o Initialize ownerships and permissions. They were garbage (0) for
root mounts since vfs_mountroot_try() doesn't ask for them to be set
and msdosfs's old incomplete code to set them was removed. The
garbage happened to give the correct ownerships root:wheel, but it
gave permissions 000 so init could not be execed. Use the macros
for root: wheel and 0755. (The removed code gave 0:0 and 0777. 0755
is more normal and secure, thought wrong for /tmp.)
o Check the readonly flag for initial (non-MNT_UPDATE) mounts in the
correct place, as in ffs. For root mounts, it is only passed in
mp->mnt_flags, since vfs_mountroot_try() only passes it as a flag
and nothing translates the flag to the "ro" option string. msdosfs
only looked for it in the string, so it gave a rw mount for root
mounts without even clearing the flag in mp->mnt_flags, so the final
state was inconsistent. Checking the flag only in mp->mnt_flags
works for initial userland mounts too. The MNT_UPDATE case is
messier.
The main point that should work but doesn't is fsck of msdosfs root
while it is mounted ro. This needs mainly MNT_RELOAD support to work.
It should be possible to run fsck -p and succeed provided the fs is
consistent, not just for msdosfs, but this fails because fsck -p always
tries to open the device rw. The hack that allows open for writing
in ffs is not implemented in msdosfs, since without MNT_RELOAD support
writing could only be harmful. So fsck must be turned off to use
msdosfs as root. This is quite dangerous, since msdosfs is still missing
actually using its fs-dirty flag internally, so it is happy to mount
dirty fileystems rw.
Unrelated changes:
- Fix missing error handling for MNT_UPDATE from rw to ro.
- Catch up with renaming msdos to msdosfs in a string.
Approved by: re (kensmith)
This gives a very large speedup for small block sizes (in my tests,
about 5 times for write and 3 times for read with a block size of 512,
if clustering is possible) and a moderate speedup for the moderatatly
large block sizes that should be used on non-small media (4K is the
best size in most cases, and the speedup for that is about 1.3 times
for write and 1.2 times for read). mmap() should benefit from clustering
like read()/write(), but the current implementation of vm only supports
clustering (at least for getpages) if the fs block size is >= PAGE SIZE.
msdosfs is now only slightly slower than ffs with soft updates for
writing and slightly faster for reading when both use their best block
sizes. Writing is slower for msdosfs because of more sync writes.
Reading is faster for msdosfs because indirect blocks interfere with
clustering in ffs.
The changes in msdosfs_read() and msdosfs_write() are simpler merges
of corresponding code in ffs (after fixing some style bugs in ffs).
msdosfs_bmap() needs fs-specific code. This implementation loops
calling a lower level bmap function to do the hard parts. This is a
bit inefficient, but is efficient enough since msdsfs_bmap() is only
called when there is physical i/o to do.
Approved by: re (hrs)
In msdosfs_read(), mainly reorder the main loop to the same order as in
ffs_read().
In msdosfs_write() and extendfile(), use vfs_bio_clrbuf() instead of
clrbuf(). I think this just just a bogus optimization, but ffs always
does it and msdosfs already did it in one place, and it is what I've
tested.
In msdosfs_write(), merge good bits from a comment in ffs_write(), and
fix 1 style bug.
In the main comment for msdosfs_pcbmap(), improve wording and catch
up with 13 years of changes in the function. This comment belongs in
VOP_BMAP.9 but that doesn't exist.
In msdosfs_bmap(), return EFBIG if the requested cluster number is out
of bounds instead of blindly truncating it, and fix many style bugs.
Approved by: re (hrs)
to the FAT is possible.
Make the FAT block size less arbitrary before it is rounded up:
- for FAT12, default to 3*512 instead of to 3 sectors. The magic 3 is
the default number of 512-byte FAT sectors on a floppy drive. That
many sectors is too many if the sector size is larger.
- for !FAT12, default to PAGE_SIZE instead of to 4096. Remove
MSDOSFS_DFLTBSIZE since it only obfuscated this 4096.
For reading the BPB, use a block size of 8192 instead of 2048 so that
sector sizes up to 8192 can work. We should try several sizes, or just
try the maximum supported size (MAXBSIZE = 64K). I use 8192 because
that is enough for DVD-RW's (even 2048 is enough) and 8192 has been
tested a lot in use by ffs.
This completes fixing msdosfs for some large sector sizes (up to 8K
for read and 64K for write). Microsoft documents support for sector
sizes up to 4K in mdosfs. ffs is currently limited to 8K for both
read and write.
Approved by: re (kensmith)
Approved by: nyan (several years ago)
part of fixing msdosfs for large sector sizes. One of the fixed bugs
was fatal for large sector sizes.
1. The fsinfo block has size 512, but it was misunderstood and declared
as having size 1024, with nothing in the second 512 bytes except a
signature at the end. The second 512 bytes actually normally (if
the file system was created by Windows) consist of a second boot
sector which is normally (in WinXP) empty except for a signature --
the normal layout is one boot sector, one fsinfo sector, another
boot sector, then these 3 sectors duplicated. However, other
layouts are valid. newfs_msdos produces a valid layout with one
boot sector, one fsinfo sector, then these 2 sectors duplicated.
The signature check for the extra part of the fsinfo was thus
normally checking the signature in either the second boot sector
or the first boot sector in the copy, and thus accidentally
succeeding. The extra signature check would just fail for weirder
layouts with 512-byte sectors, and for normal layouts with any other
sector size.
Remove the extra bytes and the extra signature check.
2. Old versions did i/o to the fsinfo block using size 1024, with the
second half only used for the extra signature check on read. This
was harmless for sector size 512, and worked accidentally for sector
size 1024. The i/o just failed for larger sector sizes.
The version being fixed did i/o to the fsinfo block using size
fsi_size(pmp) = (1024 << ((pmp)->pm_BlkPerSec >> 2)). This
expression makes no sense. It happens to work for sector small
sector sizes, but for sector size 32K it gives the preposterous
value of 64M and thus causes panics. A sector size of 32768 is
necessary for at least some DVD-RW's (where the minimum write size
is 32768 although the minimum read size is 2048).
Now that the size of the fsinfo block is 512, it always fits in
one sector so there is no need for a macro to express it. Just
use the sector size where the old code uses 1024.
Approved by: re (kensmith)
Approved by: nyan (several years ago for a different version of (2))
of the the first cluster in a file (and, if the allocation cannot be
continued contiguously, for subsequent clusters in a file) was randomized
in an attempt to leave space for contiguous allocation of subsequent
clusters in each file when there are multiple writers. This reduced
internal fragmentation by a few percent, but it increased external
fragmentation by up to a few thousand percent.
Use simple sequential allocation instead. Actually maintain the fsinfo
sequence index for this. The read and write of this index from/to
disk still have many non-critical bugs, but we now write an index that
has something to do with our allocations instead of being modified
garbage. If there is no fsinfo on the disk, then we maintain the index
internally and don't go near the bugs for writing it.
Allocating the first free cluster gives a layout that is almost as good
(better in some cases), but takes too much CPU if the FAT is large and
the first free cluster is not near the beginning.
The effect of this change for untar and tar of a slightly reduced copy
of /usr/src on a new file system was:
Before (msdosfs 4K-clusters):
untar: 459.57 real untar from cached file (actually a pipe)
tar: 342.50 real tar from uncached tree to /dev/zero
Before (ffs2 soft updates 4K-blocks 4K-frags)
untar: 39.18 real
tar: 29.94 real
Before (ffs2 soft updates 16K-blocks 2K-frags)
untar: 31.35 real
tar: 18.30 real
After (msdosfs 4K-clusters):
untar 54.83 real
tar 16.18 real
All of these times can be improved further.
With multiple concurrent writers or readers (especially readers), the
improvement is smaller, but I couldn't find any case where it is
negative. 342 seconds for tarring up about 342 MB on a ~47MB/S partition
is just hard to unimprove on. (This operation would take about 7.3
seconds with reasonably localized allocation and perfect read-ahead.)
However, for active file systems, 342 seconds is closer to normal than
the 16+ seconds above or the 11 seconds with other changes (best I've
measured -- won easily by msdosfs!). E.g., my active /usr/src on ffs1
is quite old and fragmented, so reading to prepare for the above
benchmark takes about 6 times longer than reading back the fresh copies
of it.
Approved by: re (kensmith)
some cases, move to priv_check() if it was an operation on a thread and
no other flags were present.
Eliminate caller-side jail exception checking (also now-unused); jail
privilege exception code now goes solely in kern_jail.c.
We can't yet eliminate suser() due to some cases in the KAME code where
a privilege check is performed and then used in many different deferred
paths. Do, however, move those prototypes to priv.h.
Reviewed by: csjp
Obtained from: TrustedBSD Project
late stages of unmount). On failure, the vnode is recycled.
Add insmntque1(), to allow for file system specific cleanup when
recycling vnode on failure.
Change getnewvnode() to no longer call insmntque(). Previously,
embryonic vnodes were put onto the list of vnode belonging to a file
system, which is unsafe for a file system marked MPSAFE.
Change vfs_hash_insert() to no longer lock the vnode. The caller now
has that responsibility.
Change most file systems to lock the vnode and call insmntque() or
insmntque1() after a new vnode has been sufficiently setup. Handle
failed insmntque*() calls by propagating errors to callers, possibly
after some file system specific cleanup.
Approved by: re (kensmith)
Reviewed by: kib
In collaboration with: kib
This way we may support multiple structures in v_data vnode field within
one file system without using black magic.
Vnode-to-file-handle should be VOP in the first place, but was made VFS
operation to keep interface as compatible as possible with SUN's VFS.
BTW. Now Solaris also implements vnode-to-file-handle as VOP operation.
VFS_VPTOFH() was left for API backward compatibility, but is marked for
removal before 8.0-RELEASE.
Approved by: mckusick
Discussed with: many (on IRC)
Tested with: ufs, msdosfs, cd9660, nullfs and zfs
#ifdef MSDOSFS_LARGE to run-time checks to see if "-o large" was specified.
Test case provided by Oliver Fromme:
truncate -s 200G test.img
mdconfig -a -t vnode -f test.img -u 9
newfs_msdos -s 419430400 -n 1 /dev/md9 zip250
mount -t msdosfs /dev/md9 /mnt # should fail
mount -t msdosfs -o large /dev/md9 /mnt # should succeed
PR: 105964
Requested by: Oliver Fromme <olli lurza secnetix de>
Tested by: trhodes
MFC after: 2 weeks
from just before extending a file. This has the desired effect
of keeping the write speed constant. And yes, that helps a lot
copying large files always at full speed now, and I have seen
improvements using benchmarks/bonnie.
Stolen from: NetBSD
Reviewed by: bde
do not call markvoldirty() until the mount has been flagged as read-write.
Due to the nature of the msdosfs code, this bug only seemed to appear for
FAT-16 and FAT-32.
This fixes the testcase:
#!/bin/sh
dd if=/dev/zero bs=1m count=1 oseek=119 of=image.msdos
mdconfig -a -t vnode -f image.msdos
newfs_msdos -F 16 /dev/md0 fd120m
mount_msdosfs -o ro /dev/md0 /mnt
mount | grep md0
mount -u -o rw /dev/md0; echo $?
mount | grep md0
umount /mnt
mdconfig -d -u 0
PR: 105412
Tested by: Eugene Grosbein <eugen grosbein pp ru>
This macro was written expecting a 32-bit unsigned long, and
doesn't work properly on 64-bit systems. This bug caused vn_stat()
to return incorrect values for files larger than 2gb on msdosfs filesystems
on 64-bit systems.
PR: 106703
Submitted by: Axel Gonzalez <loox e-shell net>
MFC after: 3 days
This bug caused vn_stat() to fail on files larger than 2gb on msdosfs
filesystems on AMD64.
PR: 106703
Tested by: Axel Gonzalez <loox e-shell net>
MFC after: 3 days
an "export" flag indicating that we are trying to NFS export the
filesystem, and the MSDOSFS_LARGEFS flag is set on the filesystem,
then deny the mount update and export request. Otherwise,
let the full mount update proceed normally.
MSDOSFS_LARGES and NFS don't mix because of the way inodes are calculated
for MSDOSFS_LARGEFS.
MFC after: 3 days
set birthtime to FAT CTime (creation time) and in the other cases
set birthtime to -1.
o Set ctime to mtime instead of FAT CTime which has completely
different meaning.
PR: kern/106018
Submitted by: Oliver Fromme
MFC after: 1 month
LCASE_BASE or LCASE_EXT or both are set. But dos2unixfn uses
dos2unixchr separately for the basename and the extension. So if
either LCASE_BASE or LCASE_EXT is set, dos2unixfn will convert both
the basename and extension to lowercase because it is blindly
passing in the state of both flags to dos2unixchr. The bit masks I
used ensure that only the state of LCASE_BASE gets passed to
dos2unixchr when the basename is converted, and only the state of
LCASE_EXT is passed in when the extension is converted.
PR: kern/86655
Submitted by: Micah Lieske
MFC after: 3 weeks
specific privilege names to a broad range of privileges. These may
require some future tweaking.
Sponsored by: nCircle Network Security, Inc.
Obtained from: TrustedBSD Project
Discussed on: arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
Alex Lyashkov <umka at sevcity dot net>,
Skip Ford <skip dot ford at verizon dot net>,
Antoine Brodin <antoine dot brodin at laposte dot net>
- remove call to getmntopts(), and just pass -o options to
nmount(). This removes some confusion as to what options
msdosfs can parse, by pushing the responsibility of option parsing
to the VFS and FS specific code in the kernel.
msdosfs_vfsops.c:
- add "force" and "sync" to msdosfs_opts. They used to be specified
in mount_msdosfs.c, so move them here. It's not clear whethere these
options should be placed into global_opts in vfs_mount.c or not.
Motivated by: marcus
directory. vrele() may lock the passed vnode, which in these cases would
give an invalid lock order of child -> parent. These situations are
deadlock prone although do not typically deadlock because the vrele
is typically not releasing the last reference to the vnode. Users of
vrele must consider it as a call to vn_lock() and order it appropriately.
MFC After: 1 week
Sponsored by: Isilon Systems, Inc.
Tested by: kkenn
last few days. I tracked it down to the fact that nfs_reclaim()
is setting vp->v_data to NULL _before_ calling vnode_destroy_object().
After silence from the mailing list I checked further and discovered
that ufs_reclaim() is unique among FreeBSD filesystems for calling
vnode_destroy_object() early, long before tossing v_data or much
of anything else, for that matter. The rest, including NFS, appear
to be identical, as if they were just clones of one original routine.
The enclosed patch fixes all file systems in essentially the same
way, by moving the call to vnode_destroy_object() to early in the
routine (before the call to vfs_hash_remove(), if any). I have
only tested NFS, but I've now run for over eighteen hours with the
patch where I wouldn't get past four or five without it.
Submitted by: Frank Mayhar
Requested by: Mohan Srinivasan
MFC After: 1 week
synonyms for "shortname" and "longname" mount options. The old
(before nmount()) mount_msdosfs program accepted "shortnames" and "longnames",
but the kernel nmount() checked for "shortname" and "longname".
So, make the kernel accept "shortnames", "longnames", "shortname", "longname"
for forwards and backwarsd compatibility.
Discovered by: Rainer Hurling <rhurlin at gwdg dot de>
- Prefer '_' to ' ', as it results in more easily parsed results in
memory monitoring tools such as vmstat.
- Remove punctuation that is incompatible with using memory type names
as file names, such as '/' characters.
- Disambiguate some collisions by adding subsystem prefixes to some
memory types.
- Generally prefer lower case to upper case.
- If the same type is defined in multiple architecture directories,
attempt to use the same name in additional cases.
Not all instances were caught in this change, so more work is required to
finish this conversion. Similar changes are required for UMA zone names.
There seems to be very little documentary evidence outside this
implementation to suggest a these checks are neccessary, and more
than one camera-formatted flash disk fails the check, but mounts
successfully on most other systems.
Reviewed By: bde@
If a character cannot be converted to DOS code page,
unix2doschr() returned `0'. As a result, unix2dosfn()
was forced to return `0', so we saw a file which was
composed of these characters as `Invalid argument'.
To correct this, if a character can be converted to
Unicode, unix2doschr() now returns `1' which is a magic
number to make unix2dosfn() know that the character
must be converted to `_'.
[2] unix2dosfn()
The above-mentioned solution only works if a file
has both of Unicode name and DOS code page name.
Unicode name would not be recorded if file name
can be settled within 11 bytes (DOS short name)
and if no conversion from Unix charset to DOS code
page has occurred. Thus, FreeBSD can create a file
which has only short name, but there is no guarantee
that the short name contains allways valid characters
because we leave it to people by using mount_msdosfs(8)
to select which conversion is used between DOS code
page and unix charset.
To avoid this, Unicode file name should be recorded
unless a character is an ascii character. This is
the way Windows XP do.
PR: 77074 [1]
MFC after: 1 week
Since the name cache is case-sensitive and msdosfs isn't,
creating a file 'foo' won't invalidate a negative entry for 'FOO'.
There are similar problems related to 8.3 filenames.
A better solution is to override VOP_LOOKUP with a method that
canonicalizes the name, then calls vfs_cache_lookup(). Unfortunately,
it's not quite that simple because vfs_cache_lookup() will call
msdosfs_lookup() on a cache miss, and msdosfs_lookup() needs a way to
get at the original component name.
than WIN_CHARS bytes, we shift the suffix (previous substrings) upwards
by the amount this substring exceeds its WIN_CHARS slot. Profiling shows
this change is indistinguishable from the previous code at 95% confidence.
This bug would result in attempts to access or create files or directories
with multi-byte characters returning an error but no data loss.
Reported and tested by: avatar
MFC after: 3 days
these filesystems will support shared locks until they are explicitly
modified to do so. Careful review must be done to ensure that this
is safe for each individual filesystem.
Sponsored by: Isilon Systems, Inc.
the filesystem. Check that rather than VI_XLOCK.
- VOP_INACTIVE should no longer drop the vnode lock.
- The vnode lock is required around calls to vrecycle() and vgone().
Sponsored by: Isilon Systems, Inc.
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
(msdosfs uses normal 8-char indentation almost everywhere else),
too-long lines, and minor English usage errors. The verbose formal
comment before the new function is still abnormal.
(mainly unsorting). There were no changes related to the dirty flag
here. The reference NetBSD implementation put msdosfs_advlock() in a
different place. This commit only moves its declarations and changes
some of the function body to be like the NetBSD version.
Introduce two new macros MNT_ILOCK(mp)/MNT_IUNLOCK(mp) to
operate on this mutex transparently.
Eventually new mutex will be protecting more fields in
struct mount, not only vnode list.
Discussed with: jeff
wasn't curthread, i.e. when we receive a thread pointer to use
as a function argument. Use VOP_UNLOCK/vrele in these cases.
The only case there td != curthread known at the moment is
boot() calling sync with thread0 pointer.
This fixes the panic on shutdown people have reported.
struct msdosfsmount so that this file has the same prerequisites as
it used to. The new prerequistite was a meta-style bug. It required
many style bugs (unsorted includes ...) elsewhere.
Formatted prototypes in KNF. Resisted urge to sort all the prototypes,
to minimise differences with NetBSD. (NetBSD has reformatted the
prototypes but has not sorted them and still uses __P(()).)
masks for files and directories. This should make some
of the Midnight Commander users happy.
Remove an extra ')' in the manual page.
PR: 35699
Submitted by: Eugene Grosbein <eugen@grosbein.pp.ru> (original version)
Tested by: simon
contain the filedescriptor number on opens from userland.
The index is used rather than a "struct file *" since it conveys a bit
more information, which may be useful to in particular fdescfs and /dev/fd/*
For now pass -1 all over the place.
the user requests a read-only mount. This is necessary because we
don't do the VOP_OPEN again if they upgrade a read-only mount to
read-write.
Fixes lockup when creating files on msdosfs mounts that have been
mounted read-only then upgraded to read-write. The exact cause of
the lockup is not known, but it is likely to be the kernel getting
stuck in an infinite loop trying to write dirty buffers to a device
without write permission.
Reported/tested by andreas, discussed with phk.
an MSDOSFS file system either failed, silently corrupted the file, or
sometimes corrupted the neighboring file.
PR: 53695
Submitted by: Ariff Abdullah <skywizard@MyBSD.org.my> (original version)
MFC: 3 days
on my system where I preload msdosfs and have it in my kernel.
There's likely another bug that's causing msdosfs_init() to be called
multiple times, but this makes that harmless.
- Define one flag GB_LOCK_NOWAIT that tells getblk() to pass the LK_NOWAIT
flag to the initial BUF_LOCK(). This will eventually be used in cases
were we want to use a buffer only if it is not currently in use.
- Convert all consumers of the getblk() api to use this extra parameter.
Reviwed by: arch
Not objected to by: mckusick
Remove extraneous uses of vop_null, instead defering to the default op.
Rename vnode type "vfs" to the more descriptive "syncer".
Fix formatting for various filesystems that use vop_print.
that is protected by the vnode lock.
- Move B_SCANNED into b_vflags and call it BV_SCANNED.
- Create a vop_stdfsync() modeled after spec's sync.
- Replace spec_fsync, msdos_fsync, and hpfs_fsync with the stdfsync and some
fs specific processing. This gives all of these filesystems proper
behavior wrt MNT_WAIT/NOWAIT and the use of the B_SCANNED flag.
- Annotate the locking in buf.h
prevent the compiler from optimizing assignments into byte-copy
operations which might make access to the individual fields non-atomic.
Use the individual fields throughout, and don't bother locking them with
Giant: it is no longer needed.
Inspired by: tjr
to sort out disk-io from file-io in the vm/buffer/filesystem space.
The intent is to sort VOP_STRATEGY calls into those which operate
on "real" vnodes and those which operate on VCHR vnodes. For
the latter kind, the call will be changed to VOP_SPECSTRATEGY,
possibly conditionally for those places where dual-use happens.
Add a default VOP_SPECSTRATEGY method which will call the normal
VOP_STRATEGY. First time it is called it will print debugging
information. This will only happen if a normal vnode is passed
to VOP_SPECSTRATEGY by mistake.
Add a real VOP_SPECSTRATEGY in specfs, which does what VOP_STRATEGY
does on a VCHR vnode today.
Add a new VOP_STRATEGY method in specfs to catch instances where
the conversion to VOP_SPECSTRATEGY has not yet happened. Handle
the request just like we always did, but first time called print
debugging information.
Apart up to two instances of console messages per boot, this amounts
to a glorified no-op commit.
If you get any of the messages on your console I would very much
like a copy of them mailed to phk@freebsd.org
kern/vfs_defaults.c it is wrong for the individual filesystems to use
the std* functions as that prevents override of the default.
Found by: src/tools/tools/vop_table
terminating zero (it was treated as length missmatch). The mtools create
such slots if the name len is the product of 13 (max number of unicode
chars fitting in directory slot).
MFC after: 1 week
