| /* |
| * 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, cur_chunk, 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; |
| 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) |
| return error; |
| |
| tp = xfs_trans_alloc(mp, XFS_TRANS_SYMLINK); |
| /* |
| * 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) |
| goto out_trans_cancel; |
| |
| 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 out_trans_cancel; |
| } |
| |
| /* |
| * Reserve disk quota : blocks and inode. |
| */ |
| error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp, |
| pdqp, resblks, 1, 0); |
| if (error) |
| goto out_trans_cancel; |
| |
| /* |
| * Check for ability to enter directory entry, if no space reserved. |
| */ |
| if (!resblks) { |
| error = xfs_dir_canenter(tp, dp, link_name); |
| if (error) |
| goto out_trans_cancel; |
| } |
| /* |
| * 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) |
| goto out_trans_cancel; |
| |
| /* |
| * Now we join the directory inode to the transaction. We do not do it |
| * earlier because xfs_dir_ialloc might commit the previous transaction |
| * (and release all the locks). An error from here on 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 out_bmap_cancel; |
| |
| if (resblks) |
| resblks -= fs_blocks; |
| ip->i_d.di_size = pathlen; |
| 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, |
| BTOBB(byte_cnt), 0); |
| if (!bp) { |
| error = -ENOMEM; |
| goto out_bmap_cancel; |
| } |
| bp->b_ops = &xfs_symlink_buf_ops; |
| |
| byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt); |
| byte_cnt = min(byte_cnt, pathlen); |
| |
| 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_buf_set_type(tp, bp, XFS_BLFT_SYMLINK_BUF); |
| xfs_trans_log_buf(tp, bp, 0, (buf + byte_cnt - 1) - |
| (char *)bp->b_addr); |
| } |
| ASSERT(pathlen == 0); |
| } |
| |
| /* |
| * 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 out_bmap_cancel; |
| 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 out_bmap_cancel; |
| |
| error = xfs_trans_commit(tp); |
| if (error) |
| goto out_release_inode; |
| |
| xfs_qm_dqrele(udqp); |
| xfs_qm_dqrele(gdqp); |
| xfs_qm_dqrele(pdqp); |
| |
| *ipp = ip; |
| return 0; |
| |
| out_bmap_cancel: |
| xfs_bmap_cancel(&free_list); |
| out_trans_cancel: |
| xfs_trans_cancel(tp); |
| out_release_inode: |
| /* |
| * Wait until after the current transaction is aborted to finish the |
| * setup of the inode and release the inode. This prevents recursive |
| * transactions and deadlocks from xfs_inactive. |
| */ |
| if (ip) { |
| xfs_finish_inode_setup(ip); |
| IRELE(ip); |
| } |
| |
| xfs_qm_dqrele(udqp); |
| xfs_qm_dqrele(gdqp); |
| xfs_qm_dqrele(pdqp); |
| |
| if (unlock_dp_on_error) |
| xfs_iunlock(dp, XFS_ILOCK_EXCL); |
| return error; |
| } |
| |
| /* |
| * Free a symlink that has blocks associated with it. |
| */ |
| STATIC int |
| xfs_inactive_symlink_rmt( |
| struct xfs_inode *ip) |
| { |
| 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; |
| int size; |
| xfs_trans_t *tp; |
| |
| mp = ip->i_mount; |
| ASSERT(ip->i_df.if_flags & XFS_IFEXTENTS); |
| /* |
| * 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); |
| |
| tp = xfs_trans_alloc(mp, XFS_TRANS_INACTIVE); |
| error = xfs_trans_reserve(tp, &M_RES(mp)->tr_itruncate, 0, 0); |
| if (error) { |
| xfs_trans_cancel(tp); |
| return error; |
| } |
| |
| xfs_ilock(ip, XFS_ILOCK_EXCL); |
| xfs_trans_ijoin(tp, ip, 0); |
| |
| /* |
| * 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_symlink_blocks(mp, size), |
| mval, &nmaps, 0); |
| if (error) |
| goto error_trans_cancel; |
| /* |
| * Invalidate the block(s). No validation is done. |
| */ |
| 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 error_bmap_cancel; |
| } |
| xfs_trans_binval(tp, bp); |
| } |
| /* |
| * Unmap the dead block(s) to the free_list. |
| */ |
| error = xfs_bunmapi(tp, ip, 0, size, 0, nmaps, |
| &first_block, &free_list, &done); |
| if (error) |
| goto error_bmap_cancel; |
| ASSERT(done); |
| /* |
| * Commit the first transaction. This logs the EFI and the inode. |
| */ |
| error = xfs_bmap_finish(&tp, &free_list, &committed); |
| if (error) |
| goto error_bmap_cancel; |
| /* |
| * 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); |
| /* |
| * 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_bmap_cancel(&free_list); |
| 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 > MAXPATHLEN) { |
| 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); |
| } |