erofs: support superblock checksum (b858a484) · Commits · 戴 / test

fs/erofs/Kconfig

+1 −0

Original line number	Diff line number	Diff line
		@@ -3,6 +3,7 @@
		config EROFS_FS
		tristate "EROFS filesystem support"
		depends on BLOCK
		select LIBCRC32C
		help
		EROFS (Enhanced Read-Only File System) is a lightweight
		read-only file system with modern designs (eg. page-sized

fs/erofs/erofs_fs.h

+2 −1

Original line number	Diff line number	Diff line
		@@ -11,6 +11,8 @@

		#define EROFS_SUPER_OFFSET 1024

		#define EROFS_FEATURE_COMPAT_SB_CHKSUM 0x00000001

		/*
		* Any bits that aren't in EROFS_ALL_FEATURE_INCOMPAT should
		* be incompatible with this kernel version.
		@@ -37,7 +39,6 @@ struct erofs_super_block {
		__u8 uuid[16]; /* 128-bit uuid for volume */
		__u8 volume_name[16]; /* volume name */
		__le32 feature_incompat;

		__u8 reserved2[44];
		};

fs/erofs/internal.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -85,6 +85,7 @@ struct erofs_sb_info {

		u8 uuid[16]; /* 128-bit uuid for volume */
		u8 volume_name[16]; /* volume name */
		u32 feature_compat;
		u32 feature_incompat;

		unsigned int mount_opt;

fs/erofs/super.c

+34 −2

Original line number	Diff line number	Diff line
		@@ -9,6 +9,7 @@
		#include <linux/statfs.h>
		#include <linux/parser.h>
		#include <linux/seq_file.h>
		#include <linux/crc32c.h>
		#include "xattr.h"

		#define CREATE_TRACE_POINTS
		@@ -46,6 +47,30 @@ void _erofs_info(struct super_block sb, const char function,
		va_end(args);
		}

		static int erofs_superblock_csum_verify(struct super_block sb, void sbdata)
		{
		struct erofs_super_block *dsb;
		u32 expected_crc, crc;

		dsb = kmemdup(sbdata + EROFS_SUPER_OFFSET,
		EROFS_BLKSIZ - EROFS_SUPER_OFFSET, GFP_KERNEL);
		if (!dsb)
		return -ENOMEM;

		expected_crc = le32_to_cpu(dsb->checksum);
		dsb->checksum = 0;
		/* to allow for x86 boot sectors and other oddities. */
		crc = crc32c(~0, dsb, EROFS_BLKSIZ - EROFS_SUPER_OFFSET);
		kfree(dsb);

		if (crc != expected_crc) {
		erofs_err(sb, "invalid checksum 0x%08x, 0x%08x expected",
		crc, expected_crc);
		return -EBADMSG;
		}
		return 0;
		}

		static void erofs_inode_init_once(void *ptr)
		{
		struct erofs_inode *vi = ptr;
		@@ -112,7 +137,7 @@ static int erofs_read_superblock(struct super_block *sb)

		sbi = EROFS_SB(sb);

		data = kmap_atomic(page);
		data = kmap(page);
		dsb = (struct erofs_super_block *)(data + EROFS_SUPER_OFFSET);

		ret = -EINVAL;
		@@ -121,6 +146,13 @@ static int erofs_read_superblock(struct super_block *sb)
		goto out;
		}

		sbi->feature_compat = le32_to_cpu(dsb->feature_compat);
		if (sbi->feature_compat & EROFS_FEATURE_COMPAT_SB_CHKSUM) {
		ret = erofs_superblock_csum_verify(sb, data);
		if (ret)
		goto out;
		}

		blkszbits = dsb->blkszbits;
		/* 9(512 bytes) + LOG_SECTORS_PER_BLOCK == LOG_BLOCK_SIZE */
		if (blkszbits != LOG_BLOCK_SIZE) {
		@@ -155,7 +187,7 @@ static int erofs_read_superblock(struct super_block *sb)
		}
		ret = 0;
		out:
		kunmap_atomic(data);
		kunmap(page);
		put_page(page);
		return ret;
		}

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