Merge tag 'vfs-6.18-rc1.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs mount updates from Christian Brauner:
 "This contains some work around mount api handling:

   - Output the warning message for mnt_too_revealing() triggered during
     fsmount() to the fscontext log. This makes it possible for the
     mount tool to output appropriate warnings on the command line.

     For example, with the newest fsopen()-based mount(8) from
     util-linux, the error messages now look like:

       # mount -t proc proc /tmp
       mount: /tmp: fsmount() failed: VFS: Mount too revealing.
              dmesg(1) may have more information after failed mount system call.

   - Do not consume fscontext log entries when returning -EMSGSIZE

     Userspace generally expects APIs that return -EMSGSIZE to allow for
     them to adjust their buffer size and retry the operation.

     However, the fscontext log would previously clear the message even
     in the -EMSGSIZE case.

     Given that it is very cheap for us to check whether the buffer is
     too small before we remove the message from the ring buffer, let's
     just do that instead.

   - Drop an unused argument from do_remount()"

* tag 'vfs-6.18-rc1.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  vfs: fs/namespace.c: remove ms_flags argument from do_remount
  selftests/filesystems: add basic fscontext log tests
  fscontext: do not consume log entries when returning -EMSGSIZE
  vfs: output mount_too_revealing() errors to fscontext
  docs/vfs: Remove mentions to the old mount API helpers
  fscontext: add custom-prefix log helpers
  fs: Remove mount_bdev
  fs: Remove mount_nodev

2 files changed, 14 insertions, 10 deletions

diff --git a/include/linux/fs.h b/include/linux/fs.h
index e90384db5544..5265b76759f1 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2713,12 +2713,6 @@ static inline bool is_mgtime(const struct inode *inode)
 	return inode->i_opflags & IOP_MGTIME;
 }
 
-extern struct dentry *mount_bdev(struct file_system_type *fs_type,
-	int flags, const char *dev_name, void *data,
-	int (*fill_super)(struct super_block *, void *, int));
-extern struct dentry *mount_nodev(struct file_system_type *fs_type,
-	int flags, void *data,
-	int (*fill_super)(struct super_block *, void *, int));
 extern struct dentry *mount_subtree(struct vfsmount *mnt, const char *path);
 void retire_super(struct super_block *sb);
 void generic_shutdown_super(struct super_block *sb);
diff --git a/include/linux/fs_context.h b/include/linux/fs_context.h
index 7773eb870039..671f031be173 100644
--- a/include/linux/fs_context.h
+++ b/include/linux/fs_context.h
@@ -186,10 +186,12 @@ struct fc_log {
 extern __attribute__((format(printf, 4, 5)))
 void logfc(struct fc_log *log, const char *prefix, char level, const char *fmt, ...);
 
-#define __logfc(fc, l, fmt, ...) logfc((fc)->log.log, NULL, \
-					l, fmt, ## __VA_ARGS__)
-#define __plog(p, l, fmt, ...) logfc((p)->log, (p)->prefix, \
-					l, fmt, ## __VA_ARGS__)
+#define __logfc(fc, l, fmt, ...) \
+	logfc((fc)->log.log, NULL, (l), (fmt), ## __VA_ARGS__)
+#define __plogp(p, prefix, l, fmt, ...) \
+	logfc((p)->log, (prefix), (l), (fmt), ## __VA_ARGS__)
+#define __plog(p, l, fmt, ...) __plogp(p, (p)->prefix, l, fmt, ## __VA_ARGS__)
+
 /**
  * infof - Store supplementary informational message
  * @fc: The context in which to log the informational message
@@ -201,6 +203,8 @@ void logfc(struct fc_log *log, const char *prefix, char level, const char *fmt,
 #define infof(fc, fmt, ...) __logfc(fc, 'i', fmt, ## __VA_ARGS__)
 #define info_plog(p, fmt, ...) __plog(p, 'i', fmt, ## __VA_ARGS__)
 #define infofc(fc, fmt, ...) __plog((&(fc)->log), 'i', fmt, ## __VA_ARGS__)
+#define infofcp(fc, prefix, fmt, ...) \
+	__plogp((&(fc)->log), prefix, 'i', fmt, ## __VA_ARGS__)
 
 /**
  * warnf - Store supplementary warning message
@@ -213,6 +217,8 @@ void logfc(struct fc_log *log, const char *prefix, char level, const char *fmt,
 #define warnf(fc, fmt, ...) __logfc(fc, 'w', fmt, ## __VA_ARGS__)
 #define warn_plog(p, fmt, ...) __plog(p, 'w', fmt, ## __VA_ARGS__)
 #define warnfc(fc, fmt, ...) __plog((&(fc)->log), 'w', fmt, ## __VA_ARGS__)
+#define warnfcp(fc, prefix, fmt, ...) \
+	__plogp((&(fc)->log), prefix, 'w', fmt, ## __VA_ARGS__)
 
 /**
  * errorf - Store supplementary error message
@@ -225,6 +231,8 @@ void logfc(struct fc_log *log, const char *prefix, char level, const char *fmt,
 #define errorf(fc, fmt, ...) __logfc(fc, 'e', fmt, ## __VA_ARGS__)
 #define error_plog(p, fmt, ...) __plog(p, 'e', fmt, ## __VA_ARGS__)
 #define errorfc(fc, fmt, ...) __plog((&(fc)->log), 'e', fmt, ## __VA_ARGS__)
+#define errorfcp(fc, prefix, fmt, ...) \
+	__plogp((&(fc)->log), prefix, 'e', fmt, ## __VA_ARGS__)
 
 /**
  * invalf - Store supplementary invalid argument error message
@@ -237,5 +245,7 @@ void logfc(struct fc_log *log, const char *prefix, char level, const char *fmt,
 #define invalf(fc, fmt, ...) (errorf(fc, fmt, ## __VA_ARGS__), -EINVAL)
 #define inval_plog(p, fmt, ...) (error_plog(p, fmt, ## __VA_ARGS__), -EINVAL)
 #define invalfc(fc, fmt, ...) (errorfc(fc, fmt, ## __VA_ARGS__), -EINVAL)
+#define invalfcp(fc, prefix, fmt, ...) \
+	(errorfcp(fc, prefix, fmt, ## __VA_ARGS__), -EINVAL)
 
 #endif /* _LINUX_FS_CONTEXT_H */