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-rw-r--r--fs/xfs/xfs_utils.c488
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diff --git a/fs/xfs/xfs_utils.c b/fs/xfs/xfs_utils.c
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+/*
+ * Copyright (c) 2000-2002 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_rw.h"
+#include "xfs_itable.h"
+#include "xfs_utils.h"
+
+/*
+ * xfs_get_dir_entry is used to get a reference to an inode given
+ * its parent directory inode and the name of the file. It does
+ * not lock the child inode, and it unlocks the directory before
+ * returning. The directory's generation number is returned for
+ * use by a later call to xfs_lock_dir_and_entry.
+ */
+int
+xfs_get_dir_entry(
+ vname_t *dentry,
+ xfs_inode_t **ipp)
+{
+ vnode_t *vp;
+ bhv_desc_t *bdp;
+
+ vp = VNAME_TO_VNODE(dentry);
+ bdp = vn_bhv_lookup_unlocked(VN_BHV_HEAD(vp), &xfs_vnodeops);
+ if (!bdp) {
+ *ipp = NULL;
+ return XFS_ERROR(ENOENT);
+ }
+ VN_HOLD(vp);
+ *ipp = XFS_BHVTOI(bdp);
+ return 0;
+}
+
+int
+xfs_dir_lookup_int(
+ bhv_desc_t *dir_bdp,
+ uint lock_mode,
+ vname_t *dentry,
+ xfs_ino_t *inum,
+ xfs_inode_t **ipp)
+{
+ vnode_t *dir_vp;
+ xfs_inode_t *dp;
+ int error;
+
+ dir_vp = BHV_TO_VNODE(dir_bdp);
+ vn_trace_entry(dir_vp, __FUNCTION__, (inst_t *)__return_address);
+
+ dp = XFS_BHVTOI(dir_bdp);
+
+ error = XFS_DIR_LOOKUP(dp->i_mount, NULL, dp,
+ VNAME(dentry), VNAMELEN(dentry), inum);
+ if (!error) {
+ /*
+ * Unlock the directory. We do this because we can't
+ * hold the directory lock while doing the vn_get()
+ * in xfs_iget(). Doing so could cause us to hold
+ * a lock while waiting for the inode to finish
+ * being inactive while it's waiting for a log
+ * reservation in the inactive routine.
+ */
+ xfs_iunlock(dp, lock_mode);
+ error = xfs_iget(dp->i_mount, NULL, *inum, 0, 0, ipp, 0);
+ xfs_ilock(dp, lock_mode);
+
+ if (error) {
+ *ipp = NULL;
+ } else if ((*ipp)->i_d.di_mode == 0) {
+ /*
+ * The inode has been freed. Something is
+ * wrong so just get out of here.
+ */
+ xfs_iunlock(dp, lock_mode);
+ xfs_iput_new(*ipp, 0);
+ *ipp = NULL;
+ xfs_ilock(dp, lock_mode);
+ error = XFS_ERROR(ENOENT);
+ }
+ }
+ return error;
+}
+
+/*
+ * Allocates a new inode from disk and return a pointer to the
+ * incore copy. This routine will internally commit the current
+ * transaction and allocate a new one if the Space Manager needed
+ * to do an allocation to replenish the inode free-list.
+ *
+ * This routine is designed to be called from xfs_create and
+ * xfs_create_dir.
+ *
+ */
+int
+xfs_dir_ialloc(
+ xfs_trans_t **tpp, /* input: current transaction;
+ output: may be a new transaction. */
+ xfs_inode_t *dp, /* directory within whose allocate
+ the inode. */
+ mode_t mode,
+ nlink_t nlink,
+ xfs_dev_t rdev,
+ cred_t *credp,
+ prid_t prid, /* project id */
+ int okalloc, /* ok to allocate new space */
+ xfs_inode_t **ipp, /* pointer to inode; it will be
+ locked. */
+ int *committed)
+
+{
+ xfs_trans_t *tp;
+ xfs_trans_t *ntp;
+ xfs_inode_t *ip;
+ xfs_buf_t *ialloc_context = NULL;
+ boolean_t call_again = B_FALSE;
+ int code;
+ uint log_res;
+ uint log_count;
+ void *dqinfo;
+ uint tflags;
+
+ tp = *tpp;
+ ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
+
+ /*
+ * xfs_ialloc will return a pointer to an incore inode if
+ * the Space Manager has an available inode on the free
+ * list. Otherwise, it will do an allocation and replenish
+ * the freelist. Since we can only do one allocation per
+ * transaction without deadlocks, we will need to commit the
+ * current transaction and start a new one. We will then
+ * need to call xfs_ialloc again to get the inode.
+ *
+ * If xfs_ialloc did an allocation to replenish the freelist,
+ * it returns the bp containing the head of the freelist as
+ * ialloc_context. We will hold a lock on it across the
+ * transaction commit so that no other process can steal
+ * the inode(s) that we've just allocated.
+ */
+ code = xfs_ialloc(tp, dp, mode, nlink, rdev, credp, prid, okalloc,
+ &ialloc_context, &call_again, &ip);
+
+ /*
+ * Return an error if we were unable to allocate a new inode.
+ * This should only happen if we run out of space on disk or
+ * encounter a disk error.
+ */
+ if (code) {
+ *ipp = NULL;
+ return code;
+ }
+ if (!call_again && (ip == NULL)) {
+ *ipp = NULL;
+ return XFS_ERROR(ENOSPC);
+ }
+
+ /*
+ * If call_again is set, then we were unable to get an
+ * inode in one operation. We need to commit the current
+ * transaction and call xfs_ialloc() again. It is guaranteed
+ * to succeed the second time.
+ */
+ if (call_again) {
+
+ /*
+ * Normally, xfs_trans_commit releases all the locks.
+ * We call bhold to hang on to the ialloc_context across
+ * the commit. Holding this buffer prevents any other
+ * processes from doing any allocations in this
+ * allocation group.
+ */
+ xfs_trans_bhold(tp, ialloc_context);
+ /*
+ * Save the log reservation so we can use
+ * them in the next transaction.
+ */
+ log_res = xfs_trans_get_log_res(tp);
+ log_count = xfs_trans_get_log_count(tp);
+
+ /*
+ * We want the quota changes to be associated with the next
+ * transaction, NOT this one. So, detach the dqinfo from this
+ * and attach it to the next transaction.
+ */
+ dqinfo = NULL;
+ tflags = 0;
+ if (tp->t_dqinfo) {
+ dqinfo = (void *)tp->t_dqinfo;
+ tp->t_dqinfo = NULL;
+ tflags = tp->t_flags & XFS_TRANS_DQ_DIRTY;
+ tp->t_flags &= ~(XFS_TRANS_DQ_DIRTY);
+ }
+
+ ntp = xfs_trans_dup(tp);
+ code = xfs_trans_commit(tp, 0, NULL);
+ tp = ntp;
+ if (committed != NULL) {
+ *committed = 1;
+ }
+ /*
+ * If we get an error during the commit processing,
+ * release the buffer that is still held and return
+ * to the caller.
+ */
+ if (code) {
+ xfs_buf_relse(ialloc_context);
+ if (dqinfo) {
+ tp->t_dqinfo = dqinfo;
+ XFS_TRANS_FREE_DQINFO(tp->t_mountp, tp);
+ }
+ *tpp = ntp;
+ *ipp = NULL;
+ return code;
+ }
+ code = xfs_trans_reserve(tp, 0, log_res, 0,
+ XFS_TRANS_PERM_LOG_RES, log_count);
+ /*
+ * Re-attach the quota info that we detached from prev trx.
+ */
+ if (dqinfo) {
+ tp->t_dqinfo = dqinfo;
+ tp->t_flags |= tflags;
+ }
+
+ if (code) {
+ xfs_buf_relse(ialloc_context);
+ *tpp = ntp;
+ *ipp = NULL;
+ return code;
+ }
+ xfs_trans_bjoin(tp, ialloc_context);
+
+ /*
+ * Call ialloc again. Since we've locked out all
+ * other allocations in this allocation group,
+ * this call should always succeed.
+ */
+ code = xfs_ialloc(tp, dp, mode, nlink, rdev, credp, prid,
+ okalloc, &ialloc_context, &call_again, &ip);
+
+ /*
+ * If we get an error at this point, return to the caller
+ * so that the current transaction can be aborted.
+ */
+ if (code) {
+ *tpp = tp;
+ *ipp = NULL;
+ return code;
+ }
+ ASSERT ((!call_again) && (ip != NULL));
+
+ } else {
+ if (committed != NULL) {
+ *committed = 0;
+ }
+ }
+
+ *ipp = ip;
+ *tpp = tp;
+
+ return 0;
+}
+
+/*
+ * Decrement the link count on an inode & log the change.
+ * If this causes the link count to go to zero, initiate the
+ * logging activity required to truncate a file.
+ */
+int /* error */
+xfs_droplink(
+ xfs_trans_t *tp,
+ xfs_inode_t *ip)
+{
+ int error;
+
+ xfs_ichgtime(ip, XFS_ICHGTIME_CHG);
+
+ ASSERT (ip->i_d.di_nlink > 0);
+ ip->i_d.di_nlink--;
+ xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+
+ error = 0;
+ if (ip->i_d.di_nlink == 0) {
+ /*
+ * We're dropping the last link to this file.
+ * Move the on-disk inode to the AGI unlinked list.
+ * From xfs_inactive() we will pull the inode from
+ * the list and free it.
+ */
+ error = xfs_iunlink(tp, ip);
+ }
+ return error;
+}
+
+/*
+ * This gets called when the inode's version needs to be changed from 1 to 2.
+ * Currently this happens when the nlink field overflows the old 16-bit value
+ * or when chproj is called to change the project for the first time.
+ * As a side effect the superblock version will also get rev'd
+ * to contain the NLINK bit.
+ */
+void
+xfs_bump_ino_vers2(
+ xfs_trans_t *tp,
+ xfs_inode_t *ip)
+{
+ xfs_mount_t *mp;
+ unsigned long s;
+
+ ASSERT(ismrlocked (&ip->i_lock, MR_UPDATE));
+ ASSERT(ip->i_d.di_version == XFS_DINODE_VERSION_1);
+
+ ip->i_d.di_version = XFS_DINODE_VERSION_2;
+ ip->i_d.di_onlink = 0;
+ memset(&(ip->i_d.di_pad[0]), 0, sizeof(ip->i_d.di_pad));
+ mp = tp->t_mountp;
+ if (!XFS_SB_VERSION_HASNLINK(&mp->m_sb)) {
+ s = XFS_SB_LOCK(mp);
+ if (!XFS_SB_VERSION_HASNLINK(&mp->m_sb)) {
+ XFS_SB_VERSION_ADDNLINK(&mp->m_sb);
+ XFS_SB_UNLOCK(mp, s);
+ xfs_mod_sb(tp, XFS_SB_VERSIONNUM);
+ } else {
+ XFS_SB_UNLOCK(mp, s);
+ }
+ }
+ /* Caller must log the inode */
+}
+
+/*
+ * Increment the link count on an inode & log the change.
+ */
+int
+xfs_bumplink(
+ xfs_trans_t *tp,
+ xfs_inode_t *ip)
+{
+ if (ip->i_d.di_nlink >= XFS_MAXLINK)
+ return XFS_ERROR(EMLINK);
+ xfs_ichgtime(ip, XFS_ICHGTIME_CHG);
+
+ ASSERT(ip->i_d.di_nlink > 0);
+ ip->i_d.di_nlink++;
+ if ((ip->i_d.di_version == XFS_DINODE_VERSION_1) &&
+ (ip->i_d.di_nlink > XFS_MAXLINK_1)) {
+ /*
+ * The inode has increased its number of links beyond
+ * what can fit in an old format inode. It now needs
+ * to be converted to a version 2 inode with a 32 bit
+ * link count. If this is the first inode in the file
+ * system to do this, then we need to bump the superblock
+ * version number as well.
+ */
+ xfs_bump_ino_vers2(tp, ip);
+ }
+
+ xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+ return 0;
+}
+
+/*
+ * Try to truncate the given file to 0 length. Currently called
+ * only out of xfs_remove when it has to truncate a file to free
+ * up space for the remove to proceed.
+ */
+int
+xfs_truncate_file(
+ xfs_mount_t *mp,
+ xfs_inode_t *ip)
+{
+ xfs_trans_t *tp;
+ int error;
+
+#ifdef QUOTADEBUG
+ /*
+ * This is called to truncate the quotainodes too.
+ */
+ if (XFS_IS_UQUOTA_ON(mp)) {
+ if (ip->i_ino != mp->m_sb.sb_uquotino)
+ ASSERT(ip->i_udquot);
+ }
+ if (XFS_IS_GQUOTA_ON(mp)) {
+ if (ip->i_ino != mp->m_sb.sb_gquotino)
+ ASSERT(ip->i_gdquot);
+ }
+#endif
+ /*
+ * Make the call to xfs_itruncate_start before starting the
+ * transaction, because we cannot make the call while we're
+ * in a transaction.
+ */
+ xfs_ilock(ip, XFS_IOLOCK_EXCL);
+ xfs_itruncate_start(ip, XFS_ITRUNC_DEFINITE, (xfs_fsize_t)0);
+
+ tp = xfs_trans_alloc(mp, XFS_TRANS_TRUNCATE_FILE);
+ if ((error = xfs_trans_reserve(tp, 0, XFS_ITRUNCATE_LOG_RES(mp), 0,
+ XFS_TRANS_PERM_LOG_RES,
+ XFS_ITRUNCATE_LOG_COUNT))) {
+ xfs_trans_cancel(tp, 0);
+ xfs_iunlock(ip, XFS_IOLOCK_EXCL);
+ return error;
+ }
+
+ /*
+ * Follow the normal truncate locking protocol. Since we
+ * hold the inode in the transaction, we know that it's number
+ * of references will stay constant.
+ */
+ xfs_ilock(ip, XFS_ILOCK_EXCL);
+ xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
+ xfs_trans_ihold(tp, ip);
+ /*
+ * Signal a sync xaction. The only case where that isn't
+ * the case is if we're truncating an already unlinked file
+ * on a wsync fs. In that case, we know the blocks can't
+ * reappear in the file because the links to file are
+ * permanently toast. Currently, we're always going to
+ * want a sync transaction because this code is being
+ * called from places where nlink is guaranteed to be 1
+ * but I'm leaving the tests in to protect against future
+ * changes -- rcc.
+ */
+ error = xfs_itruncate_finish(&tp, ip, (xfs_fsize_t)0,
+ XFS_DATA_FORK,
+ ((ip->i_d.di_nlink != 0 ||
+ !(mp->m_flags & XFS_MOUNT_WSYNC))
+ ? 1 : 0));
+ if (error) {
+ xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES |
+ XFS_TRANS_ABORT);
+ } else {
+ xfs_ichgtime(ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
+ error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES,
+ NULL);
+ }
+ xfs_iunlock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
+
+ return error;
+}
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-12-15 16:35:45 +0000