Remove the page_table_lock from around the calls to unmap_vmas, and replace
the pte_offset_map in zap_pte_range by pte_offset_map_lock: all callers are
now safe to descend without page_table_lock.
Don't attempt fancy locking for hugepages, just take page_table_lock in
unmap_hugepage_range. Which makes zap_hugepage_range, and the hugetlb test in
zap_page_range, redundant: unmap_vmas calls unmap_hugepage_range anyway. Nor
does unmap_vmas have much use for its mm arg now.
The tlb_start_vma and tlb_end_vma in unmap_page_range are now called without
page_table_lock: if they're implemented at all, they typically come down to
flush_cache_range (usually done outside page_table_lock) and flush_tlb_range
(which we already audited for the mprotect case).
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Convert those common loops using page_table_lock on the outside and
pte_offset_map within to use just pte_offset_map_lock within instead.
These all hold mmap_sem (some exclusively, some not), so at no level can a
page table be whipped away from beneath them. But whereas pte_alloc loops
tested with the "atomic" pmd_present, these loops are testing with pmd_none,
which on i386 PAE tests both lower and upper halves.
That's now unsafe, so add a cast into pmd_none to test only the vital lower
half: we lose a little sensitivity to a corrupt middle directory, but not
enough to worry about. It appears that i386 and UML were the only
architectures vulnerable in this way, and pgd and pud no problem.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Second step in pushing down the page_table_lock. Remove the temporary
bridging hack from __pud_alloc, __pmd_alloc, __pte_alloc: expect callers not
to hold page_table_lock, whether it's on init_mm or a user mm; take
page_table_lock internally to check if a racing task already allocated.
Convert their callers from common code. But avoid coming back to change them
again later: instead of moving the spin_lock(&mm->page_table_lock) down,
switch over to new macros pte_alloc_map_lock and pte_unmap_unlock, which
encapsulate the mapping+locking and unlocking+unmapping together, and in the
end may use alternatives to the mm page_table_lock itself.
These callers all hold mmap_sem (some exclusively, some not), so at no level
can a page table be whipped away from beneath them; and pte_alloc uses the
"atomic" pmd_present to test whether it needs to allocate. It appears that on
all arches we can safely descend without page_table_lock.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
update_mem_hiwater has attracted various criticisms, in particular from those
concerned with mm scalability. Originally it was called whenever rss or
total_vm got raised. Then many of those callsites were replaced by a timer
tick call from account_system_time. Now Frank van Maarseveen reports that to
be found inadequate. How about this? Works for Frank.
Replace update_mem_hiwater, a poor combination of two unrelated ops, by macros
update_hiwater_rss and update_hiwater_vm. Don't attempt to keep
mm->hiwater_rss up to date at timer tick, nor every time we raise rss (usually
by 1): those are hot paths. Do the opposite, update only when about to lower
rss (usually by many), or just before final accounting in do_exit. Handle
mm->hiwater_vm in the same way, though it's much less of an issue. Demand
that whoever collects these hiwater statistics do the work of taking the
maximum with rss or total_vm.
And there has been no collector of these hiwater statistics in the tree. The
new convention needs an example, so match Frank's usage by adding a VmPeak
line above VmSize to /proc/<pid>/status, and also a VmHWM line above VmRSS
(High-Water-Mark or High-Water-Memory).
There was a particular anomaly during mremap move, that hiwater_vm might be
captured too high. A fleeting such anomaly remains, but it's quickly
corrected now, whereas before it would stick.
What locking? None: if the app is racy then these statistics will be racy,
it's not worth any overhead to make them exact. But whenever it suits,
hiwater_vm is updated under exclusive mmap_sem, and hiwater_rss under
page_table_lock (for now) or with preemption disabled (later on): without
going to any trouble, minimize the time between reading current values and
updating, to minimize those occasions when a racing thread bumps a count up
and back down in between.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove PageReserved() calls from core code by tightening VM_RESERVED
handling in mm/ to cover PageReserved functionality.
PageReserved special casing is removed from get_page and put_page.
All setting and clearing of PageReserved is retained, and it is now flagged
in the page_alloc checks to help ensure we don't introduce any refcount
based freeing of Reserved pages.
MAP_PRIVATE, PROT_WRITE of VM_RESERVED regions is tentatively being
deprecated. We never completely handled it correctly anyway, and is be
reintroduced in future if required (Hugh has a proof of concept).
Once PageReserved() calls are removed from kernel/power/swsusp.c, and all
arch/ and driver code, the Set and Clear calls, and the PG_reserved bit can
be trivially removed.
Last real user of PageReserved is swsusp, which uses PageReserved to
determine whether a struct page points to valid memory or not. This still
needs to be addressed (a generic page_is_ram() should work).
A last caveat: the ZERO_PAGE is now refcounted and managed with rmap (and
thus mapcounted and count towards shared rss). These writes to the struct
page could cause excessive cacheline bouncing on big systems. There are a
number of ways this could be addressed if it is an issue.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Refcount bug fix for filemap_xip.c
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I was lazy when we added anon_rss, and chose to change as few places as
possible. So currently each anonymous page has to be counted twice, in rss
and in anon_rss. Which won't be so good if those are atomic counts in some
configurations.
Change that around: keep file_rss and anon_rss separately, and add them
together (with get_mm_rss macro) when the total is needed - reading two
atomics is much cheaper than updating two atomics. And update anon_rss
upfront, typically in memory.c, not tucked away in page_add_anon_rmap.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
How is anon_rss initialized? In dup_mmap, and by mm_alloc's memset; but
that's not so good if an mm_counter_t is a special type. And how is rss
initialized? By set_mm_counter, all over the place. Come on, we just need to
initialize them both at once by set_mm_counter in mm_init (which follows the
memcpy when forking).
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The NUMA policy code predated nodemask_t so it used open coded bitmaps.
Convert everything to nodemask_t. Big patch, but shouldn't have any actual
behaviour changes (except I removed one unnecessary check against
node_online_map and one unnecessary BUG_ON)
Signed-off-by: "Andi Kleen" <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The xtTruncate code was only doing this for leaf pages. When a file is
horribly fragmented, we may truncate a file leaving an internal page with
an invalid head.next field, which may cause a stale page to be referenced.
Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
The previous patch adding the ability to nest struct class_device
changed the paramaters to the call class_device_create(). This patch
fixes up all in-kernel users of the function.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
A "coldplug + udevstart" can be simple like this:
for i in /sys/block/*/*/uevent; do echo 1 > $i; done
for i in /sys/class/*/*/uevent; do echo 1 > $i; done
for i in /sys/bus/*/devices/*/uevent; do echo 1 > $i; done
Signed-off-by: Kay Sievers <kay.sievers@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
- ->releasepage() annotated (s/int/gfp_t), instances updated
- missing gfp_t in fs/* added
- fixed misannotation from the original sweep caught by bitwise checks:
XFS used __nocast both for gfp_t and for flags used by XFS allocator.
The latter left with unsigned int __nocast; we might want to add a
different type for those but for now let's leave them alone. That,
BTW, is a case when __nocast use had been actively confusing - it had
been used in the same code for two different and similar types, with
no way to catch misuses. Switch of gfp_t to bitwise had caught that
immediately...
One tricky bit is left alone to be dealt with later - mapping->flags is
a mix of gfp_t and error indications. Left alone for now.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Beginning of gfp_t annotations:
- -Wbitwise added to CHECKFLAGS
- old __bitwise renamed to __bitwise__
- __bitwise defined to either __bitwise__ or nothing, depending on
__CHECK_ENDIAN__ being defined
- gfp_t switched from __nocast to __bitwise__
- force cast to gfp_t added to __GFP_... constants
- new helper - gfp_zone(); extracts zone bits out of gfp_t value and casts
the result to int
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
struct gendisk has these two fields: stamp, stamp_idle. Update to
stamp_idle is always in sync with stamp and they are always the same.
Therefore, it does not add any value in having two fields tracking
same timestamp. Suggest to remove it.
Also, we should only update gendisk stats with non-zero value.
Advantage is that we don't have to needlessly calculate memory address,
and then add zero to the content.
Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Jens Axboe <axboe@suse.de>
Optimise attribute revalidation when hardlinking. Add post-op attributes
for the directory and the original inode.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
"Optional" means that the close call will not fail if the getattr
at the end of the compound fails.
If it does succeed, try to refresh inode attributes.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Since the directory attributes change every time we CREATE a file,
we might as well pick up the new directory attributes in the same
compound.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
nfs_lookup() used to consult a lookup cache before trying an actual wire
lookup operation. The lookup cache would be invalid, of course, if the
parent directory's mtime had changed, so nfs_lookup performed an inode
revalidation on the parent.
Since nfs_lookup() doesn't use a cache anymore, the revalidation is no
longer necessary. There are cases where it will generate a lot of
unnecessary GETATTR traffic.
See http://bugzilla.linux-nfs.org/show_bug.cgi?id=9
Test-plan:
Use lndir and "rm -rf" and watch for excess GETATTR traffic or application
level errors.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Since we almost always call nfs_end_data_update() after we called
nfs_refresh_inode(), we now end up marking the inode metadata
as needing revalidation immediately after having updated it.
This patch rearranges things so that we mark the inode as needing
revalidation _before_ we call nfs_refresh_inode() on those operations
that need it.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Allow nfs_refresh_inode() also to update attributes on the inode if the
RPC call was sent after the last call to nfs_update_inode().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
unaligned structures coming in off the wire
gcc on arm processors generates very odd code with pragma pack specified -
although it does pack the structures in some sense - it does not allow you
to access unaligned elements in nested structures at the right offset as other
architectures do. Oddly enough though, specifying the structures as packed
the long way - one by one with the packed attribute does work. Rather than
fighting over whether this is a gcc bug or some obscure side effect
of pragma pack, it is easier to do what most (all but 96 other places in
the kernel) do - and replace pragma pack with dozens of attribute(packed)
structure qualifiers. Much more verbose ... but at least it works.
Signed-off-by: David Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com> CG: -----------------------------------------------------------------------
fsck_hfs reveals lots of temporary files accumulating in the hidden
directory "\000\000\000HFS+ Private Data". According to the HFS+
documentation these are files which are unlinked while in use. However,
there may be a bug in the Linux hfsplus implementation which causes this to
happen even when the files are not in use. It looks like the "opencnt"
field is never initialized as (I think) it should be in hfsplus_read_inode.
This means that a file can appear to be still in use when in fact it has
been closed. This patch seems to fix it for me.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix a bug which was reported and diagnosed by
Stefan Jones <stefan.jones@churchillrandoms.co.uk>
IDR trees include a cache of idr_layer objects. There's no way to destroy
this cache, so when we discard an overall idr tree we end up leaking some
memory.
Add and use idr_destroy() for this. v9fs and infiniband also need to use
idr_destroy() to avoid leaks.
Or, we make the cache global, like radix_tree_preload(). Which is probably
better. Later.
Cc: Eric Van Hensbergen <ericvh@ericvh.myip.org>
Cc: Roland Dreier <rolandd@cisco.com>
Cc: Robert Love <rml@novell.com>
Cc: John McCutchan <ttb@tentacle.dhs.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Another case of missing call to security_file_permission: aio functions
(namely, io_submit) does not check credentials with security modules.
Below is the simple patch to the problem. It seems that it is enough to
check for rights at the request submission time.
Signed-off-by: Kostik Belousov <kostikbel@gmail.com>
Signed-off-by: Chris Wright <chrisw@osdl.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
need to get in ahead of it that depend on that file handle. Fixes
occassional bad file handle errors on write with heavy use multiple process
cases.
Signed-off-by: Steve French <sfrench@us.ibm.com>
Many thanks to Alberto Patino for testing and reporting the data
corruption. And many apologies for corrupting his partition.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
resp_len is passed in as buffer size to decode routine; make sure it's
set right in case where userspace provides less than a page's worth of
buffer.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Stop handing garbage to userspace in the case where a weird server clears the
acl bit in the getattr return (despite the fact that they've already claimed
acl support.)
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Storing a pointer to the struct rpc_task in the nfs_seqid is broken
since the nfs_seqid may be freed well after the task has been destroyed.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If someone tries to rename a directory onto an empty directory, we
currently fail and return EBUSY.
This patch ensures that we try the rename if both source and target
are directories, and that we fail with a correct error of EISDIR if
the source is not a directory.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We currently fail Connectathon test 6.10 in the case of 32-bit locks due
to incorrect error checking.
Also add support for l->l_len < 0 to 64-bit locks.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If the server is in the unconfirmed OPEN state for a given open owner
and receives a second OPEN for the same open owner, it will cancel the
state of the first request and set up an OPEN_CONFIRM for the second.
This can cause a race that is discussed in rfc3530 on page 181.
The following patch allows the client to recover by retrying the
original open request.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This will allow nfs_permission() to perform additional optimizations when
walking the path, by folding the ACCESS(MAY_EXEC) call on the directory
into the lookup revalidation.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Make NFSv4 return the fully initialized file pointer with the
stateid that it created in the lookup w/intent.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This is needed by NFSv4 for atomicity reasons: our open command is in
fact a lookup+open, so we need to be able to propagate open context
information from lookup() into the resulting struct file's
private_data field.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We no longer need to worry about collisions between close() and the state
recovery code, since the new close will automatically recheck the
file state once it is done waiting on its sequence slot.
Ditto for the nfs4_proc_locku() procedure.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Once the state_owner and lock_owner semaphores get removed, it will be
possible for other OPEN requests to reopen the same file if they have
lower sequence ids than our CLOSE call.
This patch ensures that we recheck the file state once
nfs_wait_on_sequence() has completed waiting.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
NFSv4 file state-changing functions such as OPEN, CLOSE, LOCK,... are all
labelled with "sequence identifiers" in order to prevent the server from
reordering RPC requests, as this could cause its file state to
become out of sync with the client.
Currently the NFS client code enforces this ordering locally using
semaphores to restrict access to structures until the RPC call is done.
This, of course, only works with synchronous RPC calls, since the
user process must first grab the semaphore.
By dropping semaphores, and instead teaching the RPC engine to hold
the RPC calls until they are ready to be sent, we can extend this
process to work nicely with asynchronous RPC calls too.
This patch adds a new list called "rpc_sequence" that defines the order
of the RPC calls to be sent. We add one such list for each state_owner.
When an RPC call is ready to be sent, it checks if it is top of the
rpc_sequence list. If so, it proceeds. If not, it goes back to sleep,
and loops until it hits top of the list.
Once the RPC call has completed, it can then bump the sequence id counter,
and remove itself from the rpc_sequence list, and then wake up the next
sleeper.
Note that the state_owner sequence ids and lock_owner sequence ids are
all indexed to the same rpc_sequence list, so OPEN, LOCK,... requests
are all ordered w.r.t. each other.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
lock_kiocb() was introduced to serialize retrying and cancellation. In the
process of doing so it tried to sleep waiting for KIF_LOCKED while holding
the ctx_lock spinlock. Recent fixes have ensured that multiple concurrent
retries won't be attempted for a given iocb. Cancel has other problems and
has no significant in-tree users that have been complaining about it. So
for the immediate future we'll revert sleeping with the lock held and will
address proper cancellation and retry serialization in the future.
Signed-off-by: Zach Brown <zach.brown@oracle.com>
Acked-by: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Currently you do not get all the map entries on nommu systems because the
start function doesn't index into the list using the value of "pos".
Signed-off-by: David McCullough <davidm@snapgear.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Oopsable since nfs_wait_on_inode() can get called as part of iput_final().
Unnecessary since the caller had better be damned sure that the inode won't
disappear from underneath it anyway.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If the data cache has been marked as potentially invalid by nfs_refresh_inode,
we should invalidate it rather than assume that changes are due to our own
activity.
Also ensure that we always start with a valid cache before declaring it
to be protected by a delegation.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
"proc_smaps_operations" is not defined in case of "CONFIG_MMU=n".
Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
New cifs_writepages routine was not updated bytes written in cifs stats.
Also added ability to clear /proc/fs/cifs/Stats by writing (0 or 1) to it.
Signed-off-by: Steve French <sfrench@us.ibm.com>
Nir Tzachar <tzachar@cs.bgu.ac.il> points out that if an ELF file specifies a
zero-length bss at a whacky address, we cannot load that binary because
padzero() tries to zero out the end of the page at the whacky address, and
that may not be writeable.
See also http://bugzilla.kernel.org/show_bug.cgi?id=5411
So teach load_elf_binary() to skip the bss settng altogether if the elf file
has a zero-length bss segment.
Cc: Roland McGrath <roland@redhat.com>
Cc: Daniel Jacobowitz <dan@debian.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Here is a compatibility fix between Linux and Solaris when used with VxFS
filesystems: Solaris usually accepts acl entries in any order, but with
VxFS it replies with NFSERR_INVAL when it sees a four-entry acl that is not
in canonical form. It may also fail with other non-canonical acls -- I
can't tell, because that case never triggers: We only send non-canonical
acls when we fake up an ACL_MASK entry.
Instead of adding fake ACL_MASK entries at the end, inserting them in the
correct position makes Solaris+VxFS happy. The Linux client and server
sides don't care about entry order. The three-entry-acl special case in
which we need a fake ACL_MASK entry was handled in xdr_nfsace_encode. The
patch moves this into nfsacl_encode.
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
v9fs_file_read and v9fs_file_write use kmalloc to allocate buffers as big
as the data buffer received as parameter. kmalloc cannot be used to
allocate buffers bigger than 128K, so reading/writing data in chunks bigger
than 128k fails.
This patch reorganizes v9fs_file_read and v9fs_file_write to allocate only
buffers as big as the maximum data that can be sent in one 9P message.
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
file operations ->write(), ->aio_write(), and ->writev() for regular
files. This replaces the old use of generic_file_write(), et al and
the address space operations ->prepare_write and ->commit_write.
This means that both sparse and non-sparse (unencrypted and
uncompressed) files can now be extended using the normal write(2)
code path. There are two limitations at present and these are that
we never create sparse files and that we only have limited support
for highly fragmented files, i.e. ones whose data attribute is split
across multiple extents. When such a case is encountered,
EOPNOTSUPP is returned.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
and cond_resched() in the main loop as we could be dirtying a lot of
pages and this ensures we play nice with the VM and the system as a
whole.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
The third param in this call to vmap shouldn't be GFP_KERNEL, which
makes no sense, but rather VM_MAP. Thanks to Al Viro for spotting
this.
Signed-off-by: Tom Zanussi <zanussi@us.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- added typedef unsigned int __nocast gfp_t;
- replaced __nocast uses for gfp flags with gfp_t - it gives exactly
the same warnings as far as sparse is concerned, doesn't change
generated code (from gcc point of view we replaced unsigned int with
typedef) and documents what's going on far better.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
These changes to debug code and new stats are helpful in
debugging potential tcp performance/configuration problems under cifs.
Signed-off-by: Steve French <sfrench@us.ibm.com>
The nameidata "last.name" is always allocated with "__getname()", and
should always be free'd with "__putname()".
Using "putname()" without the underscores will leak memory, because the
allocation will have been hidden from the AUDITSYSCALL code.
Arguably the real bug is that the AUDITSYSCALL code is really broken,
but in the meantime this fixes the problem people see.
Reported by Robert Derr, patch by Rick Lindsley.
Acked-by: Al Viro <viro@ftp.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This allows cifs_writepages to send data in larger chunks from the page
cache, without requiring larger memory allocations in other cases.
Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
bfs_fill_super() walks the inode table to get the bitmap of free inodes
and collect stats. It has no business using iget() for that - it's a
lot of extra work, extra icache pollution and more complex code.
Switched to walking the damn thing directly.
Note: that also allows to kill ->i_dsk_ino in there - separate patch if
Tigran can confirm that this field can be zero only for deleted inodes
(i.e. something that could only be found during that scan and not by
normal lookups).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
the initial implementation of file truncation. Now both open(2)ing
a file with the O_TRUNC flag and the {,f}truncate(2) system calls
will resize a file appropriately. The limitations are that only
uncompressed and unencrypted files are supported. Also, there is
only very limited support for highly fragmented files (the ones whose
$DATA attribute is split into multiple attribute extents).
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
extend the allocation of an attributes. Optionally, the data size,
but not the initialized size can be extended, too.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
which is zero for a resident attribute but should no longer be zero
once the attribute is non-resident as it then has real clusters
allocated.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
as an extra parameter. This is needed since we need to know the size
before we can map the mft record and our callers always know it. The
reason we cannot simply read the size from the vfs inode i_size is
that this is not necessarily uptodate. This happens when
ntfs_attr_make_non_resident() is called in the ->truncate call path.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
specifying whether the cluster are being allocated to extend an
attribute or to fill a hole.
- Change ntfs_attr_make_non_resident() to call ntfs_cluster_alloc()
with @is_extension set to TRUE and remove the runlist terminator
fixup code as this is now done by ntfs_cluster_alloc().
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
search context as argument. This allows calling it with the mft
record mapped. Update all callers.
- Fix potential deadlock in ntfs_mft_data_extend_allocation_nolock()
error handling by passing in the active search context when calling
ntfs_cluster_free().
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
search context as argument. This allows calling it with the mft
record mapped. Update all callers.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
eliminate the double copy, and improve cifs write performance and
help the server by upping the typical write size from 4K to 16K
(or even larger if wsize set explicitly) for servers which support this.
Part 1 of 2
Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
This patch fixes up a few problems with jfs's reserved inodes.
1. There is no need for the jfs code setting the I_DIRTY bits in i_state.
I am ashamed that the code ever did this, and surprised it hasn't been
noticed until now.
2. Make sure special inodes are on an inode hash list. If the inodes are
unhashed, __mark_inode_dirty will fail to put the inode on the
superblock's dirty list, and the data will not be flushed under memory
pressure.
3. Force writing journal data to disk when metapage_writepage is unable to
write a metadata page due to pending journal I/O.
Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
Check O_DIRECT and return -EINVAL error in open. dentry_open() also checks
this but only after the open method is called. This patch optimizes away
the unnecessary upcalls in this case.
It could be a correctness issue too: if filesystem has open() with side
effect, then it should fail before doing the open, not after.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Calling truncate() on hostfs spits a kernel warning "Something isn't
implemented here", but it still works fine.
Indeed, hostfs i_op->truncate doesn't do anything. But hostfs_setattr() ->
set_attr() correctly detects ATTR_SIZE and calls truncate() on the host. So
we should be safe (using ftruncate() may be better, in case the file is
unlinked on the host, but we aren't sure to have the file open for writing,
and reopening it would cause the same races; plus nobody should expect UML to
be so careful).
So, the warning is wrong, because the current implementation is working. Al,
am I correct, and can the warning be therefore dropped?
CC: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Recently aio_p{read,write} changed to perform retries internally rather
than returning -EIOCBRETRY. This inadvertantly resulted in always calling
aio_{read,write} with ki_left at 0 which would in turn immediately return
0. Harmless, but we can avoid this call by checking in the caller.
Signed-off-by: Zach Brown <zach.brown@oracle.com>
Signed-off-by: Benjamin LaHaise <bcrl@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Only one of the run or kick path is supposed to put an iocb on the run
list. If both of them do it than one of them can end up referencing a
freed iocb. The kick path could delete the task_list item from the wait
queue before getting the ctx_lock and putting the iocb on the run list.
The run path was testing the task_list item outside the lock so that it
could catch ki_retry methods that return -EIOCBRETRY *without* putting the
iocb on a wait queue and promising to call kick_iocb. This unlocked check
could then race with the kick path to cause both to try and put the iocb on
the run list.
The patch stops the run path from testing task_list by requring that any
ki_retry that returns -EIOCBRETRY *must* guarantee that kick_iocb() will be
called in the future. aio_p{read,write}, the only in-tree -EIOCBRETRY
users, are updated.
Signed-off-by: Zach Brown <zach.brown@oracle.com>
Signed-off-by: Benjamin LaHaise <bcrl@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Only one of the run or kick path is supposed to put an iocb on the run
list. If both of them do it than one of them can end up referencing a
freed iocb. The kick patch could set the Kicked bit before acquiring the
ctx_lock and putting the iocb on the run list. The run path, while holding
the ctx_lock, could see this partial kick and mistake it for a kick that
was deferred while it was doing work with the run_list NULLed out. It
would then race with the kick thread to add the iocb to the run list.
This patch moves the kick setting under the ctx_lock so that only one of
the kick or run path queues the iocb on the run list, as intended.
Signed-off-by: Zach Brown <zach.brown@oracle.com>
Signed-off-by: Benjamin LaHaise <bcrl@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
it seems that readv(2)/writev(2) syscalls do not call
file_permission callback. Looks like this is overlook.
I have filled the issue into redhat bugzilla as
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=169433
and got the recommendation to post this on lsm mailing list.
The following trivial patch solves the problem.
Signed-off-by: Kostik Belousov <kostikbel@gmail.com>
Signed-off-by: Chris Wright <chrisw@osdl.org>
Fid management cleanup. The patch attempts to fix the races in dentry's
fid management.
Dentries don't keep the opened fids anymore, they are moved to the file
structs. Ideally there should be no more than one fid with fidcreate equal
to zero in the dentry's list of fids.
v9fs_fid_create initializes the important fields (fid, fidcreated) before
v9fs_fid is added to the list. v9fs_fid_lookup returns only fids that are
not created by v9fs_create. v9fs_fid_get_created returns the fid created
by the same process by v9fs_create (if any) and removes it from dentry's
list
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix failure paths in ext3_new_inode() and clean up duplicated code: -
DQUOT_DROP() was not being called if ext3_init_security() failed.
Signed-off-by: Chris Sykes <chris@sigsegv.plus.com>
Cc: Stephen Smalley <sds@epoch.ncsc.mil>
Cc: Jan Kara <jack@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix failure paths in ext2_new_inode() and clean up duplicated code: -
DQUOT_DROP() was not being called if ext2_init_security() failed.
Signed-off-by: Chris Sykes <chris@sigsegv.plus.com>
Cc: Stephen Smalley <sds@epoch.ncsc.mil>
Cc: Jan Kara <jack@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch checks reserved node ID values returned by lookup and creation
operations. In case one of the reserved values is sent, return -EIO.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add information about required version of the userspace library/utilities
to Documentation/Changes. Also add pointer to this and to FUSE
documentation from Kconfig.
Thanks to Anton Altaparmakov for the reminder.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
restart pages in the journal without multi sector transfer protection
fixups (i.e. the update sequence array is empty and in fact does not
exist).
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
This creates the directory structure under arch/powerpc and a bunch
of Kconfig files. It does a first-cut merge of arch/powerpc/mm,
arch/powerpc/lib and arch/powerpc/platforms/powermac. This is enough
to build a 32-bit powermac kernel with ARCH=powerpc.
For now we are getting some unmerged files from arch/ppc/kernel and
arch/ppc/syslib, or arch/ppc64/kernel. This makes some minor changes
to files in those directories and files outside arch/powerpc.
The boot directory is still not merged. That's going to be interesting.
Signed-off-by: Paul Mackerras <paulus@samba.org>
cifsd had been preventing software suspend from completing.
Signed-off-by: pavel@suse.de
Signed-off-by: Steve French <sfrench@us.ibm.com> lightly modified
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Currently rpc_mkdir/rpc_rmdir and rpc_mkpipe/mk_unlink have an API that's
a little unfortunate. They take a path relative to the rpc_pipefs root and
thus need to perform a full lookup. If you look at debugfs or usbfs they
always store the dentry for directories they created and thus can pass in
a dentry + single pathname component pair into their equivalents of the
above functions.
And in fact rpc_pipefs actually stores a dentry for all but one component so
this change not only simplifies the core rpc_pipe code but also the callers.
Unfortuntately this code path is only used by the NFS4 idmapper and
AUTH_GSSAPI for which I don't have a test enviroment. Could someone give
it a spin? It's the last bit needed before we can rework the
lookup_hash API
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Each transport implementation can now set unique bind, connect,
reestablishment, and idle timeout values. These are variables,
allowing the values to be modified dynamically. This permits
exponential backoff of any of these values, for instance.
As an example, we implement exponential backoff for the connection
reestablishment timeout.
Test-plan:
Destructive testing (unplugging the network temporarily). Connectathon
with UDP and TCP.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Get rid of the "xprt->nocong" variable.
Test-plan:
Use WAN simulation to cause sporadic bursty packet loss with UDP mounts.
Look for significant regression in performance or client stability.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Now we can fix up the last few places that use the "xprt->stream"
variable, and get rid of it from the rpc_xprt structure.
Test-plan:
Destructive testing (unplugging the network temporarily). Connectathon
with UDP and TCP.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Implement a best practice: don't use exponential backoff when computing
retransmit timeout values on TCP connections, but simply retransmit
at regular intervals.
This also fixes a bug introduced when xprt_reset_majortimeo() was added.
Test-plan:
Enable RPC debugging and watch timeout behavior on a NFS/TCP mount.
Version: Thu, 11 Aug 2005 16:02:19 -0400
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Fixes a condition whereby the kernel is returning the non-POSIX error
EBADCOOKIE to userspace.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
[PATCH] Fix miscompare in __posix_lock_file
If an application requests the same lock twice, the
kernel should just leave the existing lock in place.
Currently, it will install a second lock of the same type.
Signed-off-by: Olaf Kirch <okir@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
When doing a rename on top of an existing file that is not in use,
the inode of the overwritten file will remain in the icache.
The fix is to decrement i_nlink of the overwritten inode, like we
do for unlink, rmdir etc already.
Problem diagnosed by Olaf Kirch. This patch is a slight variation
on his fix.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
since we otherwise get into a lock reversal deadlock if a read locked
runlist is passed in. In the process also change it to take an ntfs
inode instead of a vfs inode as parameter.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
nfs_readpage_release() causes an oops while accessing a file with NFS
debugging turned on (echo 32767 > /proc/sys/sunrpc/nfs_debug) and a kernel
built with CONFIG_DEBUG_SLAB.
This patch moves the debugging statement above nfs_release_request() to
avoid accessing freed memory.
Signed-off-by: Nick Wilson <njw@osdl.org>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix some warnings and a build error when EXT3_DEBUG is enabled.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
EXT3_MOUNT_DATA_FLAGS is not a boolean. This fixes it.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If error occurs while in v9fs_get_sb after it calles sget, the dentry object
of the root and its inode may be freed twice -- once while handling the error
in v9fs_get_sb, and second time when v9fs_get_sb calles deactivate_super
(which in turn calls v9fs_kill_super)
The patch removes the unnecessary code that frees the root dentry and its
inode.
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
v9fs_vfs_readlink allocates space for the link using __getname and
errorneously uses strlen on the newly allocated buffer to check if the buffer
passed by the user is bigger than the one returned by __getname.
The patch replaces the strlen usage to PATH_MAX, which is the actual size of
the buffers returned by __getname.
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When a new session is created it uses a template object of the specified
transport type to instantiate its own copy. The code for the making a copy of
the template object was lost, and the object itself is attached to the v9fs
session. This leads to many sessions using the same transport instead of
having their own copy.
The patch puts back the code that makes a copy of the template object.
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When v9fs_deserealize_fcall deserializes a Rwalk message, it incorrectly
allocates space for the qid array in the source instead of the destination
buffer.
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
buf_check_size function checks if the conv buffer has enough space for the
performed operation, but it doesn't return the result back to the calling
function, only logs an error in the log.
The report-back-error functionality was lost when buf_check_size was
converted from macro to inline function. The return in the macro used to
exit from the functions that include it, after the conversion it just exits
from the inline function itself.
The patch makes buf_check_size to return flag and all functions that use
it check if they should perform the operation, or exit.
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
fs/proc/base.c: In function `proc_task_root_link':
fs/proc/base.c:364: warning: ISO C90 forbids mixed declarations and code
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Most important of these fixes mapchars on bigendian and a few statfs fields
Signed-off-by: Shaggy (shaggy@austin.ibm.com)
Signed-off-by: Steve French (sfrench@us.ibm.com)
functional, and the length check is fixed so readdir does not throw a
warning message when windows me messes up the response to FindFirst
of an empty dir (with only . and ..).
Signed-off-by: Steve French (sfrench@us.ibm.com)
During a forensic analysis on the fat file system, I found than the result for
the last access date on this file system was different between the stat
command and the istat command (package tct-utils).
The istat command display a true date (the right windows date) but the stat
primitive (so stat, find, ls command) displays a wrong date.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When the main thread of a thread group has done pthread_exit() and died,
the other threads are still happily running, but will not be visible
under /proc because their leader is no longer accessible.
This fixes the access control so that we can see the sub-threads again.
Signed-off-by: Sripathi Kodi <sripathik@in.ibm.com>
Acked-by: Al Viro <viro@ftp.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
ME, and do not set ctime unless explicitly requested with atime and/or
mtime (it gets thrown away by most servers anyway as there is no way to set
this via posix).
Signed-off-by: Steve French (sfrench@us.ibm.com)
This patch fixes miss-sync issue on write() system call. This updates
inode attrs flags, mtime and ctime on every comit_write call, due to
locking.
Signed-off-by: Hiroyuki Machida <machida@sm.sony.co.jp>
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
With the new fdtable locking rules, you have to protect fdtable with either
->file_lock or rcu_read_lock/unlock(). There are some places where we
aren't doing either. This patch fixes those places.
Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add smp_mb__after_clear_bit() to unlock_kiocb()
AIO's use of wait_on_bit_lock()/wake_up_bit() forgot to add a barrier
between clearing its lock bit and calling wake_up_bit() so wake_up_bit()'s
unlocked waitqueue_active() can race. This puts AIO's use in line with the
others and the comment above wake_up_bit().
Signed-off-by: Zach Brown <zach.brown@oracle.com>
Acked-by: Benjamin LaHaise <bcrl@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Al found a potential problem in epoll_create(), where the
file->private_data member was set after fd_install(). This is obviously
wrong since another thread might do a close() on that fd# before we set the
file->private_data member. This goes over 2.6.13 and passes a few basic
tests I've done here.
(akpm: snuck in a kzalloc() cleanup too)
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
we do not request more than negotiated buffer size even if buffer
size is small (smaller than one page)
Signed-off-by: Steve French (sfrench@us.ibm.com)
The fix in inode.c is a real bug. It could result in undeleted, yet
unconnected files on big-endian hardware.
The others are trivial.
Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
Missing acct_update_integrals() and update_mem_hiwater() calls
compared to it's native counterpart.
Signed-off-by: David S. Miller <davem@davemloft.net>
Noted by David Miller:
"The bug is that free_fd_array() takes a "num" argument, but when
calling it from __free_fdtable() we're instead passing in the size in
bytes (ie. "num * sizeof(struct file *)")."
Yes it is a bug. I think I messed it up while merging newer
changes with an older version where I was using size in bytes
to optimize.
Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Pavel Emelianov and Kirill Korotaev observe that fs and arch users of
security_vm_enough_memory tend to forget to vm_unacct_memory when a
failure occurs further down (typically in setup_arg_pages variants).
These are all users of insert_vm_struct, and that reservation will only
be unaccounted on exit if the vma is marked VM_ACCOUNT: which in some
cases it is (hidden inside VM_STACK_FLAGS) and in some cases it isn't.
So x86_64 32-bit and ppc64 vDSO ELFs have been leaking memory into
Committed_AS each time they're run. But don't add VM_ACCOUNT to them,
it's inappropriate to reserve against the very unlikely case that gdb
be used to COW a vDSO page - we ought to do something about that in
do_wp_page, but there are yet other inconsistencies to be resolved.
The safe and economical way to fix this is to let insert_vm_struct do
the security_vm_enough_memory check when it finds VM_ACCOUNT is set.
And the MIPS irix_brk has been calling security_vm_enough_memory before
calling do_brk which repeats it, doubly accounting and so also leaking.
Remove that, and all the fs and arch calls to security_vm_enough_memory:
give it a less misleading name later on.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-Off-By: Kirill Korotaev <dev@sw.ru>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It turns out that the BUG_ON() in fs/exec.c: de_thread() is unreliable
and can trigger due to the test itself being racy.
de_thread() does
while (atomic_read(&sig->count) > count) {
}
.....
.....
BUG_ON(!thread_group_empty(current));
but release_task does
write_lock_irq(&tasklist_lock)
__exit_signal
(this is where atomic_dec(&sig->count) is run)
__exit_sighand
__unhash_process
takes write lock on tasklist_lock
remove itself out of PIDTYPE_TGID list
write_unlock_irq(&tasklist_lock)
so there's a clear (although small) window between the
atomic_dec(&sig->count) and the actual PIDTYPE_TGID unhashing of the
thread.
And actually there is no need for all threads to have exited at this
point, so we simply kill the BUG_ON.
Big thanks to Marc Lehmann who provided the test-case.
Fixes Bug 5170 (http://bugme.osdl.org/show_bug.cgi?id=5170)
Signed-off-by: Alexander Nyberg <alexn@telia.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We could try to unlock the state lock here without having first locked it.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In the case of a lock which introduces a new lockowner, the openowner's
sequence id should be incremented, even when the operation fails, if the
error is a sequence-id-mutating error. The current code fails to do that
in some cases. Fix this by using the same sequence-id-incrementing
mechanism that all other such operations use.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It seems more natural to move the setting of the replay_owner into the
relevant procedure instead of doing it in nfsv4_proc_compound.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Demote some printk's that look like they could be triggered by non-buggy
clients to dprintk's. (For example, stale clientid's are normal
occurrences on reboot, and on a server with a lot of clients these messages
could become annoying.)
Also remove some redundant dprintk's (e.g. no need for both STALE_CLIENTID
and its callers to do dprintks).
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
reiserfs should use mark_inode_dirty during reiserfs_file_write and
reiserfs_commit_write. This makes sure the inode is properly flagged as
dirty, which is used during O_SYNC to decide when to trigger log commits.
This patch also removes the O_SYNC check from reiserfs_commit_write, since
that gets dealt with properly at higher layers once we start using
mark_inode_dirty.
Thanks to Hifumi Hisashi <hifumi.hisashi@lab.ntt.co.jp> for catching this.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When open(O_CREAT) is called and the error, ENFILE, is returned, the file
may be created anyway. This is counter intuitive, against the SUS V3
specification, and may cause applications to misbehave if they are not
coded correctly to handle this semantic. The SUS V3 specification
explicitly states "No files shall be created or modified if the function
returns -1.".
The error, ENFILE, is used to indicate the system wide open file table is
full and no more file structs can be allocated.
This is due to an ordering problem. The entry in the directory is created
before the file struct is allocated. If the allocation for the file struct
fails, then the system call must return an error, but the directory entry
was already created and can not be safely removed.
The solution to this situation is relatively easy. The file struct should
be allocated before the directory entry is created. If the allocation
fails, then the error can be returned directly. If the creation of the
directory entry fails, then the file struct can be easily freed.
Signed-off-by: Peter Staubach <staubach@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
an octal number to conform to how chmod(1) works, too. Thanks to
Giuseppe Bilotta and Horst von Brand for pointing out the errors of
my ways.
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
Clash due to new delete_inode behavior (the filesystem now needs to do
the truncate_inode_pages() call itself).
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use schedule_timeout_{,un}interruptible() instead of
set_current_state()/schedule_timeout() to reduce kernel size. Also use helper
functions to convert between human time units and jiffies rather than constant
HZ division to avoid rounding errors.
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Every file should #include the header with the prototypes of the global
functions it is offering.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
First one is list_for_each_entry (thanks maks), second 2 list_for_each_safe.
Signed-off-by: Maximilian Attems <janitor@sternwelten.at>
Signed-off-by: Domen Puncer <domen@coderock.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make code more readable with list_for_each_entry.
Signed-off-by: Maximilian Attems <janitor@sternwelten.at>
Signed-off-by: Domen Puncer <domen@coderock.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use list_for_each_entry to make code more readable.
Signed-off-by: Maximilian Attems <janitor@sternwelten.at>
Signed-off-by: Domen Puncer <domen@coderock.org>
Cc: <jffs-dev@axis.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch implements a task state bit (TASK_NONINTERACTIVE), which can be
used by blocking points to mark the task's wait as "non-interactive". This
does not mean the task will be considered a CPU-hog - the wait will simply
not have an effect on the waiting task's priority - positive or negative
alike. Right now only pipe_wait() will make use of it, because it's a
common source of not-so-interactive waits (kernel compilation jobs, etc.).
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch (written by me and also containing many suggestions of Arjan van
de Ven) does a major cleanup of the spinlock code. It does the following
things:
- consolidates and enhances the spinlock/rwlock debugging code
- simplifies the asm/spinlock.h files
- encapsulates the raw spinlock type and moves generic spinlock
features (such as ->break_lock) into the generic code.
- cleans up the spinlock code hierarchy to get rid of the spaghetti.
Most notably there's now only a single variant of the debugging code,
located in lib/spinlock_debug.c. (previously we had one SMP debugging
variant per architecture, plus a separate generic one for UP builds)
Also, i've enhanced the rwlock debugging facility, it will now track
write-owners. There is new spinlock-owner/CPU-tracking on SMP builds too.
All locks have lockup detection now, which will work for both soft and hard
spin/rwlock lockups.
The arch-level include files now only contain the minimally necessary
subset of the spinlock code - all the rest that can be generalized now
lives in the generic headers:
include/asm-i386/spinlock_types.h | 16
include/asm-x86_64/spinlock_types.h | 16
I have also split up the various spinlock variants into separate files,
making it easier to see which does what. The new layout is:
SMP | UP
----------------------------|-----------------------------------
asm/spinlock_types_smp.h | linux/spinlock_types_up.h
linux/spinlock_types.h | linux/spinlock_types.h
asm/spinlock_smp.h | linux/spinlock_up.h
linux/spinlock_api_smp.h | linux/spinlock_api_up.h
linux/spinlock.h | linux/spinlock.h
/*
* here's the role of the various spinlock/rwlock related include files:
*
* on SMP builds:
*
* asm/spinlock_types.h: contains the raw_spinlock_t/raw_rwlock_t and the
* initializers
*
* linux/spinlock_types.h:
* defines the generic type and initializers
*
* asm/spinlock.h: contains the __raw_spin_*()/etc. lowlevel
* implementations, mostly inline assembly code
*
* (also included on UP-debug builds:)
*
* linux/spinlock_api_smp.h:
* contains the prototypes for the _spin_*() APIs.
*
* linux/spinlock.h: builds the final spin_*() APIs.
*
* on UP builds:
*
* linux/spinlock_type_up.h:
* contains the generic, simplified UP spinlock type.
* (which is an empty structure on non-debug builds)
*
* linux/spinlock_types.h:
* defines the generic type and initializers
*
* linux/spinlock_up.h:
* contains the __raw_spin_*()/etc. version of UP
* builds. (which are NOPs on non-debug, non-preempt
* builds)
*
* (included on UP-non-debug builds:)
*
* linux/spinlock_api_up.h:
* builds the _spin_*() APIs.
*
* linux/spinlock.h: builds the final spin_*() APIs.
*/
All SMP and UP architectures are converted by this patch.
arm, i386, ia64, ppc, ppc64, s390/s390x, x64 was build-tested via
crosscompilers. m32r, mips, sh, sparc, have not been tested yet, but should
be mostly fine.
From: Grant Grundler <grundler@parisc-linux.org>
Booted and lightly tested on a500-44 (64-bit, SMP kernel, dual CPU).
Builds 32-bit SMP kernel (not booted or tested). I did not try to build
non-SMP kernels. That should be trivial to fix up later if necessary.
I converted bit ops atomic_hash lock to raw_spinlock_t. Doing so avoids
some ugly nesting of linux/*.h and asm/*.h files. Those particular locks
are well tested and contained entirely inside arch specific code. I do NOT
expect any new issues to arise with them.
If someone does ever need to use debug/metrics with them, then they will
need to unravel this hairball between spinlocks, atomic ops, and bit ops
that exist only because parisc has exactly one atomic instruction: LDCW
(load and clear word).
From: "Luck, Tony" <tony.luck@intel.com>
ia64 fix
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjanv@infradead.org>
Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Cc: Matthew Wilcox <willy@debian.org>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Mikael Pettersson <mikpe@csd.uu.se>
Signed-off-by: Benoit Boissinot <benoit.boissinot@ens-lyon.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Andrew lost this in patch reject resolution, and never noticed, since
the compat code isn't in use on x86.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This converts the final 20 DEFINE_SPINLOCK holdouts. (another 580 places
are already using DEFINE_SPINLOCK). Build tested on x86.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch removes ability to interrupt and restart operations while there
hasn't been any side-effect.
The reason: applications. There are some apps it seems that generate
signals at a fast rate. This means, that if the operation cannot make
enough progress between two signals, it will be restarted for ever. This
bug actually manifested itself with 'krusader' trying to open a file for
writing under sshfs. Thanks to Eduard Czimbalmos for the report.
The problem can be solved just by making open() uninterruptible, because in
this case it was the truncate operation that slowed down the progress. But
it's better to solve this by simply not allowing interrupts at all (except
SIGKILL), because applications don't expect file operations to be
interruptible anyway. As an added bonus the code is simplified somewhat.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds a new FSYNCDIR request, which is sent when fsync is called
on directories. This operation is available in libfuse 2.3-pre1 or
greater.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Don't change mtime/ctime/atime to local time on read/write. Rather invalidate
file attributes, so next stat() will force a GETATTR call. Bug reported by
Ben Grimm.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make data caching behavior selectable on a per-open basis instead of
per-mount. Compatibility for the old mount options 'kernel_cache' and
'direct_io' is retained in the userspace library (version 2.4.0-pre1 or
later).
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch removes a long lasting "hack" in FUSE, which used a separate
channel (a file descriptor refering to a disk-file) to transfer directory
contents from userspace to the kernel.
The patch adds three new operations (OPENDIR, READDIR, RELEASEDIR), which
have semantics and implementation exactly maching the respective file
operations (OPEN, READ, RELEASE).
This simplifies the directory reading code. Also disk space is not
necessary, which can be important in embedded systems.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds support for the "direct_io" mount option of FUSE.
When this mount option is specified, the page cache is bypassed for
read and write operations. This is useful for example, if the
filesystem doesn't know the size of files before reading them, or when
any kind of caching is harmful.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Check for the presence of all mandatory mount options.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch tightens the check for allowing processes to access non-privileged
mounts. The rational is that the filesystem implementation can control the
behavior or get otherwise unavailable information of the filesystem user. If
the filesystem user process has the same uid, gid, and is not suid or sgid
application, then access is safe. Otherwise access is not allowed unless the
"allow_other" mount option is given (for which policy is controlled by the
userspace mount utility).
Thanks to everyone linux-fsdevel, especially Martin Mares who helped uncover
problems with the previous approach.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds readpages support to FUSE.
With the help of the readpages() operation multiple reads are bundled
together and sent as a single request to userspace. This can improve
reading performace.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds the extended attribute operations to FUSE.
The following operations are added:
o getxattr
o setxattr
o listxattr
o removexattr
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds miscellaneous mount options to the FUSE filesystem.
The following mount options are added:
o default_permissions: check permissions with generic_permission()
o allow_other: allow other users to access files
o allow_root: allow root to access files
o kernel_cache: don't invalidate page cache on open
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds the file operations of FUSE.
The following operations are added:
o open
o flush
o release
o fsync
o readpage
o commit_write
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds the write filesystem operations of FUSE.
The following operations are added:
o setattr
o symlink
o mknod
o mkdir
o create
o unlink
o rmdir
o rename
o link
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds the read-only filesystem operations of FUSE.
This contains the following files:
o dir.c
- directory, symlink and file-inode operations
The following operations are added:
o lookup
o getattr
o readlink
o follow_link
o directory open
o readdir
o directory release
o permission
o dentry revalidate
o statfs
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This adds the FUSE device handling functions.
This contains the following files:
o dev.c
- fuse device operations (read, write, release, poll)
- registers misc device
- support for sending requests to userspace
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds FUSE core.
This contains the following files:
o inode.c
- superblock operations (alloc_inode, destroy_inode, read_inode,
clear_inode, put_super, show_options)
- registers FUSE filesystem
o fuse_i.h
- private header file
Requirements
============
The most important difference between orinary filesystems and FUSE is
the fact, that the filesystem data/metadata is provided by a userspace
process run with the privileges of the mount "owner" instead of the
kernel, or some remote entity usually running with elevated
privileges.
The security implication of this is that a non-privileged user must
not be able to use this capability to compromise the system. Obvious
requirements arising from this are:
- mount owner should not be able to get elevated privileges with the
help of the mounted filesystem
- mount owner should not be able to induce undesired behavior in
other users' or the super user's processes
- mount owner should not get illegitimate access to information from
other users' and the super user's processes
These are currently ensured with the following constraints:
1) mount is only allowed to directory or file which the mount owner
can modify without limitation (write access + no sticky bit for
directories)
2) nosuid,nodev mount options are forced
3) any process running with fsuid different from the owner is denied
all access to the filesystem
1) and 2) are ensured by the "fusermount" mount utility which is a
setuid root application doing the actual mount operation.
3) is ensured by a check in the permission() method in kernel
I started thinking about doing 3) in a different way because Christoph
H. made a big deal out of it, saying that FUSE is unacceptable into
mainline in this form.
The suggested use of private namespaces would be OK, but in their
current form have many limitations that make their use impractical (as
discussed in this thread).
Suggested improvements that would address these limitations:
- implement shared subtrees
- allow a process to join an existing namespace (make namespaces
first-class objects)
- implement the namespace creation/joining in a PAM module
With all that in place the check of owner against current->fsuid may
be removed from the FUSE kernel module, without compromising the
security requirements.
Suid programs still interesting questions, since they get access even
to the private namespace causing some information leak (exact
order/timing of filesystem operations performed), giving some
ptrace-like capabilities to unprivileged users. BTW this problem is
not strictly limited to the namespace approach, since suid programs
setting fsuid and accessing users' files will succeed with the current
approach too.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch attempts to do a better job of cleaning up after detecting errors
on the transport. This should also improve error reporting on broken
connections to servers.
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
LANL reported some issues with random crashes during mount of legacy protocol
servers (9P2000 versus 9P2000.u) -- crash was always happening in readlink
(which should never happen in legacy mode). Added some sanity conditionals to
the get_inode code which should prevent the errors LANL was seeing. Code
tested benign through regression.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Cleanup code in v9fs vfs_inode as suggested by Alexey Dobriyan. Did some
major revamping of the v9fs setattr code to remove unnecessary allocations and
clean up some dead-code.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Change magic error numbers to system defined constants in v9fs error.h As
suggested by Jan-Benedict Glaw.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This part of the patch contains debug and other misc routines.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Support for force umount
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This part of the patch contains transport routines.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This part of the patch contains the 9P protocol functions.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This part of the patch contains VFS superblock and mapping code.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This part of the patch contains the VFS inode interfaces.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This part of the patch contains the VFS file, dentry & directory interfaces.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
OVERVIEW
V9FS is a distributed file system for Linux which provides an
implementation of the Plan 9 resource sharing protocol 9P. It can be
used to share all sorts of resources: static files, synthetic file servers
(such as /proc or /sys), devices, and application file servers (such as
FUSE).
BACKGROUND
Plan 9 (http://plan9.bell-labs.com/plan9) is a research operating
system and associated applications suite developed by the Computing
Science Research Center of AT&T Bell Laboratories (now a part of
Lucent Technologies), the same group that developed UNIX , C, and C++.
Plan 9 was initially released in 1993 to universities, and then made
generally available in 1995. Its core operating systems code laid the
foundation for the Inferno Operating System released as a product by
Lucent Bell-Labs in 1997. The Inferno venture was the only commercial
embodiment of Plan 9 and is currently maintained as a product by Vita
Nuova (http://www.vitanuova.com). After updated releases in 2000 and
2002, Plan 9 was open-sourced under the OSI approved Lucent Public
License in 2003.
The Plan 9 project was started by Ken Thompson and Rob Pike in 1985.
Their intent was to explore potential solutions to some of the
shortcomings of UNIX in the face of the widespread use of high-speed
networks to connect machines. In UNIX, networking was an afterthought
and UNIX clusters became little more than a network of stand-alone
systems. Plan 9 was designed from first principles as a seamless
distributed system with integrated secure network resource sharing.
Applications and services were architected in such a way as to allow
for implicit distribution across a cluster of systems. Configuring an
environment to use remote application components or services in place
of their local equivalent could be achieved with a few simple command
line instructions. For the most part, application implementations
operated independent of the location of their actual resources.
Commercial operating systems haven't changed much in the 20 years
since Plan 9 was conceived. Network and distributed systems support is
provided by a patchwork of middle-ware, with an endless number of
packages supplying pieces of the puzzle. Matters are complicated by
the use of different complicated protocols for individual services,
and separate implementations for kernel and application resources.
The V9FS project (http://v9fs.sourceforge.net) is an attempt to bring
Plan 9's unified approach to resource sharing to Linux and other
operating systems via support for the 9P2000 resource sharing
protocol.
V9FS HISTORY
V9FS was originally developed by Ron Minnich and Maya Gokhale at Los
Alamos National Labs (LANL) in 1997. In November of 2001, Greg Watson
setup a SourceForge project as a public repository for the code which
supported the Linux 2.4 kernel.
About a year ago, I picked up the initial attempt Ron Minnich had
made to provide 2.6 support and got the code integrated into a 2.6.5
kernel. I then went through a line-for-line re-write attempting to
clean-up the code while more closely following the Linux Kernel style
guidelines. I co-authored a paper with Ron Minnich on the V9FS Linux
support including performance comparisons to NFSv3 using Bonnie and
PostMark - this paper appeared at the USENIX/FREENIX 2005
conference in April 2005:
( http://www.usenix.org/events/usenix05/tech/freenix/hensbergen.html ).
CALL FOR PARTICIPATION/REQUEST FOR COMMENTS
Our 2.6 kernel support is stabilizing and we'd like to begin pursuing
its integration into the official kernel tree. We would appreciate any
review, comments, critiques, and additions from this community and are
actively seeking people to join our project and help us produce
something that would be acceptable and useful to the Linux community.
STATUS
The code is reasonably stable, although there are no doubt corner cases
our regression tests haven't discovered yet. It is in regular use by several
of the developers and has been tested on x86 and PowerPC
(32-bit and 64-bit) in both small and large (LANL cluster) deployments.
Our current regression tests include fsx, bonnie, and postmark.
It was our intention to keep things as simple as possible for this
release -- trying to focus on correctness within the core of the
protocol support versus a rich set of features. For example: a more
complete security model and cache layer are in the road map, but
excluded from this release. Additionally, we have removed support for
mmap operations at Al Viro's request.
PERFORMANCE
Detailed performance numbers and analysis are included in the FREENIX
paper, but we show comparable performance to NFSv3 for large file
operations based on the Bonnie benchmark, and superior performance for
many small file operations based on the PostMark benchmark. Somewhat
preliminary graphs (from the FREENIX paper) are available
(http://v9fs.sourceforge.net/perf/index.html).
RESOURCES
The source code is available in a few different forms:
tarballs: http://v9fs.sf.net
CVSweb: http://cvs.sourceforge.net/viewcvs.py/v9fs/linux-9p/
CVS: :pserver:anonymous@cvs.sourceforge.net:/cvsroot/v9fs/linux-9p
Git: rsync://v9fs.graverobber.org/v9fs (webgit: http://v9fs.graverobber.org)
9P: tcp!v9fs.graverobber.org!6564
The user-level server is available from either the Plan 9 distribution
or from http://v9fs.sf.net
Other support applications are still being developed, but preliminary
version can be downloaded from sourceforge.
Documentation on the protocol has historically been the Plan 9 Man
pages (http://plan9.bell-labs.com/sys/man/5/INDEX.html), but there is
an effort under way to write a more complete Internet-Draft style
specification (http://v9fs.sf.net/rfc).
There are a couple of mailing lists supporting v9fs, but the most used
is v9fs-developer@lists.sourceforge.net -- please direct/cc your
comments there so the other v9fs contibutors can participate in the
conversation. There is also an IRC channel: irc://freenode.net/#v9fs
This part of the patch contains Documentation, Makefiles, and configuration
file changes.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
