574 lines
13 KiB
C
574 lines
13 KiB
C
/*
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* Copyright (c) 2000-2006 Silicon Graphics, Inc.
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* Copyright (c) 2012-2013 Red Hat, Inc.
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* All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it would be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "xfs.h"
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#include "xfs_shared.h"
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#include "xfs_fs.h"
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#include "xfs_format.h"
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#include "xfs_log_format.h"
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#include "xfs_trans_resv.h"
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#include "xfs_bit.h"
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#include "xfs_mount.h"
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#include "xfs_da_format.h"
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#include "xfs_da_btree.h"
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#include "xfs_defer.h"
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#include "xfs_dir2.h"
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#include "xfs_inode.h"
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#include "xfs_ialloc.h"
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#include "xfs_alloc.h"
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#include "xfs_bmap.h"
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#include "xfs_bmap_btree.h"
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#include "xfs_bmap_util.h"
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#include "xfs_error.h"
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#include "xfs_quota.h"
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#include "xfs_trans_space.h"
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#include "xfs_trace.h"
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#include "xfs_symlink.h"
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#include "xfs_trans.h"
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#include "xfs_log.h"
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/* ----- Kernel only functions below ----- */
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int
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xfs_readlink_bmap_ilocked(
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struct xfs_inode *ip,
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char *link)
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{
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struct xfs_mount *mp = ip->i_mount;
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struct xfs_bmbt_irec mval[XFS_SYMLINK_MAPS];
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struct xfs_buf *bp;
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xfs_daddr_t d;
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char *cur_chunk;
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int pathlen = ip->i_d.di_size;
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int nmaps = XFS_SYMLINK_MAPS;
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int byte_cnt;
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int n;
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int error = 0;
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int fsblocks = 0;
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int offset;
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ASSERT(xfs_isilocked(ip, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
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fsblocks = xfs_symlink_blocks(mp, pathlen);
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error = xfs_bmapi_read(ip, 0, fsblocks, mval, &nmaps, 0);
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if (error)
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goto out;
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offset = 0;
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for (n = 0; n < nmaps; n++) {
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d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
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byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
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bp = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt), 0,
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&xfs_symlink_buf_ops);
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if (!bp)
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return -ENOMEM;
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error = bp->b_error;
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if (error) {
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xfs_buf_ioerror_alert(bp, __func__);
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xfs_buf_relse(bp);
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/* bad CRC means corrupted metadata */
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if (error == -EFSBADCRC)
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error = -EFSCORRUPTED;
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goto out;
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}
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byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
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if (pathlen < byte_cnt)
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byte_cnt = pathlen;
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cur_chunk = bp->b_addr;
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if (xfs_sb_version_hascrc(&mp->m_sb)) {
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if (!xfs_symlink_hdr_ok(ip->i_ino, offset,
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byte_cnt, bp)) {
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error = -EFSCORRUPTED;
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xfs_alert(mp,
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"symlink header does not match required off/len/owner (0x%x/Ox%x,0x%llx)",
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offset, byte_cnt, ip->i_ino);
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xfs_buf_relse(bp);
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goto out;
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}
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cur_chunk += sizeof(struct xfs_dsymlink_hdr);
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}
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memcpy(link + offset, cur_chunk, byte_cnt);
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pathlen -= byte_cnt;
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offset += byte_cnt;
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xfs_buf_relse(bp);
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}
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ASSERT(pathlen == 0);
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link[ip->i_d.di_size] = '\0';
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error = 0;
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out:
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return error;
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}
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int
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xfs_readlink(
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struct xfs_inode *ip,
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char *link)
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{
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struct xfs_mount *mp = ip->i_mount;
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xfs_fsize_t pathlen;
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int error = 0;
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trace_xfs_readlink(ip);
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ASSERT(!(ip->i_df.if_flags & XFS_IFINLINE));
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if (XFS_FORCED_SHUTDOWN(mp))
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return -EIO;
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xfs_ilock(ip, XFS_ILOCK_SHARED);
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pathlen = ip->i_d.di_size;
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if (!pathlen)
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goto out;
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if (pathlen < 0 || pathlen > XFS_SYMLINK_MAXLEN) {
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xfs_alert(mp, "%s: inode (%llu) bad symlink length (%lld)",
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__func__, (unsigned long long) ip->i_ino,
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(long long) pathlen);
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ASSERT(0);
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error = -EFSCORRUPTED;
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goto out;
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}
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error = xfs_readlink_bmap_ilocked(ip, link);
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out:
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xfs_iunlock(ip, XFS_ILOCK_SHARED);
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return error;
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}
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int
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xfs_symlink(
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struct xfs_inode *dp,
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struct xfs_name *link_name,
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const char *target_path,
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umode_t mode,
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struct xfs_inode **ipp)
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{
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struct xfs_mount *mp = dp->i_mount;
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struct xfs_trans *tp = NULL;
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struct xfs_inode *ip = NULL;
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int error = 0;
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int pathlen;
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struct xfs_defer_ops dfops;
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xfs_fsblock_t first_block;
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bool unlock_dp_on_error = false;
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xfs_fileoff_t first_fsb;
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xfs_filblks_t fs_blocks;
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int nmaps;
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struct xfs_bmbt_irec mval[XFS_SYMLINK_MAPS];
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xfs_daddr_t d;
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const char *cur_chunk;
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int byte_cnt;
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int n;
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xfs_buf_t *bp;
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prid_t prid;
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struct xfs_dquot *udqp = NULL;
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struct xfs_dquot *gdqp = NULL;
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struct xfs_dquot *pdqp = NULL;
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uint resblks;
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*ipp = NULL;
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trace_xfs_symlink(dp, link_name);
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if (XFS_FORCED_SHUTDOWN(mp))
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return -EIO;
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/*
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* Check component lengths of the target path name.
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*/
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pathlen = strlen(target_path);
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if (pathlen >= XFS_SYMLINK_MAXLEN) /* total string too long */
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return -ENAMETOOLONG;
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udqp = gdqp = NULL;
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prid = xfs_get_initial_prid(dp);
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/*
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* Make sure that we have allocated dquot(s) on disk.
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*/
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error = xfs_qm_vop_dqalloc(dp,
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xfs_kuid_to_uid(current_fsuid()),
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xfs_kgid_to_gid(current_fsgid()), prid,
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XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
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&udqp, &gdqp, &pdqp);
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if (error)
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return error;
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/*
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* The symlink will fit into the inode data fork?
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* There can't be any attributes so we get the whole variable part.
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*/
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if (pathlen <= XFS_LITINO(mp, dp->i_d.di_version))
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fs_blocks = 0;
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else
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fs_blocks = xfs_symlink_blocks(mp, pathlen);
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resblks = XFS_SYMLINK_SPACE_RES(mp, link_name->len, fs_blocks);
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error = xfs_trans_alloc(mp, &M_RES(mp)->tr_symlink, resblks, 0, 0, &tp);
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if (error)
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goto out_release_inode;
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xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
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unlock_dp_on_error = true;
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/*
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* Check whether the directory allows new symlinks or not.
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*/
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if (dp->i_d.di_flags & XFS_DIFLAG_NOSYMLINKS) {
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error = -EPERM;
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goto out_trans_cancel;
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}
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/*
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* Reserve disk quota : blocks and inode.
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*/
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error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp,
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pdqp, resblks, 1, 0);
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if (error)
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goto out_trans_cancel;
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/*
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* Initialize the bmap freelist prior to calling either
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* bmapi or the directory create code.
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*/
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xfs_defer_init(&dfops, &first_block);
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/*
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* Allocate an inode for the symlink.
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*/
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error = xfs_dir_ialloc(&tp, dp, S_IFLNK | (mode & ~S_IFMT), 1, 0,
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prid, &ip, NULL);
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if (error)
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goto out_trans_cancel;
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/*
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* Now we join the directory inode to the transaction. We do not do it
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* earlier because xfs_dir_ialloc might commit the previous transaction
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* (and release all the locks). An error from here on will result in
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* the transaction cancel unlocking dp so don't do it explicitly in the
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* error path.
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*/
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xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
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unlock_dp_on_error = false;
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/*
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* Also attach the dquot(s) to it, if applicable.
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*/
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xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
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if (resblks)
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resblks -= XFS_IALLOC_SPACE_RES(mp);
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/*
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* If the symlink will fit into the inode, write it inline.
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*/
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if (pathlen <= XFS_IFORK_DSIZE(ip)) {
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xfs_init_local_fork(ip, XFS_DATA_FORK, target_path, pathlen);
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ip->i_d.di_size = pathlen;
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ip->i_d.di_format = XFS_DINODE_FMT_LOCAL;
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xfs_trans_log_inode(tp, ip, XFS_ILOG_DDATA | XFS_ILOG_CORE);
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} else {
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int offset;
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first_fsb = 0;
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nmaps = XFS_SYMLINK_MAPS;
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error = xfs_bmapi_write(tp, ip, first_fsb, fs_blocks,
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XFS_BMAPI_METADATA, &first_block, resblks,
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mval, &nmaps, &dfops);
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if (error)
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goto out_bmap_cancel;
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if (resblks)
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resblks -= fs_blocks;
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ip->i_d.di_size = pathlen;
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xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
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cur_chunk = target_path;
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offset = 0;
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for (n = 0; n < nmaps; n++) {
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char *buf;
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d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
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byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
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bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
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BTOBB(byte_cnt), 0);
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if (!bp) {
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error = -ENOMEM;
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goto out_bmap_cancel;
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}
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bp->b_ops = &xfs_symlink_buf_ops;
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byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
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byte_cnt = min(byte_cnt, pathlen);
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buf = bp->b_addr;
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buf += xfs_symlink_hdr_set(mp, ip->i_ino, offset,
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byte_cnt, bp);
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memcpy(buf, cur_chunk, byte_cnt);
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cur_chunk += byte_cnt;
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pathlen -= byte_cnt;
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offset += byte_cnt;
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xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SYMLINK_BUF);
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xfs_trans_log_buf(tp, bp, 0, (buf + byte_cnt - 1) -
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(char *)bp->b_addr);
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}
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ASSERT(pathlen == 0);
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}
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/*
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* Create the directory entry for the symlink.
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*/
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error = xfs_dir_createname(tp, dp, link_name, ip->i_ino,
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&first_block, &dfops, resblks);
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if (error)
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goto out_bmap_cancel;
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xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
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xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
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/*
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* If this is a synchronous mount, make sure that the
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* symlink transaction goes to disk before returning to
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* the user.
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*/
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if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC)) {
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xfs_trans_set_sync(tp);
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}
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error = xfs_defer_finish(&tp, &dfops);
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if (error)
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goto out_bmap_cancel;
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error = xfs_trans_commit(tp);
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if (error)
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goto out_release_inode;
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xfs_qm_dqrele(udqp);
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xfs_qm_dqrele(gdqp);
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xfs_qm_dqrele(pdqp);
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*ipp = ip;
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return 0;
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out_bmap_cancel:
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xfs_defer_cancel(&dfops);
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out_trans_cancel:
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xfs_trans_cancel(tp);
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out_release_inode:
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/*
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* Wait until after the current transaction is aborted to finish the
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* setup of the inode and release the inode. This prevents recursive
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* transactions and deadlocks from xfs_inactive.
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*/
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if (ip) {
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xfs_finish_inode_setup(ip);
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IRELE(ip);
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}
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xfs_qm_dqrele(udqp);
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xfs_qm_dqrele(gdqp);
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xfs_qm_dqrele(pdqp);
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if (unlock_dp_on_error)
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xfs_iunlock(dp, XFS_ILOCK_EXCL);
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return error;
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}
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/*
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* Free a symlink that has blocks associated with it.
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*/
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STATIC int
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xfs_inactive_symlink_rmt(
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struct xfs_inode *ip)
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{
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xfs_buf_t *bp;
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int done;
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int error;
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xfs_fsblock_t first_block;
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struct xfs_defer_ops dfops;
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int i;
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xfs_mount_t *mp;
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xfs_bmbt_irec_t mval[XFS_SYMLINK_MAPS];
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int nmaps;
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int size;
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xfs_trans_t *tp;
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mp = ip->i_mount;
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ASSERT(ip->i_df.if_flags & XFS_IFEXTENTS);
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/*
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* We're freeing a symlink that has some
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* blocks allocated to it. Free the
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* blocks here. We know that we've got
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* either 1 or 2 extents and that we can
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* free them all in one bunmapi call.
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*/
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ASSERT(ip->i_d.di_nextents > 0 && ip->i_d.di_nextents <= 2);
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error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
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if (error)
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return error;
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xfs_ilock(ip, XFS_ILOCK_EXCL);
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xfs_trans_ijoin(tp, ip, 0);
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/*
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* Lock the inode, fix the size, and join it to the transaction.
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* Hold it so in the normal path, we still have it locked for
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* the second transaction. In the error paths we need it
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* held so the cancel won't rele it, see below.
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*/
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size = (int)ip->i_d.di_size;
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ip->i_d.di_size = 0;
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xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
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/*
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* Find the block(s) so we can inval and unmap them.
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*/
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done = 0;
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xfs_defer_init(&dfops, &first_block);
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nmaps = ARRAY_SIZE(mval);
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error = xfs_bmapi_read(ip, 0, xfs_symlink_blocks(mp, size),
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mval, &nmaps, 0);
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if (error)
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goto error_trans_cancel;
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/*
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* Invalidate the block(s). No validation is done.
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*/
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for (i = 0; i < nmaps; i++) {
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bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
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XFS_FSB_TO_DADDR(mp, mval[i].br_startblock),
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XFS_FSB_TO_BB(mp, mval[i].br_blockcount), 0);
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if (!bp) {
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error = -ENOMEM;
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goto error_bmap_cancel;
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}
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xfs_trans_binval(tp, bp);
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}
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/*
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* Unmap the dead block(s) to the dfops.
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*/
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error = xfs_bunmapi(tp, ip, 0, size, 0, nmaps,
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&first_block, &dfops, &done);
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if (error)
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goto error_bmap_cancel;
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ASSERT(done);
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/*
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* Commit the first transaction. This logs the EFI and the inode.
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*/
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xfs_defer_ijoin(&dfops, ip);
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error = xfs_defer_finish(&tp, &dfops);
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if (error)
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goto error_bmap_cancel;
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/*
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* The first xact was committed, so add the inode to the new one.
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* Mark it dirty so it will be logged and moved forward in the log as
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* part of every commit.
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*/
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xfs_trans_ijoin(tp, ip, 0);
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xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
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/*
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|
* Commit the transaction containing extent freeing and EFDs.
|
|
*/
|
|
error = xfs_trans_commit(tp);
|
|
if (error) {
|
|
ASSERT(XFS_FORCED_SHUTDOWN(mp));
|
|
goto error_unlock;
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
|
|
xfs_iunlock(ip, XFS_ILOCK_EXCL);
|
|
return 0;
|
|
|
|
error_bmap_cancel:
|
|
xfs_defer_cancel(&dfops);
|
|
error_trans_cancel:
|
|
xfs_trans_cancel(tp);
|
|
error_unlock:
|
|
xfs_iunlock(ip, XFS_ILOCK_EXCL);
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* xfs_inactive_symlink - free a symlink
|
|
*/
|
|
int
|
|
xfs_inactive_symlink(
|
|
struct xfs_inode *ip)
|
|
{
|
|
struct xfs_mount *mp = ip->i_mount;
|
|
int pathlen;
|
|
|
|
trace_xfs_inactive_symlink(ip);
|
|
|
|
if (XFS_FORCED_SHUTDOWN(mp))
|
|
return -EIO;
|
|
|
|
xfs_ilock(ip, XFS_ILOCK_EXCL);
|
|
|
|
/*
|
|
* Zero length symlinks _can_ exist.
|
|
*/
|
|
pathlen = (int)ip->i_d.di_size;
|
|
if (!pathlen) {
|
|
xfs_iunlock(ip, XFS_ILOCK_EXCL);
|
|
return 0;
|
|
}
|
|
|
|
if (pathlen < 0 || pathlen > XFS_SYMLINK_MAXLEN) {
|
|
xfs_alert(mp, "%s: inode (0x%llx) bad symlink length (%d)",
|
|
__func__, (unsigned long long)ip->i_ino, pathlen);
|
|
xfs_iunlock(ip, XFS_ILOCK_EXCL);
|
|
ASSERT(0);
|
|
return -EFSCORRUPTED;
|
|
}
|
|
|
|
if (ip->i_df.if_flags & XFS_IFINLINE) {
|
|
if (ip->i_df.if_bytes > 0)
|
|
xfs_idata_realloc(ip, -(ip->i_df.if_bytes),
|
|
XFS_DATA_FORK);
|
|
xfs_iunlock(ip, XFS_ILOCK_EXCL);
|
|
ASSERT(ip->i_df.if_bytes == 0);
|
|
return 0;
|
|
}
|
|
|
|
xfs_iunlock(ip, XFS_ILOCK_EXCL);
|
|
|
|
/* remove the remote symlink */
|
|
return xfs_inactive_symlink_rmt(ip);
|
|
}
|