/* * Copyright (c) 2002-2014 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@ */ #ifndef _HFS_CNODE_H_ #define _HFS_CNODE_H_ #include #ifdef KERNEL #ifdef __APPLE_API_PRIVATE #include #include #include #include #include #include #include #include #include #if HFS_COMPRESSION #include #endif #if CONFIG_PROTECT #include #endif /* * The filefork is used to represent an HFS file fork (data or resource). * Reading or writing any of these fields requires holding cnode lock. */ struct filefork { struct cnode *ff_cp; /* cnode associated with this fork */ struct rl_head ff_invalidranges; /* Areas of disk that should read back as zeroes */ union { void *ffu_sysfileinfo; /* additional info for system files */ char *ffu_symlinkptr; /* symbolic link pathname */ } ff_union; struct cat_fork ff_data; /* fork data (size, extents) */ }; typedef struct filefork filefork_t; #define HFS_TEMPLOOKUP_NAMELEN 32 /* * Catalog Lookup struct (runtime) * * This is used so that when we need to malloc a container for a catalog * lookup operation, we can acquire memory for everything in one fell swoop * as opposed to putting many of these objects on the stack. The cat_fork * data structure can take up 100+bytes easily, and that can add to stack * overhead. * * As a result, we use this to easily pass around the memory needed for a * lookup operation. */ struct cat_lookup_buffer { struct cat_desc lookup_desc; struct cat_attr lookup_attr; struct filefork lookup_fork; struct componentname lookup_cn; char lookup_name[HFS_TEMPLOOKUP_NAMELEN]; /* for open-unlinked paths only */ }; /* Aliases for common fields */ #define ff_size ff_data.cf_size #define ff_new_size ff_data.cf_new_size #define ff_clumpsize ff_data.cf_clump #define ff_bytesread ff_data.cf_bytesread #define ff_blocks ff_data.cf_blocks #define ff_extents ff_data.cf_extents #define ff_unallocblocks ff_data.cf_vblocks #define ff_symlinkptr ff_union.ffu_symlinkptr #define ff_sysfileinfo ff_union.ffu_sysfileinfo /* The btree code still needs these... */ #define fcbEOF ff_size #define fcbExtents ff_extents #define fcbBTCBPtr ff_sysfileinfo typedef u_int8_t atomicflag_t; /* * Hardlink Origin (for hardlinked directories). */ struct linkorigin { TAILQ_ENTRY(linkorigin) lo_link; /* chain */ void * lo_thread; /* thread that performed the lookup */ cnid_t lo_cnid; /* hardlink's cnid */ cnid_t lo_parentcnid; /* hardlink's parent cnid */ }; typedef struct linkorigin linkorigin_t; #define MAX_CACHED_ORIGINS 10 #define MAX_CACHED_FILE_ORIGINS 8 /* * The cnode is used to represent each active (or recently active) * file or directory in the HFS filesystem. * * Reading or writing any of these fields requires holding c_lock. */ struct cnode { lck_rw_t c_rwlock; /* cnode's lock */ thread_t c_lockowner; /* cnode's lock owner (exclusive case only) */ lck_rw_t c_truncatelock; /* protects file from truncation during read/write */ thread_t c_truncatelockowner; /* truncate lock owner (exclusive case only) */ LIST_ENTRY(cnode) c_hash; /* cnode's hash chain */ u_int32_t c_flag; /* cnode's runtime flags */ u_int32_t c_hflag; /* cnode's flags for maintaining hash - protected by global hash lock */ struct vnode *c_vp; /* vnode for data fork or dir */ struct vnode *c_rsrc_vp; /* vnode for resource fork */ struct dquot *c_dquot[MAXQUOTAS]; /* cnode's quota info */ u_int32_t c_childhint; /* catalog hint for children (small dirs only) */ u_int32_t c_dirthreadhint; /* catalog hint for directory's thread rec */ struct cat_desc c_desc; /* cnode's descriptor */ struct cat_attr c_attr; /* cnode's attributes */ TAILQ_HEAD(hfs_originhead, linkorigin) c_originlist; /* hardlink origin cache */ TAILQ_HEAD(hfs_hinthead, directoryhint) c_hintlist; /* readdir directory hint list */ int16_t c_dirhinttag; /* directory hint tag */ union { int16_t cu_dirhintcnt; /* directory hint count */ int16_t cu_syslockcount; /* system file use only */ } c_union; u_int32_t c_dirchangecnt; /* changes each insert/delete (in-core only) */ struct filefork *c_datafork; /* cnode's data fork */ struct filefork *c_rsrcfork; /* cnode's rsrc fork */ atomicflag_t c_touch_acctime; atomicflag_t c_touch_chgtime; atomicflag_t c_touch_modtime; // The following flags are protected by the truncate lock union { struct { bool c_need_dvnode_put_after_truncate_unlock : 1; bool c_need_rvnode_put_after_truncate_unlock : 1; #if HFS_COMPRESSION bool c_need_decmpfs_reset : 1; #endif }; uint8_t c_tflags; }; #if HFS_COMPRESSION decmpfs_cnode *c_decmp; #endif /* HFS_COMPRESSION */ #if CONFIG_PROTECT cprotect_t c_cpentry; /* content protection data */ #endif }; typedef struct cnode cnode_t; /* Aliases for common cnode fields */ #define c_cnid c_desc.cd_cnid #define c_hint c_desc.cd_hint #define c_parentcnid c_desc.cd_parentcnid #define c_encoding c_desc.cd_encoding #define c_fileid c_attr.ca_fileid #define c_mode c_attr.ca_mode #define c_linkcount c_attr.ca_linkcount #define c_uid c_attr.ca_uid #define c_gid c_attr.ca_gid #define c_rdev c_attr.ca_union1.cau_rdev #define c_atime c_attr.ca_atime #define c_mtime c_attr.ca_mtime #define c_ctime c_attr.ca_ctime #define c_itime c_attr.ca_itime #define c_btime c_attr.ca_btime #define c_bsdflags c_attr.ca_flags #define c_finderinfo c_attr.ca_finderinfo #define c_blocks c_attr.ca_union2.cau_blocks #define c_entries c_attr.ca_union2.cau_entries #define c_zftimeout c_childhint #define c_dirhintcnt c_union.cu_dirhintcnt #define c_syslockcount c_union.cu_syslockcount /* hash maintenance flags kept in c_hflag and protected by hfs_chash_mutex */ #define H_ALLOC 0x00001 /* CNode is being allocated */ #define H_ATTACH 0x00002 /* CNode is being attached to by another vnode */ #define H_TRANSIT 0x00004 /* CNode is getting recycled */ #define H_WAITING 0x00008 /* CNode is being waited for */ /* * Runtime cnode flags (kept in c_flag) */ #define C_NEED_RVNODE_PUT 0x0000001 /* Need to do a vnode_put on c_rsrc_vp after the unlock */ #define C_NEED_DVNODE_PUT 0x0000002 /* Need to do a vnode_put on c_vp after the unlock */ #define C_ZFWANTSYNC 0x0000004 /* fsync requested and file has holes */ #define C_FROMSYNC 0x0000008 /* fsync was called from sync */ #define C_MODIFIED 0x0000010 /* CNode has been modified */ #define C_NOEXISTS 0x0000020 /* CNode has been deleted, catalog entry is gone */ #define C_DELETED 0x0000040 /* CNode has been marked to be deleted */ #define C_HARDLINK 0x0000080 /* CNode is a hard link (file or dir) */ #define C_FORCEUPDATE 0x0000100 /* force the catalog entry update */ #define C_HASXATTRS 0x0000200 /* cnode has extended attributes */ #define C_NEG_ENTRIES 0x0000400 /* directory has negative name entries */ /* * For C_SSD_STATIC: SSDs may want to deal with the file payload data in a * different manner knowing that the content is not likely to be modified. This is * purely advisory at the HFS level, and is not maintained after the cnode goes out of core. */ #define C_SSD_STATIC 0x0000800 /* Assume future writes contain static content */ #define C_NEED_DATA_SETSIZE 0x0001000 /* Do a ubc_setsize(0) on c_rsrc_vp after the unlock */ #define C_NEED_RSRC_SETSIZE 0x0002000 /* Do a ubc_setsize(0) on c_vp after the unlock */ #define C_DIR_MODIFICATION 0x0004000 /* Directory is being modified, wait for lookups */ #define C_ALWAYS_ZEROFILL 0x0008000 /* Always zero-fill the file on an fsync */ #define C_RENAMED 0x0010000 /* cnode was deleted as part of rename; C_DELETED should also be set */ #define C_NEEDS_DATEADDED 0x0020000 /* cnode needs date-added written to the finderinfo bit */ #define C_BACKINGSTORE 0x0040000 /* cnode is a backing store for an existing or currently-mounting filesystem */ /* * This flag indicates the cnode might be dirty because it * was mapped writable so if we get any page-outs, update * the modification and change times. */ #define C_MIGHT_BE_DIRTY_FROM_MAPPING 0x0080000 /* * For C_SSD_GREEDY_MODE: SSDs may want to write the file payload data using the greedy mode knowing * that the content needs to be written out to the disk quicker than normal at the expense of storage efficiency. * This is purely advisory at the HFS level, and is not maintained after the cnode goes out of core. */ #define C_SSD_GREEDY_MODE 0x0100000 /* Assume future writes are recommended to be written in SLC mode */ /* 0x0200000 is currently unused */ #define C_IO_ISOCHRONOUS 0x0400000 /* device-specific isochronous throughput I/O */ #define ZFTIMELIMIT (5 * 60) /* * The following is the "invisible" bit from the fdFlags field * in the FndrFileInfo. */ enum { kFinderInvisibleMask = 1 << 14 }; /* * Convert between cnode pointers and vnode pointers */ #define VTOC(vp) ((struct cnode *)vnode_fsnode((vp))) #define CTOV(cp,rsrc) (((rsrc) && S_ISREG((cp)->c_mode)) ? \ (cp)->c_rsrc_vp : (cp)->c_vp) /* * Convert between vnode pointers and file forks * * Note: no CTOF since that is ambiguous */ #define FTOC(fp) ((fp)->ff_cp) #define VTOF(vp) ((vp) == VTOC((vp))->c_rsrc_vp ? \ VTOC((vp))->c_rsrcfork : \ VTOC((vp))->c_datafork) #define VCTOF(vp, cp) ((vp) == (cp)->c_rsrc_vp ? \ (cp)->c_rsrcfork : \ (cp)->c_datafork) #define FTOV(fp) ((fp) == FTOC(fp)->c_rsrcfork ? \ FTOC(fp)->c_rsrc_vp : \ FTOC(fp)->c_vp) /* * This is a helper function used for determining whether or not a cnode has become open * unlinked in between the time we acquired its vnode and the time we acquire the cnode lock * to start manipulating it. Due to the SMP nature of VFS, it is probably necessary to * use this macro every time we acquire a cnode lock, as the content of the Cnode may have * been modified in betweeen the lookup and a VNOP. Whether or not to call this is dependent * upon the VNOP in question. Sometimes it is OK to use an open-unlinked file, for example, in, * reading. But other times, such as on the source of a VNOP_RENAME, it should be disallowed. */ int hfs_checkdeleted(struct cnode *cp); /* * Test for a resource fork */ #define FORK_IS_RSRC(fp) ((fp) == FTOC(fp)->c_rsrcfork) #define VNODE_IS_RSRC(vp) ((vp) == VTOC((vp))->c_rsrc_vp) #if HFS_COMPRESSION /* * VTOCMP(vp) returns a pointer to vp's decmpfs_cnode; this could be NULL * if the file is not compressed or if hfs_file_is_compressed() hasn't * yet been called on this file. */ #define VTOCMP(vp) (VTOC((vp))->c_decmp) int hfs_file_is_compressed(struct cnode *cp, int skiplock); int hfs_uncompressed_size_of_compressed_file(struct hfsmount *hfsmp, struct vnode *vp, cnid_t fid, off_t *size, int skiplock); int hfs_hides_rsrc(vfs_context_t ctx, struct cnode *cp, int skiplock); int hfs_hides_xattr(vfs_context_t ctx, struct cnode *cp, const char *name, int skiplock); #endif #define ATIME_ONDISK_ACCURACY 300 /* This overlays the FileID portion of NFS file handles. */ struct hfsfid { u_int32_t hfsfid_cnid; /* Catalog node ID. */ u_int32_t hfsfid_gen; /* Generation number (create date). */ }; /* Get new default vnode */ extern 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); /* Input flags for hfs_getnewvnode */ #define GNV_WANTRSRC 0x01 /* Request the resource fork vnode. */ #define GNV_SKIPLOCK 0x02 /* Skip taking the cnode lock (when getting resource fork). */ #define GNV_CREATE 0x04 /* The vnode is for a newly created item. */ #define GNV_NOCACHE 0x08 /* Delay entering this item in the name cache */ /* Output flags for hfs_getnewvnode */ #define GNV_CHASH_RENAMED 0x01 /* The cnode was renamed in-flight */ #define GNV_CAT_DELETED 0x02 /* The cnode was deleted from the catalog */ #define GNV_NEW_CNODE 0x04 /* We are vending out a newly initialized cnode */ #define GNV_CAT_ATTRCHANGED 0x08 /* Something in struct cat_attr changed in between cat_lookups */ /* Touch cnode times based on c_touch_xxx flags */ extern void hfs_touchtimes(struct hfsmount *, struct cnode *); extern void hfs_write_dateadded (struct cat_attr *cattrp, u_int32_t dateadded); extern u_int32_t hfs_get_dateadded (struct cnode *cp); extern u_int32_t hfs_get_dateadded_from_blob(const uint8_t * /* finderinfo */, mode_t /* mode */); /* Gen counter methods */ extern void hfs_write_gencount(struct cat_attr *cattrp, uint32_t gencount); extern uint32_t hfs_get_gencount(struct cnode *cp); extern uint32_t hfs_incr_gencount (struct cnode *cp); extern uint32_t hfs_get_gencount_from_blob(const uint8_t * /* finderinfo */, mode_t /* mode */); /* Document id methods */ extern uint32_t hfs_get_document_id(struct cnode * /* cp */); extern uint32_t hfs_get_document_id_from_blob(const uint8_t * /* finderinfo */, mode_t /* mode */); /* Zero-fill file and push regions out to disk */ enum { // Use this flag if you're going to sync later HFS_FILE_DONE_NO_SYNC = 1, }; typedef uint32_t hfs_file_done_opts_t; extern int hfs_filedone(struct vnode *vp, vfs_context_t context, hfs_file_done_opts_t opts); /* * HFS cnode hash functions. */ extern void hfs_chashinit(void); extern void hfs_chashinit_finish(struct hfsmount *hfsmp); extern void hfs_delete_chash(struct hfsmount *hfsmp); extern int hfs_chashremove(struct hfsmount *hfsmp, struct cnode *cp); extern void hfs_chash_abort(struct hfsmount *hfsmp, struct cnode *cp); extern void hfs_chash_rehash(struct hfsmount *hfsmp, struct cnode *cp1, struct cnode *cp2); extern void hfs_chashwakeup(struct hfsmount *hfsmp, struct cnode *cp, int flags); extern void hfs_chash_mark_in_transit(struct hfsmount *hfsmp, struct cnode *cp); extern struct vnode * hfs_chash_getvnode(struct hfsmount *hfsmp, ino_t inum, int wantrsrc, int skiplock, int allow_deleted); extern struct cnode * hfs_chash_getcnode(struct hfsmount *hfsmp, ino_t inum, struct vnode **vpp, int wantrsrc, int skiplock, int *out_flags, int *hflags); extern int hfs_chash_snoop(struct hfsmount *, ino_t, int, int (*)(const cnode_t *, void *), void *); extern int hfs_valid_cnode(struct hfsmount *hfsmp, struct vnode *dvp, struct componentname *cnp, cnid_t cnid, struct cat_attr *cattr, int *error); extern int hfs_chash_set_childlinkbit(struct hfsmount *hfsmp, cnid_t cnid); /* * HFS cnode lock functions. * * HFS Locking Order: * * 1. cnode truncate lock (if needed) -- see below for more on this * * + hfs_vnop_pagein/out handles recursive use of this lock (by * using flag option HFS_LOCK_SKIP_IF_EXCLUSIVE) although there * are issues with this (see #16620278). * * + If locking multiple cnodes then the truncate lock must be taken on * both (in address order), before taking the cnode locks. * * 2. cnode lock (in parent-child order if related, otherwise by address order) * * 3. journal (if needed) * * 4. system files (as needed) * * A. Catalog B-tree file * B. Attributes B-tree file * C. Startup file (if there is one) * D. Allocation Bitmap file (always exclusive, supports recursion) * E. Overflow Extents B-tree file (always exclusive, supports recursion) * * 5. hfs mount point (always last) * * * I. HFS cnode hash lock (must not acquire any new locks while holding this lock, always taken last) */ /* * -- The Truncate Lock -- * * The truncate lock is used for a few purposes (more than its name * might suggest). The first thing to note is that the cnode lock * cannot be held whilst issuing any I/O other than metadata changes, * so the truncate lock, in either shared or exclusive form, must * usually be held in these cases. This includes calls to ubc_setsize * where the new size is less than the current size known to the VM * subsystem (for two reasons: a) because reaping pages can block * (e.g. on pages that are busy or being cleaned); b) reaping pages * might require page-in for tasks that have that region mapped * privately). The same applies to other calls into the VM subsystem. * * Here are some (but not necessarily all) cases that the truncate * lock protects for: * * + When reading and writing a file, we hold the truncate lock * shared to ensure that the underlying blocks cannot be deleted * and on systems that use content protection, this also ensures * the keys remain valid (which might be being used by the * underlying layers). * * + We need to protect against the following sequence of events: * * A file is initially size X. A thread issues an append to that * file. Another thread truncates the file and then extends it * to a a new size Y. Now the append can be applied at offset X * and then the data is lost when the file is truncated; or it * could be applied after the truncate, i.e. at offset 0; or it * can be applied at offset Y. What we *cannot* do is apply the * append at offset X and for the data to be visible at the end. * (Note that we are free to choose when we apply the append * operation.) * * To solve this, we keep things simple and take the truncate lock * exclusively in order to sequence the append with other size * changes. Therefore any size change must take the truncate lock * exclusively. * * (N.B. we could do better and allow readers to run concurrently * during the append and other size changes.) * * So here are the rules: * * + If you plan to change ff_size, you must take the truncate lock * exclusively, *but* be careful what I/O you do whilst you have * the truncate lock exclusively and try and avoid it if you can: * if the VM subsystem tries to do something with some pages on a * different thread and you try and do some I/O with those same * pages, we will deadlock. (See #16620278.) * * + If you do anything that requires blocks to not be deleted or * encrpytion keys to remain valid, you must take the truncate lock * shared. * * + And it follows therefore, that if you want to delete blocks or * delete keys, you must take the truncate lock exclusively. * * N.B. ff_size is actually protected by the cnode lock and so you * must hold the cnode lock exclusively to change it and shared to * read it. * */ enum hfs_locktype { HFS_SHARED_LOCK = 1, HFS_EXCLUSIVE_LOCK = 2 }; /* Option flags for cnode and truncate lock functions */ enum hfs_lockflags { HFS_LOCK_DEFAULT = 0x0, /* Default flag, no options provided */ HFS_LOCK_ALLOW_NOEXISTS = 0x1, /* Allow locking of all cnodes, including cnode marked deleted with no catalog entry */ HFS_LOCK_SKIP_IF_EXCLUSIVE = 0x2, /* Skip locking if the current thread already holds the lock exclusive */ // Used when you do not want to check return from hfs_lock HFS_LOCK_ALWAYS = HFS_LOCK_ALLOW_NOEXISTS, }; #define HFS_SHARED_OWNER (void *)0xffffffff void hfs_lock_always(cnode_t *cnode, enum hfs_locktype); int hfs_lock(struct cnode *, enum hfs_locktype, enum hfs_lockflags); int hfs_lockpair(struct cnode *, struct cnode *, enum hfs_locktype); int hfs_lockfour(struct cnode *, struct cnode *, struct cnode *, struct cnode *, enum hfs_locktype, struct cnode **); void hfs_unlock(struct cnode *); void hfs_unlockpair(struct cnode *, struct cnode *); void hfs_unlockfour(struct cnode *, struct cnode *, struct cnode *, struct cnode *); void hfs_lock_truncate(struct cnode *, enum hfs_locktype, enum hfs_lockflags); void hfs_unlock_truncate(struct cnode *, enum hfs_lockflags); int hfs_try_trunclock(struct cnode *, enum hfs_locktype, enum hfs_lockflags); void hfs_clear_might_be_dirty_flag(cnode_t *cp); // cnode must be locked static inline __attribute__((pure)) bool hfs_has_rsrc(const cnode_t *cp) { if (cp->c_rsrcfork) return cp->c_rsrcfork->ff_blocks > 0; else return cp->c_datafork && cp->c_blocks > cp->c_datafork->ff_blocks; } #endif /* __APPLE_API_PRIVATE */ #endif /* KERNEL */ #endif /* ! _HFS_CNODE_H_ */