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-rw-r--r--fs/xfs/xfs_rename.c673
1 files changed, 673 insertions, 0 deletions
diff --git a/fs/xfs/xfs_rename.c b/fs/xfs/xfs_rename.c
new file mode 100644
index 000000000000..cb13f9a1d45b
--- /dev/null
+++ b/fs/xfs/xfs_rename.c
@@ -0,0 +1,673 @@
+/*
+ * Copyright (c) 2000-2003 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 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.
+ *
+ * Further, this software is distributed without any warranty that it is
+ * free of the rightful claim of any third person regarding infringement
+ * or the like. Any license provided herein, whether implied or
+ * otherwise, applies only to this software file. Patent licenses, if
+ * any, provided herein do not apply to combinations of this program with
+ * other software, or any other product whatsoever.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write the Free Software Foundation, Inc., 59
+ * Temple Place - Suite 330, Boston MA 02111-1307, USA.
+ *
+ * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
+ * Mountain View, CA 94043, or:
+ *
+ * http://www.sgi.com
+ *
+ * For further information regarding this notice, see:
+ *
+ * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
+ */
+
+#include "xfs.h"
+#include "xfs_macros.h"
+#include "xfs_types.h"
+#include "xfs_inum.h"
+#include "xfs_log.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_dir.h"
+#include "xfs_dir2.h"
+#include "xfs_dmapi.h"
+#include "xfs_mount.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_attr_sf.h"
+#include "xfs_dir_sf.h"
+#include "xfs_dir2_sf.h"
+#include "xfs_dinode.h"
+#include "xfs_inode_item.h"
+#include "xfs_inode.h"
+#include "xfs_bmap.h"
+#include "xfs_error.h"
+#include "xfs_quota.h"
+#include "xfs_refcache.h"
+#include "xfs_utils.h"
+#include "xfs_trans_space.h"
+#include "xfs_da_btree.h"
+#include "xfs_dir_leaf.h"
+
+
+/*
+ * Given an array of up to 4 inode pointers, unlock the pointed to inodes.
+ * If there are fewer than 4 entries in the array, the empty entries will
+ * be at the end and will have NULL pointers in them.
+ */
+STATIC void
+xfs_rename_unlock4(
+ xfs_inode_t **i_tab,
+ uint lock_mode)
+{
+ int i;
+
+ xfs_iunlock(i_tab[0], lock_mode);
+ for (i = 1; i < 4; i++) {
+ if (i_tab[i] == NULL) {
+ break;
+ }
+ /*
+ * Watch out for duplicate entries in the table.
+ */
+ if (i_tab[i] != i_tab[i-1]) {
+ xfs_iunlock(i_tab[i], lock_mode);
+ }
+ }
+}
+
+#ifdef DEBUG
+int xfs_rename_skip, xfs_rename_nskip;
+#endif
+
+/*
+ * The following routine will acquire the locks required for a rename
+ * operation. The code understands the semantics of renames and will
+ * validate that name1 exists under dp1 & that name2 may or may not
+ * exist under dp2.
+ *
+ * We are renaming dp1/name1 to dp2/name2.
+ *
+ * Return ENOENT if dp1 does not exist, other lookup errors, or 0 for success.
+ */
+STATIC int
+xfs_lock_for_rename(
+ xfs_inode_t *dp1, /* old (source) directory inode */
+ xfs_inode_t *dp2, /* new (target) directory inode */
+ vname_t *vname1,/* old entry name */
+ vname_t *vname2,/* new entry name */
+ xfs_inode_t **ipp1, /* inode of old entry */
+ xfs_inode_t **ipp2, /* inode of new entry, if it
+ already exists, NULL otherwise. */
+ xfs_inode_t **i_tab,/* array of inode returned, sorted */
+ int *num_inodes) /* number of inodes in array */
+{
+ xfs_inode_t *ip1, *ip2, *temp;
+ xfs_ino_t inum1, inum2;
+ int error;
+ int i, j;
+ uint lock_mode;
+ int diff_dirs = (dp1 != dp2);
+
+ ip2 = NULL;
+
+ /*
+ * First, find out the current inums of the entries so that we
+ * can determine the initial locking order. We'll have to
+ * sanity check stuff after all the locks have been acquired
+ * to see if we still have the right inodes, directories, etc.
+ */
+ lock_mode = xfs_ilock_map_shared(dp1);
+ error = xfs_get_dir_entry(vname1, &ip1);
+ if (error) {
+ xfs_iunlock_map_shared(dp1, lock_mode);
+ return error;
+ }
+
+ inum1 = ip1->i_ino;
+
+ ASSERT(ip1);
+ ITRACE(ip1);
+
+ /*
+ * Unlock dp1 and lock dp2 if they are different.
+ */
+
+ if (diff_dirs) {
+ xfs_iunlock_map_shared(dp1, lock_mode);
+ lock_mode = xfs_ilock_map_shared(dp2);
+ }
+
+ error = xfs_dir_lookup_int(XFS_ITOBHV(dp2), lock_mode,
+ vname2, &inum2, &ip2);
+ if (error == ENOENT) { /* target does not need to exist. */
+ inum2 = 0;
+ } else if (error) {
+ /*
+ * If dp2 and dp1 are the same, the next line unlocks dp1.
+ * Got it?
+ */
+ xfs_iunlock_map_shared(dp2, lock_mode);
+ IRELE (ip1);
+ return error;
+ } else {
+ ITRACE(ip2);
+ }
+
+ /*
+ * i_tab contains a list of pointers to inodes. We initialize
+ * the table here & we'll sort it. We will then use it to
+ * order the acquisition of the inode locks.
+ *
+ * Note that the table may contain duplicates. e.g., dp1 == dp2.
+ */
+ i_tab[0] = dp1;
+ i_tab[1] = dp2;
+ i_tab[2] = ip1;
+ if (inum2 == 0) {
+ *num_inodes = 3;
+ i_tab[3] = NULL;
+ } else {
+ *num_inodes = 4;
+ i_tab[3] = ip2;
+ }
+
+ /*
+ * Sort the elements via bubble sort. (Remember, there are at
+ * most 4 elements to sort, so this is adequate.)
+ */
+ for (i=0; i < *num_inodes; i++) {
+ for (j=1; j < *num_inodes; j++) {
+ if (i_tab[j]->i_ino < i_tab[j-1]->i_ino) {
+ temp = i_tab[j];
+ i_tab[j] = i_tab[j-1];
+ i_tab[j-1] = temp;
+ }
+ }
+ }
+
+ /*
+ * We have dp2 locked. If it isn't first, unlock it.
+ * If it is first, tell xfs_lock_inodes so it can skip it
+ * when locking. if dp1 == dp2, xfs_lock_inodes will skip both
+ * since they are equal. xfs_lock_inodes needs all these inodes
+ * so that it can unlock and retry if there might be a dead-lock
+ * potential with the log.
+ */
+
+ if (i_tab[0] == dp2 && lock_mode == XFS_ILOCK_SHARED) {
+#ifdef DEBUG
+ xfs_rename_skip++;
+#endif
+ xfs_lock_inodes(i_tab, *num_inodes, 1, XFS_ILOCK_SHARED);
+ } else {
+#ifdef DEBUG
+ xfs_rename_nskip++;
+#endif
+ xfs_iunlock_map_shared(dp2, lock_mode);
+ xfs_lock_inodes(i_tab, *num_inodes, 0, XFS_ILOCK_SHARED);
+ }
+
+ /*
+ * Set the return value. Null out any unused entries in i_tab.
+ */
+ *ipp1 = *ipp2 = NULL;
+ for (i=0; i < *num_inodes; i++) {
+ if (i_tab[i]->i_ino == inum1) {
+ *ipp1 = i_tab[i];
+ }
+ if (i_tab[i]->i_ino == inum2) {
+ *ipp2 = i_tab[i];
+ }
+ }
+ for (;i < 4; i++) {
+ i_tab[i] = NULL;
+ }
+ return 0;
+}
+
+
+int rename_which_error_return = 0;
+
+/*
+ * xfs_rename
+ */
+int
+xfs_rename(
+ bhv_desc_t *src_dir_bdp,
+ vname_t *src_vname,
+ vnode_t *target_dir_vp,
+ vname_t *target_vname,
+ cred_t *credp)
+{
+ xfs_trans_t *tp;
+ xfs_inode_t *src_dp, *target_dp, *src_ip, *target_ip;
+ xfs_mount_t *mp;
+ int new_parent; /* moving to a new dir */
+ int src_is_directory; /* src_name is a directory */
+ int error;
+ xfs_bmap_free_t free_list;
+ xfs_fsblock_t first_block;
+ int cancel_flags;
+ int committed;
+ xfs_inode_t *inodes[4];
+ int target_ip_dropped = 0; /* dropped target_ip link? */
+ vnode_t *src_dir_vp;
+ bhv_desc_t *target_dir_bdp;
+ int spaceres;
+ int target_link_zero = 0;
+ int num_inodes;
+ char *src_name = VNAME(src_vname);
+ char *target_name = VNAME(target_vname);
+ int src_namelen = VNAMELEN(src_vname);
+ int target_namelen = VNAMELEN(target_vname);
+
+ src_dir_vp = BHV_TO_VNODE(src_dir_bdp);
+ vn_trace_entry(src_dir_vp, "xfs_rename", (inst_t *)__return_address);
+ vn_trace_entry(target_dir_vp, "xfs_rename", (inst_t *)__return_address);
+
+ /*
+ * Find the XFS behavior descriptor for the target directory
+ * vnode since it was not handed to us.
+ */
+ target_dir_bdp = vn_bhv_lookup_unlocked(VN_BHV_HEAD(target_dir_vp),
+ &xfs_vnodeops);
+ if (target_dir_bdp == NULL) {
+ return XFS_ERROR(EXDEV);
+ }
+
+ src_dp = XFS_BHVTOI(src_dir_bdp);
+ target_dp = XFS_BHVTOI(target_dir_bdp);
+ mp = src_dp->i_mount;
+
+ if (DM_EVENT_ENABLED(src_dir_vp->v_vfsp, src_dp, DM_EVENT_RENAME) ||
+ DM_EVENT_ENABLED(target_dir_vp->v_vfsp,
+ target_dp, DM_EVENT_RENAME)) {
+ error = XFS_SEND_NAMESP(mp, DM_EVENT_RENAME,
+ src_dir_vp, DM_RIGHT_NULL,
+ target_dir_vp, DM_RIGHT_NULL,
+ src_name, target_name,
+ 0, 0, 0);
+ if (error) {
+ return error;
+ }
+ }
+ /* Return through std_return after this point. */
+
+ /*
+ * Lock all the participating inodes. Depending upon whether
+ * the target_name exists in the target directory, and
+ * whether the target directory is the same as the source
+ * directory, we can lock from 2 to 4 inodes.
+ * xfs_lock_for_rename() will return ENOENT if src_name
+ * does not exist in the source directory.
+ */
+ tp = NULL;
+ error = xfs_lock_for_rename(src_dp, target_dp, src_vname,
+ target_vname, &src_ip, &target_ip, inodes,
+ &num_inodes);
+
+ if (error) {
+ rename_which_error_return = __LINE__;
+ /*
+ * We have nothing locked, no inode references, and
+ * no transaction, so just get out.
+ */
+ goto std_return;
+ }
+
+ ASSERT(src_ip != NULL);
+
+ if ((src_ip->i_d.di_mode & S_IFMT) == S_IFDIR) {
+ /*
+ * Check for link count overflow on target_dp
+ */
+ if (target_ip == NULL && (src_dp != target_dp) &&
+ target_dp->i_d.di_nlink >= XFS_MAXLINK) {
+ rename_which_error_return = __LINE__;
+ error = XFS_ERROR(EMLINK);
+ xfs_rename_unlock4(inodes, XFS_ILOCK_SHARED);
+ goto rele_return;
+ }
+ }
+
+ new_parent = (src_dp != target_dp);
+ src_is_directory = ((src_ip->i_d.di_mode & S_IFMT) == S_IFDIR);
+
+ /*
+ * Drop the locks on our inodes so that we can start the transaction.
+ */
+ xfs_rename_unlock4(inodes, XFS_ILOCK_SHARED);
+
+ XFS_BMAP_INIT(&free_list, &first_block);
+ tp = xfs_trans_alloc(mp, XFS_TRANS_RENAME);
+ cancel_flags = XFS_TRANS_RELEASE_LOG_RES;
+ spaceres = XFS_RENAME_SPACE_RES(mp, target_namelen);
+ error = xfs_trans_reserve(tp, spaceres, XFS_RENAME_LOG_RES(mp), 0,
+ XFS_TRANS_PERM_LOG_RES, XFS_RENAME_LOG_COUNT);
+ if (error == ENOSPC) {
+ spaceres = 0;
+ error = xfs_trans_reserve(tp, 0, XFS_RENAME_LOG_RES(mp), 0,
+ XFS_TRANS_PERM_LOG_RES, XFS_RENAME_LOG_COUNT);
+ }
+ if (error) {
+ rename_which_error_return = __LINE__;
+ xfs_trans_cancel(tp, 0);
+ goto rele_return;
+ }
+
+ /*
+ * Attach the dquots to the inodes
+ */
+ if ((error = XFS_QM_DQVOPRENAME(mp, inodes))) {
+ xfs_trans_cancel(tp, cancel_flags);
+ rename_which_error_return = __LINE__;
+ goto rele_return;
+ }
+
+ /*
+ * Reacquire the inode locks we dropped above.
+ */
+ xfs_lock_inodes(inodes, num_inodes, 0, XFS_ILOCK_EXCL);
+
+ /*
+ * Join all the inodes to the transaction. From this point on,
+ * we can rely on either trans_commit or trans_cancel to unlock
+ * them. Note that we need to add a vnode reference to the
+ * directories since trans_commit & trans_cancel will decrement
+ * them when they unlock the inodes. Also, we need to be careful
+ * not to add an inode to the transaction more than once.
+ */
+ VN_HOLD(src_dir_vp);
+ xfs_trans_ijoin(tp, src_dp, XFS_ILOCK_EXCL);
+ if (new_parent) {
+ VN_HOLD(target_dir_vp);
+ xfs_trans_ijoin(tp, target_dp, XFS_ILOCK_EXCL);
+ }
+ if ((src_ip != src_dp) && (src_ip != target_dp)) {
+ xfs_trans_ijoin(tp, src_ip, XFS_ILOCK_EXCL);
+ }
+ if ((target_ip != NULL) &&
+ (target_ip != src_ip) &&
+ (target_ip != src_dp) &&
+ (target_ip != target_dp)) {
+ xfs_trans_ijoin(tp, target_ip, XFS_ILOCK_EXCL);
+ }
+
+ /*
+ * Set up the target.
+ */
+ if (target_ip == NULL) {
+ /*
+ * If there's no space reservation, check the entry will
+ * fit before actually inserting it.
+ */
+ if (spaceres == 0 &&
+ (error = XFS_DIR_CANENTER(mp, tp, target_dp, target_name,
+ target_namelen))) {
+ rename_which_error_return = __LINE__;
+ goto error_return;
+ }
+ /*
+ * If target does not exist and the rename crosses
+ * directories, adjust the target directory link count
+ * to account for the ".." reference from the new entry.
+ */
+ error = XFS_DIR_CREATENAME(mp, tp, target_dp, target_name,
+ target_namelen, src_ip->i_ino,
+ &first_block, &free_list, spaceres);
+ if (error == ENOSPC) {
+ rename_which_error_return = __LINE__;
+ goto error_return;
+ }
+ if (error) {
+ rename_which_error_return = __LINE__;
+ goto abort_return;
+ }
+ xfs_ichgtime(target_dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
+
+ if (new_parent && src_is_directory) {
+ error = xfs_bumplink(tp, target_dp);
+ if (error) {
+ rename_which_error_return = __LINE__;
+ goto abort_return;
+ }
+ }
+ } else { /* target_ip != NULL */
+
+ /*
+ * If target exists and it's a directory, check that both
+ * target and source are directories and that target can be
+ * destroyed, or that neither is a directory.
+ */
+ if ((target_ip->i_d.di_mode & S_IFMT) == S_IFDIR) {
+ /*
+ * Make sure target dir is empty.
+ */
+ if (!(XFS_DIR_ISEMPTY(target_ip->i_mount, target_ip)) ||
+ (target_ip->i_d.di_nlink > 2)) {
+ error = XFS_ERROR(EEXIST);
+ rename_which_error_return = __LINE__;
+ goto error_return;
+ }
+ }
+
+ /*
+ * Link the source inode under the target name.
+ * If the source inode is a directory and we are moving
+ * it across directories, its ".." entry will be
+ * inconsistent until we replace that down below.
+ *
+ * In case there is already an entry with the same
+ * name at the destination directory, remove it first.
+ */
+ error = XFS_DIR_REPLACE(mp, tp, target_dp, target_name,
+ target_namelen, src_ip->i_ino, &first_block,
+ &free_list, spaceres);
+ if (error) {
+ rename_which_error_return = __LINE__;
+ goto abort_return;
+ }
+ xfs_ichgtime(target_dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
+
+ /*
+ * Decrement the link count on the target since the target
+ * dir no longer points to it.
+ */
+ error = xfs_droplink(tp, target_ip);
+ if (error) {
+ rename_which_error_return = __LINE__;
+ goto abort_return;
+ }
+ target_ip_dropped = 1;
+
+ if (src_is_directory) {
+ /*
+ * Drop the link from the old "." entry.
+ */
+ error = xfs_droplink(tp, target_ip);
+ if (error) {
+ rename_which_error_return = __LINE__;
+ goto abort_return;
+ }
+ }
+
+ /* Do this test while we still hold the locks */
+ target_link_zero = (target_ip)->i_d.di_nlink==0;
+
+ } /* target_ip != NULL */
+
+ /*
+ * Remove the source.
+ */
+ if (new_parent && src_is_directory) {
+
+ /*
+ * Rewrite the ".." entry to point to the new
+ * directory.
+ */
+ error = XFS_DIR_REPLACE(mp, tp, src_ip, "..", 2,
+ target_dp->i_ino, &first_block,
+ &free_list, spaceres);
+ ASSERT(error != EEXIST);
+ if (error) {
+ rename_which_error_return = __LINE__;
+ goto abort_return;
+ }
+ xfs_ichgtime(src_ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
+
+ } else {
+ /*
+ * We always want to hit the ctime on the source inode.
+ * We do it in the if clause above for the 'new_parent &&
+ * src_is_directory' case, and here we get all the other
+ * cases. This isn't strictly required by the standards
+ * since the source inode isn't really being changed,
+ * but old unix file systems did it and some incremental
+ * backup programs won't work without it.
+ */
+ xfs_ichgtime(src_ip, XFS_ICHGTIME_CHG);
+ }
+
+ /*
+ * Adjust the link count on src_dp. This is necessary when
+ * renaming a directory, either within one parent when
+ * the target existed, or across two parent directories.
+ */
+ if (src_is_directory && (new_parent || target_ip != NULL)) {
+
+ /*
+ * Decrement link count on src_directory since the
+ * entry that's moved no longer points to it.
+ */
+ error = xfs_droplink(tp, src_dp);
+ if (error) {
+ rename_which_error_return = __LINE__;
+ goto abort_return;
+ }
+ }
+
+ error = XFS_DIR_REMOVENAME(mp, tp, src_dp, src_name, src_namelen,
+ src_ip->i_ino, &first_block, &free_list, spaceres);
+ if (error) {
+ rename_which_error_return = __LINE__;
+ goto abort_return;
+ }
+ xfs_ichgtime(src_dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
+
+ /*
+ * Update the generation counts on all the directory inodes
+ * that we're modifying.
+ */
+ src_dp->i_gen++;
+ xfs_trans_log_inode(tp, src_dp, XFS_ILOG_CORE);
+
+ if (new_parent) {
+ target_dp->i_gen++;
+ xfs_trans_log_inode(tp, target_dp, XFS_ILOG_CORE);
+ }
+
+ /*
+ * If there was a target inode, take an extra reference on
+ * it here so that it doesn't go to xfs_inactive() from
+ * within the commit.
+ */
+ if (target_ip != NULL) {
+ IHOLD(target_ip);
+ }
+
+ /*
+ * If this is a synchronous mount, make sure that the
+ * rename transaction goes to disk before returning to
+ * the user.
+ */
+ if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC)) {
+ xfs_trans_set_sync(tp);
+ }
+
+ /*
+ * Take refs. for vop_link_removed calls below. No need to worry
+ * about directory refs. because the caller holds them.
+ *
+ * Do holds before the xfs_bmap_finish since it might rele them down
+ * to zero.
+ */
+
+ if (target_ip_dropped)
+ IHOLD(target_ip);
+ IHOLD(src_ip);
+
+ error = xfs_bmap_finish(&tp, &free_list, first_block, &committed);
+ if (error) {
+ xfs_bmap_cancel(&free_list);
+ xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES |
+ XFS_TRANS_ABORT));
+ if (target_ip != NULL) {
+ IRELE(target_ip);
+ }
+ if (target_ip_dropped) {
+ IRELE(target_ip);
+ }
+ IRELE(src_ip);
+ goto std_return;
+ }
+
+ /*
+ * trans_commit will unlock src_ip, target_ip & decrement
+ * the vnode references.
+ */
+ error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES, NULL);
+ if (target_ip != NULL) {
+ xfs_refcache_purge_ip(target_ip);
+ IRELE(target_ip);
+ }
+ /*
+ * Let interposed file systems know about removed links.
+ */
+ if (target_ip_dropped) {
+ VOP_LINK_REMOVED(XFS_ITOV(target_ip), target_dir_vp,
+ target_link_zero);
+ IRELE(target_ip);
+ }
+
+ FSC_NOTIFY_NAME_CHANGED(XFS_ITOV(src_ip));
+
+ IRELE(src_ip);
+
+ /* Fall through to std_return with error = 0 or errno from
+ * xfs_trans_commit */
+std_return:
+ if (DM_EVENT_ENABLED(src_dir_vp->v_vfsp, src_dp, DM_EVENT_POSTRENAME) ||
+ DM_EVENT_ENABLED(target_dir_vp->v_vfsp,
+ target_dp, DM_EVENT_POSTRENAME)) {
+ (void) XFS_SEND_NAMESP (mp, DM_EVENT_POSTRENAME,
+ src_dir_vp, DM_RIGHT_NULL,
+ target_dir_vp, DM_RIGHT_NULL,
+ src_name, target_name,
+ 0, error, 0);
+ }
+ return error;
+
+ abort_return:
+ cancel_flags |= XFS_TRANS_ABORT;
+ /* FALLTHROUGH */
+ error_return:
+ xfs_bmap_cancel(&free_list);
+ xfs_trans_cancel(tp, cancel_flags);
+ goto std_return;
+
+ rele_return:
+ IRELE(src_ip);
+ if (target_ip != NULL) {
+ IRELE(target_ip);
+ }
+ goto std_return;
+}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.