870 lines
22 KiB
C
870 lines
22 KiB
C
/*
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* Copyright (c) 2000-2005 Silicon Graphics, Inc.
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* All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it would be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "xfs.h"
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#include "xfs_fs.h"
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#include "xfs_types.h"
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#include "xfs_bit.h"
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#include "xfs_log.h"
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#include "xfs_inum.h"
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#include "xfs_trans.h"
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#include "xfs_sb.h"
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#include "xfs_ag.h"
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#include "xfs_dir2.h"
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#include "xfs_dmapi.h"
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#include "xfs_mount.h"
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#include "xfs_bmap_btree.h"
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#include "xfs_alloc_btree.h"
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#include "xfs_ialloc_btree.h"
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#include "xfs_dir2_sf.h"
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#include "xfs_attr_sf.h"
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#include "xfs_dinode.h"
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#include "xfs_inode.h"
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#include "xfs_btree.h"
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#include "xfs_ialloc.h"
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#include "xfs_quota.h"
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#include "xfs_utils.h"
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/*
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* Look up an inode by number in the given file system.
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* The inode is looked up in the cache held in each AG.
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* If the inode is found in the cache, attach it to the provided
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* vnode.
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*
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* If it is not in core, read it in from the file system's device,
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* add it to the cache and attach the provided vnode.
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*
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* The inode is locked according to the value of the lock_flags parameter.
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* This flag parameter indicates how and if the inode's IO lock and inode lock
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* should be taken.
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*
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* mp -- the mount point structure for the current file system. It points
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* to the inode hash table.
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* tp -- a pointer to the current transaction if there is one. This is
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* simply passed through to the xfs_iread() call.
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* ino -- the number of the inode desired. This is the unique identifier
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* within the file system for the inode being requested.
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* lock_flags -- flags indicating how to lock the inode. See the comment
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* for xfs_ilock() for a list of valid values.
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* bno -- the block number starting the buffer containing the inode,
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* if known (as by bulkstat), else 0.
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*/
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STATIC int
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xfs_iget_core(
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bhv_vnode_t *vp,
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xfs_mount_t *mp,
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xfs_trans_t *tp,
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xfs_ino_t ino,
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uint flags,
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uint lock_flags,
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xfs_inode_t **ipp,
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xfs_daddr_t bno)
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{
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xfs_inode_t *ip;
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xfs_inode_t *iq;
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bhv_vnode_t *inode_vp;
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int error;
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xfs_icluster_t *icl, *new_icl = NULL;
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unsigned long first_index, mask;
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xfs_perag_t *pag;
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xfs_agino_t agino;
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/* the radix tree exists only in inode capable AGs */
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if (XFS_INO_TO_AGNO(mp, ino) >= mp->m_maxagi)
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return EINVAL;
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/* get the perag structure and ensure that it's inode capable */
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pag = xfs_get_perag(mp, ino);
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if (!pag->pagi_inodeok)
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return EINVAL;
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ASSERT(pag->pag_ici_init);
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agino = XFS_INO_TO_AGINO(mp, ino);
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again:
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read_lock(&pag->pag_ici_lock);
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ip = radix_tree_lookup(&pag->pag_ici_root, agino);
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if (ip != NULL) {
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/*
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* If INEW is set this inode is being set up
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* we need to pause and try again.
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*/
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if (xfs_iflags_test(ip, XFS_INEW)) {
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read_unlock(&pag->pag_ici_lock);
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delay(1);
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XFS_STATS_INC(xs_ig_frecycle);
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goto again;
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}
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inode_vp = XFS_ITOV_NULL(ip);
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if (inode_vp == NULL) {
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/*
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* If IRECLAIM is set this inode is
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* on its way out of the system,
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* we need to pause and try again.
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*/
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if (xfs_iflags_test(ip, XFS_IRECLAIM)) {
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read_unlock(&pag->pag_ici_lock);
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delay(1);
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XFS_STATS_INC(xs_ig_frecycle);
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goto again;
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}
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ASSERT(xfs_iflags_test(ip, XFS_IRECLAIMABLE));
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/*
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* If lookup is racing with unlink, then we
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* should return an error immediately so we
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* don't remove it from the reclaim list and
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* potentially leak the inode.
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*/
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if ((ip->i_d.di_mode == 0) &&
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!(flags & XFS_IGET_CREATE)) {
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read_unlock(&pag->pag_ici_lock);
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xfs_put_perag(mp, pag);
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return ENOENT;
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}
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/*
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* There may be transactions sitting in the
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* incore log buffers or being flushed to disk
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* at this time. We can't clear the
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* XFS_IRECLAIMABLE flag until these
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* transactions have hit the disk, otherwise we
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* will void the guarantee the flag provides
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* xfs_iunpin()
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*/
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if (xfs_ipincount(ip)) {
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read_unlock(&pag->pag_ici_lock);
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xfs_log_force(mp, 0,
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XFS_LOG_FORCE|XFS_LOG_SYNC);
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XFS_STATS_INC(xs_ig_frecycle);
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goto again;
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}
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vn_trace_exit(ip, "xfs_iget.alloc",
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(inst_t *)__return_address);
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XFS_STATS_INC(xs_ig_found);
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xfs_iflags_clear(ip, XFS_IRECLAIMABLE);
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read_unlock(&pag->pag_ici_lock);
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XFS_MOUNT_ILOCK(mp);
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list_del_init(&ip->i_reclaim);
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XFS_MOUNT_IUNLOCK(mp);
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goto finish_inode;
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} else if (vp != inode_vp) {
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struct inode *inode = vn_to_inode(inode_vp);
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/* The inode is being torn down, pause and
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* try again.
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*/
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if (inode->i_state & (I_FREEING | I_CLEAR)) {
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read_unlock(&pag->pag_ici_lock);
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delay(1);
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XFS_STATS_INC(xs_ig_frecycle);
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goto again;
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}
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/* Chances are the other vnode (the one in the inode) is being torn
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* down right now, and we landed on top of it. Question is, what do
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* we do? Unhook the old inode and hook up the new one?
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*/
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cmn_err(CE_PANIC,
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"xfs_iget_core: ambiguous vns: vp/0x%p, invp/0x%p",
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inode_vp, vp);
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}
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/*
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* Inode cache hit
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*/
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read_unlock(&pag->pag_ici_lock);
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XFS_STATS_INC(xs_ig_found);
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finish_inode:
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if (ip->i_d.di_mode == 0) {
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if (!(flags & XFS_IGET_CREATE)) {
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xfs_put_perag(mp, pag);
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return ENOENT;
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}
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xfs_iocore_inode_reinit(ip);
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}
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if (lock_flags != 0)
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xfs_ilock(ip, lock_flags);
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xfs_iflags_clear(ip, XFS_ISTALE);
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vn_trace_exit(ip, "xfs_iget.found",
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(inst_t *)__return_address);
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goto return_ip;
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}
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/*
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* Inode cache miss
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*/
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read_unlock(&pag->pag_ici_lock);
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XFS_STATS_INC(xs_ig_missed);
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/*
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* Read the disk inode attributes into a new inode structure and get
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* a new vnode for it. This should also initialize i_ino and i_mount.
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*/
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error = xfs_iread(mp, tp, ino, &ip, bno,
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(flags & XFS_IGET_BULKSTAT) ? XFS_IMAP_BULKSTAT : 0);
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if (error) {
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xfs_put_perag(mp, pag);
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return error;
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}
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vn_trace_exit(ip, "xfs_iget.alloc", (inst_t *)__return_address);
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xfs_inode_lock_init(ip, vp);
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xfs_iocore_inode_init(ip);
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if (lock_flags)
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xfs_ilock(ip, lock_flags);
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if ((ip->i_d.di_mode == 0) && !(flags & XFS_IGET_CREATE)) {
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xfs_idestroy(ip);
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xfs_put_perag(mp, pag);
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return ENOENT;
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}
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/*
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* This is a bit messy - we preallocate everything we _might_
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* need before we pick up the ici lock. That way we don't have to
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* juggle locks and go all the way back to the start.
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*/
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new_icl = kmem_zone_alloc(xfs_icluster_zone, KM_SLEEP);
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if (radix_tree_preload(GFP_KERNEL)) {
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delay(1);
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goto again;
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}
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mask = ~(((XFS_INODE_CLUSTER_SIZE(mp) >> mp->m_sb.sb_inodelog)) - 1);
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first_index = agino & mask;
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write_lock(&pag->pag_ici_lock);
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/*
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* Find the cluster if it exists
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*/
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icl = NULL;
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if (radix_tree_gang_lookup(&pag->pag_ici_root, (void**)&iq,
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first_index, 1)) {
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if ((iq->i_ino & mask) == first_index)
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icl = iq->i_cluster;
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}
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/*
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* insert the new inode
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*/
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error = radix_tree_insert(&pag->pag_ici_root, agino, ip);
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if (unlikely(error)) {
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BUG_ON(error != -EEXIST);
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write_unlock(&pag->pag_ici_lock);
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radix_tree_preload_end();
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xfs_idestroy(ip);
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XFS_STATS_INC(xs_ig_dup);
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goto again;
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}
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/*
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* These values _must_ be set before releasing ihlock!
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*/
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ip->i_udquot = ip->i_gdquot = NULL;
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xfs_iflags_set(ip, XFS_INEW);
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ASSERT(ip->i_cluster == NULL);
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if (!icl) {
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spin_lock_init(&new_icl->icl_lock);
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INIT_HLIST_HEAD(&new_icl->icl_inodes);
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icl = new_icl;
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new_icl = NULL;
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} else {
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ASSERT(!hlist_empty(&icl->icl_inodes));
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}
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spin_lock(&icl->icl_lock);
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hlist_add_head(&ip->i_cnode, &icl->icl_inodes);
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ip->i_cluster = icl;
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spin_unlock(&icl->icl_lock);
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write_unlock(&pag->pag_ici_lock);
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radix_tree_preload_end();
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if (new_icl)
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kmem_zone_free(xfs_icluster_zone, new_icl);
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/*
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* Link ip to its mount and thread it on the mount's inode list.
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*/
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XFS_MOUNT_ILOCK(mp);
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if ((iq = mp->m_inodes)) {
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ASSERT(iq->i_mprev->i_mnext == iq);
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ip->i_mprev = iq->i_mprev;
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iq->i_mprev->i_mnext = ip;
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iq->i_mprev = ip;
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ip->i_mnext = iq;
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} else {
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ip->i_mnext = ip;
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ip->i_mprev = ip;
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}
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mp->m_inodes = ip;
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XFS_MOUNT_IUNLOCK(mp);
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xfs_put_perag(mp, pag);
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return_ip:
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ASSERT(ip->i_df.if_ext_max ==
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XFS_IFORK_DSIZE(ip) / sizeof(xfs_bmbt_rec_t));
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ASSERT(((ip->i_d.di_flags & XFS_DIFLAG_REALTIME) != 0) ==
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((ip->i_iocore.io_flags & XFS_IOCORE_RT) != 0));
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xfs_iflags_set(ip, XFS_IMODIFIED);
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*ipp = ip;
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/*
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* If we have a real type for an on-disk inode, we can set ops(&unlock)
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* now. If it's a new inode being created, xfs_ialloc will handle it.
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*/
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bhv_vfs_init_vnode(XFS_MTOVFS(mp), vp, ip, 1);
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return 0;
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}
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/*
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* The 'normal' internal xfs_iget, if needed it will
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* 'allocate', or 'get', the vnode.
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*/
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int
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xfs_iget(
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xfs_mount_t *mp,
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xfs_trans_t *tp,
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xfs_ino_t ino,
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uint flags,
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uint lock_flags,
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xfs_inode_t **ipp,
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xfs_daddr_t bno)
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{
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struct inode *inode;
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bhv_vnode_t *vp = NULL;
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int error;
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XFS_STATS_INC(xs_ig_attempts);
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retry:
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if ((inode = iget_locked(XFS_MTOVFS(mp)->vfs_super, ino))) {
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xfs_inode_t *ip;
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vp = vn_from_inode(inode);
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if (inode->i_state & I_NEW) {
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vn_initialize(inode);
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error = xfs_iget_core(vp, mp, tp, ino, flags,
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lock_flags, ipp, bno);
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if (error) {
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vn_mark_bad(vp);
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if (inode->i_state & I_NEW)
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unlock_new_inode(inode);
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iput(inode);
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}
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} else {
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/*
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* If the inode is not fully constructed due to
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* filehandle mismatches wait for the inode to go
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* away and try again.
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*
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* iget_locked will call __wait_on_freeing_inode
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* to wait for the inode to go away.
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*/
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if (is_bad_inode(inode) ||
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((ip = xfs_vtoi(vp)) == NULL)) {
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iput(inode);
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delay(1);
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goto retry;
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}
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if (lock_flags != 0)
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xfs_ilock(ip, lock_flags);
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XFS_STATS_INC(xs_ig_found);
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*ipp = ip;
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error = 0;
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}
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} else
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error = ENOMEM; /* If we got no inode we are out of memory */
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return error;
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}
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/*
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* Do the setup for the various locks within the incore inode.
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*/
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void
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xfs_inode_lock_init(
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xfs_inode_t *ip,
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bhv_vnode_t *vp)
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{
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mrlock_init(&ip->i_lock, MRLOCK_ALLOW_EQUAL_PRI|MRLOCK_BARRIER,
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"xfsino", ip->i_ino);
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mrlock_init(&ip->i_iolock, MRLOCK_BARRIER, "xfsio", ip->i_ino);
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init_waitqueue_head(&ip->i_ipin_wait);
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atomic_set(&ip->i_pincount, 0);
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initnsema(&ip->i_flock, 1, "xfsfino");
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}
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/*
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* Look for the inode corresponding to the given ino in the hash table.
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* If it is there and its i_transp pointer matches tp, return it.
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* Otherwise, return NULL.
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*/
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xfs_inode_t *
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xfs_inode_incore(xfs_mount_t *mp,
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xfs_ino_t ino,
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xfs_trans_t *tp)
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{
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xfs_inode_t *ip;
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xfs_perag_t *pag;
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pag = xfs_get_perag(mp, ino);
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read_lock(&pag->pag_ici_lock);
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ip = radix_tree_lookup(&pag->pag_ici_root, XFS_INO_TO_AGINO(mp, ino));
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read_unlock(&pag->pag_ici_lock);
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xfs_put_perag(mp, pag);
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/* the returned inode must match the transaction */
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if (ip && (ip->i_transp != tp))
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return NULL;
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return ip;
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}
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/*
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* Decrement reference count of an inode structure and unlock it.
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*
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* ip -- the inode being released
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* lock_flags -- this parameter indicates the inode's locks to be
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* to be released. See the comment on xfs_iunlock() for a list
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* of valid values.
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*/
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void
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xfs_iput(xfs_inode_t *ip,
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uint lock_flags)
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{
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bhv_vnode_t *vp = XFS_ITOV(ip);
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vn_trace_entry(ip, "xfs_iput", (inst_t *)__return_address);
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xfs_iunlock(ip, lock_flags);
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VN_RELE(vp);
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}
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/*
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* Special iput for brand-new inodes that are still locked
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*/
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void
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xfs_iput_new(xfs_inode_t *ip,
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uint lock_flags)
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{
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bhv_vnode_t *vp = XFS_ITOV(ip);
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struct inode *inode = vn_to_inode(vp);
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vn_trace_entry(ip, "xfs_iput_new", (inst_t *)__return_address);
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if ((ip->i_d.di_mode == 0)) {
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ASSERT(!xfs_iflags_test(ip, XFS_IRECLAIMABLE));
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vn_mark_bad(vp);
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}
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if (inode->i_state & I_NEW)
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unlock_new_inode(inode);
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if (lock_flags)
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xfs_iunlock(ip, lock_flags);
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VN_RELE(vp);
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}
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/*
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* This routine embodies the part of the reclaim code that pulls
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* the inode from the inode hash table and the mount structure's
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* inode list.
|
|
* This should only be called from xfs_reclaim().
|
|
*/
|
|
void
|
|
xfs_ireclaim(xfs_inode_t *ip)
|
|
{
|
|
bhv_vnode_t *vp;
|
|
|
|
/*
|
|
* Remove from old hash list and mount list.
|
|
*/
|
|
XFS_STATS_INC(xs_ig_reclaims);
|
|
|
|
xfs_iextract(ip);
|
|
|
|
/*
|
|
* Here we do a spurious inode lock in order to coordinate with
|
|
* xfs_sync(). This is because xfs_sync() references the inodes
|
|
* in the mount list without taking references on the corresponding
|
|
* vnodes. We make that OK here by ensuring that we wait until
|
|
* the inode is unlocked in xfs_sync() before we go ahead and
|
|
* free it. We get both the regular lock and the io lock because
|
|
* the xfs_sync() code may need to drop the regular one but will
|
|
* still hold the io lock.
|
|
*/
|
|
xfs_ilock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
|
|
|
|
/*
|
|
* Release dquots (and their references) if any. An inode may escape
|
|
* xfs_inactive and get here via vn_alloc->vn_reclaim path.
|
|
*/
|
|
XFS_QM_DQDETACH(ip->i_mount, ip);
|
|
|
|
/*
|
|
* Pull our behavior descriptor from the vnode chain.
|
|
*/
|
|
vp = XFS_ITOV_NULL(ip);
|
|
if (vp) {
|
|
vn_to_inode(vp)->i_private = NULL;
|
|
ip->i_vnode = NULL;
|
|
}
|
|
|
|
/*
|
|
* Free all memory associated with the inode.
|
|
*/
|
|
xfs_iunlock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
|
|
xfs_idestroy(ip);
|
|
}
|
|
|
|
/*
|
|
* This routine removes an about-to-be-destroyed inode from
|
|
* all of the lists in which it is located with the exception
|
|
* of the behavior chain.
|
|
*/
|
|
void
|
|
xfs_iextract(
|
|
xfs_inode_t *ip)
|
|
{
|
|
xfs_mount_t *mp = ip->i_mount;
|
|
xfs_perag_t *pag = xfs_get_perag(mp, ip->i_ino);
|
|
xfs_inode_t *iq;
|
|
|
|
write_lock(&pag->pag_ici_lock);
|
|
radix_tree_delete(&pag->pag_ici_root, XFS_INO_TO_AGINO(mp, ip->i_ino));
|
|
write_unlock(&pag->pag_ici_lock);
|
|
xfs_put_perag(mp, pag);
|
|
|
|
/*
|
|
* Remove from cluster list
|
|
*/
|
|
mp = ip->i_mount;
|
|
spin_lock(&ip->i_cluster->icl_lock);
|
|
hlist_del(&ip->i_cnode);
|
|
spin_unlock(&ip->i_cluster->icl_lock);
|
|
|
|
/* was last inode in cluster? */
|
|
if (hlist_empty(&ip->i_cluster->icl_inodes))
|
|
kmem_zone_free(xfs_icluster_zone, ip->i_cluster);
|
|
|
|
/*
|
|
* Remove from mount's inode list.
|
|
*/
|
|
XFS_MOUNT_ILOCK(mp);
|
|
ASSERT((ip->i_mnext != NULL) && (ip->i_mprev != NULL));
|
|
iq = ip->i_mnext;
|
|
iq->i_mprev = ip->i_mprev;
|
|
ip->i_mprev->i_mnext = iq;
|
|
|
|
/*
|
|
* Fix up the head pointer if it points to the inode being deleted.
|
|
*/
|
|
if (mp->m_inodes == ip) {
|
|
if (ip == iq) {
|
|
mp->m_inodes = NULL;
|
|
} else {
|
|
mp->m_inodes = iq;
|
|
}
|
|
}
|
|
|
|
/* Deal with the deleted inodes list */
|
|
list_del_init(&ip->i_reclaim);
|
|
|
|
mp->m_ireclaims++;
|
|
XFS_MOUNT_IUNLOCK(mp);
|
|
}
|
|
|
|
/*
|
|
* This is a wrapper routine around the xfs_ilock() routine
|
|
* used to centralize some grungy code. It is used in places
|
|
* that wish to lock the inode solely for reading the extents.
|
|
* The reason these places can't just call xfs_ilock(SHARED)
|
|
* is that the inode lock also guards to bringing in of the
|
|
* extents from disk for a file in b-tree format. If the inode
|
|
* is in b-tree format, then we need to lock the inode exclusively
|
|
* until the extents are read in. Locking it exclusively all
|
|
* the time would limit our parallelism unnecessarily, though.
|
|
* What we do instead is check to see if the extents have been
|
|
* read in yet, and only lock the inode exclusively if they
|
|
* have not.
|
|
*
|
|
* The function returns a value which should be given to the
|
|
* corresponding xfs_iunlock_map_shared(). This value is
|
|
* the mode in which the lock was actually taken.
|
|
*/
|
|
uint
|
|
xfs_ilock_map_shared(
|
|
xfs_inode_t *ip)
|
|
{
|
|
uint lock_mode;
|
|
|
|
if ((ip->i_d.di_format == XFS_DINODE_FMT_BTREE) &&
|
|
((ip->i_df.if_flags & XFS_IFEXTENTS) == 0)) {
|
|
lock_mode = XFS_ILOCK_EXCL;
|
|
} else {
|
|
lock_mode = XFS_ILOCK_SHARED;
|
|
}
|
|
|
|
xfs_ilock(ip, lock_mode);
|
|
|
|
return lock_mode;
|
|
}
|
|
|
|
/*
|
|
* This is simply the unlock routine to go with xfs_ilock_map_shared().
|
|
* All it does is call xfs_iunlock() with the given lock_mode.
|
|
*/
|
|
void
|
|
xfs_iunlock_map_shared(
|
|
xfs_inode_t *ip,
|
|
unsigned int lock_mode)
|
|
{
|
|
xfs_iunlock(ip, lock_mode);
|
|
}
|
|
|
|
/*
|
|
* The xfs inode contains 2 locks: a multi-reader lock called the
|
|
* i_iolock and a multi-reader lock called the i_lock. This routine
|
|
* allows either or both of the locks to be obtained.
|
|
*
|
|
* The 2 locks should always be ordered so that the IO lock is
|
|
* obtained first in order to prevent deadlock.
|
|
*
|
|
* ip -- the inode being locked
|
|
* lock_flags -- this parameter indicates the inode's locks
|
|
* to be locked. It can be:
|
|
* XFS_IOLOCK_SHARED,
|
|
* XFS_IOLOCK_EXCL,
|
|
* XFS_ILOCK_SHARED,
|
|
* XFS_ILOCK_EXCL,
|
|
* XFS_IOLOCK_SHARED | XFS_ILOCK_SHARED,
|
|
* XFS_IOLOCK_SHARED | XFS_ILOCK_EXCL,
|
|
* XFS_IOLOCK_EXCL | XFS_ILOCK_SHARED,
|
|
* XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL
|
|
*/
|
|
void
|
|
xfs_ilock(xfs_inode_t *ip,
|
|
uint lock_flags)
|
|
{
|
|
/*
|
|
* You can't set both SHARED and EXCL for the same lock,
|
|
* and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
|
|
* and XFS_ILOCK_EXCL are valid values to set in lock_flags.
|
|
*/
|
|
ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
|
|
(XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
|
|
ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
|
|
(XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
|
|
ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_DEP_MASK)) == 0);
|
|
|
|
if (lock_flags & XFS_IOLOCK_EXCL) {
|
|
mrupdate_nested(&ip->i_iolock, XFS_IOLOCK_DEP(lock_flags));
|
|
} else if (lock_flags & XFS_IOLOCK_SHARED) {
|
|
mraccess_nested(&ip->i_iolock, XFS_IOLOCK_DEP(lock_flags));
|
|
}
|
|
if (lock_flags & XFS_ILOCK_EXCL) {
|
|
mrupdate_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
|
|
} else if (lock_flags & XFS_ILOCK_SHARED) {
|
|
mraccess_nested(&ip->i_lock, XFS_ILOCK_DEP(lock_flags));
|
|
}
|
|
xfs_ilock_trace(ip, 1, lock_flags, (inst_t *)__return_address);
|
|
}
|
|
|
|
/*
|
|
* This is just like xfs_ilock(), except that the caller
|
|
* is guaranteed not to sleep. It returns 1 if it gets
|
|
* the requested locks and 0 otherwise. If the IO lock is
|
|
* obtained but the inode lock cannot be, then the IO lock
|
|
* is dropped before returning.
|
|
*
|
|
* ip -- the inode being locked
|
|
* lock_flags -- this parameter indicates the inode's locks to be
|
|
* to be locked. See the comment for xfs_ilock() for a list
|
|
* of valid values.
|
|
*
|
|
*/
|
|
int
|
|
xfs_ilock_nowait(xfs_inode_t *ip,
|
|
uint lock_flags)
|
|
{
|
|
int iolocked;
|
|
int ilocked;
|
|
|
|
/*
|
|
* You can't set both SHARED and EXCL for the same lock,
|
|
* and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
|
|
* and XFS_ILOCK_EXCL are valid values to set in lock_flags.
|
|
*/
|
|
ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
|
|
(XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
|
|
ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
|
|
(XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
|
|
ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_DEP_MASK)) == 0);
|
|
|
|
iolocked = 0;
|
|
if (lock_flags & XFS_IOLOCK_EXCL) {
|
|
iolocked = mrtryupdate(&ip->i_iolock);
|
|
if (!iolocked) {
|
|
return 0;
|
|
}
|
|
} else if (lock_flags & XFS_IOLOCK_SHARED) {
|
|
iolocked = mrtryaccess(&ip->i_iolock);
|
|
if (!iolocked) {
|
|
return 0;
|
|
}
|
|
}
|
|
if (lock_flags & XFS_ILOCK_EXCL) {
|
|
ilocked = mrtryupdate(&ip->i_lock);
|
|
if (!ilocked) {
|
|
if (iolocked) {
|
|
mrunlock(&ip->i_iolock);
|
|
}
|
|
return 0;
|
|
}
|
|
} else if (lock_flags & XFS_ILOCK_SHARED) {
|
|
ilocked = mrtryaccess(&ip->i_lock);
|
|
if (!ilocked) {
|
|
if (iolocked) {
|
|
mrunlock(&ip->i_iolock);
|
|
}
|
|
return 0;
|
|
}
|
|
}
|
|
xfs_ilock_trace(ip, 2, lock_flags, (inst_t *)__return_address);
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* xfs_iunlock() is used to drop the inode locks acquired with
|
|
* xfs_ilock() and xfs_ilock_nowait(). The caller must pass
|
|
* in the flags given to xfs_ilock() or xfs_ilock_nowait() so
|
|
* that we know which locks to drop.
|
|
*
|
|
* ip -- the inode being unlocked
|
|
* lock_flags -- this parameter indicates the inode's locks to be
|
|
* to be unlocked. See the comment for xfs_ilock() for a list
|
|
* of valid values for this parameter.
|
|
*
|
|
*/
|
|
void
|
|
xfs_iunlock(xfs_inode_t *ip,
|
|
uint lock_flags)
|
|
{
|
|
/*
|
|
* You can't set both SHARED and EXCL for the same lock,
|
|
* and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED,
|
|
* and XFS_ILOCK_EXCL are valid values to set in lock_flags.
|
|
*/
|
|
ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) !=
|
|
(XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
|
|
ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) !=
|
|
(XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
|
|
ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_IUNLOCK_NONOTIFY |
|
|
XFS_LOCK_DEP_MASK)) == 0);
|
|
ASSERT(lock_flags != 0);
|
|
|
|
if (lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) {
|
|
ASSERT(!(lock_flags & XFS_IOLOCK_SHARED) ||
|
|
(ismrlocked(&ip->i_iolock, MR_ACCESS)));
|
|
ASSERT(!(lock_flags & XFS_IOLOCK_EXCL) ||
|
|
(ismrlocked(&ip->i_iolock, MR_UPDATE)));
|
|
mrunlock(&ip->i_iolock);
|
|
}
|
|
|
|
if (lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) {
|
|
ASSERT(!(lock_flags & XFS_ILOCK_SHARED) ||
|
|
(ismrlocked(&ip->i_lock, MR_ACCESS)));
|
|
ASSERT(!(lock_flags & XFS_ILOCK_EXCL) ||
|
|
(ismrlocked(&ip->i_lock, MR_UPDATE)));
|
|
mrunlock(&ip->i_lock);
|
|
|
|
/*
|
|
* Let the AIL know that this item has been unlocked in case
|
|
* it is in the AIL and anyone is waiting on it. Don't do
|
|
* this if the caller has asked us not to.
|
|
*/
|
|
if (!(lock_flags & XFS_IUNLOCK_NONOTIFY) &&
|
|
ip->i_itemp != NULL) {
|
|
xfs_trans_unlocked_item(ip->i_mount,
|
|
(xfs_log_item_t*)(ip->i_itemp));
|
|
}
|
|
}
|
|
xfs_ilock_trace(ip, 3, lock_flags, (inst_t *)__return_address);
|
|
}
|
|
|
|
/*
|
|
* give up write locks. the i/o lock cannot be held nested
|
|
* if it is being demoted.
|
|
*/
|
|
void
|
|
xfs_ilock_demote(xfs_inode_t *ip,
|
|
uint lock_flags)
|
|
{
|
|
ASSERT(lock_flags & (XFS_IOLOCK_EXCL|XFS_ILOCK_EXCL));
|
|
ASSERT((lock_flags & ~(XFS_IOLOCK_EXCL|XFS_ILOCK_EXCL)) == 0);
|
|
|
|
if (lock_flags & XFS_ILOCK_EXCL) {
|
|
ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE));
|
|
mrdemote(&ip->i_lock);
|
|
}
|
|
if (lock_flags & XFS_IOLOCK_EXCL) {
|
|
ASSERT(ismrlocked(&ip->i_iolock, MR_UPDATE));
|
|
mrdemote(&ip->i_iolock);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* The following three routines simply manage the i_flock
|
|
* semaphore embedded in the inode. This semaphore synchronizes
|
|
* processes attempting to flush the in-core inode back to disk.
|
|
*/
|
|
void
|
|
xfs_iflock(xfs_inode_t *ip)
|
|
{
|
|
psema(&(ip->i_flock), PINOD|PLTWAIT);
|
|
}
|
|
|
|
int
|
|
xfs_iflock_nowait(xfs_inode_t *ip)
|
|
{
|
|
return (cpsema(&(ip->i_flock)));
|
|
}
|
|
|
|
void
|
|
xfs_ifunlock(xfs_inode_t *ip)
|
|
{
|
|
ASSERT(issemalocked(&(ip->i_flock)));
|
|
vsema(&(ip->i_flock));
|
|
}
|