long filename. Each substring is indexed by the windows ID, a
sequential one-based value. The previous code was extremely slow,
doing a malloc/strcpy/free for each substring.
This code optimizes these routines with this in mind, using the ID
to index into a single array and concatenating each WIN_CHARS chunk
at once. (The last chunk is variable-length.)
This code has been tested as working on an FS with difficult filename
sizes (255, 13, 26, etc.) It gives a 77.1% decrease in profiled
time (total across all functions) and a 73.7% decrease in wall time.
Test was "ls -laR > /dev/null".
Per-function time savings:
mbnambuf_init: -90.7%
mbnambuf_write: -18.7%
mbnambuf_flush: -67.1%
MFC after: 1 month
on my P3, microbenchmarks show the unrolled version is 78x faster. In
actual use (recursive ls), this gives an average of 9% improvement in
system time and 2% improvement in wall time.
called in "open", causing mmap() to fail.
Where possible, pass size of file to vnode_create_vobject() rather
than having it find it out the hard way via VOP_LOOKUP
Reviewed by: phk
with NFS.
We are moving responsibility for creating the vnode_pager object into
the filesystems which own the vnode, and this is one of the places
we have to cover.
We call vnode_create_vobject() directly because we own the vnode.
If we can get the size easily, pass it as an argument to save the
call to VOP_GETATTR() in vnode_create_vobject()
I'm not sure why a credential was added to these in the first place, it is
not used anywhere and it doesn't make much sense:
The credentials for syncing a file (ability to write to the
file) should be checked at the system call level.
Credentials for syncing one or more filesystems ("none")
should be checked at the system call level as well.
If the filesystem implementation needs a particular credential
to carry out the syncing it would logically have to the
cached mount credential, or a credential cached along with
any delayed write data.
Discussed with: rwatson
Add a vfs_cmount() function which converts omount argument stucture
to nmount arguments.
Convert vfs_omount() to vfs_mount() and parse nmount arguments.
This is 100% compatible with existing userland.
Later on, but before userland gets converted to nmount we may want
to revisit the names of the mountoptions, for instance it may make
sense to use consistent options for charset conversion etc.
doesn't. Most of the implementations have grown weeds for this so they
copy some fields from mnt_stat if the passed argument isn't that.
Fix this the cleaner way: Always call the implementation on mnt_stat
and copy that in toto to the VFS_STATFS argument if different.
initializations but we did have lofty goals and big ideals.
Adjust to more contemporary circumstances and gain type checking.
Replace the entire vop_t frobbing thing with properly typed
structures. The only casualty is that we can not add a new
VOP_ method with a loadable module. History has not given
us reason to belive this would ever be feasible in the the
first place.
Eliminate in toto VOCALL(), vop_t, VNODEOP_SET() etc.
Give coda correct prototypes and function definitions for
all vop_()s.
Generate a bit more data from the vnode_if.src file: a
struct vop_vector and protype typedefs for all vop methods.
Add a new vop_bypass() and make vop_default be a pointer
to another struct vop_vector.
Remove a lot of vfs_init since vop_vector is ready to use
from the compiler.
Cast various vop_mumble() to void * with uppercase name,
for instance VOP_PANIC, VOP_NULL etc.
Implement VCALL() by making vdesc_offset the offsetof() the
relevant function pointer in vop_vector. This is disgusting
but since the code is generated by a script comparatively
safe. The alternative for nullfs etc. would be much worse.
Fix up all vnode method vectors to remove casts so they
become typesafe. (The bulk of this is generated by scripts)
instead of a vnode for it.
The vnode_pager does not and should not have any interest in what
the filesystem uses for backend.
(vfs_cluster doesn't use the backing store argument.)
(disabled) defid_gen members from u_long to u_int32_t so that alignment
requirements don't cause the structure to become larger than struct fid
on LP64 platforms. This fixes NFS exports of msdos filesystems on at
least amd64.
PR: 71173
Fix a problem in previous: we can't blindly assume that we have
wincnt entries available at the offset the file has been found. If the dos
directory entry is not preceded by appropriate number of long name
entries (happens e.g. when the filesystem is corrupted, or when
the filename complies to DOS rules and doesn't use any long name entry),
we would overwrite random directory entries.
There are still some problems, the whole thing has to be revisited and solved
right.
Submitted by: Xin LI
Fix a panic that occurred when trying to traverse a corrupt msdosfs
filesystem. With this particular corruption, the code in pcbmap()
would compute an offset into an array that was way out of bounds,
so check the bounds before trying to access and return an error if
the offset would be out of bounds.
Submitted by: Xin LI
field.
Replace three instances of longhaired initialization va_filerev fields.
Added XXX comment wondering why we don't use random bits instead of
uptime of the system for this purpose.
- Use copyinstr() to read cs_win, cs_dos, cs_local strings from the
mount argument structure instead of reading through user-space pointers(!).
- When mounting a filesystem, or updating an existing mount, only try to
update the iconv handles from the information in the mount argument
structure if the structure itself has the MSDOSFSMNT_KICONV flag set.
- Attempt to handle failure of update_mp() in the MNT_UPDATE case.
and refuse initializing filesystems with a wrong version. This will
aid maintenance activites on the 5-stable branch.
s/vfs_mount/vfs_omount/
s/vfs_nmount/vfs_mount/
Name our filesystems mount function consistently.
Eliminate the namiedata argument to both vfs_mount and vfs_omount.
It was originally there to save stack space. A few places abused
it to get hold of some credentials to pass around. Effectively
it is unused.
Reorganize the root filesystem selection code.
Add local rootvp variables as needed.
Remove checks for miniroot's in the swappartition. We never did that
and most of the filesystems could never be used for that, but it had
still been copy&pasted all over the place.
somewhat clearer, but more importantly allows for a consistent naming
scheme for suser_cred flags.
The old name is still defined, but will be removed in a few days (unless I
hear any complaints...)
Discussed with: rwatson, scottl
Requested by: jhb
This is to allow filesystems to decide based on the passed thread
which vnode to return.
Several filesystems used curthread, they now use the passed thread.
our cached 'next vnode' being removed from this mountpoint. If we
find that it was recycled, we restart our traversal from the start
of the list.
Code to do that is in all local disk filesystems (and a few other
places) and looks roughly like this:
MNT_ILOCK(mp);
loop:
for (vp = TAILQ_FIRST(&mp...);
(vp = nvp) != NULL;
nvp = TAILQ_NEXT(vp,...)) {
if (vp->v_mount != mp)
goto loop;
MNT_IUNLOCK(mp);
...
MNT_ILOCK(mp);
}
MNT_IUNLOCK(mp);
The code which takes vnodes off a mountpoint looks like this:
MNT_ILOCK(vp->v_mount);
...
TAILQ_REMOVE(&vp->v_mount->mnt_nvnodelist, vp, v_nmntvnodes);
...
MNT_IUNLOCK(vp->v_mount);
...
vp->v_mount = something;
(Take a moment and try to spot the locking error before you read on.)
On a SMP system, one CPU could have removed nvp from our mountlist
but not yet gotten to assign a new value to vp->v_mount while another
CPU simultaneously get to the top of the traversal loop where it
finds that (vp->v_mount != mp) is not true despite the fact that
the vnode has indeed been removed from our mountpoint.
Fix:
Introduce the macro MNT_VNODE_FOREACH() to traverse the list of
vnodes on a mountpoint while taking into account that vnodes may
be removed from the list as we go. This saves approx 65 lines of
duplicated code.
Split the insmntque() which potentially moves a vnode from one mount
point to another into delmntque() and insmntque() which does just
what the names say.
Fix delmntque() to set vp->v_mount to NULL while holding the
mountpoint lock.
FAT32 filesystems to be mounted, subject to some fairly serious limitations.
This works by extending the internal pseudo-inode-numbers generated from
the file's starting cluster number to 64-bits, then creating a table
mapping these into arbitrary 32-bit inode numbers, which can fit in
struct dirent's d_fileno and struct vattr's va_fileid fields. The mappings
do not persist across unmounts or reboots, so it's not possible to export
these filesystems through NFS. The mapping table may grow to be rather
large, and may grow large enough to exhaust kernel memory on filesystems
with millions of files.
Don't enable this option unless you understand the consequences.
255; USB keychains exist that use 256 as the number of heads. This
check has also been removed in Darwin (along with most of the other
head/sector sanity checks).
by 1 u_int if the number of clusters was 1 more than a multiple of
(8 * sizeof(u_int)). The bitmap is malloced and large (often huge), so
fatal overrun probably only occurred if the number of clusters was 1
more than 1 multiple of PAGE_SIZE/8.
to size_t *, which is incorrect because they may have different widths.
This caused some subtle forms of corruption, the mostly frequently
reported one being that the last character of a filename was sometimes
duplicated on amd64.
it means that the correct value is unknown. Since this value is just
a hint to improve performance, initially assume that the first non-reserved
cluster is free, then correct this assumption if necessary before writing
the FSInfo block back to disk.
PR: 62826
MFC after: 2 weeks
- don't unlock the vnode after vinvalbuf() only to have to relock it
almost immediately.
- don't refer to devices classified by vn_isdisk() as block devices.
- struct plimit includes a mutex to protect a reference count. The plimit
structure is treated similarly to struct ucred in that is is always copy
on write, so having a reference to a structure is sufficient to read from
it without needing a further lock.
- The proc lock protects the p_limit pointer and must be held while reading
limits from a process to keep the limit structure from changing out from
under you while reading from it.
- Various global limits that are ints are not protected by a lock since
int writes are atomic on all the archs we support and thus a lock
wouldn't buy us anything.
- All accesses to individual resource limits from a process are abstracted
behind a simple lim_rlimit(), lim_max(), and lim_cur() API that return
either an rlimit, or the current or max individual limit of the specified
resource from a process.
- dosetrlimit() was renamed to kern_setrlimit() to match existing style of
other similar syscall helper functions.
- The alpha OSF/1 compat layer no longer calls getrlimit() and setrlimit()
(it didn't used the stackgap when it should have) but uses lim_rlimit()
and kern_setrlimit() instead.
- The svr4 compat no longer uses the stackgap for resource limits calls,
but uses lim_rlimit() and kern_setrlimit() instead.
- The ibcs2 compat no longer uses the stackgap for resource limits. It
also no longer uses the stackgap for accessing sysctl's for the
ibcs2_sysconf() syscall but uses kernel_sysctl() instead. As a result,
ibcs2_sysconf() no longer needs Giant.
- The p_rlimit macro no longer exists.
Submitted by: mtm (mostly, I only did a few cleanups and catchups)
Tested on: i386
Compiled on: alpha, amd64