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Message-Id: <20200720155902.181712-25-hch@lst.de>
Date: Mon, 20 Jul 2020 17:59:02 +0200
From: Christoph Hellwig <hch@....de>
To: Al Viro <viro@...iv.linux.org.uk>,
Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
"Rafael J. Wysocki" <rafael@...nel.org>,
linux-kernel@...r.kernel.org, linux-raid@...r.kernel.org,
linux-fsdevel@...r.kernel.org, linux-api@...r.kernel.org
Subject: [PATCH 24/24] fs: add a kern_stat helper
Add a simple helper to stat/lstat with a kernel space file name and
switch the early init code over to it.
Signed-off-by: Christoph Hellwig <hch@....de>
---
drivers/md/md-autodetect.c | 2 +-
fs/stat.c | 32 ++++++++++++++++++++++----------
include/linux/fs.h | 1 +
init/initramfs.c | 3 ++-
4 files changed, 26 insertions(+), 12 deletions(-)
diff --git a/drivers/md/md-autodetect.c b/drivers/md/md-autodetect.c
index 14b6e86814c061..5bd52ec05ed821 100644
--- a/drivers/md/md-autodetect.c
+++ b/drivers/md/md-autodetect.c
@@ -151,7 +151,7 @@ static void __init md_setup_drive(struct md_setup_args *args)
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))
+ if (kern_stat(comp_name, &stat, 0) == 0 && S_ISBLK(stat.mode))
dev = new_decode_dev(stat.rdev);
if (!dev) {
pr_warn("md: Unknown device name: %s\n", devname);
diff --git a/fs/stat.c b/fs/stat.c
index dacecdda2e7967..3c976b92db00ca 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -151,7 +151,7 @@ int vfs_fstat(int fd, struct kstat *stat)
/**
* vfs_statx - Get basic and extra attributes by filename
* @dfd: A file descriptor representing the base dir for a relative filename
- * @filename: The name of the file of interest
+ * @name: The name of the file of interest
* @flags: Flags to control the query
* @stat: The result structure to fill in.
* @request_mask: STATX_xxx flags indicating what the caller wants
@@ -163,16 +163,16 @@ int vfs_fstat(int fd, struct kstat *stat)
*
* 0 will be returned on success, and a -ve error code if unsuccessful.
*/
-static int vfs_statx(int dfd, const char __user *filename, int flags,
+static int vfs_statx(int dfd, struct filename *name, int flags,
struct kstat *stat, u32 request_mask)
{
struct path path;
unsigned lookup_flags = 0;
- int error;
+ int error = -EINVAL;
if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | AT_EMPTY_PATH |
AT_STATX_SYNC_TYPE))
- return -EINVAL;
+ goto out_putname;
if (!(flags & AT_SYMLINK_NOFOLLOW))
lookup_flags |= LOOKUP_FOLLOW;
@@ -182,9 +182,9 @@ static int vfs_statx(int dfd, const char __user *filename, int flags,
lookup_flags |= LOOKUP_EMPTY;
retry:
- error = user_path_at(dfd, filename, lookup_flags, &path);
+ error = filename_lookup(dfd, name, lookup_flags, &path, NULL);
if (error)
- goto out;
+ return error;
error = vfs_getattr(&path, stat, request_mask, flags);
stat->mnt_id = real_mount(path.mnt)->mnt_id;
@@ -197,15 +197,25 @@ static int vfs_statx(int dfd, const char __user *filename, int flags,
lookup_flags |= LOOKUP_REVAL;
goto retry;
}
-out:
+out_putname:
+ if (!IS_ERR(name))
+ putname(name);
return error;
}
+int __init kern_stat(const char *filename, struct kstat *stat, int flags)
+{
+ return vfs_statx(AT_FDCWD, getname_kernel(filename),
+ flags | AT_NO_AUTOMOUNT, stat, STATX_BASIC_STATS);
+}
+
int vfs_fstatat(int dfd, const char __user *filename,
struct kstat *stat, int flags)
{
- return vfs_statx(dfd, filename, flags | AT_NO_AUTOMOUNT,
- stat, STATX_BASIC_STATS);
+ int lookup_flags = (flags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0;
+
+ return vfs_statx(dfd, getname_flags(filename, lookup_flags, NULL),
+ flags | AT_NO_AUTOMOUNT, stat, STATX_BASIC_STATS);
}
#ifdef __ARCH_WANT_OLD_STAT
@@ -569,6 +579,7 @@ cp_statx(const struct kstat *stat, struct statx __user *buffer)
int do_statx(int dfd, const char __user *filename, unsigned flags,
unsigned int mask, struct statx __user *buffer)
{
+ int lookup_flags = (flags & AT_EMPTY_PATH) ? LOOKUP_EMPTY : 0;
struct kstat stat;
int error;
@@ -577,7 +588,8 @@ int do_statx(int dfd, const char __user *filename, unsigned flags,
if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE)
return -EINVAL;
- error = vfs_statx(dfd, filename, flags, &stat, mask);
+ error = vfs_statx(dfd, getname_flags(filename, lookup_flags, NULL),
+ flags, &stat, mask);
if (error)
return error;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 0e0cd6a988bb38..d1f8edb39cf969 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3671,5 +3671,6 @@ int __init kern_link(const char *oldname, const char *newname);
int __init kern_symlink(const char *oldname, const char *newname);
int kern_unlink(const char *pathname);
int __init kern_rmdir(const char *pathname);
+int __init kern_stat(const char *filename, struct kstat *stat, int flags);
#endif /* _LINUX_FS_H */
diff --git a/init/initramfs.c b/init/initramfs.c
index d72594298133a7..6c605f23900fa1 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -296,7 +296,8 @@ static void __init clean_path(char *path, umode_t fmode)
{
struct kstat st;
- if (!vfs_lstat(path, &st) && (st.mode ^ fmode) & S_IFMT) {
+ if (kern_stat(path, &st, AT_SYMLINK_NOFOLLOW) &&
+ (st.mode ^ fmode) & S_IFMT) {
if (S_ISDIR(st.mode))
kern_rmdir(path);
else
--
2.27.0
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