xfs: split out the remote symlink handling (1fb7e48d) · Commits · e / devices / android_kernel_fairphone_FP4

fs/xfs/Makefile

+2 −1

Original line number	Diff line number	Diff line
		@@ -50,6 +50,7 @@ xfs-y += xfs_aops.o \
		xfs_mru_cache.o \
		xfs_rename.o \
		xfs_super.o \
		xfs_symlink.o \
		xfs_trans.o \
		xfs_utils.o \
		xfs_vnodeops.o \
		@@ -81,7 +82,7 @@ xfs-y += xfs_alloc.o \
		xfs_inode_buf.o \
		xfs_log_recover.o \
		xfs_mount.o \
		xfs_symlink.o \
		xfs_symlink_remote.o \
		xfs_trans_resv.o

		# low-level transaction/log code

fs/xfs/xfs_format.h

+42 −0

Original line number	Diff line number	Diff line
		@@ -27,6 +27,12 @@
		* xfs_log_format.h. Everything else goes here.
		*/

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

		/*
		* RealTime Device format definitions
		*/
		@@ -123,5 +129,41 @@ typedef struct xfs_dqblk {

		#define XFS_DQUOT_CRC_OFF offsetof(struct xfs_dqblk, dd_crc)

		/*
		* Remote symlink format and access functions.
		*/
		#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 3 extents back from
		* bmapi when crc headers are taken into account.
		*/
		#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);
		int xfs_symlink_hdr_set(struct xfs_mount *mp, xfs_ino_t ino, uint32_t offset,
		uint32_t size, struct xfs_buf *bp);
		bool xfs_symlink_hdr_ok(struct xfs_mount *mp, xfs_ino_t ino, uint32_t offset,
		uint32_t size, struct xfs_buf *bp);
		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;

		#endif /* __XFS_FORMAT_H__ */

fs/xfs/xfs_symlink.c

+0 −172

Original line number	Diff line number	Diff line
		@@ -32,8 +32,6 @@
		#include "xfs_ialloc_btree.h"
		#include "xfs_dinode.h"
		#include "xfs_inode.h"
		#include "xfs_inode_item.h"
		#include "xfs_itable.h"
		#include "xfs_ialloc.h"
		#include "xfs_alloc.h"
		#include "xfs_bmap.h"
		@@ -41,178 +39,8 @@
		#include "xfs_quota.h"
		#include "xfs_utils.h"
		#include "xfs_trans_space.h"
		#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 buflen = XFS_SYMLINK_BUF_SPACE(mp, mp->m_sb.sb_blocksize);

		return (pathlen + buflen - 1) / buflen;
		}

		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(
		struct xfs_trans *tp,
		struct xfs_buf *bp,
		struct xfs_inode *ip,
		struct xfs_ifork *ifp)
		{
		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;
		}

		/*
		* 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

fs/xfs/xfs_symlink.h

+1 −41

Original line number	Diff line number	Diff line
		@@ -17,51 +17,11 @@
		#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 3 extents back from
		* bmapi when crc headers are taken into account.
		*/
		#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);
		bool xfs_symlink_hdr_ok(struct xfs_mount *mp, xfs_ino_t ino, uint32_t offset,
		uint32_t size, struct xfs_buf *bp);
		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__
		/* Kernel only symlink defintions */

		int xfs_symlink(struct xfs_inode dp, struct xfs_name link_name,
		const char target_path, umode_t mode, struct xfs_inode *ipp);
		int xfs_readlink(struct xfs_inode ip, char link);
		int xfs_inactive_symlink(struct xfs_inode ip, struct xfs_trans *tpp);

		#endif /* __KERNEL__ */
		#endif /* __XFS_SYMLINK_H */

fs/xfs/xfs_symlink_remote.c

0 → 100644

+199 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (c) 2000-2006 Silicon Graphics, Inc.
		* Copyright (c) 2012-2013 Red Hat, Inc.
		* All rights reserved.
		*
		* This program is free software; you can redistribute it and/or
		* modify it under the terms of the GNU General Public License as
		* published by the Free Software Foundation.
		*
		* This program is distributed in the hope that it would be useful,
		* but WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		* GNU General Public License for more details.
		*
		* You should have received a copy of the GNU General Public License
		* along with this program; if not, write the Free Software Foundation,
		* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
		*/
		#include "xfs.h"
		#include "xfs_fs.h"
		#include "xfs_format.h"
		#include "xfs_log.h"
		#include "xfs_trans.h"
		#include "xfs_sb.h"
		#include "xfs_mount.h"
		#include "xfs_bmap_btree.h"
		#include "xfs_inode.h"
		#include "xfs_error.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 buflen = XFS_SYMLINK_BUF_SPACE(mp, mp->m_sb.sb_blocksize);

		return (pathlen + buflen - 1) / buflen;
		}

		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(
		struct xfs_trans *tp,
		struct xfs_buf *bp,
		struct xfs_inode *ip,
		struct xfs_ifork *ifp)
		{
		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;
		}

		/*
		* 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);
		}