xfs: add CRC checks to remote symlinks (f948dd76) · Commits · 戴 / test

fs/xfs/xfs_buf_item.h

+3 −1

Original line number	Diff line number	Diff line
		@@ -49,6 +49,7 @@ extern kmem_zone_t *xfs_buf_item_zone;
		#define XFS_BLF_AGFL_BUF (1<<7)
		#define XFS_BLF_AGI_BUF (1<<8)
		#define XFS_BLF_DINO_BUF (1<<9)
		#define XFS_BLF_SYMLINK_BUF (1<<10)

		#define XFS_BLF_TYPE_MASK \
		(XFS_BLF_UDQUOT_BUF \| \
		@@ -58,7 +59,8 @@ extern kmem_zone_t *xfs_buf_item_zone;
		XFS_BLF_AGF_BUF \| \
		XFS_BLF_AGFL_BUF \| \
		XFS_BLF_AGI_BUF \| \
		XFS_BLF_DINO_BUF)
		XFS_BLF_DINO_BUF \| \
		XFS_BLF_SYMLINK_BUF)

		#define XFS_BLF_CHUNK 128
		#define XFS_BLF_SHIFT 7

fs/xfs/xfs_log_recover.c

+9 −0

Original line number	Diff line number	Diff line
		@@ -45,6 +45,7 @@
		#include "xfs_cksum.h"
		#include "xfs_trace.h"
		#include "xfs_icache.h"
		#include "xfs_symlink.h"

		STATIC int
		xlog_find_zeroed(
		@@ -2002,6 +2003,14 @@ xlog_recover_do_reg_buffer(
		}
		bp->b_ops = &xfs_inode_buf_ops;
		break;
		case XFS_BLF_SYMLINK_BUF:
		if ((__be32 )bp->b_addr != cpu_to_be32(XFS_SYMLINK_MAGIC)) {
		xfs_warn(mp, "Bad symlink block magic!");
		ASSERT(0);
		break;
		}
		bp->b_ops = &xfs_symlink_buf_ops;
		break;
		default:
		break;
		}

fs/xfs/xfs_symlink.c

+240 −39

Original line number	Diff line number	Diff line
		@@ -43,6 +43,152 @@
		#include "xfs_log_priv.h"
		#include "xfs_trace.h"
		#include "xfs_symlink.h"
		#include "xfs_cksum.h"
		#include "xfs_buf_item.h"


		/*
		* Each contiguous block has a header, so it is not just a simple pathlen
		* to FSB conversion.
		*/
		int
		xfs_symlink_blocks(
		struct xfs_mount *mp,
		int pathlen)
		{
		int fsblocks = 0;
		int len = pathlen;

		do {
		fsblocks++;
		len -= XFS_SYMLINK_BUF_SPACE(mp, mp->m_sb.sb_blocksize);
		} while (len > 0);

		ASSERT(fsblocks <= XFS_SYMLINK_MAPS);
		return fsblocks;
		}

		static int
		xfs_symlink_hdr_set(
		struct xfs_mount *mp,
		xfs_ino_t ino,
		uint32_t offset,
		uint32_t size,
		struct xfs_buf *bp)
		{
		struct xfs_dsymlink_hdr *dsl = bp->b_addr;

		if (!xfs_sb_version_hascrc(&mp->m_sb))
		return 0;

		dsl->sl_magic = cpu_to_be32(XFS_SYMLINK_MAGIC);
		dsl->sl_offset = cpu_to_be32(offset);
		dsl->sl_bytes = cpu_to_be32(size);
		uuid_copy(&dsl->sl_uuid, &mp->m_sb.sb_uuid);
		dsl->sl_owner = cpu_to_be64(ino);
		dsl->sl_blkno = cpu_to_be64(bp->b_bn);
		bp->b_ops = &xfs_symlink_buf_ops;

		return sizeof(struct xfs_dsymlink_hdr);
		}

		/*
		* Checking of the symlink header is split into two parts. the verifier does
		* CRC, location and bounds checking, the unpacking function checks the path
		* parameters and owner.
		*/
		bool
		xfs_symlink_hdr_ok(
		struct xfs_mount *mp,
		xfs_ino_t ino,
		uint32_t offset,
		uint32_t size,
		struct xfs_buf *bp)
		{
		struct xfs_dsymlink_hdr *dsl = bp->b_addr;

		if (offset != be32_to_cpu(dsl->sl_offset))
		return false;
		if (size != be32_to_cpu(dsl->sl_bytes))
		return false;
		if (ino != be64_to_cpu(dsl->sl_owner))
		return false;

		/* ok */
		return true;
		}

		static bool
		xfs_symlink_verify(
		struct xfs_buf *bp)
		{
		struct xfs_mount *mp = bp->b_target->bt_mount;
		struct xfs_dsymlink_hdr *dsl = bp->b_addr;

		if (!xfs_sb_version_hascrc(&mp->m_sb))
		return false;
		if (dsl->sl_magic != cpu_to_be32(XFS_SYMLINK_MAGIC))
		return false;
		if (!uuid_equal(&dsl->sl_uuid, &mp->m_sb.sb_uuid))
		return false;
		if (bp->b_bn != be64_to_cpu(dsl->sl_blkno))
		return false;
		if (be32_to_cpu(dsl->sl_offset) +
		be32_to_cpu(dsl->sl_bytes) >= MAXPATHLEN)
		return false;
		if (dsl->sl_owner == 0)
		return false;

		return true;
		}

		static void
		xfs_symlink_read_verify(
		struct xfs_buf *bp)
		{
		struct xfs_mount *mp = bp->b_target->bt_mount;

		/* no verification of non-crc buffers */
		if (!xfs_sb_version_hascrc(&mp->m_sb))
		return;

		if (!xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
		offsetof(struct xfs_dsymlink_hdr, sl_crc)) \|\|
		!xfs_symlink_verify(bp)) {
		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
		xfs_buf_ioerror(bp, EFSCORRUPTED);
		}
		}

		static void
		xfs_symlink_write_verify(
		struct xfs_buf *bp)
		{
		struct xfs_mount *mp = bp->b_target->bt_mount;
		struct xfs_buf_log_item *bip = bp->b_fspriv;

		/* no verification of non-crc buffers */
		if (!xfs_sb_version_hascrc(&mp->m_sb))
		return;

		if (!xfs_symlink_verify(bp)) {
		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
		xfs_buf_ioerror(bp, EFSCORRUPTED);
		return;
		}

		if (bip) {
		struct xfs_dsymlink_hdr *dsl = bp->b_addr;
		dsl->sl_lsn = cpu_to_be64(bip->bli_item.li_lsn);
		}
		xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
		offsetof(struct xfs_dsymlink_hdr, sl_crc));
		}

		const struct xfs_buf_ops xfs_symlink_buf_ops = {
		.verify_read = xfs_symlink_read_verify,
		.verify_write = xfs_symlink_write_verify,
		};

		void
		xfs_symlink_local_to_remote(
		@@ -51,38 +197,60 @@ xfs_symlink_local_to_remote(
		struct xfs_inode *ip,
		struct xfs_ifork *ifp)
		{
		/* remote symlink blocks are not verifiable until CRCs come along */
		struct xfs_mount *mp = ip->i_mount;
		char *buf;

		if (!xfs_sb_version_hascrc(&mp->m_sb)) {
		bp->b_ops = NULL;
		memcpy(bp->b_addr, ifp->if_u1.if_data, ifp->if_bytes);
		return;
		}

		/* ----- Kernel only functions below ----- */
		/*
		* As this symlink fits in an inode literal area, it must also fit in
		* the smallest buffer the filesystem supports.
		*/
		ASSERT(BBTOB(bp->b_length) >=
		ifp->if_bytes + sizeof(struct xfs_dsymlink_hdr));

		bp->b_ops = &xfs_symlink_buf_ops;

		buf = bp->b_addr;
		buf += xfs_symlink_hdr_set(mp, ip->i_ino, 0, ifp->if_bytes, bp);
		memcpy(buf, ifp->if_u1.if_data, ifp->if_bytes);
		}

		/* ----- Kernel only functions below ----- */
		STATIC int
		xfs_readlink_bmap(
		xfs_inode_t *ip,
		struct xfs_inode *ip,
		char *link)
		{
		xfs_mount_t *mp = ip->i_mount;
		struct xfs_mount *mp = ip->i_mount;
		struct xfs_bmbt_irec mval[XFS_SYMLINK_MAPS];
		struct xfs_buf *bp;
		xfs_daddr_t d;
		char *cur_chunk;
		int pathlen = ip->i_d.di_size;
		int nmaps = XFS_SYMLINK_MAPS;
		xfs_bmbt_irec_t mval[XFS_SYMLINK_MAPS];
		xfs_daddr_t d;
		int byte_cnt;
		int n;
		xfs_buf_t *bp;
		int error = 0;
		int fsblocks = 0;
		int offset;

		error = xfs_bmapi_read(ip, 0, XFS_B_TO_FSB(mp, pathlen), mval, &nmaps,
		0);
		fsblocks = xfs_symlink_blocks(mp, pathlen);
		error = xfs_bmapi_read(ip, 0, fsblocks, mval, &nmaps, 0);
		if (error)
		goto out;

		offset = 0;
		for (n = 0; n < nmaps; n++) {
		d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
		byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);

		bp = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt), 0, NULL);
		bp = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt), 0,
		&xfs_symlink_buf_ops);
		if (!bp)
		return XFS_ERROR(ENOMEM);
		error = bp->b_error;
		@@ -91,13 +259,34 @@ xfs_readlink_bmap(
		xfs_buf_relse(bp);
		goto out;
		}
		byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
		if (pathlen < byte_cnt)
		byte_cnt = pathlen;

		cur_chunk = bp->b_addr;
		if (xfs_sb_version_hascrc(&mp->m_sb)) {
		if (!xfs_symlink_hdr_ok(mp, ip->i_ino, offset,
		byte_cnt, bp)) {
		error = EFSCORRUPTED;
		xfs_alert(mp,
		"symlink header does not match required off/len/owner (0x%x/Ox%x,0x%llx)",
		offset, byte_cnt, ip->i_ino);
		xfs_buf_relse(bp);
		goto out;

		}

		cur_chunk += sizeof(struct xfs_dsymlink_hdr);
		}

		memcpy(link + offset, bp->b_addr, byte_cnt);

		pathlen -= byte_cnt;
		offset += byte_cnt;

		memcpy(link, bp->b_addr, byte_cnt);
		xfs_buf_relse(bp);
		}
		ASSERT(pathlen == 0);

		link[ip->i_d.di_size] = '\0';
		error = 0;
		@@ -108,10 +297,10 @@ xfs_readlink_bmap(

		int
		xfs_readlink(
		xfs_inode_t *ip,
		struct xfs_inode *ip,
		char *link)
		{
		xfs_mount_t *mp = ip->i_mount;
		struct xfs_mount *mp = ip->i_mount;
		xfs_fsize_t pathlen;
		int error = 0;

		@@ -150,18 +339,18 @@ xfs_readlink(

		int
		xfs_symlink(
		xfs_inode_t *dp,
		struct xfs_inode *dp,
		struct xfs_name *link_name,
		const char *target_path,
		umode_t mode,
		xfs_inode_t **ipp)
		struct xfs_inode **ipp)
		{
		xfs_mount_t *mp = dp->i_mount;
		xfs_trans_t *tp;
		xfs_inode_t *ip;
		int error;
		struct xfs_mount *mp = dp->i_mount;
		struct xfs_trans *tp = NULL;
		struct xfs_inode *ip = NULL;
		int error = 0;
		int pathlen;
		xfs_bmap_free_t free_list;
		struct xfs_bmap_free free_list;
		xfs_fsblock_t first_block;
		bool unlock_dp_on_error = false;
		uint cancel_flags;
		@@ -169,7 +358,7 @@ xfs_symlink(
		xfs_fileoff_t first_fsb;
		xfs_filblks_t fs_blocks;
		int nmaps;
		xfs_bmbt_irec_t mval[XFS_SYMLINK_MAPS];
		struct xfs_bmbt_irec mval[XFS_SYMLINK_MAPS];
		xfs_daddr_t d;
		const char *cur_chunk;
		int byte_cnt;
		@@ -180,9 +369,6 @@ xfs_symlink(
		uint resblks;

		*ipp = NULL;
		error = 0;
		ip = NULL;
		tp = NULL;

		trace_xfs_symlink(dp, link_name);

		@@ -307,6 +493,8 @@ xfs_symlink(
		xfs_trans_log_inode(tp, ip, XFS_ILOG_DDATA \| XFS_ILOG_CORE);

		} else {
		int offset;

		first_fsb = 0;
		nmaps = XFS_SYMLINK_MAPS;

		@@ -322,7 +510,10 @@ xfs_symlink(
		xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);

		cur_chunk = target_path;
		offset = 0;
		for (n = 0; n < nmaps; n++) {
		char *buf;

		d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
		byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
		bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
		@@ -331,15 +522,25 @@ xfs_symlink(
		error = ENOMEM;
		goto error2;
		}
		bp->b_ops = &xfs_symlink_buf_ops;

		byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
		if (pathlen < byte_cnt) {
		byte_cnt = pathlen;
		}
		pathlen -= byte_cnt;

		memcpy(bp->b_addr, cur_chunk, byte_cnt);
		buf = bp->b_addr;
		buf += xfs_symlink_hdr_set(mp, ip->i_ino, offset,
		byte_cnt, bp);

		memcpy(buf, cur_chunk, byte_cnt);

		cur_chunk += byte_cnt;
		pathlen -= byte_cnt;
		offset += byte_cnt;

		xfs_trans_log_buf(tp, bp, 0, byte_cnt - 1);
		xfs_trans_log_buf(tp, bp, 0, (buf + byte_cnt - 1) -
		(char *)bp->b_addr);
		}
		}

		@@ -392,7 +593,7 @@ xfs_symlink(
		/*
		* Free a symlink that has blocks associated with it.
		*/
		STATIC int
		int
		xfs_inactive_symlink_rmt(
		xfs_inode_t *ip,
		xfs_trans_t **tpp)
		@@ -438,12 +639,12 @@ xfs_inactive_symlink_rmt(
		done = 0;
		xfs_bmap_init(&free_list, &first_block);
		nmaps = ARRAY_SIZE(mval);
		error = xfs_bmapi_read(ip, 0, XFS_B_TO_FSB(mp, size),
		error = xfs_bmapi_read(ip, 0, xfs_symlink_blocks(mp, size),
		mval, &nmaps, 0);
		if (error)
		goto error0;
		/*
		* Invalidate the block(s).
		* Invalidate the block(s). No validation is done.
		*/
		for (i = 0; i < nmaps; i++) {
		bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,

fs/xfs/xfs_symlink.h

+31 −3

Original line number	Diff line number	Diff line
		@@ -17,16 +17,44 @@
		#ifndef __XFS_SYMLINK_H
		#define __XFS_SYMLINK_H 1

		struct xfs_mount;
		struct xfs_trans;
		struct xfs_inode;
		struct xfs_buf;
		struct xfs_ifork;
		struct xfs_name;

		#define XFS_SYMLINK_MAGIC 0x58534c4d /* XSLM */

		struct xfs_dsymlink_hdr {
		__be32 sl_magic;
		__be32 sl_offset;
		__be32 sl_bytes;
		__be32 sl_crc;
		uuid_t sl_uuid;
		__be64 sl_owner;
		__be64 sl_blkno;
		__be64 sl_lsn;
		};

		/*
		* The maximum pathlen is 1024 bytes. Since the minimum file system
		* blocksize is 512 bytes, we can get a max of 2 extents back from
		* bmapi.
		* blocksize is 512 bytes, we can get a max of 3 extents back from
		* bmapi when crc headers are taken into account.
		*/
		#define XFS_SYMLINK_MAPS 2
		#define XFS_SYMLINK_MAPS 3

		#define XFS_SYMLINK_BUF_SPACE(mp, bufsize) \
		((bufsize) - (xfs_sb_version_hascrc(&(mp)->m_sb) ? \
		sizeof(struct xfs_dsymlink_hdr) : 0))

		int xfs_symlink_blocks(struct xfs_mount *mp, int pathlen);

		void xfs_symlink_local_to_remote(struct xfs_trans tp, struct xfs_buf bp,
		struct xfs_inode ip, struct xfs_ifork ifp);

		extern const struct xfs_buf_ops xfs_symlink_buf_ops;

		#ifdef __KERNEL__

		int xfs_symlink(struct xfs_inode dp, struct xfs_name link_name,

Admin message