X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/91447636331957f3d9b5ca5b508f07c526b0074d..ca66cea69e6e866fd781ae2260d9474bdd48f2ca:/bsd/hfs/hfs_chash.c diff --git a/bsd/hfs/hfs_chash.c b/bsd/hfs/hfs_chash.c index 1cbaf8186..4c6401fcd 100644 --- a/bsd/hfs/hfs_chash.c +++ b/bsd/hfs/hfs_chash.c @@ -1,23 +1,29 @@ /* - * Copyright (c) 2002-2005 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2002-2006 Apple Computer, Inc. All rights reserved. * - * @APPLE_LICENSE_HEADER_START@ + * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * - * The contents of this file constitute Original Code as defined in and - * are subject to the Apple Public Source License Version 1.1 (the - * "License"). You may not use this file except in compliance with the - * License. Please obtain a copy of the License at - * http://www.apple.com/publicsource and read it before using this file. + * This file contains Original Code and/or Modifications of Original Code + * as defined in and that are subject to the Apple Public Source License + * Version 2.0 (the 'License'). You may not use this file except in + * compliance with the License. The rights granted to you under the License + * may not be used to create, or enable the creation or redistribution of, + * unlawful or unlicensed copies of an Apple operating system, or to + * circumvent, violate, or enable the circumvention or violation of, any + * terms of an Apple operating system software license agreement. * - * This Original Code and all software distributed under the License are - * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER + * Please obtain a copy of the License at + * http://www.opensource.apple.com/apsl/ and read it before using this file. + * + * The Original Code and all software distributed under the License are + * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the - * License for the specific language governing rights and limitations - * under the License. + * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. + * Please see the License for the specific language governing rights and + * limitations under the License. * - * @APPLE_LICENSE_HEADER_END@ + * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* @@ -85,7 +91,6 @@ u_long cnodehash; /* size of hash table - 1 */ lck_mtx_t hfs_chash_mutex; - /* * Initialize cnode hash table. */ @@ -93,18 +98,33 @@ __private_extern__ void hfs_chashinit() { - cnodehashtbl = hashinit(desiredvnodes, M_HFSMNT, &cnodehash); - chash_lck_grp_attr= lck_grp_attr_alloc_init(); - lck_grp_attr_setstat(chash_lck_grp_attr); chash_lck_grp = lck_grp_alloc_init("cnode_hash", chash_lck_grp_attr); - chash_lck_attr = lck_attr_alloc_init(); - //lck_attr_setdebug(chash_lck_attr); lck_mtx_init(&hfs_chash_mutex, chash_lck_grp, chash_lck_attr); } +static void hfs_chash_lock(void) +{ + lck_mtx_lock(&hfs_chash_mutex); +} + +static void hfs_chash_unlock(void) +{ + lck_mtx_unlock(&hfs_chash_mutex); +} + +__private_extern__ +void +hfs_chashinit_finish() +{ + hfs_chash_lock(); + if (!cnodehashtbl) + cnodehashtbl = hashinit(desiredvnodes, M_HFSMNT, &cnodehash); + hfs_chash_unlock(); +} + /* * Use the device, inum pair to find the incore cnode. @@ -118,7 +138,7 @@ hfs_chash_getvnode(dev_t dev, ino_t inum, int wantrsrc, int skiplock) struct cnode *cp; struct vnode *vp; int error; - uint32_t vid; + u_int32_t vid; /* * Go through the hash list @@ -126,7 +146,7 @@ hfs_chash_getvnode(dev_t dev, ino_t inum, int wantrsrc, int skiplock) * allocated, wait for it to be finished and then try again. */ loop: - lck_mtx_lock(&hfs_chash_mutex); + hfs_chash_lock(); for (cp = CNODEHASH(dev, inum)->lh_first; cp; cp = cp->c_hash.le_next) { if ((cp->c_fileid != inum) || (cp->c_dev != dev)) continue; @@ -138,22 +158,13 @@ loop: "hfs_chash_getvnode", 0); goto loop; } - /* - * Skip cnodes that are not in the name space anymore - * note that this check is done outside of the proper - * lock to catch nodes already in this state... this - * state must be rechecked after we acquire the cnode lock - */ - if (cp->c_flag & (C_NOEXISTS | C_DELETED)) { - continue; - } /* Obtain the desired vnode. */ vp = wantrsrc ? cp->c_rsrc_vp : cp->c_vp; if (vp == NULLVP) goto exit; vid = vnode_vid(vp); - lck_mtx_unlock(&hfs_chash_mutex); + hfs_chash_unlock(); if ((error = vnode_getwithvid(vp, vid))) { /* @@ -169,10 +180,10 @@ loop: /* * Skip cnodes that are not in the name space anymore - * we need to check again with the cnode lock held - * because we may have blocked acquiring the vnode ref - * or the lock on the cnode which would allow the node - * to be unlinked + * we need to check with the cnode lock held because + * we may have blocked acquiring the vnode ref or the + * lock on the cnode which would allow the node to be + * unlinked */ if (cp->c_flag & (C_NOEXISTS | C_DELETED)) { if (!skiplock) @@ -184,16 +195,13 @@ loop: return (vp); } exit: - lck_mtx_unlock(&hfs_chash_mutex); + hfs_chash_unlock(); return (NULL); } /* - * Use the device, fileid pair to find the incore cnode. - * If no cnode if found one is created - * - * If it is in core, but locked, wait for it. + * Use the device, fileid pair to snoop an incore cnode. */ __private_extern__ int @@ -208,7 +216,7 @@ hfs_chash_snoop(dev_t dev, ino_t inum, int (*callout)(const struct cat_desc *, * If a cnode is in the process of being cleaned out or being * allocated, wait for it to be finished and then try again. */ - lck_mtx_lock(&hfs_chash_mutex); + hfs_chash_lock(); for (cp = CNODEHASH(dev, inum)->lh_first; cp; cp = cp->c_hash.le_next) { if ((cp->c_fileid != inum) || (cp->c_dev != dev)) continue; @@ -218,7 +226,7 @@ hfs_chash_snoop(dev_t dev, ino_t inum, int (*callout)(const struct cat_desc *, } break; } - lck_mtx_unlock(&hfs_chash_mutex); + hfs_chash_unlock(); return (result); } @@ -228,6 +236,9 @@ hfs_chash_snoop(dev_t dev, ino_t inum, int (*callout)(const struct cat_desc *, * If no cnode if found one is created * * If it is in core, but locked, wait for it. + * + * If the cnode is C_DELETED, then return NULL since that + * inum is no longer valid for lookups (open-unlinked file). */ __private_extern__ struct cnode * @@ -236,7 +247,7 @@ hfs_chash_getcnode(dev_t dev, ino_t inum, struct vnode **vpp, int wantrsrc, int struct cnode *cp; struct cnode *ncp = NULL; vnode_t vp; - uint32_t vid; + u_int32_t vid; /* * Go through the hash list @@ -244,7 +255,7 @@ hfs_chash_getcnode(dev_t dev, ino_t inum, struct vnode **vpp, int wantrsrc, int * allocated, wait for it to be finished and then try again. */ loop: - lck_mtx_lock(&hfs_chash_mutex); + hfs_chash_lock(); loop_with_lock: for (cp = CNODEHASH(dev, inum)->lh_first; cp; cp = cp->c_hash.le_next) { @@ -260,15 +271,6 @@ loop_with_lock: "hfs_chash_getcnode", 0); goto loop_with_lock; } - /* - * Skip cnodes that are not in the name space anymore - * note that this check is done outside of the proper - * lock to catch nodes already in this state... this - * state must be rechecked after we acquire the cnode lock - */ - if (cp->c_flag & (C_NOEXISTS | C_DELETED)) { - continue; - } vp = wantrsrc ? cp->c_rsrc_vp : cp->c_vp; if (vp == NULL) { /* @@ -276,11 +278,11 @@ loop_with_lock: */ SET(cp->c_hflag, H_ATTACH); - lck_mtx_unlock(&hfs_chash_mutex); + hfs_chash_unlock(); } else { vid = vnode_vid(vp); - lck_mtx_unlock(&hfs_chash_mutex); + hfs_chash_unlock(); if (vnode_getwithvid(vp, vid)) goto loop; @@ -294,32 +296,37 @@ loop_with_lock: FREE_ZONE(ncp, sizeof(struct cnode), M_HFSNODE); ncp = NULL; } - if (!skiplock && hfs_lock(cp, HFS_EXCLUSIVE_LOCK) != 0) { - if (vp != NULLVP) - vnode_put(vp); - lck_mtx_lock(&hfs_chash_mutex); - if (vp == NULLVP) - CLR(cp->c_hflag, H_ATTACH); - goto loop_with_lock; + if (!skiplock) { + hfs_lock(cp, HFS_FORCE_LOCK); } + /* * Skip cnodes that are not in the name space anymore - * we need to check again with the cnode lock held - * because we may have blocked acquiring the vnode ref - * or the lock on the cnode which would allow the node - * to be unlinked + * we need to check with the cnode lock held because + * we may have blocked acquiring the vnode ref or the + * lock on the cnode which would allow the node to be + * unlinked. + * + * Don't return a cnode in this case since the inum + * is no longer valid for lookups. */ - if (cp->c_flag & (C_NOEXISTS | C_DELETED)) { + if ((cp->c_flag & (C_NOEXISTS | C_DELETED)) && !wantrsrc) { if (!skiplock) hfs_unlock(cp); - if (vp != NULLVP) + if (vp != NULLVP) { vnode_put(vp); - lck_mtx_lock(&hfs_chash_mutex); - - if (vp == NULLVP) - CLR(cp->c_hflag, H_ATTACH); - goto loop_with_lock; + } else { + hfs_chash_lock(); + CLR(cp->c_hflag, H_ATTACH); + if (ISSET(cp->c_hflag, H_WAITING)) { + CLR(cp->c_hflag, H_WAITING); + wakeup((caddr_t)cp); + } + hfs_chash_unlock(); + } + vp = NULL; + cp = NULL; } *vpp = vp; return (cp); @@ -328,11 +335,11 @@ loop_with_lock: /* * Allocate a new cnode */ - if (skiplock) + if (skiplock && !wantrsrc) panic("%s - should never get here when skiplock is set \n", __FUNCTION__); if (ncp == NULL) { - lck_mtx_unlock(&hfs_chash_mutex); + hfs_chash_unlock(); MALLOC_ZONE(ncp, struct cnode *, sizeof(struct cnode), M_HFSNODE, M_WAITOK); /* @@ -347,6 +354,8 @@ loop_with_lock: SET(ncp->c_hflag, H_ALLOC); ncp->c_fileid = inum; ncp->c_dev = dev; + TAILQ_INIT(&ncp->c_hintlist); /* make the list empty */ + TAILQ_INIT(&ncp->c_originlist); lck_rw_init(&ncp->c_rwlock, hfs_rwlock_group, hfs_lock_attr); if (!skiplock) @@ -354,7 +363,7 @@ loop_with_lock: /* Insert the new cnode with it's H_ALLOC flag set */ LIST_INSERT_HEAD(CNODEHASH(dev, inum), ncp, c_hash); - lck_mtx_unlock(&hfs_chash_mutex); + hfs_chash_unlock(); *vpp = NULL; return (ncp); @@ -365,7 +374,7 @@ __private_extern__ void hfs_chashwakeup(struct cnode *cp, int hflags) { - lck_mtx_lock(&hfs_chash_mutex); + hfs_chash_lock(); CLR(cp->c_hflag, hflags); @@ -373,7 +382,7 @@ hfs_chashwakeup(struct cnode *cp, int hflags) CLR(cp->c_hflag, H_WAITING); wakeup((caddr_t)cp); } - lck_mtx_unlock(&hfs_chash_mutex); + hfs_chash_unlock(); } @@ -384,14 +393,14 @@ __private_extern__ void hfs_chash_rehash(struct cnode *cp1, struct cnode *cp2) { - lck_mtx_lock(&hfs_chash_mutex); + hfs_chash_lock(); LIST_REMOVE(cp1, c_hash); LIST_REMOVE(cp2, c_hash); LIST_INSERT_HEAD(CNODEHASH(cp1->c_dev, cp1->c_fileid), cp1, c_hash); LIST_INSERT_HEAD(CNODEHASH(cp2->c_dev, cp2->c_fileid), cp2, c_hash); - lck_mtx_unlock(&hfs_chash_mutex); + hfs_chash_unlock(); } @@ -402,18 +411,19 @@ __private_extern__ int hfs_chashremove(struct cnode *cp) { - lck_mtx_lock(&hfs_chash_mutex); + hfs_chash_lock(); /* Check if a vnode is getting attached */ if (ISSET(cp->c_hflag, H_ATTACH)) { - lck_mtx_unlock(&hfs_chash_mutex); + hfs_chash_unlock(); return (EBUSY); } - LIST_REMOVE(cp, c_hash); - cp->c_hash.le_next = NULL; - cp->c_hash.le_prev = NULL; - - lck_mtx_unlock(&hfs_chash_mutex); + if (cp->c_hash.le_next || cp->c_hash.le_prev) { + LIST_REMOVE(cp, c_hash); + cp->c_hash.le_next = NULL; + cp->c_hash.le_prev = NULL; + } + hfs_chash_unlock(); return (0); } @@ -424,7 +434,7 @@ __private_extern__ void hfs_chash_abort(struct cnode *cp) { - lck_mtx_lock(&hfs_chash_mutex); + hfs_chash_lock(); LIST_REMOVE(cp, c_hash); cp->c_hash.le_next = NULL; @@ -435,20 +445,77 @@ hfs_chash_abort(struct cnode *cp) CLR(cp->c_hflag, H_WAITING); wakeup((caddr_t)cp); } - lck_mtx_unlock(&hfs_chash_mutex); + hfs_chash_unlock(); } /* - * mark a cnode as in transistion + * mark a cnode as in transition */ __private_extern__ void hfs_chash_mark_in_transit(struct cnode *cp) { - lck_mtx_lock(&hfs_chash_mutex); + hfs_chash_lock(); SET(cp->c_hflag, H_TRANSIT); - lck_mtx_unlock(&hfs_chash_mutex); + hfs_chash_unlock(); +} + +/* Search a cnode in the hash. This function does not return cnode which + * are getting created, destroyed or in transition. Note that this function + * does not acquire the cnode hash mutex, and expects the caller to acquire it. + * On success, returns pointer to the cnode found. On failure, returns NULL. + */ +static +struct cnode * +hfs_chash_search_cnid(dev_t dev, cnid_t cnid) +{ + struct cnode *cp; + + for (cp = CNODEHASH(dev, cnid)->lh_first; cp; cp = cp->c_hash.le_next) { + if ((cp->c_fileid == cnid) && (cp->c_dev == dev)) { + break; + } + } + + /* If cnode is being created or reclaimed, return error. */ + if (cp && ISSET(cp->c_hflag, H_ALLOC | H_TRANSIT | H_ATTACH)) { + cp = NULL; + } + + return cp; +} + +/* Search a cnode corresponding to given device and ID in the hash. If the + * found cnode has kHFSHasChildLinkBit cleared, set it. If the cnode is not + * found, no new cnode is created and error is returned. + * + * Return values - + * -1 : The cnode was not found. + * 0 : The cnode was found, and the kHFSHasChildLinkBit was already set. + * 1 : The cnode was found, the kHFSHasChildLinkBit was not set, and the + * function had to set that bit. + */ +__private_extern__ +int +hfs_chash_set_childlinkbit(dev_t dev, cnid_t cnid) +{ + int retval = -1; + struct cnode *cp; + + hfs_chash_lock(); + cp = hfs_chash_search_cnid(dev, cnid); + if (cp) { + if (cp->c_attr.ca_recflags & kHFSHasChildLinkMask) { + retval = 0; + } else { + cp->c_attr.ca_recflags |= kHFSHasChildLinkMask; + retval = 1; + } + } + hfs_chash_unlock(); + + return retval; }