xfs_symlink.rar_Only

/* * 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_shared.h" #include "xfs_fs.h" #include "xfs_format.h" #include "xfs_log_format.h" #include "xfs_trans_resv.h" #include "xfs_bit.h" #include "xfs_mount.h" #include "xfs_da_format.h" #include "xfs_da_btree.h" #include "xfs_dir2.h" #include "xfs_inode.h" #include "xfs_ialloc.h" #include "xfs_alloc.h" #include "xfs_bmap.h" #include "xfs_bmap_btree.h" #include "xfs_bmap_util.h" #include "xfs_error.h" #include "xfs_quota.h" #include "xfs_trans_space.h" #include "xfs_trace.h" #include "xfs_symlink.h" #include "xfs_trans.h" #include "xfs_log.h" /* ----- Kernel only functions below ----- */ STATIC int xfs_readlink_bmap( struct xfs_inode *ip, char *link) { 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; int byte_cnt; int n; int error = 0; int fsblocks = 0; int offset; 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, &xfs_symlink_buf_ops); if (!bp) return -ENOMEM; error = bp->b_error; if (error) { xfs_buf_ioerror_alert(bp, __func__); xfs_buf_relse(bp); /* bad CRC means corrupted metadata */ if (error == -EFSBADCRC) error = -EFSCORRUPTED; 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(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; xfs_buf_relse(bp); } ASSERT(pathlen == 0); link[ip->i_d.di_size] = '\0'; error = 0; out: return error; } int xfs_readlink( struct xfs_inode *ip, char *link) { struct xfs_mount *mp = ip->i_mount; xfs_fsize_t pathlen; int error = 0; trace_xfs_readlink(ip); if (XFS_FORCED_SHUTDOWN(mp)) return -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 = -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( struct xfs_inode *dp, struct xfs_name *link_name, const char *target_path, umode_t mode, struct xfs_inode **ipp) { struct xfs_mount *mp = dp->i_mount; struct xfs_trans *tp = NULL; struct xfs_inode *ip = NULL; int error = 0; int pathlen; struct xfs_bmap_free 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; struct xfs_bmbt_irec 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 = NULL; struct xfs_dquot *gdqp = NULL; struct xfs_dquot *pdqp = NULL; uint resblks; *ipp = NULL; trace_xfs_symlink(dp, link_name); if (XFS_FORCED_SHUTDOWN(mp)) return -EIO; /* * Check component lengths of the target path name. */ pathlen = strlen(target_path); if (pathlen >= MAXPATHLEN) /* total string too long */ return -ENAMETOOLONG; udqp = gdqp = NULL; prid = xfs_get_initial_prid(dp); /* * Make sure that we have allocated dquot(s) on disk. */ error = xfs_qm_vop_dqalloc(dp, xfs_kuid_to_uid(current_fsuid()), xfs_kgid_to_gid(current_fsgid()), prid, XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT, &udqp, &gdqp, &pdqp); 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_symlink_blocks(mp, pathlen); resblks = XFS_SYMLINK_SPACE_RES(mp, link_name->len, fs_blocks); error = xfs_trans_reserve(tp, &M_RES(mp)->tr_symlink, resblks, 0); if (error == -ENOSPC && fs_blocks == 0) { resblks = 0; error = xfs_trans_reserve(tp, &M_RES(mp)->tr_symlink, 0, 0); } 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 = -EPERM; goto error_return; } /* * Reserve disk quota : blocks and inode. */ error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp, pdqp, resblks, 1, 0); if (error) goto error_return; /* * Check for ability to enter directory entry, if no space reserved. */ if (!resblks) { error = xfs_dir_canenter(tp, dp, link_name); 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, pdqp); 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 { int offset; 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