Unverified Commit f584714c authored by Eric Sandeen's avatar Eric Sandeen Committed by Christian Brauner
Browse files

pstore: convert to the new mount API 



Convert the pstore filesystem to the new mount API.

Cc: Kees Cook <kees@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: default avatarEric Sandeen <sandeen@redhat.com>
Link: https://lore.kernel.org/r/20250205213931.74614-2-sandeen@redhat.com


Reviewed-by: default avatarKees Cook <kees@kernel.org>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 2014c95a

fs/pstore/inode.c

+74 −35
Original line number Diff line number Diff line
@@ -14,10 +14,10 @@ 
#include <linux/init.h>

#include <linux/list.h>

#include <linux/string.h>

#include <linux/mount.h>

#include <linux/seq_file.h>

#include <linux/ramfs.h>

#include <linux/parser.h>

#include <linux/fs_parser.h>

#include <linux/fs_context.h>

#include <linux/sched.h>

#include <linux/magic.h>

#include <linux/pstore.h>
@@ -226,37 +226,38 @@ static struct inode *pstore_get_inode(struct super_block *sb) 
}



enum {

	Opt_kmsg_bytes, Opt_err

	Opt_kmsg_bytes

};



static const match_table_t tokens = {

	{Opt_kmsg_bytes, "kmsg_bytes=%u"},

	{Opt_err, NULL}

static const struct fs_parameter_spec pstore_param_spec[] = {

	fsparam_u32	("kmsg_bytes",	Opt_kmsg_bytes),

	{}

};



static void parse_options(char *options)

{

	char		*p;

	substring_t	args[MAX_OPT_ARGS];

	int		option;



	if (!options)

		return;

struct pstore_context {

	unsigned int kmsg_bytes;

};



	while ((p = strsep(&options, ",")) != NULL) {

		int token;

static int pstore_parse_param(struct fs_context *fc, struct fs_parameter *param)

{

	struct pstore_context *ctx = fc->fs_private;

	struct fs_parse_result result;

	int opt;



		if (!*p)

			continue;

	opt = fs_parse(fc, pstore_param_spec, param, &result);

	/* pstore has historically ignored invalid kmsg_bytes param */

	if (opt < 0)

		return 0;



		token = match_token(p, tokens, args);

		switch (token) {

	switch (opt) {

	case Opt_kmsg_bytes:

			if (!match_int(&args[0], &option))

				pstore_set_kmsg_bytes(option);

		ctx->kmsg_bytes = result.uint_32;

		break;

	default:

		return -EINVAL;

	}

	}



	return 0;

}



/*
@@ -269,10 +270,12 @@ static int pstore_show_options(struct seq_file *m, struct dentry *root) 
	return 0;

}



static int pstore_remount(struct super_block *sb, int *flags, char *data)

static int pstore_reconfigure(struct fs_context *fc)

{

	sync_filesystem(sb);

	parse_options(data);

	struct pstore_context *ctx = fc->fs_private;



	sync_filesystem(fc->root->d_sb);

	pstore_set_kmsg_bytes(ctx->kmsg_bytes);



	return 0;

}
@@ -281,7 +284,6 @@ static const struct super_operations pstore_ops = { 
	.statfs		= simple_statfs,

	.drop_inode	= generic_delete_inode,

	.evict_inode	= pstore_evict_inode,

	.remount_fs	= pstore_remount,

	.show_options	= pstore_show_options,

};
@@ -406,8 +408,9 @@ void pstore_get_records(int quiet) 
	inode_unlock(d_inode(root));

}



static int pstore_fill_super(struct super_block *sb, void *data, int silent)

static int pstore_fill_super(struct super_block *sb, struct fs_context *fc)

{

	struct pstore_context *ctx = fc->fs_private;

	struct inode *inode;



	sb->s_maxbytes		= MAX_LFS_FILESIZE;
@@ -417,7 +420,7 @@ static int pstore_fill_super(struct super_block *sb, void *data, int silent) 
	sb->s_op		= &pstore_ops;

	sb->s_time_gran		= 1;



	parse_options(data);

	pstore_set_kmsg_bytes(ctx->kmsg_bytes);



	inode = pstore_get_inode(sb);

	if (inode) {
@@ -438,12 +441,26 @@ static int pstore_fill_super(struct super_block *sb, void *data, int silent) 
	return 0;

}



static struct dentry *pstore_mount(struct file_system_type *fs_type,

	int flags, const char *dev_name, void *data)

static int pstore_get_tree(struct fs_context *fc)

{

	if (fc->root)

		return pstore_reconfigure(fc);



	return get_tree_single(fc, pstore_fill_super);

}



static void pstore_free_fc(struct fs_context *fc)

{

	return mount_single(fs_type, flags, data, pstore_fill_super);

	kfree(fc->fs_private);

}



static const struct fs_context_operations pstore_context_ops = {

	.parse_param	= pstore_parse_param,

	.get_tree	= pstore_get_tree,

	.reconfigure	= pstore_reconfigure,

	.free		= pstore_free_fc,

};



static void pstore_kill_sb(struct super_block *sb)

{

	guard(mutex)(&pstore_sb_lock);
@@ -456,11 +473,33 @@ static void pstore_kill_sb(struct super_block *sb) 
	INIT_LIST_HEAD(&records_list);

}



static int pstore_init_fs_context(struct fs_context *fc)

{

	struct pstore_context *ctx;



	ctx = kzalloc(sizeof(struct pstore_context), GFP_KERNEL);

	if (!ctx)

		return -ENOMEM;



	/*

	 * Global kmsg_bytes is initialized to default, and updated

	 * every time we (re)mount the single-sb filesystem with the

	 * option specified.

	 */

	ctx->kmsg_bytes = kmsg_bytes;



	fc->fs_private = ctx;

	fc->ops = &pstore_context_ops;



	return 0;

}



static struct file_system_type pstore_fs_type = {

	.owner          = THIS_MODULE,

	.name		= "pstore",

	.mount		= pstore_mount,

	.kill_sb	= pstore_kill_sb,

	.init_fs_context = pstore_init_fs_context,

	.parameters	= pstore_param_spec,

};



int __init pstore_init_fs(void)