/* * Copyright (c) 2002-2015 Apple Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * * 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. * * 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, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ #include <sys/param.h> #include <sys/systm.h> #include <sys/proc.h> #include <sys/vnode.h> #include <sys/mount.h> #include <sys/kernel.h> #include <sys/malloc.h> #include <sys/time.h> #include <sys/ubc.h> #include <sys/quota.h> #include <sys/kdebug.h> #include <libkern/OSByteOrder.h> #include <sys/buf_internal.h> #include <sys/namei.h> #include <kern/locks.h> #include <miscfs/specfs/specdev.h> #include <miscfs/fifofs/fifo.h> #include <hfs/hfs.h> #include <hfs/hfs_catalog.h> #include <hfs/hfs_cnode.h> #include <hfs/hfs_quota.h> #include <hfs/hfs_format.h> #include <hfs/hfs_kdebug.h> #include <hfs/hfs_cprotect.h> extern int prtactive; extern lck_attr_t * hfs_lock_attr; extern lck_grp_t * hfs_mutex_group; extern lck_grp_t * hfs_rwlock_group; static void hfs_reclaim_cnode(hfsmount_t *hfsmp, struct cnode *); static int hfs_cnode_teardown (struct vnode *vp, vfs_context_t ctx, int reclaim); static int hfs_isordered(struct cnode *, struct cnode *); extern int hfs_removefile_callback(struct buf *bp, void *hfsmp); __inline__ int hfs_checkdeleted (struct cnode *cp) { return ((cp->c_flag & (C_DELETED | C_NOEXISTS)) ? ENOENT : 0); } /* * Function used by a special fcntl() that decorates a cnode/vnode that * indicates it is backing another filesystem, like a disk image. * * the argument 'val' indicates whether or not to set the bit in the cnode flags * * Returns non-zero on failure. 0 on success */ int hfs_set_backingstore (struct vnode *vp, int val) { struct cnode *cp = NULL; int err = 0; cp = VTOC(vp); if (!vnode_isreg(vp) && !vnode_isdir(vp)) { return EINVAL; } /* lock the cnode */ err = hfs_lock (cp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT); if (err) { return err; } if (val) { cp->c_flag |= C_BACKINGSTORE; } else { cp->c_flag &= ~C_BACKINGSTORE; } /* unlock everything */ hfs_unlock (cp); return err; } /* * Function used by a special fcntl() that check to see if a cnode/vnode * indicates it is backing another filesystem, like a disk image. * * the argument 'val' is an output argument for whether or not the bit is set * * Returns non-zero on failure. 0 on success */ int hfs_is_backingstore (struct vnode *vp, int *val) { struct cnode *cp = NULL; int err = 0; if (!vnode_isreg(vp) && !vnode_isdir(vp)) { *val = 0; return 0; } cp = VTOC(vp); /* lock the cnode */ err = hfs_lock (cp, HFS_SHARED_LOCK, HFS_LOCK_DEFAULT); if (err) { return err; } if (cp->c_flag & C_BACKINGSTORE) { *val = 1; } else { *val = 0; } /* unlock everything */ hfs_unlock (cp); return err; } /* * hfs_cnode_teardown * * This is an internal function that is invoked from both hfs_vnop_inactive * and hfs_vnop_reclaim. As VNOP_INACTIVE is not necessarily called from vnodes * being recycled and reclaimed, it is important that we do any post-processing * necessary for the cnode in both places. Important tasks include things such as * releasing the blocks from an open-unlinked file when all references to it have dropped, * and handling resource forks separately from data forks. * * Note that we take only the vnode as an argument here (rather than the cnode). * Recall that each cnode supports two forks (rsrc/data), and we can always get the right * cnode from either of the vnodes, but the reverse is not true -- we can't determine which * vnode we need to reclaim if only the cnode is supplied. * * This function is idempotent and safe to call from both hfs_vnop_inactive and hfs_vnop_reclaim * if both are invoked right after the other. In the second call, most of this function's if() * conditions will fail, since they apply generally to cnodes still marked with C_DELETED. * As a quick check to see if this function is necessary, determine if the cnode is already * marked C_NOEXISTS. If it is, then it is safe to skip this function. The only tasks that * remain for cnodes marked in such a fashion is to teardown their fork references and * release all directory hints and hardlink origins. However, both of those are done * in hfs_vnop_reclaim. hfs_update, by definition, is not necessary if the cnode's catalog * entry is no longer there. * * 'reclaim' argument specifies whether or not we were called from hfs_vnop_reclaim. If we are * invoked from hfs_vnop_reclaim, we can not call functions that cluster_push since the UBC info * is totally gone by that point. * * Assumes that both truncate and cnode locks for 'cp' are held. */ static int hfs_cnode_teardown (struct vnode *vp, vfs_context_t ctx, int reclaim) { int forkcount = 0; enum vtype v_type; struct cnode *cp; int error = 0; bool started_tr = false; struct hfsmount *hfsmp = VTOHFS(vp); struct proc *p = vfs_context_proc(ctx); int truncated = 0; cat_cookie_t cookie; int cat_reserve = 0; int lockflags; int ea_error = 0; v_type = vnode_vtype(vp); cp = VTOC(vp); if (cp->c_datafork) { ++forkcount; } if (cp->c_rsrcfork) { ++forkcount; } /* * Push file data out for normal files that haven't been evicted from * the namespace. We only do this if this function was not called from reclaim, * because by that point the UBC information has been totally torn down. * * There should also be no way that a normal file that has NOT been deleted from * the namespace to skip INACTIVE and go straight to RECLAIM. That race only happens * when the file becomes open-unlinked. */ if ((v_type == VREG) && (!ISSET(cp->c_flag, C_DELETED)) && (!ISSET(cp->c_flag, C_NOEXISTS)) && (VTOF(vp)->ff_blocks) && (reclaim == 0)) { /* * If we're called from hfs_vnop_inactive, all this means is at the time * the logic for deciding to call this function, there were not any lingering * mmap/fd references for this file. However, there is nothing preventing the system * from creating a new reference in between the time that logic was checked * and we entered hfs_vnop_inactive. As a result, the only time we can guarantee * that there aren't any references is during vnop_reclaim. */ hfs_filedone(vp, ctx, 0); } /* * Remove any directory hints or cached origins */ if (v_type == VDIR) { hfs_reldirhints(cp, 0); } if (cp->c_flag & C_HARDLINK) { hfs_relorigins(cp); } /* * -- Handle open unlinked files -- * * If the vnode is in use, it means a force unmount is in progress * in which case we defer cleaning up until either we come back * through here via hfs_vnop_reclaim, at which point the UBC * information will have been torn down and the vnode might no * longer be in use, or if it's still in use, it will get cleaned * up when next remounted. */ if (ISSET(cp->c_flag, C_DELETED) && !vnode_isinuse(vp, 0)) { /* * This check is slightly complicated. We should only truncate data * in very specific cases for open-unlinked files. This is because * we want to ensure that the resource fork continues to be available * if the caller has the data fork open. However, this is not symmetric; * someone who has the resource fork open need not be able to access the data * fork once the data fork has gone inactive. * * If we're the last fork, then we have cleaning up to do. * * A) last fork, and vp == c_vp * Truncate away own fork data. If rsrc fork is not in core, truncate it too. * * B) last fork, and vp == c_rsrc_vp * Truncate ourselves, assume data fork has been cleaned due to C). * * If we're not the last fork, then things are a little different: * * C) not the last fork, vp == c_vp * Truncate ourselves. Once the file has gone out of the namespace, * it cannot be further opened. Further access to the rsrc fork may * continue, however. * * D) not the last fork, vp == c_rsrc_vp * Don't enter the block below, just clean up vnode and push it out of core. */ if ((v_type == VREG || v_type == VLNK) && ((forkcount == 1) || (!VNODE_IS_RSRC(vp)))) { /* Truncate away our own fork data. (Case A, B, C above) */ if (VTOF(vp)->ff_blocks != 0) { /* * SYMLINKS only: * * Encapsulate the entire change (including truncating the link) in * nested transactions if we are modifying a symlink, because we know that its * file length will be at most 4k, and we can fit both the truncation and * any relevant bitmap changes into a single journal transaction. We also want * the kill_block code to execute in the same transaction so that any dirty symlink * blocks will not be written. Otherwise, rely on * hfs_truncate doing its own transactions to ensure that we don't blow up * the journal. */ if (!started_tr && (v_type == VLNK)) { if (hfs_start_transaction(hfsmp) != 0) { error = EINVAL; goto out; } else { started_tr = true; } } /* * At this point, we have decided that this cnode is * suitable for full removal. We are about to deallocate * its blocks and remove its entry from the catalog. * If it was a symlink, then it's possible that the operation * which created it is still in the current transaction group * due to coalescing. Take action here to kill the data blocks * of the symlink out of the journal before moving to * deallocate the blocks. We need to be in the middle of * a transaction before calling buf_iterate like this. * * Note: we have to kill any potential symlink buffers out of * the journal prior to deallocating their blocks. This is so * that we don't race with another thread that may be doing an * an allocation concurrently and pick up these blocks. It could * generate I/O against them which could go out ahead of our journal * transaction. */ if (hfsmp->jnl && vnode_islnk(vp)) { buf_iterate(vp, hfs_removefile_callback, BUF_SKIP_NONLOCKED, (void *)hfsmp); } /* * This truncate call (and the one below) is fine from VNOP_RECLAIM's * context because we're only removing blocks, not zero-filling new * ones. The C_DELETED check above makes things much simpler. */ error = hfs_truncate(vp, (off_t)0, IO_NDELAY, 0, ctx); if (error) { goto out; } truncated = 1; /* (SYMLINKS ONLY): Close/End our transaction after truncating the file record */ if (started_tr) { hfs_end_transaction(hfsmp); started_tr = false; } } /* * Truncate away the resource fork, if we represent the data fork and * it is the last fork. That means, by definition, the rsrc fork is not in * core. To avoid bringing a vnode into core for the sole purpose of deleting the * data in the resource fork, we call cat_lookup directly, then hfs_release_storage * to get rid of the resource fork's data. Note that because we are holding the * cnode lock, it is impossible for a competing thread to create the resource fork * vnode from underneath us while we do this. * * This is invoked via case A above only. */ if ((cp->c_blocks > 0) && (forkcount == 1) && (vp != cp->c_rsrc_vp)) { struct cat_lookup_buffer *lookup_rsrc = NULL; struct cat_desc *desc_ptr = NULL; lockflags = 0; MALLOC(lookup_rsrc, struct cat_lookup_buffer*, sizeof (struct cat_lookup_buffer), M_TEMP, M_WAITOK); if (lookup_rsrc == NULL) { printf("hfs_cnode_teardown: ENOMEM from MALLOC\n"); error = ENOMEM; goto out; } else { bzero (lookup_rsrc, sizeof (struct cat_lookup_buffer)); } if (cp->c_desc.cd_namelen == 0) { /* Initialize the rsrc descriptor for lookup if necessary*/ MAKE_DELETED_NAME (lookup_rsrc->lookup_name, HFS_TEMPLOOKUP_NAMELEN, cp->c_fileid); lookup_rsrc->lookup_desc.cd_nameptr = (const uint8_t*) lookup_rsrc->lookup_name; lookup_rsrc->lookup_desc.cd_namelen = strlen (lookup_rsrc->lookup_name); lookup_rsrc->lookup_desc.cd_parentcnid = hfsmp->hfs_private_desc[FILE_HARDLINKS].cd_cnid; lookup_rsrc->lookup_desc.cd_cnid = cp->c_cnid; desc_ptr = &lookup_rsrc->lookup_desc; } else { desc_ptr = &cp->c_desc; } lockflags = hfs_systemfile_lock (hfsmp, SFL_CATALOG, HFS_SHARED_LOCK); error = cat_lookup (hfsmp, desc_ptr, 1, 0, (struct cat_desc *) NULL, (struct cat_attr*) NULL, &lookup_rsrc->lookup_fork.ff_data, NULL); hfs_systemfile_unlock (hfsmp, lockflags); if (error) { FREE (lookup_rsrc, M_TEMP); goto out; } /* * Make the filefork in our temporary struct look like a real * filefork. Fill in the cp, sysfileinfo and rangelist fields.. */ rl_init (&lookup_rsrc->lookup_fork.ff_invalidranges); lookup_rsrc->lookup_fork.ff_cp = cp; /* * If there were no errors, then we have the catalog's fork information * for the resource fork in question. Go ahead and delete the data in it now. */ error = hfs_release_storage (hfsmp, NULL, &lookup_rsrc->lookup_fork, cp->c_fileid); FREE(lookup_rsrc, M_TEMP); if (error) { goto out; } /* * This fileid's resource fork extents have now been fully deleted on-disk * and this CNID is no longer valid. At this point, we should be able to * zero out cp->c_blocks to indicate there is no data left in this file. */ cp->c_blocks = 0; } } /* * If we represent the last fork (or none in the case of a dir), * and the cnode has become open-unlinked... * * We check c_blocks here because it is possible in the force * unmount case for the data fork to be in use but the resource * fork to not be in use in which case we will truncate the * resource fork, but not the data fork. It will get cleaned * up upon next mount. */ if (forkcount <= 1 && !cp->c_blocks) { /* * If it has EA's, then we need to get rid of them. * * Note that this must happen outside of any other transactions * because it starts/ends its own transactions and grabs its * own locks. This is to prevent a file with a lot of attributes * from creating a transaction that is too large (which panics). */ if (ISSET(cp->c_attr.ca_recflags, kHFSHasAttributesMask)) ea_error = hfs_removeallattr(hfsmp, cp->c_fileid, &started_tr); /* * Remove the cnode's catalog entry and release all blocks it * may have been using. */ /* * Mark cnode in transit so that no one can get this * cnode from cnode hash. */ // hfs_chash_mark_in_transit(hfsmp, cp); // XXXdbg - remove the cnode from the hash table since it's deleted // otherwise someone could go to sleep on the cnode and not // be woken up until this vnode gets recycled which could be // a very long time... hfs_chashremove(hfsmp, cp); cp->c_flag |= C_NOEXISTS; // XXXdbg cp->c_rdev = 0; if (!started_tr) { if (hfs_start_transaction(hfsmp) != 0) { error = EINVAL; goto out; } started_tr = true; } /* * Reserve some space in the Catalog file. */ if ((error = cat_preflight(hfsmp, CAT_DELETE, &cookie, p))) { goto out; } cat_reserve = 1; lockflags = hfs_systemfile_lock(hfsmp, SFL_CATALOG | SFL_ATTRIBUTE, HFS_EXCLUSIVE_LOCK); if (cp->c_blocks > 0) { printf("hfs_inactive: deleting non-empty%sfile %d, " "blks %d\n", VNODE_IS_RSRC(vp) ? " rsrc " : " ", (int)cp->c_fileid, (int)cp->c_blocks); } // // release the name pointer in the descriptor so that // cat_delete() will use the file-id to do the deletion. // in the case of hard links this is imperative (in the // case of regular files the fileid and cnid are the // same so it doesn't matter). // cat_releasedesc(&cp->c_desc); /* * The descriptor name may be zero, * in which case the fileid is used. */ error = cat_delete(hfsmp, &cp->c_desc, &cp->c_attr); if (error && truncated && (error != ENXIO)) { printf("hfs_inactive: couldn't delete a truncated file!"); } /* Update HFS Private Data dir */ if (error == 0) { hfsmp->hfs_private_attr[FILE_HARDLINKS].ca_entries--; if (vnode_isdir(vp)) { DEC_FOLDERCOUNT(hfsmp, hfsmp->hfs_private_attr[FILE_HARDLINKS]); } (void)cat_update(hfsmp, &hfsmp->hfs_private_desc[FILE_HARDLINKS], &hfsmp->hfs_private_attr[FILE_HARDLINKS], NULL, NULL); } hfs_systemfile_unlock(hfsmp, lockflags); if (error) { goto out; } #if QUOTA if (hfsmp->hfs_flags & HFS_QUOTAS) (void)hfs_chkiq(cp, -1, NOCRED, 0); #endif /* QUOTA */ /* Already set C_NOEXISTS at the beginning of this block */ cp->c_flag &= ~C_DELETED; cp->c_touch_chgtime = TRUE; cp->c_touch_modtime = TRUE; if (error == 0) hfs_volupdate(hfsmp, (v_type == VDIR) ? VOL_RMDIR : VOL_RMFILE, 0); } } // if <open unlinked> hfs_update(vp, reclaim ? HFS_UPDATE_FORCE : 0); /* * Since we are about to finish what might be an inactive call, propagate * any remaining modified or touch bits from the cnode to the vnode. This * serves as a hint to vnode recycling that we shouldn't recycle this vnode * synchronously. * * For now, if the node *only* has a dirty atime, we don't mark * the vnode as dirty. VFS's asynchronous recycling can actually * lead to worse performance than having it synchronous. When VFS * is fixed to be more performant, we can be more honest about * marking vnodes as dirty when it's only the atime that's dirty. */ if (hfs_is_dirty(cp) == HFS_DIRTY || ISSET(cp->c_flag, C_DELETED)) { vnode_setdirty(vp); } else { vnode_cleardirty(vp); } out: if (cat_reserve) cat_postflight(hfsmp, &cookie, p); if (started_tr) { hfs_end_transaction(hfsmp); started_tr = false; } return error; } /* * hfs_vnop_inactive * * The last usecount on the vnode has gone away, so we need to tear down * any remaining data still residing in the cnode. If necessary, write out * remaining blocks or delete the cnode's entry in the catalog. */ int hfs_vnop_inactive(struct vnop_inactive_args *ap) { struct vnode *vp = ap->a_vp; struct cnode *cp; struct hfsmount *hfsmp = VTOHFS(vp); struct proc *p = vfs_context_proc(ap->a_context); int error = 0; int took_trunc_lock = 0; enum vtype v_type; v_type = vnode_vtype(vp); cp = VTOC(vp); if ((hfsmp->hfs_flags & HFS_READ_ONLY) || vnode_issystem(vp) || (hfsmp->hfs_freezing_proc == p)) { error = 0; goto inactive_done; } /* * For safety, do NOT call vnode_recycle from inside this function. This can cause * problems in the following scenario: * * vnode_create -> vnode_reclaim_internal -> vclean -> VNOP_INACTIVE * * If we're being invoked as a result of a reclaim that was already in-flight, then we * cannot call vnode_recycle again. Being in reclaim means that there are no usecounts or * iocounts by definition. As a result, if we were to call vnode_recycle, it would immediately * try to re-enter reclaim again and panic. * * Currently, there are three things that can cause us (VNOP_INACTIVE) to get called. * 1) last usecount goes away on the vnode (vnode_rele) * 2) last iocount goes away on a vnode that previously had usecounts but didn't have * vnode_recycle called (vnode_put) * 3) vclean by way of reclaim * * In this function we would generally want to call vnode_recycle to speed things * along to ensure that we don't leak blocks due to open-unlinked files. However, by * virtue of being in this function already, we can call hfs_cnode_teardown, which * will release blocks held by open-unlinked files, and mark them C_NOEXISTS so that * there's no entry in the catalog and no backing store anymore. If that's the case, * then we really don't care all that much when the vnode actually goes through reclaim. * Further, the HFS VNOPs that manipulated the namespace in order to create the open- * unlinked file in the first place should have already called vnode_recycle on the vnode * to guarantee that it would go through reclaim in a speedy way. */ if (cp->c_flag & C_NOEXISTS) { /* * If the cnode has already had its cat entry removed, then * just skip to the end. We don't need to do anything here. */ error = 0; goto inactive_done; } if ((v_type == VREG || v_type == VLNK)) { hfs_lock_truncate(cp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_DEFAULT); took_trunc_lock = 1; } (void) hfs_lock(cp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_ALLOW_NOEXISTS); /* * Call cnode_teardown to push out dirty blocks to disk, release open-unlinked * files' blocks from being in use, and move the cnode from C_DELETED to C_NOEXISTS. */ error = hfs_cnode_teardown (vp, ap->a_context, 0); /* * Drop the truncate lock before unlocking the cnode * (which can potentially perform a vnode_put and * recycle the vnode which in turn might require the * truncate lock) */ if (took_trunc_lock) { hfs_unlock_truncate(cp, HFS_LOCK_DEFAULT); } hfs_unlock(cp); inactive_done: return error; } /* * File clean-up (zero fill and shrink peof). */ int hfs_filedone(struct vnode *vp, vfs_context_t context, hfs_file_done_opts_t opts) { struct cnode *cp; struct filefork *fp; struct hfsmount *hfsmp; off_t leof; u_int32_t blks, blocksize; cp = VTOC(vp); fp = VTOF(vp); hfsmp = VTOHFS(vp); leof = fp->ff_size; if ((hfsmp->hfs_flags & HFS_READ_ONLY) || (fp->ff_blocks == 0)) return (0); hfs_flush_invalid_ranges(vp); blocksize = VTOVCB(vp)->blockSize; blks = leof / blocksize; if (((off_t)blks * (off_t)blocksize) != leof) blks++; /* * Shrink the peof to the smallest size neccessary to contain the leof. */ if (blks < fp->ff_blocks) { (void) hfs_truncate(vp, leof, IO_NDELAY, HFS_TRUNCATE_SKIPTIMES, context); } if (!ISSET(opts, HFS_FILE_DONE_NO_SYNC)) { hfs_unlock(cp); cluster_push(vp, IO_CLOSE); hfs_lock(cp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_ALLOW_NOEXISTS); /* * If the hfs_truncate didn't happen to flush the vnode's * information out to disk, force it to be updated now that * all invalid ranges have been zero-filled and validated: */ hfs_update(vp, 0); } return (0); } /* * Reclaim a cnode so that it can be used for other purposes. */ int hfs_vnop_reclaim(struct vnop_reclaim_args *ap) { struct vnode *vp = ap->a_vp; struct cnode *cp; struct filefork *fp = NULL; struct filefork *altfp = NULL; struct hfsmount *hfsmp = VTOHFS(vp); vfs_context_t ctx = ap->a_context; int reclaim_cnode = 0; int err = 0; enum vtype v_type; v_type = vnode_vtype(vp); cp = VTOC(vp); /* * We don't take the truncate lock since by the time reclaim comes along, * all dirty pages have been synced and nobody should be competing * with us for this thread. */ (void) hfs_lock(cp, HFS_EXCLUSIVE_LOCK, HFS_LOCK_ALLOW_NOEXISTS); /* * Sync to disk any remaining data in the cnode/vnode. This includes * a call to hfs_update if the cnode has outbound data. * * If C_NOEXISTS is set on the cnode, then there's nothing teardown needs to do * because the catalog entry for this cnode is already gone. */ if (!ISSET(cp->c_flag, C_NOEXISTS)) { err = hfs_cnode_teardown(vp, ctx, 1); } /* * Keep track of an inactive hot file. Don't bother on ssd's since * the tracking is done differently (it's done at read() time) */ if (!vnode_isdir(vp) && !vnode_issystem(vp) && !(cp->c_flag & (C_DELETED | C_NOEXISTS)) && !(hfsmp->hfs_flags & HFS_CS_HOTFILE_PIN)) { (void) hfs_addhotfile(vp); } vnode_removefsref(vp); /* * Find file fork for this vnode (if any) * Also check if another fork is active */ if (cp->c_vp == vp) { fp = cp->c_datafork; altfp = cp->c_rsrcfork; cp->c_datafork = NULL; cp->c_vp = NULL; } else if (cp->c_rsrc_vp == vp) { fp = cp->c_rsrcfork; altfp = cp->c_datafork; cp->c_rsrcfork = NULL; cp->c_rsrc_vp = NULL; } else { panic("hfs_vnop_reclaim: vp points to wrong cnode (vp=%p cp->c_vp=%p cp->c_rsrc_vp=%p)\n", vp, cp->c_vp, cp->c_rsrc_vp); } /* * On the last fork, remove the cnode from its hash chain. */ if (altfp == NULL) { /* If we can't remove it then the cnode must persist! */ if (hfs_chashremove(hfsmp, cp) == 0) reclaim_cnode = 1; /* * Remove any directory hints */ if (vnode_isdir(vp)) { hfs_reldirhints(cp, 0); } if(cp->c_flag & C_HARDLINK) { hfs_relorigins(cp); } } /* Release the file fork and related data */ if (fp) { /* Dump cached symlink data */ if (vnode_islnk(vp) && (fp->ff_symlinkptr != NULL)) { FREE(fp->ff_symlinkptr, M_TEMP); } rl_remove_all(&fp->ff_invalidranges); FREE_ZONE(fp, sizeof(struct filefork), M_HFSFORK); } /* * If there was only one active fork then we can release the cnode. */ if (reclaim_cnode) { hfs_chashwakeup(hfsmp, cp, H_ALLOC | H_TRANSIT); hfs_unlock(cp); hfs_reclaim_cnode(hfsmp, cp); } else { /* * cnode in use. If it is a directory, it could have * no live forks. Just release the lock. */ hfs_unlock(cp); } vnode_clearfsnode(vp); return (0); } extern int (**hfs_vnodeop_p) (void *); extern int (**hfs_specop_p) (void *); #if FIFO extern int (**hfs_fifoop_p) (void *); #endif #if CONFIG_HFS_STD extern int (**hfs_std_vnodeop_p) (void *); #endif /* * hfs_getnewvnode - get new default vnode * * The vnode is returned with an iocount and the cnode locked. * The cnode of the parent vnode 'dvp' may or may not be locked, depending on * the circumstances. The cnode in question (if acquiring the resource fork), * may also already be locked at the time we enter this function. * * Note that there are both input and output flag arguments to this function. * If one of the input flags (specifically, GNV_USE_VP), is set, then * hfs_getnewvnode will use the parameter *vpp, which is traditionally only * an output parameter, as both an input and output parameter. It will use * the vnode provided in the output, and pass it to vnode_create with the * proper flavor so that a new vnode is _NOT_ created on our behalf when * we dispatch to VFS. This may be important in various HFS vnode creation * routines, such a create or get-resource-fork, because we risk deadlock if * jetsam is involved. * * Deadlock potential exists if jetsam is synchronously invoked while we are waiting * for a vnode to be recycled in order to give it the identity we want. If jetsam * happens to target a process for termination that is blocked in-kernel, waiting to * acquire the cnode lock on our parent 'dvp', while our current thread has it locked, * neither side will make forward progress and the watchdog timer will eventually fire. * To prevent this, a caller of hfs_getnewvnode may choose to proactively force * any necessary vnode reclamation/recycling while it is not holding any locks and * thus not prone to deadlock. If this is the case, GNV_USE_VP will be set and * the parameter will be used as described above. * * !!! <NOTE> !!!! * In circumstances when GNV_USE_VP is set, this function _MUST_ clean up and either consume * or dispose of the provided vnode. We funnel all errors to a single return value so that * if provided_vp is still non-NULL, then we will dispose of the vnode. This will occur in * all error cases of this function -- anywhere we zero/NULL out the *vpp parameter. It may * also occur if the current thread raced with another to create the same vnode, and we * find the entry already present in the cnode hash. * !!! </NOTE> !!! */ int hfs_getnewvnode( struct hfsmount *hfsmp, struct vnode *dvp, struct componentname *cnp, struct cat_desc *descp, int flags, struct cat_attr *attrp, struct cat_fork *forkp, struct vnode **vpp, int *out_flags) { struct mount *mp = HFSTOVFS(hfsmp); struct vnode *vp = NULL; struct vnode **cvpp; struct vnode *tvp = NULLVP; struct cnode *cp = NULL; struct filefork *fp = NULL; int hfs_standard = 0; int retval = 0; int issystemfile; int wantrsrc; int hflags = 0; int need_update_identity = 0; struct vnode_fsparam vfsp; enum vtype vtype; struct vnode *provided_vp = NULL; #if QUOTA int i; #endif /* QUOTA */ hfs_standard = (hfsmp->hfs_flags & HFS_STANDARD); if (flags & GNV_USE_VP) { /* Store the provided VP for later use */ provided_vp = *vpp; } /* Zero out the vpp regardless of provided input */ *vpp = NULL; /* Zero out the out_flags */ *out_flags = 0; if (attrp->ca_fileid == 0) { retval = ENOENT; goto gnv_exit; } #if !FIFO if (IFTOVT(attrp->ca_mode) == VFIFO) { retval = ENOTSUP; goto gnv_exit; } #endif /* !FIFO */ vtype = IFTOVT(attrp->ca_mode); issystemfile = (descp->cd_flags & CD_ISMETA) && (vtype == VREG); wantrsrc = flags & GNV_WANTRSRC; /* Sanity check the vtype and mode */ if (vtype == VBAD) { /* Mark the FS as corrupt and bail out */ hfs_mark_inconsistent(hfsmp, HFS_INCONSISTENCY_DETECTED); retval = EINVAL; goto gnv_exit; } #ifdef HFS_CHECK_LOCK_ORDER /* * The only case where it's permissible to hold the parent cnode * lock is during a create operation (hfs_makenode) or when * we don't need the cnode lock (GNV_SKIPLOCK). */ if ((dvp != NULL) && (flags & (GNV_CREATE | GNV_SKIPLOCK)) == 0 && VTOC(dvp)->c_lockowner == current_thread()) { panic("hfs_getnewvnode: unexpected hold of parent cnode %p", VTOC(dvp)); } #endif /* HFS_CHECK_LOCK_ORDER */ /* * Get a cnode (new or existing) */ cp = hfs_chash_getcnode(hfsmp, attrp->ca_fileid, vpp, wantrsrc, (flags & GNV_SKIPLOCK), out_flags, &hflags); /* * If the id is no longer valid for lookups we'll get back a NULL cp. */ if (cp == NULL) { retval = ENOENT; goto gnv_exit; } /* * We may have been provided a vnode via * GNV_USE_VP. In this case, we have raced with * a 2nd thread to create the target vnode. The provided * vnode that was passed in will be dealt with at the * end of the function, as we don't zero out the field * until we're ready to pass responsibility to VFS. */ /* * If we get a cnode/vnode pair out of hfs_chash_getcnode, then update the * descriptor in the cnode as needed if the cnode represents a hardlink. * We want the caller to get the most up-to-date copy of the descriptor * as possible. However, we only do anything here if there was a valid vnode. * If there isn't a vnode, then the cnode is brand new and needs to be initialized * as it doesn't have a descriptor or cat_attr yet. * * If we are about to replace the descriptor with the user-supplied one, then validate * that the descriptor correctly acknowledges this item is a hardlink. We could be * subject to a race where the calling thread invoked cat_lookup, got a valid lookup * result but the file was not yet a hardlink. With sufficient delay between there * and here, we might accidentally copy in the raw inode ID into the descriptor in the * call below. If the descriptor's CNID is the same as the fileID then it must * not yet have been a hardlink when the lookup occurred. */ if (!(hfs_checkdeleted(cp))) { // // If the bytes of the filename in the descp do not match the bytes in the // cnp (and we're not looking up the resource fork), then we want to update // the vnode identity to contain the bytes that HFS stores so that when an // fsevent gets generated, it has the correct filename. otherwise daemons // that match filenames produced by fsevents with filenames they have stored // elsewhere (e.g. bladerunner, backupd, mds), the filenames will not match. // See: <rdar://problem/8044697> FSEvents doesn't always decompose diacritical unicode chars in the paths of the changed directories // for more details. // #ifdef CN_WANTSRSRCFORK if (*vpp && cnp && cnp->cn_nameptr && !(cnp->cn_flags & CN_WANTSRSRCFORK) && descp && descp->cd_nameptr && strncmp((const char *)cnp->cn_nameptr, (const char *)descp->cd_nameptr, descp->cd_namelen) != 0) { #else if (*vpp && cnp && cnp->cn_nameptr && descp && descp->cd_nameptr && strncmp((const char *)cnp->cn_nameptr, (const char *)descp->cd_nameptr, descp->cd_namelen) != 0) { #endif vnode_update_identity (*vpp, dvp, (const char *)descp->cd_nameptr, descp->cd_namelen, 0, VNODE_UPDATE_NAME); } if ((cp->c_flag & C_HARDLINK) && descp->cd_nameptr && descp->cd_namelen > 0) { /* If cnode is uninitialized, its c_attr will be zeroed out; cnids wont match. */ if ((descp->cd_cnid == cp->c_attr.ca_fileid) && (attrp->ca_linkcount != cp->c_attr.ca_linkcount)){ if ((flags & GNV_SKIPLOCK) == 0) { /* * Then we took the lock. Drop it before calling * vnode_put, which may invoke hfs_vnop_inactive and need to take * the cnode lock again. */ hfs_unlock(cp); } /* * Emit ERECYCLE and GNV_CAT_ATTRCHANGED to * force a re-drive in the lookup routine. * Drop the iocount on the vnode obtained from * chash_getcnode if needed. */ if (*vpp != NULL) { vnode_put (*vpp); *vpp = NULL; } /* * If we raced with VNOP_RECLAIM for this vnode, the hash code could * have observed it after the c_vp or c_rsrc_vp fields had been torn down; * the hash code peeks at those fields without holding the cnode lock because * it needs to be fast. As a result, we may have set H_ATTACH in the chash * call above. Since we're bailing out, unset whatever flags we just set, and * wake up all waiters for this cnode. */ if (hflags) { hfs_chashwakeup(hfsmp, cp, hflags); } *out_flags = GNV_CAT_ATTRCHANGED; retval = ERECYCLE; goto gnv_exit; } else { /* * Otherwise, CNID != fileid. Go ahead and copy in the new descriptor. * * Replacing the descriptor here is fine because we looked up the item without * a vnode in hand before. If a vnode existed, its identity must be attached to this * item. We are not susceptible to the lookup fastpath issue at this point. */ replace_desc(cp, descp); /* * This item was a hardlink, and its name needed to be updated. By replacing the * descriptor above, we've now updated the cnode's internal representation of * its link ID/CNID, parent ID, and its name. However, VFS must now be alerted * to the fact that this vnode now has a new parent, since we cannot guarantee * that the new link lived in the same directory as the alternative name for * this item. */ if ((*vpp != NULL) && (cnp || cp->c_desc.cd_nameptr)) { /* we could be requesting the rsrc of a hardlink file... */ #ifdef CN_WANTSRSRCFORK if (cp->c_desc.cd_nameptr && (cnp == NULL || !(cnp->cn_flags & CN_WANTSRSRCFORK))) { #else if (cp->c_desc.cd_nameptr) { #endif // // Update the identity with what we have stored on disk as // the name of this file. This is related to: // <rdar://problem/8044697> FSEvents doesn't always decompose diacritical unicode chars in the paths of the changed directories // vnode_update_identity (*vpp, dvp, (const char *)cp->c_desc.cd_nameptr, cp->c_desc.cd_namelen, 0, (VNODE_UPDATE_PARENT | VNODE_UPDATE_NAME)); } else if (cnp) { vnode_update_identity (*vpp, dvp, cnp->cn_nameptr, cnp->cn_namelen, cnp->cn_hash, (VNODE_UPDATE_PARENT | VNODE_UPDATE_NAME)); } } } } } /* * At this point, we have performed hardlink and open-unlinked checks * above. We have now validated the state of the vnode that was given back * to us from the cnode hash code and find it safe to return. */ if (*vpp != NULL) { retval = 0; goto gnv_exit; } /* * If this is a new cnode then initialize it. */ if (ISSET(cp->c_hflag, H_ALLOC)) { lck_rw_init(&cp->c_truncatelock, hfs_rwlock_group, hfs_lock_attr); #if HFS_COMPRESSION cp->c_decmp = NULL; #endif /* Make sure its still valid (ie exists on disk). */ if (!(flags & GNV_CREATE)) { int error = 0; if (!hfs_valid_cnode (hfsmp, dvp, (wantrsrc ? NULL : cnp), cp->c_fileid, attrp, &error)) { hfs_chash_abort(hfsmp, cp); if ((flags & GNV_SKIPLOCK) == 0) { hfs_unlock(cp); } hfs_reclaim_cnode(hfsmp, cp); *vpp = NULL; /* * If we hit this case, that means that the entry was there in the catalog when * we did a cat_lookup earlier. Think hfs_lookup. However, in between the time * that we checked the catalog and the time we went to get a vnode/cnode for it, * it had been removed from the namespace and the vnode totally reclaimed. As a result, * it's not there in the catalog during the check in hfs_valid_cnode and we bubble out * an ENOENT. To indicate to the caller that they should really double-check the * entry (it could have been renamed over and gotten a new fileid), we mark a bit * in the output flags. */ if (error == ENOENT) { *out_flags = GNV_CAT_DELETED; retval = ENOENT; goto gnv_exit; } /* * Also, we need to protect the cat_attr acquired during hfs_lookup and passed into * this function as an argument because the catalog may have changed w.r.t hardlink * link counts and the firstlink field. If that validation check fails, then let * lookup re-drive itself to get valid/consistent data with the same failure condition below. */ if (error == ERECYCLE) { *out_flags = GNV_CAT_ATTRCHANGED; retval = ERECYCLE; goto gnv_exit; } } } bcopy(attrp, &cp->c_attr, sizeof(struct cat_attr)); bcopy(descp, &cp->c_desc, sizeof(struct cat_desc)); /* The name was inherited so clear descriptor state... */ descp->cd_namelen = 0; descp->cd_nameptr = NULL; descp->cd_flags &= ~CD_HASBUF; /* Tag hardlinks */ if ((vtype == VREG || vtype == VDIR || vtype == VSOCK || vtype == VFIFO) && (descp->cd_cnid != attrp->ca_fileid || ISSET(attrp->ca_recflags, kHFSHasLinkChainMask))) { cp->c_flag |= C_HARDLINK; } /* * Fix-up dir link counts. * * Earlier versions of Leopard used ca_linkcount for posix * nlink support (effectively the sub-directory count + 2). * That is now accomplished using the ca_dircount field with * the corresponding kHFSHasFolderCountMask flag. * * For directories the ca_linkcount is the true link count, * tracking the number of actual hardlinks to a directory. * * We only do this if the mount has HFS_FOLDERCOUNT set; * at the moment, we only set that for HFSX volumes. */ if ((hfsmp->hfs_flags & HFS_FOLDERCOUNT) && (vtype == VDIR) && !(attrp->ca_recflags & kHFSHasFolderCountMask) && (cp->c_attr.ca_linkcount > 1)) { if (cp->c_attr.ca_entries == 0) cp->c_attr.ca_dircount = 0; else cp->c_attr.ca_dircount = cp->c_attr.ca_linkcount - 2; cp->c_attr.ca_linkcount = 1; cp->c_attr.ca_recflags |= kHFSHasFolderCountMask; if ( !(hfsmp->hfs_flags & HFS_READ_ONLY) ) cp->c_flag |= C_MODIFIED; } #if QUOTA if (hfsmp->hfs_flags & HFS_QUOTAS) { for (i = 0; i < MAXQUOTAS; i++) cp->c_dquot[i] = NODQUOT; } #endif /* QUOTA */ /* Mark the output flag that we're vending a new cnode */ *out_flags |= GNV_NEW_CNODE; } if (vtype == VDIR) { if (cp->c_vp != NULL) panic("hfs_getnewvnode: orphaned vnode (data)"); cvpp = &cp->c_vp; } else { if (forkp && attrp->ca_blocks < forkp->cf_blocks) panic("hfs_getnewvnode: bad ca_blocks (too small)"); /* * Allocate and initialize a file fork... */ MALLOC_ZONE(fp, struct filefork *, sizeof(struct filefork), M_HFSFORK, M_WAITOK); fp->ff_cp = cp; if (forkp) bcopy(forkp, &fp->ff_data, sizeof(struct cat_fork)); else bzero(&fp->ff_data, sizeof(struct cat_fork)); rl_init(&fp->ff_invalidranges); fp->ff_sysfileinfo = 0; if (wantrsrc) { if (cp->c_rsrcfork != NULL) panic("hfs_getnewvnode: orphaned rsrc fork"); if (cp->c_rsrc_vp != NULL) panic("hfs_getnewvnode: orphaned vnode (rsrc)"); cp->c_rsrcfork = fp; cvpp = &cp->c_rsrc_vp; if ( (tvp = cp->c_vp) != NULLVP ) cp->c_flag |= C_NEED_DVNODE_PUT; } else { if (cp->c_datafork != NULL) panic("hfs_getnewvnode: orphaned data fork"); if (cp->c_vp != NULL) panic("hfs_getnewvnode: orphaned vnode (data)"); cp->c_datafork = fp; cvpp = &cp->c_vp; if ( (tvp = cp->c_rsrc_vp) != NULLVP) cp->c_flag |= C_NEED_RVNODE_PUT; } } if (tvp != NULLVP) { /* * grab an iocount on the vnode we weren't * interested in (i.e. we want the resource fork * but the cnode already has the data fork) * to prevent it from being * recycled by us when we call vnode_create * which will result in a deadlock when we * try to take the cnode lock in hfs_vnop_fsync or * hfs_vnop_reclaim... vnode_get can be called here * because we already hold the cnode lock which will * prevent the vnode from changing identity until * we drop it.. vnode_get will not block waiting for * a change of state... however, it will return an * error if the current iocount == 0 and we've already * started to terminate the vnode... we don't need/want to * grab an iocount in the case since we can't cause * the fileystem to be re-entered on this thread for this vp * * the matching vnode_put will happen in hfs_unlock * after we've dropped the cnode lock */ if ( vnode_get(tvp) != 0) cp->c_flag &= ~(C_NEED_RVNODE_PUT | C_NEED_DVNODE_PUT); } vfsp.vnfs_mp = mp; vfsp.vnfs_vtype = vtype; vfsp.vnfs_str = "hfs"; if ((cp->c_flag & C_HARDLINK) && (vtype == VDIR)) { vfsp.vnfs_dvp = NULL; /* no parent for me! */ vfsp.vnfs_cnp = NULL; /* no name for me! */ } else { vfsp.vnfs_dvp = dvp; vfsp.vnfs_cnp = cnp; } vfsp.vnfs_fsnode = cp; /* * Special Case HFS Standard VNOPs from HFS+, since * HFS standard is readonly/deprecated as of 10.6 */ #if FIFO if (vtype == VFIFO ) vfsp.vnfs_vops = hfs_fifoop_p; else #endif if (vtype == VBLK || vtype == VCHR) vfsp.vnfs_vops = hfs_specop_p; #if CONFIG_HFS_STD else if (hfs_standard) vfsp.vnfs_vops = hfs_std_vnodeop_p; #endif else vfsp.vnfs_vops = hfs_vnodeop_p; if (vtype == VBLK || vtype == VCHR) vfsp.vnfs_rdev = attrp->ca_rdev; else vfsp.vnfs_rdev = 0; if (forkp) vfsp.vnfs_filesize = forkp->cf_size; else vfsp.vnfs_filesize = 0; vfsp.vnfs_flags = VNFS_ADDFSREF; #ifdef CN_WANTSRSRCFORK if (cnp && cnp->cn_nameptr && !(cnp->cn_flags & CN_WANTSRSRCFORK) && cp->c_desc.cd_nameptr && strncmp((const char *)cnp->cn_nameptr, (const char *)cp->c_desc.cd_nameptr, cp->c_desc.cd_namelen) != 0) { #else if (cnp && cnp->cn_nameptr && cp->c_desc.cd_nameptr && strncmp((const char *)cnp->cn_nameptr, (const char *)cp->c_desc.cd_nameptr, cp->c_desc.cd_namelen) != 0) { #endif // // We don't want VFS to add an entry for this vnode because the name in the // cnp does not match the bytes stored on disk for this file. Instead we'll // update the identity later after the vnode is created and we'll do so with // the correct bytes for this filename. For more details, see: // <rdar://problem/8044697> FSEvents doesn't always decompose diacritical unicode chars in the paths of the changed directories // vfsp.vnfs_flags |= VNFS_NOCACHE; need_update_identity = 1; } else if (dvp == NULLVP || cnp == NULL || !(cnp->cn_flags & MAKEENTRY) || (flags & GNV_NOCACHE)) { vfsp.vnfs_flags |= VNFS_NOCACHE; } /* Tag system files */ vfsp.vnfs_marksystem = issystemfile; /* Tag root directory */ if (descp->cd_cnid == kHFSRootFolderID) vfsp.vnfs_markroot = 1; else vfsp.vnfs_markroot = 0; /* * If provided_vp was non-NULL, then it is an already-allocated (but not * initialized) vnode. We simply need to initialize it to this identity. * If it was NULL, then assume that we need to call vnode_create with the * normal arguments/types. */ if (provided_vp) { vp = provided_vp; /* * After we assign the value of provided_vp into 'vp' (so that it can be * mutated safely by vnode_initialize), we can NULL it out. At this point, the disposal * and handling of the provided vnode will be the responsibility of VFS, which will * clean it up and vnode_put it properly if vnode_initialize fails. */ provided_vp = NULL; retval = vnode_initialize (VNCREATE_FLAVOR, VCREATESIZE, &vfsp, &vp); /* See error handling below for resolving provided_vp */ } else { /* Do a standard vnode_create */ retval = vnode_create (VNCREATE_FLAVOR, VCREATESIZE, &vfsp, &vp); } /* * We used a local variable to hold the result of vnode_create/vnode_initialize so that * on error cases in vnode_create we won't accidentally harm the cnode's fields */ if (retval) { /* Clean up if we encountered an error */ if (fp) { if (fp == cp->c_datafork) cp->c_datafork = NULL; else cp->c_rsrcfork = NULL; FREE_ZONE(fp, sizeof(struct filefork), M_HFSFORK); } /* * If this is a newly created cnode or a vnode reclaim * occurred during the attachment, then cleanup the cnode. */ if ((cp->c_vp == NULL) && (cp->c_rsrc_vp == NULL)) { hfs_chash_abort(hfsmp, cp); hfs_reclaim_cnode(hfsmp, cp); } else { hfs_chashwakeup(hfsmp, cp, H_ALLOC | H_ATTACH); if ((flags & GNV_SKIPLOCK) == 0){ hfs_unlock(cp); } } *vpp = NULL; goto gnv_exit; } /* If no error, then assign the value into the cnode's fields */ *cvpp = vp; vnode_settag(vp, VT_HFS); if (cp->c_flag & C_HARDLINK) { vnode_setmultipath(vp); } if (cp->c_attr.ca_recflags & kHFSFastDevCandidateMask) { vnode_setfastdevicecandidate(vp); } if (cp->c_attr.ca_recflags & kHFSAutoCandidateMask) { vnode_setautocandidate(vp); } if (vp && need_update_identity) { // // As above, update the name of the vnode if the bytes stored in hfs do not match // the bytes in the cnp. See this radar: // <rdar://problem/8044697> FSEvents doesn't always decompose diacritical unicode chars in the paths of the changed directories // for more details. // vnode_update_identity (vp, dvp, (const char *)cp->c_desc.cd_nameptr, cp->c_desc.cd_namelen, 0, VNODE_UPDATE_NAME); } /* * Tag resource fork vnodes as needing an VNOP_INACTIVE * so that any deferred removes (open unlinked files) * have the chance to process the resource fork. */ if (VNODE_IS_RSRC(vp)) { int err; KERNEL_DEBUG_CONSTANT(HFSDBG_GETNEWVNODE, VM_KERNEL_ADDRPERM(cp->c_vp), VM_KERNEL_ADDRPERM(cp->c_rsrc_vp), 0, 0, 0); /* Force VL_NEEDINACTIVE on this vnode */ err = vnode_ref(vp); if (err == 0) { vnode_rele(vp); } } hfs_chashwakeup(hfsmp, cp, H_ALLOC | H_ATTACH); /* * Stop tracking an active hot file. */ if (!(flags & GNV_CREATE) && (vtype != VDIR) && !issystemfile && !(hfsmp->hfs_flags & HFS_CS_HOTFILE_PIN)) { (void) hfs_removehotfile(vp); } #if CONFIG_PROTECT /* Initialize the cp data structures. The key should be in place now. */ if (!issystemfile && (*out_flags & GNV_NEW_CNODE)) { cp_entry_init(cp, mp); } #endif *vpp = vp; retval = 0; gnv_exit: if (provided_vp) { /* Release our empty vnode if it was not used */ vnode_put (provided_vp); } return retval; } static void hfs_reclaim_cnode(hfsmount_t *hfsmp, struct cnode *cp) { #if QUOTA int i; for (i = 0; i < MAXQUOTAS; i++) { if (cp->c_dquot[i] != NODQUOT) { dqreclaim(cp->c_dquot[i]); cp->c_dquot[i] = NODQUOT; } } #endif /* QUOTA */ /* * If the descriptor has a name then release it */ if ((cp->c_desc.cd_flags & CD_HASBUF) && (cp->c_desc.cd_nameptr != 0)) { const char *nameptr; nameptr = (const char *) cp->c_desc.cd_nameptr; cp->c_desc.cd_nameptr = 0; cp->c_desc.cd_flags &= ~CD_HASBUF; cp->c_desc.cd_namelen = 0; vfs_removename(nameptr); } /* * We only call this function if we are in hfs_vnop_reclaim and * attempting to reclaim a cnode with only one live fork. Because the vnode * went through reclaim, any future attempts to use this item will have to * go through lookup again, which will need to create a new vnode. Thus, * destroying the locks below is safe. */ lck_rw_destroy(&cp->c_rwlock, hfs_rwlock_group); lck_rw_destroy(&cp->c_truncatelock, hfs_rwlock_group); #if HFS_COMPRESSION if (cp->c_decmp) { decmpfs_cnode_destroy(cp->c_decmp); FREE_ZONE(cp->c_decmp, sizeof(*(cp->c_decmp)), M_DECMPFS_CNODE); } #endif #if CONFIG_PROTECT cp_entry_destroy(hfsmp, cp->c_cpentry); cp->c_cpentry = NULL; #else (void)hfsmp; // Prevent compiler warning #endif bzero(cp, sizeof(struct cnode)); FREE_ZONE(cp, sizeof(struct cnode), M_HFSNODE); } /* * hfs_valid_cnode * * This function is used to validate data that is stored in-core against what is contained * in the catalog. Common uses include validating that the parent-child relationship still exist * for a specific directory entry (guaranteeing it has not been renamed into a different spot) at * the point of the check. */ int hfs_valid_cnode(struct hfsmount *hfsmp, struct vnode *dvp, struct componentname *cnp, cnid_t cnid, struct cat_attr *cattr, int *error) { struct cat_attr attr; struct cat_desc cndesc; int stillvalid = 0; int lockflags; /* System files are always valid */ if (cnid < kHFSFirstUserCatalogNodeID) { *error = 0; return (1); } /* XXX optimization: check write count in dvp */ lockflags = hfs_systemfile_lock(hfsmp, SFL_CATALOG, HFS_SHARED_LOCK); if (dvp && cnp) { int lookup = 0; struct cat_fork fork; bzero(&cndesc, sizeof(cndesc)); cndesc.cd_nameptr = (const u_int8_t *)cnp->cn_nameptr; cndesc.cd_namelen = cnp->cn_namelen; cndesc.cd_parentcnid = VTOC(dvp)->c_fileid; cndesc.cd_hint = VTOC(dvp)->c_childhint; /* * We have to be careful when calling cat_lookup. The result argument * 'attr' may get different results based on whether or not you ask * for the filefork to be supplied as output. This is because cat_lookupbykey * will attempt to do basic validation/smoke tests against the resident * extents if there are no overflow extent records, but it needs someplace * in memory to store the on-disk fork structures. * * Since hfs_lookup calls cat_lookup with a filefork argument, we should * do the same here, to verify that block count differences are not * due to calling the function with different styles. cat_lookupbykey * will request the volume be fsck'd if there is true on-disk corruption * where the number of blocks does not match the number generated by * summing the number of blocks in the resident extents. */ lookup = cat_lookup (hfsmp, &cndesc, 0, 0, NULL, &attr, &fork, NULL); if ((lookup == 0) && (cnid == attr.ca_fileid)) { stillvalid = 1; *error = 0; } else { *error = ENOENT; } /* * In hfs_getnewvnode, we may encounter a time-of-check vs. time-of-vnode creation * race. Specifically, if there is no vnode/cnode pair for the directory entry * being looked up, we have to go to the catalog. But since we don't hold any locks (aside * from the dvp in 'shared' mode) there is nothing to protect us against the catalog record * changing in between the time we do the cat_lookup there and the time we re-grab the * catalog lock above to do another cat_lookup. * * However, we need to check more than just the CNID and parent-child name relationships above. * Hardlinks can suffer the same race in the following scenario: Suppose we do a * cat_lookup, and find a leaf record and a raw inode for a hardlink. Now, we have * the cat_attr in hand (passed in above). But in between then and now, the vnode was * created by a competing hfs_getnewvnode call, and is manipulated and reclaimed before we get * a chance to do anything. This is possible if there are a lot of threads thrashing around * with the cnode hash. In this case, if we don't check/validate the cat_attr in-hand, we will * blindly stuff it into the cnode, which will make the in-core data inconsistent with what is * on disk. So validate the cat_attr below, if required. This race cannot happen if the cnode/vnode * already exists, as it does in the case of rename and delete. */ if (stillvalid && cattr != NULL) { if (cattr->ca_linkcount != attr.ca_linkcount) { stillvalid = 0; *error = ERECYCLE; goto notvalid; } if (cattr->ca_union1.cau_linkref != attr.ca_union1.cau_linkref) { stillvalid = 0; *error = ERECYCLE; goto notvalid; } if (cattr->ca_union3.cau_firstlink != attr.ca_union3.cau_firstlink) { stillvalid = 0; *error = ERECYCLE; goto notvalid; } if (cattr->ca_union2.cau_blocks != attr.ca_union2.cau_blocks) { stillvalid = 0; *error = ERECYCLE; goto notvalid; } } } else { if (cat_idlookup(hfsmp, cnid, 0, 0, NULL, NULL, NULL) == 0) { stillvalid = 1; *error = 0; } else { *error = ENOENT; } } notvalid: hfs_systemfile_unlock(hfsmp, lockflags); return (stillvalid); } /* * Per HI and Finder requirements, HFS should add in the * date/time that a particular directory entry was added * to the containing directory. * This is stored in the extended Finder Info for the * item in question. * * Note that this field is also set explicitly in the hfs_vnop_setxattr code. * We must ignore user attempts to set this part of the finderinfo, and * so we need to save a local copy of the date added, write in the user * finderinfo, then stuff the value back in. */ void hfs_write_dateadded (struct cat_attr *attrp, u_int32_t dateadded) { u_int8_t *finfo = NULL; /* overlay the FinderInfo to the correct pointer, and advance */ finfo = (u_int8_t*)attrp->ca_finderinfo; finfo = finfo + 16; /* * Make sure to write it out as big endian, since that's how * finder info is defined. * * NOTE: This is a Unix-epoch timestamp, not a HFS/Traditional Mac timestamp. */ if (S_ISREG(attrp->ca_mode)) { struct FndrExtendedFileInfo *extinfo = (struct FndrExtendedFileInfo *)finfo; extinfo->date_added = OSSwapHostToBigInt32(dateadded); attrp->ca_recflags |= kHFSHasDateAddedMask; } else if (S_ISDIR(attrp->ca_mode)) { struct FndrExtendedDirInfo *extinfo = (struct FndrExtendedDirInfo *)finfo; extinfo->date_added = OSSwapHostToBigInt32(dateadded); attrp->ca_recflags |= kHFSHasDateAddedMask; } /* If it were neither directory/file, then we'd bail out */ return; } static u_int32_t hfs_get_dateadded_internal(const uint8_t *finderinfo, mode_t mode) { const uint8_t *finfo = NULL; u_int32_t dateadded = 0; /* overlay the FinderInfo to the correct pointer, and advance */ finfo = finderinfo + 16; /* * FinderInfo is written out in big endian... make sure to convert it to host * native before we use it. */ if (S_ISREG(mode)) { const struct FndrExtendedFileInfo *extinfo = (const struct FndrExtendedFileInfo *)finfo; dateadded = OSSwapBigToHostInt32 (extinfo->date_added); } else if (S_ISDIR(mode)) { const struct FndrExtendedDirInfo *extinfo = (const struct FndrExtendedDirInfo *)finfo; dateadded = OSSwapBigToHostInt32 (extinfo->date_added); } return dateadded; } u_int32_t hfs_get_dateadded(struct cnode *cp) { if ((cp->c_attr.ca_recflags & kHFSHasDateAddedMask) == 0) { /* Date added was never set. Return 0. */ return (0); } return (hfs_get_dateadded_internal((u_int8_t*)cp->c_finderinfo, cp->c_attr.ca_mode)); } u_int32_t hfs_get_dateadded_from_blob(const uint8_t *finderinfo, mode_t mode) { return (hfs_get_dateadded_internal(finderinfo, mode)); } /* * Per HI and Finder requirements, HFS maintains a "write/generation * count" for each file that is incremented on any write & pageout. * It should start at 1 to reserve "0" as a special value. If it * should ever wrap around, it will skip using 0. * * Note that finderinfo is manipulated in hfs_vnop_setxattr and care * is and should be taken to ignore user attempts to set the part of * the finderinfo that records the generation counter. * * Any change to the generation counter *must* not be visible before * the change that caused it (for obvious reasons), and given the * limitations of our current architecture, the change to the * generation counter may occur some time afterwards (particularly in * the case where a file is mapped writable---more on that below). * * We make no guarantees about the consistency of a file. In other * words, a reader that is operating concurrently with a writer might * see some, but not all of writer's changes, and the generation * counter will *not* necessarily tell you this has happened. To * enforce consistency, clients must make their own arrangements * e.g. use file locking. * * We treat files that are mapped writable as a special case: when * that happens, clients requesting the generation count will be told * it has a generation count of zero and they use that knowledge as a * hint that the file is changing and it therefore might be prudent to * wait until it is no longer mapped writable. Clients should *not* * rely on this behaviour however; we might decide that it's better * for us to publish the fact that a file is mapped writable via * alternate means and return the generation counter when it is mapped * writable as it still has some, albeit limited, use. We reserve the * right to make this change. * * Lastly, it's important to realise that because data and metadata * take different paths through the system, it's possible upon crash * or sudden power loss and after a restart, that a change may be * visible to the rest of the system without a corresponding change to * the generation counter. The reverse may also be true, but for all * practical applications this shouldn't be an issue. */ void hfs_write_gencount (struct cat_attr *attrp, uint32_t gencount) { u_int8_t *finfo = NULL; /* overlay the FinderInfo to the correct pointer, and advance */ finfo = (u_int8_t*)attrp->ca_finderinfo; finfo = finfo + 16; /* * Make sure to write it out as big endian, since that's how * finder info is defined. * * Generation count is only supported for files. */ if (S_ISREG(attrp->ca_mode)) { struct FndrExtendedFileInfo *extinfo = (struct FndrExtendedFileInfo *)finfo; extinfo->write_gen_counter = OSSwapHostToBigInt32(gencount); } /* If it were neither directory/file, then we'd bail out */ return; } /* * Increase the gen count by 1; if it wraps around to 0, increment by * two. The cnode *must* be locked exclusively by the caller. * * You may think holding the lock is unnecessary because we only need * to change the counter, but consider this sequence of events: thread * A calls hfs_incr_gencount and the generation counter is 2 upon * entry. A context switch occurs and thread B increments the counter * to 3, thread C now gets the generation counter (for whatever * purpose), and then another thread makes another change and the * generation counter is incremented again---it's now 4. Now thread A * continues and it sets the generation counter back to 3. So you can * see, thread C would miss the change that caused the generation * counter to increment to 4 and for this reason the cnode *must* * always be locked exclusively. */ uint32_t hfs_incr_gencount (struct cnode *cp) { u_int8_t *finfo = NULL; u_int32_t gcount = 0; /* overlay the FinderInfo to the correct pointer, and advance */ finfo = (u_int8_t*)cp->c_finderinfo; finfo = finfo + 16; /* * FinderInfo is written out in big endian... make sure to convert it to host * native before we use it. * * NOTE: the write_gen_counter is stored in the same location in both the * FndrExtendedFileInfo and FndrExtendedDirInfo structs (it's the * last 32-bit word) so it is safe to have one code path here. */ if (S_ISDIR(cp->c_attr.ca_mode) || S_ISREG(cp->c_attr.ca_mode)) { struct FndrExtendedFileInfo *extinfo = (struct FndrExtendedFileInfo *)finfo; gcount = OSSwapBigToHostInt32 (extinfo->write_gen_counter); /* Was it zero to begin with (file originated in 10.8 or earlier?) */ if (gcount == 0) { gcount++; } /* now bump it */ gcount++; /* Did it wrap around ? */ if (gcount == 0) { gcount++; } extinfo->write_gen_counter = OSSwapHostToBigInt32 (gcount); SET(cp->c_flag, C_MINOR_MOD); } else { gcount = 0; } return gcount; } /* * There is no need for any locks here (other than an iocount on an * associated vnode) because reading and writing an aligned 32 bit * integer should be atomic on all platforms we support. */ static u_int32_t hfs_get_gencount_internal(const uint8_t *finderinfo, mode_t mode) { const uint8_t *finfo = NULL; u_int32_t gcount = 0; /* overlay the FinderInfo to the correct pointer, and advance */ finfo = finderinfo; finfo = finfo + 16; /* * FinderInfo is written out in big endian... make sure to convert it to host * native before we use it. * * NOTE: the write_gen_counter is stored in the same location in both the * FndrExtendedFileInfo and FndrExtendedDirInfo structs (it's the * last 32-bit word) so it is safe to have one code path here. */ if (S_ISDIR(mode) || S_ISREG(mode)) { const struct FndrExtendedFileInfo *extinfo = (const struct FndrExtendedFileInfo *)finfo; gcount = OSSwapBigToHostInt32 (extinfo->write_gen_counter); /* * Is it zero? File might originate in 10.8 or earlier. We lie and bump it to 1, * since the incrementer code is able to handle this case and will double-increment * for us. */ if (gcount == 0) { gcount++; } } return gcount; } /* Getter for the gen count */ u_int32_t hfs_get_gencount (struct cnode *cp) { return hfs_get_gencount_internal(cp->c_finderinfo, cp->c_attr.ca_mode); } /* Getter for the gen count from a buffer (currently pointer to finderinfo)*/ u_int32_t hfs_get_gencount_from_blob (const uint8_t *finfoblob, mode_t mode) { return hfs_get_gencount_internal(finfoblob, mode); } void hfs_clear_might_be_dirty_flag(cnode_t *cp) { /* * If we're about to touch both mtime and ctime, we can clear the * C_MIGHT_BE_DIRTY_FROM_MAPPING since we can guarantee that * subsequent page-outs can only be for data made dirty before * now. */ CLR(cp->c_flag, C_MIGHT_BE_DIRTY_FROM_MAPPING); } /* * Touch cnode times based on c_touch_xxx flags * * cnode must be locked exclusive * * This will also update the volume modify time */ void hfs_touchtimes(struct hfsmount *hfsmp, struct cnode* cp) { vfs_context_t ctx; if (ISSET(hfsmp->hfs_flags, HFS_READ_ONLY) || ISSET(cp->c_flag, C_NOEXISTS)) { cp->c_touch_acctime = FALSE; cp->c_touch_chgtime = FALSE; cp->c_touch_modtime = FALSE; CLR(cp->c_flag, C_NEEDS_DATEADDED); return; } #if CONFIG_HFS_STD else if (hfsmp->hfs_flags & HFS_STANDARD) { /* HFS Standard doesn't support access times */ cp->c_touch_acctime = FALSE; } #endif ctx = vfs_context_current(); /* * Skip access time updates if: * . MNT_NOATIME is set * . a file system freeze is in progress * . a file system resize is in progress * . the vnode associated with this cnode is marked for rapid aging */ if (cp->c_touch_acctime) { if ((vfs_flags(hfsmp->hfs_mp) & MNT_NOATIME) || hfsmp->hfs_freeze_state != HFS_THAWED || (hfsmp->hfs_flags & HFS_RESIZE_IN_PROGRESS) || (cp->c_vp && ((vnode_israge(cp->c_vp) || (vfs_ctx_skipatime(ctx)))))) { cp->c_touch_acctime = FALSE; } } if (cp->c_touch_acctime || cp->c_touch_chgtime || cp->c_touch_modtime || (cp->c_flag & C_NEEDS_DATEADDED)) { struct timeval tv; int touchvol = 0; if (cp->c_touch_modtime && cp->c_touch_chgtime) hfs_clear_might_be_dirty_flag(cp); microtime(&tv); if (cp->c_touch_acctime) { /* * When the access time is the only thing changing, we * won't necessarily write it to disk immediately. We * only do the atime update at vnode recycle time, when * fsync is called or when there's another reason to write * to the metadata. */ cp->c_atime = tv.tv_sec; cp->c_touch_acctime = FALSE; } if (cp->c_touch_modtime) { cp->c_touch_modtime = FALSE; time_t new_time = tv.tv_sec; #if CONFIG_HFS_STD /* * HFS dates that WE set must be adjusted for DST */ if ((hfsmp->hfs_flags & HFS_STANDARD) && gTimeZone.tz_dsttime) { new_time += 3600; } #endif if (cp->c_mtime != new_time) { cp->c_mtime = new_time; cp->c_flag |= C_MINOR_MOD; touchvol = 1; } } if (cp->c_touch_chgtime) { cp->c_touch_chgtime = FALSE; if (cp->c_ctime != tv.tv_sec) { cp->c_ctime = tv.tv_sec; cp->c_flag |= C_MINOR_MOD; touchvol = 1; } } if (cp->c_flag & C_NEEDS_DATEADDED) { hfs_write_dateadded (&(cp->c_attr), tv.tv_sec); cp->c_flag |= C_MINOR_MOD; /* untwiddle the bit */ cp->c_flag &= ~C_NEEDS_DATEADDED; touchvol = 1; } /* Touch the volume modtime if needed */ if (touchvol) { hfs_note_header_minor_change(hfsmp); HFSTOVCB(hfsmp)->vcbLsMod = tv.tv_sec; } } } // Use this if you don't want to check the return code void hfs_lock_always(cnode_t *cp, enum hfs_locktype locktype) { hfs_lock(cp, locktype, HFS_LOCK_ALWAYS); } /* * Lock a cnode. * N.B. If you add any failure cases, *make* sure hfs_lock_always works */ int hfs_lock(struct cnode *cp, enum hfs_locktype locktype, enum hfs_lockflags flags) { thread_t thread = current_thread(); if (cp->c_lockowner == thread) { /* * Only the extents and bitmap files support lock recursion * here. The other system files support lock recursion in * hfs_systemfile_lock. Eventually, we should change to * handle recursion solely in hfs_systemfile_lock. */ if ((cp->c_fileid == kHFSExtentsFileID) || (cp->c_fileid == kHFSAllocationFileID)) { cp->c_syslockcount++; } else { panic("hfs_lock: locking against myself!"); } } else if (locktype == HFS_SHARED_LOCK) { lck_rw_lock_shared(&cp->c_rwlock); cp->c_lockowner = HFS_SHARED_OWNER; } else { /* HFS_EXCLUSIVE_LOCK */ lck_rw_lock_exclusive(&cp->c_rwlock); cp->c_lockowner = thread; /* Only the extents and bitmap files support lock recursion. */ if ((cp->c_fileid == kHFSExtentsFileID) || (cp->c_fileid == kHFSAllocationFileID)) { cp->c_syslockcount = 1; } } #ifdef HFS_CHECK_LOCK_ORDER /* * Regular cnodes (non-system files) cannot be locked * while holding the journal lock or a system file lock. */ if (!(cp->c_desc.cd_flags & CD_ISMETA) && ((cp->c_fileid > kHFSFirstUserCatalogNodeID) || (cp->c_fileid == kHFSRootFolderID))) { vnode_t vp = NULLVP; /* Find corresponding vnode. */ if (cp->c_vp != NULLVP && VTOC(cp->c_vp) == cp) { vp = cp->c_vp; } else if (cp->c_rsrc_vp != NULLVP && VTOC(cp->c_rsrc_vp) == cp) { vp = cp->c_rsrc_vp; } if (vp != NULLVP) { struct hfsmount *hfsmp = VTOHFS(vp); if (hfsmp->jnl && (journal_owner(hfsmp->jnl) == thread)) { /* This will eventually be a panic here. */ printf("hfs_lock: bad lock order (cnode after journal)\n"); } if (hfsmp->hfs_catalog_cp && hfsmp->hfs_catalog_cp->c_lockowner == thread) { panic("hfs_lock: bad lock order (cnode after catalog)"); } if (hfsmp->hfs_attribute_cp && hfsmp->hfs_attribute_cp->c_lockowner == thread) { panic("hfs_lock: bad lock order (cnode after attribute)"); } if (hfsmp->hfs_extents_cp && hfsmp->hfs_extents_cp->c_lockowner == thread) { panic("hfs_lock: bad lock order (cnode after extents)"); } } } #endif /* HFS_CHECK_LOCK_ORDER */ /* * Skip cnodes for regular files that no longer exist * (marked deleted, catalog entry gone). */ if (((flags & HFS_LOCK_ALLOW_NOEXISTS) == 0) && ((cp->c_desc.cd_flags & CD_ISMETA) == 0) && (cp->c_flag & C_NOEXISTS)) { hfs_unlock(cp); return (ENOENT); } return (0); } bool hfs_lock_upgrade(cnode_t *cp) { if (lck_rw_lock_shared_to_exclusive(&cp->c_rwlock)) { cp->c_lockowner = current_thread(); return true; } else return false; } /* * Lock a pair of cnodes. */ int hfs_lockpair(struct cnode *cp1, struct cnode *cp2, enum hfs_locktype locktype) { struct cnode *first, *last; int error; /* * If cnodes match then just lock one. */ if (cp1 == cp2) { return hfs_lock(cp1, locktype, HFS_LOCK_DEFAULT); } /* * Lock in cnode address order. */ if (cp1 < cp2) { first = cp1; last = cp2; } else { first = cp2; last = cp1; } if ( (error = hfs_lock(first, locktype, HFS_LOCK_DEFAULT))) { return (error); } if ( (error = hfs_lock(last, locktype, HFS_LOCK_DEFAULT))) { hfs_unlock(first); return (error); } return (0); } /* * Check ordering of two cnodes. Return true if they are are in-order. */ static int hfs_isordered(struct cnode *cp1, struct cnode *cp2) { if (cp1 == cp2) return (0); if (cp1 == NULL || cp2 == (struct cnode *)0xffffffff) return (1); if (cp2 == NULL || cp1 == (struct cnode *)0xffffffff) return (0); /* * Locking order is cnode address order. */ return (cp1 < cp2); } /* * Acquire 4 cnode locks. * - locked in cnode address order (lesser address first). * - all or none of the locks are taken * - only one lock taken per cnode (dup cnodes are skipped) * - some of the cnode pointers may be null */ int hfs_lockfour(struct cnode *cp1, struct cnode *cp2, struct cnode *cp3, struct cnode *cp4, enum hfs_locktype locktype, struct cnode **error_cnode) { struct cnode * a[3]; struct cnode * b[3]; struct cnode * list[4]; struct cnode * tmp; int i, j, k; int error; if (error_cnode) { *error_cnode = NULL; } if (hfs_isordered(cp1, cp2)) { a[0] = cp1; a[1] = cp2; } else { a[0] = cp2; a[1] = cp1; } if (hfs_isordered(cp3, cp4)) { b[0] = cp3; b[1] = cp4; } else { b[0] = cp4; b[1] = cp3; } a[2] = (struct cnode *)0xffffffff; /* sentinel value */ b[2] = (struct cnode *)0xffffffff; /* sentinel value */ /* * Build the lock list, skipping over duplicates */ for (i = 0, j = 0, k = 0; (i < 2 || j < 2); ) { tmp = hfs_isordered(a[i], b[j]) ? a[i++] : b[j++]; if (k == 0 || tmp != list[k-1]) list[k++] = tmp; } /* * Now we can lock using list[0 - k]. * Skip over NULL entries. */ for (i = 0; i < k; ++i) { if (list[i]) if ((error = hfs_lock(list[i], locktype, HFS_LOCK_DEFAULT))) { /* Only stuff error_cnode if requested */ if (error_cnode) { *error_cnode = list[i]; } /* Drop any locks we acquired. */ while (--i >= 0) { if (list[i]) hfs_unlock(list[i]); } return (error); } } return (0); } /* * Unlock a cnode. */ void hfs_unlock(struct cnode *cp) { vnode_t rvp = NULLVP; vnode_t vp = NULLVP; u_int32_t c_flag; /* * Only the extents and bitmap file's support lock recursion. */ if ((cp->c_fileid == kHFSExtentsFileID) || (cp->c_fileid == kHFSAllocationFileID)) { if (--cp->c_syslockcount > 0) { return; } } const thread_t thread = current_thread(); if (cp->c_lockowner == thread) { c_flag = cp->c_flag; // If we have the truncate lock, we must defer the puts if (cp->c_truncatelockowner == thread) { if (ISSET(c_flag, C_NEED_DVNODE_PUT) && !cp->c_need_dvnode_put_after_truncate_unlock) { CLR(c_flag, C_NEED_DVNODE_PUT); cp->c_need_dvnode_put_after_truncate_unlock = true; } if (ISSET(c_flag, C_NEED_RVNODE_PUT) && !cp->c_need_rvnode_put_after_truncate_unlock) { CLR(c_flag, C_NEED_RVNODE_PUT); cp->c_need_rvnode_put_after_truncate_unlock = true; } } CLR(cp->c_flag, (C_NEED_DATA_SETSIZE | C_NEED_RSRC_SETSIZE | C_NEED_DVNODE_PUT | C_NEED_RVNODE_PUT)); if (c_flag & (C_NEED_DVNODE_PUT | C_NEED_DATA_SETSIZE)) { vp = cp->c_vp; } if (c_flag & (C_NEED_RVNODE_PUT | C_NEED_RSRC_SETSIZE)) { rvp = cp->c_rsrc_vp; } cp->c_lockowner = NULL; lck_rw_unlock_exclusive(&cp->c_rwlock); } else { lck_rw_unlock_shared(&cp->c_rwlock); } /* Perform any vnode post processing after cnode lock is dropped. */ if (vp) { if (c_flag & C_NEED_DATA_SETSIZE) { ubc_setsize(vp, VTOF(vp)->ff_size); #if HFS_COMPRESSION /* * If this is a compressed file, we need to reset the * compression state. We will have set the size to zero * above and it will get fixed up later (in exactly the * same way that new vnodes are fixed up). Note that we * should only be able to get here if the truncate lock is * held exclusively and so we do the reset when that's * unlocked. */ decmpfs_cnode *dp = VTOCMP(vp); if (dp && decmpfs_cnode_get_vnode_state(dp) != FILE_TYPE_UNKNOWN) cp->c_need_decmpfs_reset = true; #endif } if (c_flag & C_NEED_DVNODE_PUT) vnode_put(vp); } if (rvp) { if (c_flag & C_NEED_RSRC_SETSIZE) ubc_setsize(rvp, VTOF(rvp)->ff_size); if (c_flag & C_NEED_RVNODE_PUT) vnode_put(rvp); } } /* * Unlock a pair of cnodes. */ void hfs_unlockpair(struct cnode *cp1, struct cnode *cp2) { hfs_unlock(cp1); if (cp2 != cp1) hfs_unlock(cp2); } /* * Unlock a group of cnodes. */ void hfs_unlockfour(struct cnode *cp1, struct cnode *cp2, struct cnode *cp3, struct cnode *cp4) { struct cnode * list[4]; int i, k = 0; if (cp1) { hfs_unlock(cp1); list[k++] = cp1; } if (cp2) { for (i = 0; i < k; ++i) { if (list[i] == cp2) goto skip1; } hfs_unlock(cp2); list[k++] = cp2; } skip1: if (cp3) { for (i = 0; i < k; ++i) { if (list[i] == cp3) goto skip2; } hfs_unlock(cp3); list[k++] = cp3; } skip2: if (cp4) { for (i = 0; i < k; ++i) { if (list[i] == cp4) return; } hfs_unlock(cp4); } } /* * Protect a cnode against a truncation. * * Used mainly by read/write since they don't hold the * cnode lock across calls to the cluster layer. * * The process doing a truncation must take the lock * exclusive. The read/write processes can take it * shared. The locktype argument is the same as supplied to * hfs_lock. */ void hfs_lock_truncate(struct cnode *cp, enum hfs_locktype locktype, enum hfs_lockflags flags) { thread_t thread = current_thread(); if (cp->c_truncatelockowner == thread) { /* * Ignore grabbing the lock if it the current thread already * holds exclusive lock. * * This is needed on the hfs_vnop_pagein path where we need to ensure * the file does not change sizes while we are paging in. However, * we may already hold the lock exclusive due to another * VNOP from earlier in the call stack. So if we already hold * the truncate lock exclusive, allow it to proceed, but ONLY if * it's in the recursive case. */ if ((flags & HFS_LOCK_SKIP_IF_EXCLUSIVE) == 0) { panic("hfs_lock_truncate: cnode %p locked!", cp); } } else if (locktype == HFS_SHARED_LOCK) { lck_rw_lock_shared(&cp->c_truncatelock); cp->c_truncatelockowner = HFS_SHARED_OWNER; } else { /* HFS_EXCLUSIVE_LOCK */ lck_rw_lock_exclusive(&cp->c_truncatelock); cp->c_truncatelockowner = thread; } } bool hfs_truncate_lock_upgrade(struct cnode *cp) { assert(cp->c_truncatelockowner == HFS_SHARED_OWNER); if (!lck_rw_lock_shared_to_exclusive(&cp->c_truncatelock)) return false; cp->c_truncatelockowner = current_thread(); return true; } void hfs_truncate_lock_downgrade(struct cnode *cp) { assert(cp->c_truncatelockowner == current_thread()); lck_rw_lock_exclusive_to_shared(&cp->c_truncatelock); cp->c_truncatelockowner = HFS_SHARED_OWNER; } /* * Attempt to get the truncate lock. If it cannot be acquired, error out. * This function is needed in the degenerate hfs_vnop_pagein during force unmount * case. To prevent deadlocks while a VM copy object is moving pages, HFS vnop pagein will * temporarily need to disable V2 semantics. */ int hfs_try_trunclock (struct cnode *cp, enum hfs_locktype locktype, enum hfs_lockflags flags) { thread_t thread = current_thread(); boolean_t didlock = false; if (cp->c_truncatelockowner == thread) { /* * Ignore grabbing the lock if the current thread already * holds exclusive lock. * * This is needed on the hfs_vnop_pagein path where we need to ensure * the file does not change sizes while we are paging in. However, * we may already hold the lock exclusive due to another * VNOP from earlier in the call stack. So if we already hold * the truncate lock exclusive, allow it to proceed, but ONLY if * it's in the recursive case. */ if ((flags & HFS_LOCK_SKIP_IF_EXCLUSIVE) == 0) { panic("hfs_lock_truncate: cnode %p locked!", cp); } } else if (locktype == HFS_SHARED_LOCK) { didlock = lck_rw_try_lock(&cp->c_truncatelock, LCK_RW_TYPE_SHARED); if (didlock) { cp->c_truncatelockowner = HFS_SHARED_OWNER; } } else { /* HFS_EXCLUSIVE_LOCK */ didlock = lck_rw_try_lock (&cp->c_truncatelock, LCK_RW_TYPE_EXCLUSIVE); if (didlock) { cp->c_truncatelockowner = thread; } } return didlock; } /* * Unlock the truncate lock, which protects against size changes. * * If HFS_LOCK_SKIP_IF_EXCLUSIVE flag was set, it means that a previous * hfs_lock_truncate() might have skipped grabbing a lock because * the current thread was already holding the lock exclusive and * we may need to return from this function without actually unlocking * the truncate lock. */ void hfs_unlock_truncate(struct cnode *cp, enum hfs_lockflags flags) { thread_t thread = current_thread(); /* * If HFS_LOCK_SKIP_IF_EXCLUSIVE is set in the flags AND the current * lock owner of the truncate lock is our current thread, then * we must have skipped taking the lock earlier by in * hfs_lock_truncate() by setting HFS_LOCK_SKIP_IF_EXCLUSIVE in the * flags (as the current thread was current lock owner). * * If HFS_LOCK_SKIP_IF_EXCLUSIVE is not set (most of the time) then * we check the lockowner field to infer whether the lock was taken * exclusively or shared in order to know what underlying lock * routine to call. */ if (flags & HFS_LOCK_SKIP_IF_EXCLUSIVE) { if (cp->c_truncatelockowner == thread) { return; } } /* HFS_LOCK_EXCLUSIVE */ if (thread == cp->c_truncatelockowner) { vnode_t vp = NULL, rvp = NULL; /* * If there are pending set sizes, the cnode lock should be dropped * first. */ #if DEBUG assert(!(cp->c_lockowner == thread && ISSET(cp->c_flag, C_NEED_DATA_SETSIZE | C_NEED_RSRC_SETSIZE))); #elif DEVELOPMENT if (cp->c_lockowner == thread && ISSET(cp->c_flag, C_NEED_DATA_SETSIZE | C_NEED_RSRC_SETSIZE)) { printf("hfs: hfs_unlock_truncate called with C_NEED_DATA/RSRC_SETSIZE set (caller: 0x%llx)\n", (uint64_t)VM_KERNEL_UNSLIDE(__builtin_return_address(0))); } #endif if (cp->c_need_dvnode_put_after_truncate_unlock) { vp = cp->c_vp; cp->c_need_dvnode_put_after_truncate_unlock = false; } if (cp->c_need_rvnode_put_after_truncate_unlock) { rvp = cp->c_rsrc_vp; cp->c_need_rvnode_put_after_truncate_unlock = false; } #if HFS_COMPRESSION bool reset_decmpfs = cp->c_need_decmpfs_reset; cp->c_need_decmpfs_reset = false; #endif cp->c_truncatelockowner = NULL; lck_rw_unlock_exclusive(&cp->c_truncatelock); #if HFS_COMPRESSION if (reset_decmpfs) { decmpfs_cnode *dp = cp->c_decmp; if (dp && decmpfs_cnode_get_vnode_state(dp) != FILE_TYPE_UNKNOWN) decmpfs_cnode_set_vnode_state(dp, FILE_TYPE_UNKNOWN, 0); } #endif // Do the puts now if (vp) vnode_put(vp); if (rvp) vnode_put(rvp); } else { /* HFS_LOCK_SHARED */ lck_rw_unlock_shared(&cp->c_truncatelock); } }