xfs: split out symlink code into it's own file. (19de7351) · Commits · 戴 / test

fs/xfs/Makefile

+3 −2

Original line number	Diff line number	Diff line
		@@ -45,11 +45,11 @@ xfs-y += xfs_aops.o \
		xfs_itable.o \
		xfs_message.o \
		xfs_mru_cache.o \
		xfs_super.o \
		xfs_xattr.o \
		xfs_rename.o \
		xfs_super.o \
		xfs_utils.o \
		xfs_vnodeops.o \
		xfs_xattr.o \
		kmem.o \
		uuid.o

		@@ -73,6 +73,7 @@ xfs-y += xfs_alloc.o \
		xfs_inode.o \
		xfs_log_recover.o \
		xfs_mount.o \
		xfs_symlink.o \
		xfs_trans.o

		# low-level transaction/log code

fs/xfs/xfs_bmap.c

+6 −15

Original line number	Diff line number	Diff line
		@@ -47,6 +47,7 @@
		#include "xfs_filestream.h"
		#include "xfs_vnodeops.h"
		#include "xfs_trace.h"
		#include "xfs_symlink.h"


		kmem_zone_t *xfs_bmap_free_item_zone;
		@@ -1321,9 +1322,10 @@ xfs_bmap_add_attrfork_extents(
		}

		/*
		* Block initialisation functions for local to extent format conversion.
		* As these get more complex, they will be moved to the relevant files,
		* but for now they are too simple to worry about.
		* Block initialisation function for local to extent format conversion.
		*
		* This shouldn't actually be called by anyone, so make sure debug kernels cause
		* a noticable failure.
		*/
		STATIC void
		xfs_bmap_local_to_extents_init_fn(
		@@ -1332,23 +1334,12 @@ xfs_bmap_local_to_extents_init_fn(
		struct xfs_inode *ip,
		struct xfs_ifork *ifp)
		{
		ASSERT(0);
		bp->b_ops = &xfs_bmbt_buf_ops;
		memcpy(bp->b_addr, ifp->if_u1.if_data, ifp->if_bytes);
		xfs_trans_buf_set_type(tp, bp, XFS_BLF_BTREE_BUF);
		}

		STATIC void
		xfs_symlink_local_to_remote(
		struct xfs_trans *tp,
		struct xfs_buf *bp,
		struct xfs_inode *ip,
		struct xfs_ifork *ifp)
		{
		/* remote symlink blocks are not verifiable until CRCs come along */
		bp->b_ops = NULL;
		memcpy(bp->b_addr, ifp->if_u1.if_data, ifp->if_bytes);
		}

		/*
		* Called from xfs_bmap_add_attrfork to handle local format files. Each
		* different data fork content type needs a different callout to do the

fs/xfs/xfs_symlink.c

0 → 100644

+529 −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_types.h"
		#include "xfs_bit.h"
		#include "xfs_log.h"
		#include "xfs_trans.h"
		#include "xfs_sb.h"
		#include "xfs_ag.h"
		#include "xfs_dir2.h"
		#include "xfs_mount.h"
		#include "xfs_da_btree.h"
		#include "xfs_bmap_btree.h"
		#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"
		#include "xfs_error.h"
		#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"

		void
		xfs_symlink_local_to_remote(
		struct xfs_trans *tp,
		struct xfs_buf *bp,
		struct xfs_inode *ip,
		struct xfs_ifork *ifp)
		{
		/* remote symlink blocks are not verifiable until CRCs come along */
		bp->b_ops = NULL;
		memcpy(bp->b_addr, ifp->if_u1.if_data, ifp->if_bytes);
		}

		/* ----- Kernel only functions below ----- */

		STATIC int
		xfs_readlink_bmap(
		xfs_inode_t *ip,
		char *link)
		{
		xfs_mount_t *mp = ip->i_mount;
		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;

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

		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);
		if (!bp)
		return XFS_ERROR(ENOMEM);
		error = bp->b_error;
		if (error) {
		xfs_buf_ioerror_alert(bp, __func__);
		xfs_buf_relse(bp);
		goto out;
		}
		if (pathlen < byte_cnt)
		byte_cnt = pathlen;
		pathlen -= byte_cnt;

		memcpy(link, bp->b_addr, byte_cnt);
		xfs_buf_relse(bp);
		}

		link[ip->i_d.di_size] = '\0';
		error = 0;

		out:
		return error;
		}

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

		trace_xfs_readlink(ip);

		if (XFS_FORCED_SHUTDOWN(mp))
		return XFS_ERROR(EIO);

		xfs_ilock(ip, XFS_ILOCK_SHARED);

		pathlen = ip->i_d.di_size;
		if (!pathlen)
		goto out;

		if (pathlen < 0 \|\| pathlen > MAXPATHLEN) {
		xfs_alert(mp, "%s: inode (%llu) bad symlink length (%lld)",
		__func__, (unsigned long long) ip->i_ino,
		(long long) pathlen);
		ASSERT(0);
		error = XFS_ERROR(EFSCORRUPTED);
		goto out;
		}


		if (ip->i_df.if_flags & XFS_IFINLINE) {
		memcpy(link, ip->i_df.if_u1.if_data, pathlen);
		link[pathlen] = '\0';
		} else {
		error = xfs_readlink_bmap(ip, link);
		}

		out:
		xfs_iunlock(ip, XFS_ILOCK_SHARED);
		return error;
		}

		int
		xfs_symlink(
		xfs_inode_t *dp,
		struct xfs_name *link_name,
		const char *target_path,
		umode_t mode,
		xfs_inode_t **ipp)
		{
		xfs_mount_t *mp = dp->i_mount;
		xfs_trans_t *tp;
		xfs_inode_t *ip;
		int error;
		int pathlen;
		xfs_bmap_free_t free_list;
		xfs_fsblock_t first_block;
		bool unlock_dp_on_error = false;
		uint cancel_flags;
		int committed;
		xfs_fileoff_t first_fsb;
		xfs_filblks_t fs_blocks;
		int nmaps;
		xfs_bmbt_irec_t mval[XFS_SYMLINK_MAPS];
		xfs_daddr_t d;
		const char *cur_chunk;
		int byte_cnt;
		int n;
		xfs_buf_t *bp;
		prid_t prid;
		struct xfs_dquot udqp, gdqp;
		uint resblks;

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

		trace_xfs_symlink(dp, link_name);

		if (XFS_FORCED_SHUTDOWN(mp))
		return XFS_ERROR(EIO);

		/*
		* Check component lengths of the target path name.
		*/
		pathlen = strlen(target_path);
		if (pathlen >= MAXPATHLEN) /* total string too long */
		return XFS_ERROR(ENAMETOOLONG);

		udqp = gdqp = NULL;
		if (dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
		prid = xfs_get_projid(dp);
		else
		prid = XFS_PROJID_DEFAULT;

		/*
		* Make sure that we have allocated dquot(s) on disk.
		*/
		error = xfs_qm_vop_dqalloc(dp, current_fsuid(), current_fsgid(), prid,
		XFS_QMOPT_QUOTALL \| XFS_QMOPT_INHERIT, &udqp, &gdqp);
		if (error)
		goto std_return;

		tp = xfs_trans_alloc(mp, XFS_TRANS_SYMLINK);
		cancel_flags = XFS_TRANS_RELEASE_LOG_RES;
		/*
		* The symlink will fit into the inode data fork?
		* There can't be any attributes so we get the whole variable part.
		*/
		if (pathlen <= XFS_LITINO(mp, dp->i_d.di_version))
		fs_blocks = 0;
		else
		fs_blocks = XFS_B_TO_FSB(mp, pathlen);
		resblks = XFS_SYMLINK_SPACE_RES(mp, link_name->len, fs_blocks);
		error = xfs_trans_reserve(tp, resblks, XFS_SYMLINK_LOG_RES(mp), 0,
		XFS_TRANS_PERM_LOG_RES, XFS_SYMLINK_LOG_COUNT);
		if (error == ENOSPC && fs_blocks == 0) {
		resblks = 0;
		error = xfs_trans_reserve(tp, 0, XFS_SYMLINK_LOG_RES(mp), 0,
		XFS_TRANS_PERM_LOG_RES, XFS_SYMLINK_LOG_COUNT);
		}
		if (error) {
		cancel_flags = 0;
		goto error_return;
		}

		xfs_ilock(dp, XFS_ILOCK_EXCL \| XFS_ILOCK_PARENT);
		unlock_dp_on_error = true;

		/*
		* Check whether the directory allows new symlinks or not.
		*/
		if (dp->i_d.di_flags & XFS_DIFLAG_NOSYMLINKS) {
		error = XFS_ERROR(EPERM);
		goto error_return;
		}

		/*
		* Reserve disk quota : blocks and inode.
		*/
		error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp, resblks, 1, 0);
		if (error)
		goto error_return;

		/*
		* Check for ability to enter directory entry, if no space reserved.
		*/
		error = xfs_dir_canenter(tp, dp, link_name, resblks);
		if (error)
		goto error_return;
		/*
		* Initialize the bmap freelist prior to calling either
		* bmapi or the directory create code.
		*/
		xfs_bmap_init(&free_list, &first_block);

		/*
		* Allocate an inode for the symlink.
		*/
		error = xfs_dir_ialloc(&tp, dp, S_IFLNK \| (mode & ~S_IFMT), 1, 0,
		prid, resblks > 0, &ip, NULL);
		if (error) {
		if (error == ENOSPC)
		goto error_return;
		goto error1;
		}

		/*
		* An error after we've joined dp to the transaction will result in the
		* transaction cancel unlocking dp so don't do it explicitly in the
		* error path.
		*/
		xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
		unlock_dp_on_error = false;

		/*
		* Also attach the dquot(s) to it, if applicable.
		*/
		xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp);

		if (resblks)
		resblks -= XFS_IALLOC_SPACE_RES(mp);
		/*
		* If the symlink will fit into the inode, write it inline.
		*/
		if (pathlen <= XFS_IFORK_DSIZE(ip)) {
		xfs_idata_realloc(ip, pathlen, XFS_DATA_FORK);
		memcpy(ip->i_df.if_u1.if_data, target_path, pathlen);
		ip->i_d.di_size = pathlen;

		/*
		* The inode was initially created in extent format.
		*/
		ip->i_df.if_flags &= ~(XFS_IFEXTENTS \| XFS_IFBROOT);
		ip->i_df.if_flags \|= XFS_IFINLINE;

		ip->i_d.di_format = XFS_DINODE_FMT_LOCAL;
		xfs_trans_log_inode(tp, ip, XFS_ILOG_DDATA \| XFS_ILOG_CORE);

		} else {
		first_fsb = 0;
		nmaps = XFS_SYMLINK_MAPS;

		error = xfs_bmapi_write(tp, ip, first_fsb, fs_blocks,
		XFS_BMAPI_METADATA, &first_block, resblks,
		mval, &nmaps, &free_list);
		if (error)
		goto error2;

		if (resblks)
		resblks -= fs_blocks;
		ip->i_d.di_size = pathlen;
		xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);

		cur_chunk = target_path;
		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_trans_get_buf(tp, mp->m_ddev_targp, d,
		BTOBB(byte_cnt), 0);
		if (!bp) {
		error = ENOMEM;
		goto error2;
		}
		if (pathlen < byte_cnt) {
		byte_cnt = pathlen;
		}
		pathlen -= byte_cnt;

		memcpy(bp->b_addr, cur_chunk, byte_cnt);
		cur_chunk += byte_cnt;

		xfs_trans_log_buf(tp, bp, 0, byte_cnt - 1);
		}
		}

		/*
		* Create the directory entry for the symlink.
		*/
		error = xfs_dir_createname(tp, dp, link_name, ip->i_ino,
		&first_block, &free_list, resblks);
		if (error)
		goto error2;
		xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD \| XFS_ICHGTIME_CHG);
		xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);

		/*
		* If this is a synchronous mount, make sure that the
		* symlink transaction goes to disk before returning to
		* the user.
		*/
		if (mp->m_flags & (XFS_MOUNT_WSYNC\|XFS_MOUNT_DIRSYNC)) {
		xfs_trans_set_sync(tp);
		}

		error = xfs_bmap_finish(&tp, &free_list, &committed);
		if (error) {
		goto error2;
		}
		error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
		xfs_qm_dqrele(udqp);
		xfs_qm_dqrele(gdqp);

		*ipp = ip;
		return 0;

		error2:
		IRELE(ip);
		error1:
		xfs_bmap_cancel(&free_list);
		cancel_flags \|= XFS_TRANS_ABORT;
		error_return:
		xfs_trans_cancel(tp, cancel_flags);
		xfs_qm_dqrele(udqp);
		xfs_qm_dqrele(gdqp);

		if (unlock_dp_on_error)
		xfs_iunlock(dp, XFS_ILOCK_EXCL);
		std_return:
		return error;
		}

		/*
		* Free a symlink that has blocks associated with it.
		*/
		STATIC int
		xfs_inactive_symlink_rmt(
		xfs_inode_t *ip,
		xfs_trans_t **tpp)
		{
		xfs_buf_t *bp;
		int committed;
		int done;
		int error;
		xfs_fsblock_t first_block;
		xfs_bmap_free_t free_list;
		int i;
		xfs_mount_t *mp;
		xfs_bmbt_irec_t mval[XFS_SYMLINK_MAPS];
		int nmaps;
		xfs_trans_t *ntp;
		int size;
		xfs_trans_t *tp;

		tp = *tpp;
		mp = ip->i_mount;
		ASSERT(ip->i_d.di_size > XFS_IFORK_DSIZE(ip));
		/*
		* We're freeing a symlink that has some
		* blocks allocated to it. Free the
		* blocks here. We know that we've got
		* either 1 or 2 extents and that we can
		* free them all in one bunmapi call.
		*/
		ASSERT(ip->i_d.di_nextents > 0 && ip->i_d.di_nextents <= 2);

		/*
		* Lock the inode, fix the size, and join it to the transaction.
		* Hold it so in the normal path, we still have it locked for
		* the second transaction. In the error paths we need it
		* held so the cancel won't rele it, see below.
		*/
		size = (int)ip->i_d.di_size;
		ip->i_d.di_size = 0;
		xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
		/*
		* Find the block(s) so we can inval and unmap them.
		*/
		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),
		mval, &nmaps, 0);
		if (error)
		goto error0;
		/*
		* Invalidate the block(s).
		*/
		for (i = 0; i < nmaps; i++) {
		bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
		XFS_FSB_TO_DADDR(mp, mval[i].br_startblock),
		XFS_FSB_TO_BB(mp, mval[i].br_blockcount), 0);
		if (!bp) {
		error = ENOMEM;
		goto error1;
		}
		xfs_trans_binval(tp, bp);
		}
		/*
		* Unmap the dead block(s) to the free_list.
		*/
		if ((error = xfs_bunmapi(tp, ip, 0, size, XFS_BMAPI_METADATA, nmaps,
		&first_block, &free_list, &done)))
		goto error1;
		ASSERT(done);
		/*
		* Commit the first transaction. This logs the EFI and the inode.
		*/
		if ((error = xfs_bmap_finish(&tp, &free_list, &committed)))
		goto error1;
		/*
		* The transaction must have been committed, since there were
		* actually extents freed by xfs_bunmapi. See xfs_bmap_finish.
		* The new tp has the extent freeing and EFDs.
		*/
		ASSERT(committed);
		/*
		* The first xact was committed, so add the inode to the new one.
		* Mark it dirty so it will be logged and moved forward in the log as
		* part of every commit.
		*/
		xfs_trans_ijoin(tp, ip, 0);
		xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
		/*
		* Get a new, empty transaction to return to our caller.
		*/
		ntp = xfs_trans_dup(tp);
		/*
		* Commit the transaction containing extent freeing and EFDs.
		* If we get an error on the commit here or on the reserve below,
		* we need to unlock the inode since the new transaction doesn't
		* have the inode attached.
		*/
		error = xfs_trans_commit(tp, 0);
		tp = ntp;
		if (error) {
		ASSERT(XFS_FORCED_SHUTDOWN(mp));
		goto error0;
		}
		/*
		* transaction commit worked ok so we can drop the extra ticket
		* reference that we gained in xfs_trans_dup()
		*/
		xfs_log_ticket_put(tp->t_ticket);

		/*
		* Remove the memory for extent descriptions (just bookkeeping).
		*/
		if (ip->i_df.if_bytes)
		xfs_idata_realloc(ip, -ip->i_df.if_bytes, XFS_DATA_FORK);
		ASSERT(ip->i_df.if_bytes == 0);
		/*
		* Put an itruncate log reservation in the new transaction
		* for our caller.
		*/
		if ((error = xfs_trans_reserve(tp, 0, XFS_ITRUNCATE_LOG_RES(mp), 0,
		XFS_TRANS_PERM_LOG_RES, XFS_ITRUNCATE_LOG_COUNT))) {
		ASSERT(XFS_FORCED_SHUTDOWN(mp));
		goto error0;
		}

		xfs_trans_ijoin(tp, ip, 0);
		*tpp = tp;
		return 0;

		error1:
		xfs_bmap_cancel(&free_list);
		error0:
		return error;
		}

fs/xfs/xfs_symlink.h

0 → 100644

+38 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (c) 2012 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
		*/
		#ifndef __XFS_SYMLINK_H
		#define __XFS_SYMLINK_H 1

		/*
		* 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.
		*/
		#define XFS_SYMLINK_MAPS 2

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

		#ifdef __KERNEL__

		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_rmt(struct xfs_inode ip, struct xfs_trans *tpp);

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

fs/xfs/xfs_vnodeops.c

+2 −476

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