[PATCH 06/24] md: open code vfs_stat in md_setup_drive
From: Christoph Hellwig <hch@lst.de>
Date: 2020-07-21 16:30:24
Also in:
linux-fsdevel, linux-raid, lkml
Subsystem:
software raid (multiple disks) support, the rest · Maintainers:
Song Liu, Yu Kuai, Linus Torvalds
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