- Intorduce and use a message type for VFS_GETDENTS, VFS_READ,
VFS_WRITE.
- Some cleanup to related functions where vir_bytes are replaced (and
casted to/from, in parameter definition and local variables as well.
This allow to see more clearly which function receives unsafe
(pointer) values, or at least values which are not supposed to be
valid in the address space of VFS. The current patch does so only
for the minimal amount of functions which are concerned with the
introduction of the new message type.
Change-Id: I0cdca97409c4016d02fae067b48bf55d37572c5c
- introduce new call numbers, names, and field aliases;
- initialize request messages to zero for all ABI calls;
- format callnr.h in the same way as com.h;
- redo call tables in both servers;
- remove param.h namespace pollution in the servers;
- make brk(2) go to VM directly, rather than through PM;
- remove obsolete BRK, UTIME, and WAIT calls;
- clean up path copying routine in VFS;
- move remaining system calls from libminlib to libc;
- correct some errno-related mistakes in libc routines.
Change-Id: I2d8ec5d061cd7e0b30c51ffd77aa72ebf84e2565
There is no need to pass pointers around when there is a structure
available that already stores other similar state, such as m_in.
Change-Id: I3164c5c55c71f443688103d1f0756c086eb05974
. add all sys/sys headers not already present to help compiling
. take netbsd dirent.h and struct dirent; main result is
introducing d_type and d_namlen that have to be set by getdents()
in all FS code implementing it
. d_off is gone
. alignment of the struct has become 8 bytes instead of 4
. remove _MAX_BLOCK_SIZE, _MIN_BLOCK_SIZE, _STATIC_BLOCK_SIZE
. libminlib: cleanup unused yet duplicate code
. mfs: throw out the long-broken v1, v2 support
. new test for dirent contents filled by getdents()
Change-Id: I1459755c7ba5e5d1c9396d3a587ce6e63ddc283e
This single function allows copying file descriptors from and to
processes, and closing a previously copied remote file descriptor.
This function replaces the five FD-related UDS backcalls. While it
limits the total number of in-flight file descriptors to OPEN_MAX,
this change greatly improves crash recovery support of UDS, since all
in-flight file descriptors will be closed instead of keeping them
open indefinitely (causing VFS to crash on system shutdown). With the
new copyfd call, UDS becomes simpler, and the concept of filps is no
longer exposed outside of VFS.
This patch also moves the checkperms(2) stub into libminlib, thus
fully abstracting away message details of VFS communication from UDS.
Change-Id: Idd32ad390a566143c8ef66955e5ae2c221cff966
This commit separates the low-level keyboard driver from TTY, putting
it in a separate driver (PCKBD). The commit also separates management
of raw input devices from TTY, and puts it in a separate server
(INPUT). All keyboard and mouse input from hardware is sent by drivers
to the INPUT server, which either sends it to a process that has
opened a raw input device, or otherwise forwards it to TTY for
standard processing.
Design by Dirk Vogt. Prototype by Uli Kastlunger.
Additional changes made to the prototype:
- the event communication is now based on USB HID codes; all input
drivers have to use USB codes to describe events;
- all TTY keymaps have been converted to USB format, with the effect
that a single keymap covers all keys; there is no (static) escaped
keymap anymore;
- further keymap tweaks now allow remapping of literally all keys;
- input device renumbering and protocol rewrite;
- INPUT server rewrite, with added support for cancel and select;
- PCKBD reimplementation, including PC/AT-to-USB translation;
- support for manipulating keyboard LEDs has been added;
- keyboard and mouse multiplexer devices have been added to INPUT,
primarily so that an X server need only open two devices;
- a new "libinputdriver" library abstracts away protocol details from
input drivers, and should be used by all future input drivers;
- both INPUT and PCKBD can be restarted;
- TTY is now scheduled by KERNEL, so that it won't be punished for
running a lot; without this, simply running "yes" on the console
kills the system;
- the KIOCBELL IOCTL has been moved to /dev/console;
- support for the SCANCODES termios setting has been removed;
- obsolete keymap compression has been removed;
- the obsolete Olivetti M24 keymap has been removed.
Change-Id: I3a672fb8c4fd566734e4b46d3994b4b7fc96d578
- prefix them with VFS_ as they are going to VFS;
- give these calls normal call numbers;
- give them their own set of message field aliases;
- also make do_mapdriver a regular call.
Change-Id: I2140439f288b06d699a1f65438bd8306509b259e
The main purpose of this patch is to fix handling of unpause calls
from PM while another call is ongoing. The solution to this problem
sparked a full revision of the threading model, consisting of a large
number of related changes:
- all active worker threads are now always associated with a process,
and every process has at most one active thread working for it;
- the process lock is always held by a process's worker thread;
- a process can now have both normal work and postponed PM work
associated to it;
- timer expiry and non-postponed PM work is done from the main thread;
- filp garbage collection is done from a thread associated with VFS;
- reboot calls from PM are now done from a thread associated with PM;
- the DS events handler is protected from starting multiple threads;
- support for a system worker thread has been removed;
- the deadlock recovery thread has been replaced by a parameter to the
worker_start() function; the number of worker threads has
consequently been increased by one;
- saving and restoring of global but per-thread variables is now
centralized in worker_suspend() and worker_resume(); err_code is now
saved and restored in all cases;
- the concept of jobs has been removed, and job_m_in now points to a
message stored in the worker thread structure instead;
- the PM lock has been removed;
- the separate exec lock has been replaced by a lock on the VM
process, which was already being locked for exec calls anyway;
- PM_UNPAUSE is now processed as a postponed PM request, from a thread
associated with the target process;
- the FP_DROP_WORK flag has been removed, since it is no longer more
than just an optimization and only applied to processes operating on
a pipe when getting killed;
- assignment to "fp" now takes place only when obtaining new work in
the main thread or a worker thread, when resuming execution of a
thread, and in the special case of exiting processes during reboot;
- there are no longer special cases where the yield() call is used to
force a thread to run.
Change-Id: I7a97b9b95c2450454a9b5318dfa0e6150d4e6858
The main motivation for this change is that only Loris supports
multithreading, and Loris supports dynamic thread allocation, so the
number of supported threads can be implemented as a bit flag (i.e.,
either 1 or "at least as many as VFS has"). The ABI break obviates the
need to support file system versioning at this time, and several
other aspects are better implemented as flags as well. Other changes:
- replace peek/bpeek test upon mount with FS flag as well;
- mark libsffs as 64-bit file size capable;
- remove old (3.2.1) getdents support.
Change-Id: I313eace9c50ed816656c31cd47d969033d952a03
m_out is shared between threads as the reply message, and it can happen
results get overwritten by another thread before the reply is sent. This
change
. makes m_out local to the message handling function,
declared on the stack of the caller
. forces callers of reply() to give it a message, or
declare the reply message has no significant fields except
for the return code by calling replycode()
Change-Id: Id06300083a63c72c00f34f86a5c7d96e4bbdf9f6
When you provided a string with junk after the terminating nul to a
UNIX domain socket and used bind(2), the canonical path function would
not properly terminate the new string. This caused VFS to return
ENAMETOOLONG on an otherwise valid path name.
Test case is added to test56.
Change-Id: I883b6be23d9e4ea13c3cee28cbb3726343df037f
This patch uses stricter locking for REQ_LINK, REQ_MKDIR, REQ_MKNOD,
REQ_RENAME, REQ_RMDIR, REQ_SLINK and REQ_UNLINK. For all requests, VFS
locks the directory in which we add or remove an inode with VNODE_WRITE.
I.e., the operations have exclusive access to that directory.
Furthermore, REQ_CHOWN, REQ_CHMOD, and REQ_FTRUNC now lock the vmnt
VMNT_READ; VMNT_WRITE was unnecessary.
.sync and fsync used unnecessarily restrictive locking type
.fsync violated locking order by obtaining a vmnt lock after a filp lock
.fsync contained a TOCTOU bug
.new_node violated locking rules (didn't upgrade lock upon file creation)
.do_pipe used unnecessarily restrictive locking type
.always lock pipes exclusively; even a read operation might require to do
a write on a vnode object (update pipe size)
.when opening a file with O_TRUNC, upgrade vnode lock when truncating
.utime used unnecessarily restrictive locking type
.path parsing:
.always acquire VMNT_WRITE or VMNT_EXCL on vmnt and downgrade to
VMNT_READ if that was what was actually requested. This prevents the
following deadlock scenario:
thread A:
lock_vmnt(vmp, TLL_READSER);
lock_vnode(vp, TLL_READSER);
upgrade_vmnt_lock(vmp, TLL_WRITE);
thread B:
lock_vmnt(vmp, TLL_READ);
lock_vnode(vp, TLL_READSER);
thread A will be stuck in upgrade_vmnt_lock and thread B is stuck in
lock_vnode. This happens when, for example, thread A tries create a
new node (open.c:new_node) and thread B tries to do eat_path to
change dir (stadir.c:do_chdir). When the path is being resolved, a
vnode is always locked with VNODE_OPCL (TLL_READSER) and then
downgraded to VNODE_READ if read-only is actually requested. Thread
A locks the vmnt with VMNT_WRITE (TLL_READSER) which still allows
VMNT_READ locks. Thread B can't acquire a lock on the vnode because
thread A has it; Thread A can't upgrade its vmnt lock to VMNT_WRITE
(TLL_WRITE) because thread B has a VMNT_READ lock on it.
By serializing vmnt locks during path parsing, thread B can only
acquire a lock on vmp when thread A has completely finished its
operation.
new_node makes the assumption that when it does last_dir on a path, a
successive advance would not yield a lock on a vmnt, because last_dir
already locked the vmnt. This is true except when last_dir resolves
to a directory on the parent vmnt of the file that was the result of
advance. For example,
# cd /
# echo foo > home
where home is on a different (sub) partition than / is (default
install). last_dir would resolve to / and advance would resolve to
/home.
With this change, last_dir resolves to the root node on the /home
partition, making the assumption valid again.
. all invocations were S or D, so can safely be dropped
to prepare for the segmentless world
. still assign D to the SCP_SEG field in the message
to make previous kernels usable
By making m_in job local (i.e., each job has its own copy of m_in instead
of refering to the global m_in) we don't have to store and restore m_in
on every thread yield. This reduces overhead. Moreover, remove the
assumption that m_in is preserved. Do_XXX functions have to copy the
system call parameters as soon as possible and only pass those copies to
other functions.
Furthermore, this patch cleans up some code and uses better types in a lot
of places.
If the provided path was only a single component (i.e., without
slashes), then last_dir would return early and skip the symlink
detection (i.e., check whether the path ends in a symlink and resolve
that first before returning). This bug triggered an assert in open
which expects that an advance after an last_dir (with VMNT_WRITE lock)
does not yield another vmnt lock.
The assert was meant as an additional check to the assert in link.c:198.
The reasoning behind the assert in link.c:198 is that once you've
obtained a write lock on a vmnt, you can't get an additional read lock
on the same vmnt. However, that does not always hold for the assert in
path.c:281 where the situation could be that you've obtained a read lock
and managed to get another read lock (this is possible). In other words,
the assert in path.c:281 is not the right place to check for that
situation.
In some places it was assumed that PATH_MAX does not include a
terminating null character.
Increases PATH_MAX to 1024 to get in sync with NetBSD. Required some
rewriting in AVFS to keep memory usage low (the stack in use by a thread
is very small).
Before safecopies, the IO_ENDPT and DL_ENDPT message fields were needed
to know which actual process to copy data from/to, as that process may
not always be the caller. Now that we have full safecopy support, these
fields have become useless for that purpose: the owner of the grant is
*always* the caller. Allowing the caller to supply another endpoint is
in fact dangerous, because the callee may then end up using a grant
from a third party. One could call this a variant of the confused
deputy problem.
From now on, safecopy calls should always use the caller's endpoint as
grant owner. This fully obsoletes the DL_ENDPT field in the
inet/ethernet protocol. IO_ENDPT has other uses besides identifying the
grant owner though. This patch renames IO_ENDPT to USER_ENDPT, not only
because that is a more fitting name (it should never be used for I/O
after all), but also in order to intentionally break any old system
source code outside the base system. If this patch breaks your code,
fixing it is fairly simple:
- DL_ENDPT should be replaced with m_source;
- IO_ENDPT should be replaced with m_source when used for safecopies;
- IO_ENDPT should be replaced with USER_ENDPT for any other use, e.g.
when setting REP_ENDPT, matching requests in CANCEL calls, getting
DEV_SELECT flags, and retrieving of the real user process's endpoint
in DEV_OPEN.
The changes in this patch are binary backward compatible.
file descriptor passing, PFS does some back calls to VFS. For example, to
verify the validity of a path provided by a process and to tell VFS it must
copy file descriptors from one process to another.
this change
- makes panic() variadic, doing full printf() formatting -
no more NO_NUM, and no more separate printf() statements
needed to print extra info (or something in hex) before panicing
- unifies panic() - same panic() name and usage for everyone -
vm, kernel and rest have different names/syntax currently
in order to implement their own luxuries, but no longer
- throws out the 1st argument, to make source less noisy.
the panic() in syslib retrieves the server name from the kernel
so it should be clear enough who is panicing; e.g.
panic("sigaction failed: %d", errno);
looks like:
at_wini(73130): panic: sigaction failed: 0
syslib:panic.c: stacktrace: 0x74dc 0x2025 0x100a
- throws out report() - printf() is more convenient and powerful
- harmonizes/fixes the use of panic() - there were a few places
that used printf-style formatting (didn't work) and newlines
(messes up the formatting) in panic()
- throws out a few per-server panic() functions
- cleans up a tie-in of tty with panic()
merging printf() and panic() statements to be done incrementally.
- Revise VFS-FS protocol and update VFS/MFS/ISOFS accordingly.
- Clean up MFS by removing old, dead code (backwards compatibility is broken by
the new VFS-FS protocol, anyway) and rewrite other parts. Also, make sure all
functions have proper banners and prototypes.
- VFS should always provide a (syntactically) valid path to the FS; no need for
the FS to do sanity checks when leaving/entering mount points.
- Fix several bugs in MFS:
- Several path lookup bugs in MFS.
- A link can be too big for the path buffer.
- A mountpoint can become inaccessible when the creation of a new inode
fails, because the inode already exists and is a mountpoint.
- Introduce support for supplemental groups.
- Add test 46 to test supplemental group functionality (and removed obsolete
suppl. tests from test 2).
- Clean up VFS (not everything is done yet).
- ISOFS now opens device read-only. This makes the -r flag in the mount command
unnecessary (but will still report to be mounted read-write).
- Introduce PipeFS. PipeFS is a new FS that handles all anonymous and
named pipes. However, named pipes still reside on the (M)FS, as they are part
of the file system on disk. To make this work VFS now has a concept of
'mapped' inodes, which causes read, write, truncate and stat requests to be
redirected to the mapped FS, and all other requests to the original FS.
