| Current Path : /sys/gnu/fs/xfs/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
| Current File : //sys/gnu/fs/xfs/xfs_rename.c |
/*
* Copyright (c) 2000-2003,2005 Silicon Graphics, 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_log.h"
#include "xfs_inum.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_da_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_dir_sf.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_inode_item.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_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;
}
/*
* xfs_rename
*/
int
xfs_rename(
bhv_desc_t *src_dir_bdp,
vname_t *src_vname,
xfs_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? */
xfs_vnode_t *src_dir_vp;
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_dp = xfs_vtoi(target_dir_vp);
if (target_dp == NULL) {
return XFS_ERROR(EXDEV);
}
src_dp = XFS_BHVTOI(src_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) {
/*
* 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) {
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) {
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);
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))) {
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) {
goto error_return;
}
if (error) {
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) {
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);
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) {
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) {
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) {
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) {
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) {
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) {
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) {
XVOP_LINK_REMOVED(XFS_ITOV(target_ip), target_dir_vp,
target_link_zero);
IRELE(target_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;
}