diff options
Diffstat (limited to 'fs/xfs/xfs_symlink.c')
| -rw-r--r-- | fs/xfs/xfs_symlink.c | 529 |
1 files changed, 529 insertions, 0 deletions
diff --git a/fs/xfs/xfs_symlink.c b/fs/xfs/xfs_symlink.c new file mode 100644 index 000000000000..7512c96c7f29 --- /dev/null +++ b/fs/xfs/xfs_symlink.c @@ -0,0 +1,529 @@ +/* + * 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; +} |