwig
2020-07-21 16:28 ` [PATCH 11/24] init: open code do_utimes in do_utime Christoph Hellwig
2020-07-21 16:28 ` [PATCH 12/24] init: add an init_mount helper Christoph Hellwig
2020-07-21 16:58   ` Al Viro
2020-07-21 16:28 ` [PATCH 13/24] init: add an init_unlink helper Christoph Hellwig
2020-07-21 17:12   ` Al Viro
2020-07-21 16:28 ` [PATCH 14/24] init: add an init_rmdir helper Christoph Hellwig
2020-07-21 16:28 ` [PATCH 15/24] init: add an init_chdir helper Christoph Hellwig
2020-07-21 16:28 ` [PATCH 16/24] init: add an init_chroot helper Christoph Hellwig
2020-07-21 17:10   ` Al Viro
2020-07-21 16:28 ` [PATCH 17/24] init: add an init_chown helper Christoph Hellwig
2020-07-21 16:28 ` [PATCH 18/24] init: add an init_chmod helper Christoph Hellwig
2020-07-21 16:28 ` [PATCH 19/24] init: add an init_eaccess helper Christoph Hellwig
2020-07-21 16:28 ` [PATCH 20/24] init: add an init_link helper Christoph Hellwig
2020-07-21 16:28 ` [PATCH 21/24] init: add an init_symlink helper Christoph Hellwig
2020-07-21 17:00   ` Al Viro
2020-07-21 16:28 ` [PATCH 22/24] init: add an init_mkdir helper Christoph Hellwig
2020-07-21 16:28 ` [PATCH 23/24] init: add an init_mknod helper Christoph Hellwig
2020-07-21 17:02   ` Al Viro
2020-07-21 16:28 ` [PATCH 24/24] init: add an init_lstat helper Christoph Hellwig

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