/* Definitions for fileserver helper functions Copyright (C) 1994, 1995, 1996 Free Software Foundation, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #ifndef _HURD_DISKFS #define _HURD_DISKFS #include #include #include #include #include #include #include /* Each user port referring to a file points to one of these (with the aid of the ports library). */ struct protid { struct port_info pi; /* libports info block */ /* User identification */ uid_t *uids, *gids; int nuids, ngids; /* Object this refers to */ struct peropen *po; /* Shared memory I/O information. */ memory_object_t shared_object; struct shared_io *mapped; }; /* One of these is created for each node opened by dir_pathtrans. */ struct peropen { int filepointer; int lock_status; int refcnt; int openstat; mach_port_t dotdotport; /* dotdot from ROOT through this peropen */ struct node *np; }; /* A unique one of these exists for each node currently in use (and possibly for some not currently in use, but with links) in the filesystem. */ struct node { struct node *next, **prevp; struct disknode *dn; struct stat dn_stat; int istranslated; /* Stat has been modified if one of the following four fields is nonzero. Also, if one of the dn_set_?time fields is nonzero, the appropriate dn_stat.st_?time field needs to be updated. */ int dn_set_ctime; int dn_set_atime; int dn_set_mtime; int dn_stat_dirty; struct mutex lock; int references; /* hard references */ int light_references; /* light references */ mach_port_t identity; /* io_identity port */ mach_port_t sockaddr; /* address for S_IFSOCK shortcut */ int owner; struct transbox transbox; struct lock_box userlock; struct conch conch; struct dirmod *dirmod_reqs; off_t allocsize; int cache_id; }; /* Possibly lookup types for diskfs_lookup call */ enum lookup_type { LOOKUP, CREATE, REMOVE, RENAME, }; /* Pending directory modification request */ struct dirmod { mach_port_t port; struct dirmod *next; }; /* Special flag for diskfs_lookup. */ #define SPEC_DOTDOT 0x10000000 /* Declarations of variables the library sets. */ extern mach_port_t diskfs_default_pager; /* send right */ extern mach_port_t diskfs_exec_ctl; /* send right */ extern mach_port_t diskfs_exec; /* send right */ extern auth_t diskfs_auth_server_port; /* send right */ /* The io_identity identity port for the filesystem. */ extern mach_port_t diskfs_fsys_identity; /* The command line diskfs was started, set by the default argument parser. If you don't use it, set this yourself. This is only used for bootstrap file systems, to give the procserver. */ extern char **diskfs_argv; /* When this is a bootstrap filesystem, the command line options passed from the kernel. If not a bootstrap filesystem, it is 0, so it can be used to distinguish between the two cases. */ extern char *diskfs_boot_flags; /* Hold this lock while do fsys level operations. Innocuous users can just hold a reader lock, and anyone who's going to do nasty things that would screw anyone else should hold a writer lock. */ extern struct rwlock diskfs_fsys_lock; extern volatile struct mapped_time_value *diskfs_mtime; /* True iff we should do every operation synchronously. It is the format-specific code's responsibility to keep allocation information permanently in sync if this is set; the rest will be done by format independent code. */ extern int diskfs_synchronous; extern spin_lock_t diskfs_node_refcnt_lock; extern int pager_port_type; struct pager; /* Port classes we manage */ extern struct port_class *diskfs_protid_class; extern struct port_class *diskfs_control_class; extern struct port_class *diskfs_execboot_class; extern struct port_class *diskfs_initboot_class; extern struct port_class *diskfs_shutdown_notification_class; extern struct port_bucket *diskfs_port_bucket; /* Declarations of things the user must or may define. */ /* The user must define this type. This should hold information between calls to diskfs_lookup and diskfs_dir{enter,rewrite,rename} so that those calls work as described below. */ struct dirstat; /* The user must define this variable; it should be the size in bytes of a struct dirstat. */ extern size_t diskfs_dirstat_size; /* The user must define this variable; it is the maximum number of links to any one file. The implementation of dir_rename does not know how to succeed if this is only one; on such formats you need to reimplement dir_rename yourself. */ extern int diskfs_link_max; /* The user must define this variable; it is the maximum number of symlinks to be traversed within a single call to dir_pathtrans. If this is exceeded, dir_pathtrans will return ELOOP. */ extern int diskfs_maxsymlinks; /* The user must define this variable and set it if the filesystem should be readonly. */ extern int diskfs_readonly; /* The user must define this variable. Set this to be the node of root of the filesystem. */ extern struct node *diskfs_root_node; /* The user must define this variable. Set this to the name of the filesystem server. */ extern char *diskfs_server_name; /* The user must define these variables. Set these to be the major, minor, and edit version numbers. */ extern int diskfs_major_version; extern int diskfs_minor_version; extern int diskfs_edit_version; /* The user may define this variable. This should be nonzero iff the filesystem format supports shortcutting symlink translation. The library guarantees that users will not be able to read or write the contents of the node directly, and the library will only do so if the symlink hook functions return EINVAL or are not defined. The library knows that the dn_stat.st_size field is the length of the symlink, even if the hook functions are used. */ int diskfs_shortcut_symlink; /* The user may define this variable. This should be nonzero iff the filesystem format supports shortcutting chrdev translation. */ int diskfs_shortcut_chrdev; /* The user may define this variable. This should be nonzero iff the filesystem format supports shortcutting blkdev translation. */ int diskfs_shortcut_blkdev; /* The user may define this variable. This should be nonzero iff the filesystem format supports shortcutting fifo translation. */ int diskfs_shortcut_fifo; /* The user may define this variable. This should be nonzero iff the filesystem format supports shortcutting ifsock translation. */ int diskfs_shortcut_ifsock; /* The user may define this variable, otherwise it has a default value of 30. diskfs_set_sync_interval is called with this value when the first diskfs thread is started up (in diskfs_spawn_first_threa). */ extern int diskfs_default_sync_interval; /* The user must define this function. Set *STATFSBUF with appropriate values to reflect the current state of the filesystem. */ error_t diskfs_set_statfs (fsys_statfsbuf_t *statfsbuf); /* The user must define this function. Lookup in directory DP (which is locked) the name NAME. TYPE will either be LOOKUP, CREATE, RENAME, or REMOVE. CRED identifies the user making the call. If the name is found, return zero, and (if NP is nonzero) set *NP to point to the node for it, locked. If the name is not found, return ENOENT, and (if NP is nonzero) set *NP to zero. If NP is zero, then the node found must not be locked, even transitorily. Lookups for REMOVE and RENAME (which must often check permissions on the node being found) will always set NP. If DS is nonzero then: For LOOKUP: set *DS to be ignored by diskfs_drop_dirstat. For CREATE: on success, set *DS to be ignored by diskfs_drop_dirstat. on failure, set *DS for a future call to diskfs_direnter. For RENAME: on success, set *DS for a future call to diskfs_dirrewrite. on failure, set *DS for a future call to diskfs_direnter. For REMOVE: on success, set *DS for a future call to diskfs_dirremove. on failure, set *DS to be ignored by diskfs_drop_dirstat. The caller of this function guarantees that if DS is nonzero, then either the appropriate call listed above or diskfs_drop_dirstat will be called with DS before the directory DP is unlocked, and guarantees that no lookup calls will be made on this directory between this lookup and the use (or descruction) of *DS. If you use the library's versions of diskfs_rename_dir, diskfs_clear_directory, and diskfs_init_dir, then lookups for `..' might have the flag SPEC_DOTDOT or'd in. This has the following special meaning: For LOOKUP: DP should be unlocked and its reference dropped before returning. For RENAME and REMOVE: The node being found (*NP) is already held locked, so don't lock it or add a reference to it. (SPEC_DOTDOT will not be given with CREATE.) Return ENOENT if NAME isn't in the directory. Return EAGAIN if NAME refers to the `..' of this filesystem's root. Return EIO if appropriate. */ error_t diskfs_lookup_hard (struct node *dp, char *name, enum lookup_type type, struct node **np, struct dirstat *ds, struct protid *cred); /* The user must define this function. Add NP to directory DP under the name NAME. This will only be called after an unsuccessful call to diskfs_lookup of type CREATE or RENAME; DP has been locked continuously since that call and DS is as that call set it, NP is locked. CRED identifies the user responsible for the call (to be used only to validate directory growth). */ error_t diskfs_direnter_hard (struct node *dp, char *name, struct node *np, struct dirstat *ds, struct protid *cred); /* The user must define this function. This will only be called after a successful call to diskfs_lookup of type RENAME; this call should change the name found in directory DP to point to node NP instead of its previous referent. DP has been locked continuously since the call to diskfs_lookup and DS is as that call set it; NP is locked. */ error_t diskfs_dirrewrite_hard (struct node *dp, struct node *np, struct dirstat *ds); /* The user must define this function. This will only be called after a successful call to diskfs_lookup of type REMOVE; this call should remove the name found from the directory DS. DP has been locked continuously since the call to diskfs_lookup and DS is as that call set it. */ error_t diskfs_dirremove_hard (struct node *dp, struct dirstat *ds); /* The user must define this function. Initialize DS such that diskfs_drop_dirstat will ignore it. */ void diskfs_null_dirstat (struct dirstat *ds); /* The user must define this function. DS has been set by a previous call to diskfs_lookup on directory DP; this function is guaranteed to be called if none of diskfs_dir{enter,rename,rewrite} is, and should free any state retained by a struct dirstat. DP has been locked continuously since the call to diskfs_lookup. */ error_t diskfs_drop_dirstat (struct node *dp, struct dirstat *ds); /* The user must define this function. Return N directory entries starting at ENTRY from locked directory node DP. Fill *DATA with the entries; that pointer currently points to *DATACNT bytes. If it isn't big enough, vm_allocate into *DATA. Set *DATACNT with the total size used. Fill AMT with the number of entries copied. Regardless, never copy more than BUFSIZ bytes. If BUFSIZ is 0, then there is no limit on *DATACNT; if N is -1, then there is no limit on AMT. */ error_t diskfs_get_directs (struct node *dp, int entry, int n, char **data, u_int *datacnt, vm_size_t bufsiz, int *amt); /* The user must define this function. For locked node NP (for which diskfs_node_translated is true) look up the name of its translator. Store the name into newly malloced storage; set *NAMELEN to the total length. */ error_t diskfs_get_translator (struct node *np, char **namep, u_int *namelen); /* The user must define this function. For locked node NP, set the name of the translating program to be NAME, length NAMELEN. CRED identifies the user responsible for the call. */ error_t diskfs_set_translator (struct node *np, char *name, u_int namelen, struct protid *cred); /* The user must define this function. Truncate locked node NP to be SIZE bytes long. (If NP is already less than or equal to SIZE bytes long, do nothing.) If this is a symlink (and diskfs_shortcut_symlink is set) then this should clear the symlink, even if diskfs_create_symlink_hook stores the link target elsewhere. */ error_t diskfs_truncate (struct node *np, off_t size); /* The user must define this function. Grow the disk allocated to locked node NP to be at least SIZE bytes, and set NP->allocsize to the actual allocated size. (If the allocated size is already SIZE bytes, do nothing.) CRED identifies the user responsible for the call. */ error_t diskfs_grow (struct node *np, off_t size, struct protid *cred); /* The user must define this function. Write to disk (synchronously iff WAIT is nonzero) from format-specific buffers any non-paged metadata. If CLEAN is nonzero, then after this is written the filesystem will be absolutely clean, and the non-paged metadata can so indicate. */ void diskfs_set_hypermetadata (int wait, int clean); /* The user must define this function. Allocate a new node to be of mode MODE in locked directory DP (don't actually set the mode or modify the dir, that will be done by the caller); the user responsible for the request can be identified with CRED. Set *NP to be the newly allocated node. */ error_t diskfs_alloc_node (struct node *dp, mode_t mode, struct node **np); /* Free node NP; the on disk copy has already been synced with diskfs_node_update (where NP->dn_stat.st_mode was 0). It's mode used to be MODE. */ void diskfs_free_node (struct node *np, mode_t mode); /* Node NP has no more references; free local state, including *NP if it isn't to be retained. diskfs_node_refcnt_lock is held. */ void diskfs_node_norefs (struct node *np); /* The user must define this function. Node NP has some light references, but has just lost its last hard references. Take steps so that if any light references can be freed, they are. NP is locked as is the pager refcount lock. This function will be called after diskfs_lost_hardrefs. */ void diskfs_try_dropping_softrefs (struct node *np); /* The user must define this funcction. Node NP has some light references but has just lost its last hard reference. NP is locked. */ void diskfs_lost_hardrefs (struct node *np); /* The user must define this function. Node NP has just acquired a hard reference where it had none previously. It is thus now OK again to have light references without real users. NP is locked. */ void diskfs_new_hardrefs (struct node *np); /* The user must define this function. Return non-zero if locked directory DP is empty. If the user does not redefine diskfs_clear_directory and diskfs_init_directory, then `empty' means `possesses entries labelled . and .. only'. CRED identifies the user making the call (if this user can't search the directory, then this routine should fail). */ int diskfs_dirempty (struct node *dp, struct protid *cred); /* The user must define this function. Sync the info in NP->dn_stat and any associated format-specific information to disk. If WAIT is true, then return only after the physicial media has been completely updated. */ void diskfs_write_disknode (struct node *np, int wait); /* The user must define this function. Sync the file contents and all associated meta data of file NP to disk (generally this will involve calling diskfs_node_update for much of the metadata). If WAIT is true, then return only after the physical media has been completely updated. */ void diskfs_file_update (struct node *np, int wait); /* The user must define this function. For each active node, call FUN. The node is to be locked around the call to FUN. If FUN returns non-zero for any node, then immediately stop, and return that value. */ error_t diskfs_node_iterate (error_t (*fun)(struct node *)); /* The user must define this function. Sync all the pagers and any data belonging on disk except for the hypermetadata. If WAIT is true, then return only after the physicial media has been completely updated. */ void diskfs_sync_everything (int wait); /* Shutdown all pagers; this is done when the filesystem is exiting and is irreversable. */ void diskfs_shutdown_pager (); /* The user must define this function. Return a memory object port (send right) for the file contents of NP. PROT is the maximum allowable access. */ mach_port_t diskfs_get_filemap (struct node *np, vm_prot_t prot); /* The user must define this function. Return true if there are pager ports exported that might be in use by users. If this returns false, then further pager creation is also blocked. */ int diskfs_pager_users (); /* Return the bitwise or of the maximum prot parameter (the second arg to diskfs_get_filemap) for all active user pagers. */ vm_prot_t diskfs_max_user_pager_prot (); /* The user must define this function. Return a `struct pager *' suitable for use as an argument to diskfs_register_memory_fault_area that refers to the pager returned by diskfs_get_filemap for node NP. NP is locked. */ struct pager *diskfs_get_filemap_pager_struct (struct node *np); /* The user may define this function. It is called when the disk has been changed from read-only to read-write mode or vice-versa. READONLY is the new state (which is also reflected in DISKFS_READONLY). This function is also called during initial startup if the filesystem is to be writable. */ void diskfs_readonly_changed (int readonly); /* The user must define this function. It must invalidate all cached global state, and re-read it as necessary from disk, without writing anything. It is always called with DISKFS_READONLY true. diskfs_node_reload is subsequently called on all active nodes, so this call needn't re-read any node-specific data. */ error_t diskfs_reload_global_state (); /* The user must define this function. It must re-read all data specific to NODE from disk, without writing anything. It is always called with DISKFS_READONLY true. */ error_t diskfs_node_reload (struct node *node); /* If this function is nonzero (and diskfs_shortcut_symlink is set) it is called to set a symlink. If it returns EINVAL or isn't set, then the normal method (writing the contents into the file data) is used. If it returns any other error, it is returned to the user. */ error_t (*diskfs_create_symlink_hook)(struct node *np, char *target); /* If this function is nonzero (and diskfs_shortcut_symlink is set) it is called to read the contents of a symlink. If it returns EINVAL or isn't set, then the normal method (reading from the file data) is used. If it returns any other error, it is returned to the user. */ error_t (*diskfs_read_symlink_hook)(struct node *np, char *target); /* The library exports the following functions for general use */ /* Returns the name and a send right for the mach device on which the file NAME is stored, and returns it in DEV_NAME (which is malloced) and PORT. Other values returned are START, the first valid offset, SIZE, the the number of blocks after START, and BLOCK_SIZE, the units in which the device is addressed. The device is opened for reading, and if the diskfs global variable DISKFS_READONLY is false, writing. */ error_t diskfs_get_file_device (char *name, char **dev_name, mach_port_t *port, off_t *start, off_t *size, size_t *block_size); /* Returns a send right to for the mach device called NAME, and returns it in PORT. Other values returned are START, the first valid offset, SIZE, the the number of blocks after START, and BLOCK_SIZE, the units in which the device is addressed. The device is opened for reading, and if the diskfs global variable DISKFS_READ_ONLY is false, writing. If NAME cannot be opened and this is a bootstrap filesystem, the user will be prompted for new names until a valid one is found. */ error_t diskfs_get_mach_device (char *name, mach_port_t *port, off_t *start, off_t *size, size_t *block_size); /* Call this after arguments have been parsed to initialize the library. You must call this before calling any other diskfs functions, and after parsing diskfs options. */ error_t diskfs_init_diskfs (void); /* Call this once the filesystem is fully initialized, to advertise the new filesystem control port to our parent filesystem. If BOOTSTRAP is set, the diskfs will call fsys_startup on that port as appropriate and return the REALNODE returned in that call; otherwise we return MACH_PORT_NULL. FLAGS specifies how to open REALNODE (from the O_* set). */ mach_port_t diskfs_startup_diskfs (mach_port_t bootstrap, int flags); /* Call this after all format-specific initialization is done (except for setting diskfs_root_node); at this point the pagers should be ready to go. */ void diskfs_spawn_first_thread (void); /* Once diskfs_root_node is set, call this if we are a bootstrap filesystem. If you call this, then the library will call diskfs_init_completed once it has a valid proc and auth port. */ void diskfs_start_bootstrap (); /* Node NP now has no more references; clean all state. The _diskfs_node_refcnt_lock must be held, and will be released upon return. NP must be locked. */ void diskfs_drop_node (struct node *np); /* Set on disk fields from NP->dn_stat; update ctime, atime, and mtime if necessary. If WAIT is true, then return only after the physical media has been completely updated. */ void diskfs_node_update (struct node *np, int wait); /* Add a hard reference to a node. If there were no hard references previously, then the node cannot be locked (because you must hold a hard reference to hold the lock). */ extern inline void diskfs_nref (struct node *np) { int new_hardref; spin_lock (&diskfs_node_refcnt_lock); np->references++; new_hardref = (np->references == 1); spin_unlock (&diskfs_node_refcnt_lock); if (new_hardref) { mutex_lock (&np->lock); diskfs_new_hardrefs (np); mutex_unlock (&np->lock); } } /* Unlock node NP and release a hard reference; if this is the last hard reference and there are no links to the file then request soft references to be dropped. */ extern inline void diskfs_nput (struct node *np) { int tried_drop_softrefs = 0; loop: spin_lock (&diskfs_node_refcnt_lock); assert (np->references); np->references--; if (np->references + np->light_references == 0) diskfs_drop_node (np); else if (np->references == 0 && !tried_drop_softrefs) { spin_unlock (&diskfs_node_refcnt_lock); diskfs_lost_hardrefs (np); if (!np->dn_stat.st_nlink) { /* There are no links. If there are soft references that can be dropped, we can't let them postpone deallocation. So attempt to drop them. But that's a user-supplied routine, which might result in further recursive calls to the ref-counting system. So we have to reacquire our reference around the call to forestall disaster. */ spin_lock (&diskfs_node_refcnt_lock); np->references++; spin_unlock (&diskfs_node_refcnt_lock); diskfs_try_dropping_softrefs (np); /* But there's no value in looping forever in this routine; only try to drop soft refs once. */ tried_drop_softrefs = 1; /* Now we can drop the reference back... */ goto loop; } mutex_unlock (&np->lock); } else { spin_unlock (&diskfs_node_refcnt_lock); mutex_unlock (&np->lock); } } /* Release a hard reference on NP. If NP is locked by anyone, then this cannot be the last hard reference (because you must hold a hard reference in order to hold the lock). If this is the last hard reference and there are no links, then request soft references to be dropped. */ extern inline void diskfs_nrele (struct node *np) { int tried_drop_softrefs = 0; loop: spin_lock (&diskfs_node_refcnt_lock); assert (np->references); np->references--; if (np->references + np->light_references == 0) { mutex_lock (&np->lock); diskfs_drop_node (np); } else if (np->references == 0) { mutex_lock (&np->lock); spin_unlock (&diskfs_node_refcnt_lock); diskfs_lost_hardrefs (np); if (!np->dn_stat.st_nlink && !tried_drop_softrefs) { /* Same issue here as in nput; see that for explanation */ spin_lock (&diskfs_node_refcnt_lock); np->references++; spin_unlock (&diskfs_node_refcnt_lock); diskfs_try_dropping_softrefs (np); tried_drop_softrefs = 1; /* Now we can drop the reference back... */ mutex_unlock (&np->lock); goto loop; } mutex_unlock (&np->lock); } else spin_unlock (&diskfs_node_refcnt_lock); } /* Add a light reference to a node. */ extern inline void diskfs_nref_light (struct node *np) { spin_lock (&diskfs_node_refcnt_lock); np->light_references++; spin_unlock (&diskfs_node_refcnt_lock); } /* Unlock node NP and release a light reference */ extern inline void diskfs_nput_light (struct node *np) { spin_lock (&diskfs_node_refcnt_lock); assert (np->light_references); np->light_references--; if (np->references + np->light_references == 0) diskfs_drop_node (np); else { spin_unlock (&diskfs_node_refcnt_lock); mutex_unlock (&np->lock); } } /* Release a light reference on NP. If NP is locked by anyone, then this cannot be the last reference (because you must hold a hard reference in order to hold the lock). */ extern inline void diskfs_nrele_light (struct node *np) { spin_lock (&diskfs_node_refcnt_lock); assert (np->light_references); np->light_references--; if (np->references + np->light_references == 0) { mutex_lock (&np->lock); diskfs_drop_node (np); } else spin_unlock (&diskfs_node_refcnt_lock); } /* Return nonzero iff the user identified by CRED has uid UID. */ extern inline int diskfs_isuid (uid_t uid, struct protid *cred) { int i; for (i = 0; i < cred->nuids; i++) if (cred->uids[i] == uid) return 1; return 0; } /* Return nonzero iff the user identified by CRED has group GRP. */ extern inline int diskfs_groupmember (uid_t grp, struct protid *cred) { int i; for (i = 0; i < cred->ngids; i++) if (cred->gids[i] == grp) return 1; return 0; } /* Check to see if the user identified by CRED is permitted to do owner-only operations on node NP; if so, return 0; if not, return EPERM. */ extern inline error_t diskfs_isowner (struct node *np, struct protid *cred) { /* Permitted if the user is the owner, superuser, or if the user is in the group of the file and has the group ID as their user ID. (This last is colloquially known as `group leader'.) */ if (diskfs_isuid (np->dn_stat.st_uid, cred) || diskfs_isuid (0, cred) || (diskfs_groupmember (np->dn_stat.st_gid, cred) && diskfs_isuid (np->dn_stat.st_gid, cred))) return 0; else return EPERM; } /* Check to see is the user identified by CRED is permitted to do operation OP on node NP. Op is one of S_IREAD, S_IWRITE, or S_IEXEC. Return 0 if the operation is permitted and EACCES if not. */ extern inline error_t diskfs_access (struct node *np, int op, struct protid *cred) { int gotit; if (diskfs_isuid (0, cred)) gotit = 1; else if (cred->nuids == 0 && (np->dn_stat.st_mode & S_IUSEUNK)) gotit = np->dn_stat.st_mode & (op << S_IUNKSHIFT); else if (!diskfs_isowner (np, cred)) gotit = np->dn_stat.st_mode & op; else if (diskfs_groupmember (np->dn_stat.st_gid, cred)) gotit = np->dn_stat.st_mode & (op >> 3); else gotit = np->dn_stat.st_mode & (op >> 6); return gotit ? 0 : EACCES; } /* Check to see if the user identified by CRED is allowed to modify directory DP with respect to existing file NP. This is the same as diskfs_access (dp, S_IWRITE, cred), except when the directory has the sticky bit set. (If there is no existing file NP, then 0 can be passed.) */ extern inline error_t diskfs_checkdirmod (struct node *dp, struct node *np, struct protid *cred) { error_t err; /* The user must be able to write the directory, but if the directory is sticky, then the user must also be either the owner of the directory or the file. */ err = diskfs_access (dp, S_IWRITE, cred); if (err) return err; if ((dp->dn_stat.st_mode & S_ISVTX) && np && !diskfs_isuid (0, cred) && !diskfs_isowner (dp, cred) && !diskfs_isowner (np, cred)) return EACCES; return 0; } /* Reading and writing of files. this is called by other filesystem routines and handles extension of files automatically. NP is the node to be read or written, and must be locked. DATA will be written or filled. OFF identifies where in thi fel the I/O is to take place (-1 is not allowed). AMT is the size of DATA and tells how much to copy. DIR is 1 for writing and 0 for reading. CRED is the user doing the access (only used to validate attempted file extension). For reads, *AMTREAD is filled with the amount actually read. */ error_t diskfs_node_rdwr (struct node *np, char *data, off_t off, size_t amt, int dir, struct protid *cred, size_t *amtread); /* Send notifications to users who have requested them with dir_notice_changes for directory DP. The type of modification and affected name are TYPE and NAME respectively. This should be called by diskfs_direnter, diskfs_dirremove, and diskfs_dirrewrite, and anything else that changes the directory, after the change is fully completed. */ void diskfs_notice_dirchange (struct node *dp, enum dir_changed_type type, char *name); /* Create a new node structure with DS as its physical disknode. The new node will have one hard reference and no light references. */ struct node *diskfs_make_node (struct disknode *dn); /* The library also exports the following functions; they are not generally useful unless you are redefining other functions the library provides. */ /* Lookup in directory DP (which is locked) the name NAME. TYPE will either be LOOKUP, CREATE, RENAME, or REMOVE. CRED identifies the user making the call. If the name is found, return zero, and (if NP is nonzero) set *NP to point to the node for it, locked. If the name is not found, return ENOENT, and (if NP is nonzero) set *NP to zero. If NP is zero, then the node found must not be locked, even transitorily. Lookups for REMOVE and RENAME (which must often check permissions on the node being found) will always set NP. If DS is nonzero then: For LOOKUP: set *DS to be ignored by diskfs_drop_dirstat. For CREATE: on success, set *DS to be ignored by diskfs_drop_dirstat. on failure, set *DS for a future call to diskfs_direnter. For RENAME: on success, set *DS for a future call to diskfs_dirrewrite. on failure, set *DS for a future call to diskfs_direnter. For REMOVE: on success, set *DS for a future call to diskfs_dirremove. on failure, set *DS to be ignored by diskfs_drop_dirstat. The caller of this function guarantees that if DS is nonzero, then either the appropriate call listed above or diskfs_drop_dirstat will be called with DS before the directory DP is unlocked, and guarantees that no lookup calls will be made on this directory between this lookup and the use (or descruction) of *DS. If you use the library's versions of diskfs_rename_dir, diskfs_clear_directory, and diskfs_init_dir, then lookups for `..' might have the flag SPEC_DOTDOT or'd in. This has the following special meaning: For LOOKUP: DP should be unlocked and its reference dropped before returning. For RENAME and REMOVE: The node being found (*NP) is already held locked, so don't lock it or add a reference to it. (SPEC_DOTDOT will not be given with CREATE.) Return ENOTDIR if DP is not a directory. Return EACCES if CRED isn't allowed to search DP. Return EACCES if completing the operation will require writing the directory and diskfs_checkdirmod won't allow the modification. Return ENOENT if NAME isn't in the directory. Return EAGAIN if NAME refers to the `..' of this filesystem's root. Return EIO if appropriate. This function is a wrapper for diskfs_lookup_hard. */ error_t diskfs_lookup (struct node *dp, char *name, enum lookup_type type, struct node **np, struct dirstat *ds, struct protid *cred); /* Add NP to directory DP under the name NAME. This will only be called after an unsuccessful call to diskfs_lookup of type CREATE or RENAME; DP has been locked continuously since that call and DS is as that call set it, NP is locked. CRED identifies the user responsible for the call (to be used only to validate directory growth). This function is a wrapper for diskfs_direnter_hard. */ error_t diskfs_direnter (struct node *dp, char *name, struct node *np, struct dirstat *ds, struct protid *cred); /* This will only be called after a successful call to diskfs_lookup of type RENAME; this call should change the name found in directory DP to point to node NP instead of its previous referent, OLDNP. DP has been locked continuously since the call to diskfs_lookup and DS is as that call set it; NP is locked. This routine should call diskfs_notice_dirchange if DP->dirmod_reqs is nonzero. NAME is the name of OLDNP inside DP; it is this reference which is being rewritten. This function is a wrapper for diskfs_dirrewrite_hard. */ error_t diskfs_dirrewrite (struct node *dp, struct node *oldnp, struct node *np, char *name, struct dirstat *ds); /* This will only be called after a successful call to diskfs_lookup of type REMOVE; this call should remove the name found from the directory DS. DP has been locked continuously since the call to diskfs_lookup and DS is as that call set it. This routine should call diskfs_notice_dirchange if DP->dirmod_reqs is nonzero. This function is a wrapper for diskfs_dirremove_hard. The entry being removed has name NAME and refers to NP. */ error_t diskfs_dirremove (struct node *dp, struct node *np, char *name, struct dirstat *ds); /* Return the node corresponding to CACHE_ID in *NPP. */ error_t diskfs_cached_lookup (int cache_id, struct node **npp); /* Create a new node. Give it MODE; if that includes IFDIR, also initialize `.' and `..' in the new directory. Return the node in NPP. CRED identifies the user responsible for the call. If NAME is nonzero, then link the new node into DIR with name NAME; DS is the result of a prior diskfs_lookup for creation (and DIR has been held locked since). DIR must always be provided as at least a hint for disk allocation strategies. */ error_t diskfs_create_node (struct node *dir, char *name, mode_t mode, struct node **newnode, struct protid *cred, struct dirstat *ds); /* Create and return a protid for an existing peropen PO in CRED. The uid set is UID (length NUIDS); the gid set is GID (length NGIDS). The node PO->np must be locked. */ error_t diskfs_create_protid (struct peropen *po, uid_t *uids, int nuids, uid_t *gids, int ngids, struct protid **cred); /* Build and return in CRED a protid which has no user identification, for peropen PO. The node PO->np must be locked. */ error_t diskfs_start_protid (struct peropen *po, struct protid **cred); /* Finish building protid CRED started with diskfs_start_protid; the uid set is UID (length NUIDS); the gid set is GID (length NGIDS). */ void diskfs_finish_protid (struct protid *cred, uid_t *uids, int nuids, gid_t *gids, int nguds); /* Create and return a new peropen structure on node NP with open flags FLAGS. */ struct peropen *diskfs_make_peropen (struct node *np, int flags, mach_port_t dotdotnode); /* Called when a protid CRED has no more references. (Because references\ to protids are maintained by the port management library, this is installed in the clean routines list.) The ports library will free the structure for us. */ void diskfs_protid_rele (void *arg); /* Decrement the reference count on a peropen structure. */ void diskfs_release_peropen (struct peropen *po); /* Node NP has just been found in DIR with NAME. If NP is null, that means that this name has been confirmed as absent in the directory. */ void diskfs_enter_lookup_cache (struct node *dir, struct node *np, char *name); /* Purge all references in the cache to NP as a node inside directory DP. */ void diskfs_purge_lookup_cache (struct node *dp, struct node *np); /* Scan the cache looking for NAME inside DIR. If we don't know anything entry at all, then return 0. If the entry is confirmed to not exist, then return -1. Otherwise, return NP for the entry, with a newly allocated reference. */ struct node *diskfs_check_lookup_cache (struct node *dir, char *name); /* Rename directory node FNP (whose parent is FDP, and which has name FROMNAME in that directory) to have name TONAME inside directory TDP. None of these nodes are locked, and none should be locked upon return. This routine is serialized, so it doesn't have to be reentrant. Directories will never be renamed except by this routine. FROMCRED and TOCRED are the users responsible for FDP/FNP and TDP respectively. This routine assumes the usual convention where `.' and `..' are represented by ordinary links; if that is not true for your format, you have to redefine this function.*/ error_t diskfs_rename_dir (struct node *fdp, struct node *fnp, char *fromname, struct node *tdp, char *toname, struct protid *fromcred, struct protid *tocred); /* Clear the `.' and `..' entries from directory DP. Its parent is PDP, and the user responsible for this is identified by CRED. Both directories must be locked. This routine assumes the usual convention where `.' and `..' are represented by ordinary links; if that is not true for your format, you have to redefine this function. */ error_t diskfs_clear_directory (struct node *dp, struct node *pdp, struct protid *cred); /* Locked node DP is a new directory; add whatever links are necessary to give it structure; its parent is the (locked) node PDP. This routine may not call diskfs_lookup on PDP. The new directory must be clear within the meaning of diskfs_dirempty. This routine assumes the usual convention where `.' and `..' are represented by ordinary links; if that is not true for your format, you have to redefine this function. CRED identifies the user making the call. */ error_t diskfs_init_dir (struct node *dp, struct node *pdp, struct protid *cred); /* If NP->dn_set_ctime is set, then modify NP->dn_stat.st_ctime appropriately; do the analogous operation for atime and mtime as well. */ void diskfs_set_node_times (struct node *np); /* Shutdown the filesystem; flags are as for fsys_shutdown. */ error_t diskfs_shutdown (int flags); /* Change an active filesystem between read-only and writable modes, setting the global variable DISKFS_READONLY to reflect the current mode. If an error is returned, nothing will have changed. DISKFS_FSYS_LOCK should be held while calling this routine. */ error_t diskfs_set_readonly (int readonly); /* Re-read all incore data structures from disk. This will only work if DISKFS_READONLY is true. DISKFS_FSYS_LOCK should be held while calling this routine. */ error_t diskfs_remount (); /* Called by S_fsys_startup for execserver bootstrap. The execserver is able to function without a real node, hence this fraud. Arguments are all as for fsys_startup in . */ error_t diskfs_execboot_fsys_startup (mach_port_t port, int flags, mach_port_t ctl, mach_port_t *real, mach_msg_type_name_t *realpoly); /* Establish a thread to sync the filesystem every INTERVAL seconds, or never, if INTERVAL is zero. If an error occurs creating the thread, it is returned, otherwise 0. Subsequent calls will create a new thread and (eventually) get rid of the old one; the old thread won't do any more syncs, regardless. */ error_t diskfs_set_sync_interval (int interval); /* Parse and execute the runtime options in ARGZ & ARGZ_LEN. EINVAL is returned if some option is unrecognized. The default definition of this routine will parse them using DISKFS_RUNTIME_ARGP, which see. */ error_t diskfs_set_options (char *argz, size_t argz_len); /* Return an argz string describing the current options. Fill *ARGZ with a pointer to newly malloced storage holding the list and *LEN to the length of that storage. The default definition of this routine simply initializes *ARGZ and *ARGZ_LEN to 0 and calls diskfs_append_std_options. */ error_t diskfs_get_options (char **argz, unsigned *argz_len); /* If this is defined or set to an argp structure, it will be used by the default diskfs_set_options to handle runtime option parsing. The default definition is initialized to a pointer to DISKFS_STD_RUNTIME_ARGP. */ extern struct argp *diskfs_runtime_argp; /* An argp for the standard diskfs runtime options. The default definition of DISKFS_RUNTIME_ARGP points to this, although if the user redefines that, he may chain this onto his argp as well. */ extern const struct argp diskfs_std_runtime_argp; /* An argp structure for the standard diskfs command line arguments. The user may call argp_parse on this to parse the command line, chain it onto the end of his own argp structure, or ignore it completely. */ extern const struct argp diskfs_std_startup_argp; /* *Appends* to ARGZ & ARGZ_LEN '\0'-separated options describing the standard diskfs option state (note that unlike diskfs_get_options, ARGZ & ARGZ_LEN must already have a sane value). */ error_t diskfs_append_std_options (char **argz, unsigned *argz_len); /* Demultiplex incoming messages on ports created by libdiskfs. */ int diskfs_demuxer (mach_msg_header_t *, mach_msg_header_t *); /* The diskfs library provides functions to demultiplex the fs, io, fsys, interrupt, and notify interfaces. All the server routines have the prefix `diskfs_S_'; `in' arguments of type file_t or io_t appear as `struct protid *' to the stub. */ /* The following are optional convenience routines and global variable, which can be used by any user program that uses a mach device to hold the underlying filesystem. */ /* A pointer to an argp structure for the standard diskfs command line arguments, that also parses a device argument. The user may call argp_parse on this to parse the command line, chain it onto the end of his own argp structure, or ignore it completely. */ extern const struct argp diskfs_std_device_startup_argp; /* The following two are set by the preceding argument parser: */ /* The device specifier given on the command line. */ extern char *diskfs_device_arg; /* True if --machdev was specified, meaning that DISKFS_DEVICE_ARG names a mach device and not a filesystem device node. */ extern int diskfs_use_mach_device; /* Uses the values of DISKFS_DEVICE_ARG and DISKFS_USE_MACH_DEVICE, and attempts to open the device and set the values of DISKFS_DEVICE, DISKFS_DEVICE_NAME, DISKFS_DEVICE_START, DISKFS_DEVICE_SIZE, and DISKFS_DEVICE_BLOCK_SIZE. */ extern error_t diskfs_device_open (); /* A mach device port for the device we're using. */ extern mach_port_t diskfs_device; /* The mach device name of DISKFS_DEVICE. May be 0 if unknown. */ extern char *diskfs_device_name; /* The first valid block of DISKFS_DEVICE, in units of DISKFS_DEVICE_BLOCK_SIZE. */ extern off_t diskfs_device_start; /* The usable size of DISKFS_DEVICE, in units of DISKFS_DEVICE_BLOCK_SIZE. */ extern off_t diskfs_device_size; /* The unit of addressing for DISKFS_DEVICE. */ extern unsigned diskfs_device_block_size; /* Some handy calculations based on DISKFS_DEVICE_BLOCK_SIZE. */ /* Log base 2 of DEVICE_BLOCK_SIZE, or 0 if it's not a power of two. */ extern unsigned diskfs_log2_device_block_size; /* Log base 2 of the number of device blocks in a vm page. This number is only valid if DISKFS_LOG2_DEVICE_BLOCK_SIZE is not 0. */ extern unsigned diskfs_log2_device_blocks_per_page; /* Write disk block ADDR with DATA of LEN bytes to DISKFS_DEVICE, waiting for completion. ADDR is offset by DISKFS_DEVICE_START. If an error occurs, EIO is returned. */ error_t diskfs_device_write_sync (off_t addr, vm_address_t data, size_t len); /* Read disk block ADDR from DISKFS_DEVICE; put the address of the data in DATA; read LEN bytes. Always *DATA should be a full page no matter what. ADDR is offset by DISKFS_DEVICE_START. If an error occurs, EIO is returned. */ error_t diskfs_device_read_sync (off_t addr, vm_address_t *data, size_t len); /* Make errors go somewhere reasonable. */ void diskfs_console_stdio (); #endif /* hurd/diskfs.h */