Commit Graph

234322 Commits

Author SHA1 Message Date
Tao Ma a5b8443b34 ocfs2: Remove masklog ML_DCACHE.
Remove mlog(0) from fs/ocfs2/dcache.c and the masklog DCACHE.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-23 22:51:49 +08:00
Tao Ma 8990e44a2b ocfs2: Remove masklog ML_NAMEI.
Remove mlog(0) from fs/ocfs2/namei.c and the masklog NAMEI finally.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-23 22:45:26 +08:00
Tao Ma f1088d471f ocfs2: Remove mlog(0) from fs/ocfs2/dir.c
This is the 2nd step to remove the debug info of NAMEI.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-23 22:30:23 +08:00
Tao Ma f32037d9bd ocfs2: remove NAMEI from symlink.c
No mlog(0,...) in symlink.c, so just remove NAMEI.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-21 11:19:02 +08:00
Tao Ma 1db986a839 ocfs2: Remove masklog ML_QUOTA.
Remove mlog(0) from fs/ocfs2/quota_global.c and
the masklog QUOTA.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-23 22:19:12 +08:00
Tao Ma 38877a4379 ocfs2: Remove mlog(0) from quota_local.c.
Remove mlog(0) from fs/ocfs2/quota_local.c.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-23 22:12:48 +08:00
Tao Ma 2661836e0c ocfs2: Remove masklog ML_RESERVATIONS.
Remove mlog(0) from fs/ocfs2/reservations.c and the masklog RESERVATIONS.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-23 22:10:56 +08:00
Tao Ma 402b418311 ocfs2: Remove masklog ML_XATTR.
Remove mlog(0) from fs/ocfs2/xattr.c and the masklog ML_XATTR.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-23 22:01:17 +08:00
Tao Ma 32a42d392b ocfs2: Remove masklog ML_SUPER.
Remove mlog(0) from fs/ocfs2/super.c and the masklog SUPER.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-23 21:29:08 +08:00
Tao Ma b5770f98b0 ocfs2: Remove mlog(0) from fs/ocfs2/heartbeat.c
This is the 2nd step to remove the debug info of SUPER.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-23 21:17:39 +08:00
Tao Ma a8731086ef ocfs2: Remove mlog(0) from fs/ocfs2/slot_map.c
This is the 1st step to remove the debug info of SUPER.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-22 22:29:08 +08:00
Tao Ma a716357c47 ocfs2: Remove masklog ML_EXTENT_MAP.
Remove mlog(0) from fs/ocfs2/extent_map.c and the masklog EXTENT_MAP.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-22 22:27:33 +08:00
Tao Ma 64f3b26927 ocfs2: Remove masklog ML_INODE.
Remove mlog(0) from fs/ocfs2/inode.c and the masklog INODE.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-22 22:24:57 +08:00
Tao Ma 6218b90e76 ocfs2: Little refactoring against ocfs2_iget.
ocfs2_iget is used to get/create inode. Only iget5_locked
will give us an inode = NULL. So move this check ahead of
ocfs2_read_locked_inode so that we don't need to check
inode before we read and unlock inode. This is also helpful
for trace event(see the next patch).

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-21 11:18:30 +08:00
Tao Ma 468eedde23 ocfs2: Remove mlog(0) from fs/ocfs2/file.c
This is the 2nd step to remove the debug info of INODE.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-22 22:14:41 +08:00
Tao Ma da561c9cfa ocfs2: remove INODE from unused files.
As there are no such debug information in fs/ocfs2/ioctl.c,
fs/ocfs2/locks.c and fs/ocfs2/sysfile.c, ML_INODE are also
removed.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-21 11:18:23 +08:00
Tao Ma 614a9e849c ocfs2: Remove FILE_IO from masklog.
Change all the "mlog(0," in fs/ocfs2/mmap.c to trace events.
And finally remove masklog FILE_IO.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-22 21:59:46 +08:00
Tao Ma 9558156bcf ocfs2: Remove mlog(0) from fs/ocfs2/aops.c
Remove all the "mlog(0," in fs/ocfs2/aops.c.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-22 21:33:59 +08:00
Tao Ma 198aac2838 ocfs2: Remove masklog ML_REFCOUNT.
Change all the "mlog(0," in fs/ocfs2/refcounttree.c to trace events.
And finally remove masklog ML_REFCOUNT.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-22 08:20:04 +08:00
Tao Ma 81bad69749 ocfs2: Remove DISK_ALLOC from masklog.
Since all 4 files, localalloc.c, suballoc.c, alloc.c and
resize.c, which use DISK_ALLOC are changed to trace events,
Remove masklog DISK_ALLOC totally.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-22 08:01:27 +08:00
Tao Ma a5438702ee ocfs2: Remove mlog(0) from fs/ocfs2/suballoc.c
This is the 4th step to remove the debug info of DISK_ALLOC.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-22 08:24:01 +08:00
Tao Ma 2f73e135b8 ocfs2: Remove mlog(0) from fs/ocfs2/suballoc.c
This is the 3rd step to remove the debug info of DISK_ALLOC.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-22 08:22:33 +08:00
Tao Ma a04733d8af ocfs2: Remove mlog(0) from fs/ocfs2/localalloc.c
This is the 2nd step to remove the debug info of DISK_ALLOC.

So this patch removes all mlog(0,...) from localalloc.c and adds
the corresponding tracepoints. Different mlogs have different
solutions.
1. Some are replaced with trace event directly.
2. Some are replaced while some new parameters are added.
3. Some are combined into one trace events.
4. Some redundant mlogs are removed.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-22 07:56:45 +08:00
Tao Ma a09d09b8f8 ocfs2: Remove mlog(0) from fs/ocfs2/alloc.c
This is the first try of replacing debug mlog(0,...) to
trace events. Wengang has did some work in his original
patch
http://oss.oracle.com/pipermail/ocfs2-devel/2009-November/005513.html
But he didn't finished it.

So this patch removes all mlog(0,...) from alloc.c and adds
the corresponding trace events. Different mlogs have different
solutions.
1. Some are replaced with trace event directly.
2. Some are replaced and some new parameters are added since
   I think we need to know the btree owner in that case.
3. Some are combined into one trace events.
4. Some redundant mlogs are removed.
What's more, it defines some event classes so that we can use
them later.

Cc: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-22 08:21:10 +08:00
Wengang Wang 80a9a84da3 ocfs2: Add ocfs2_trace.h.
About one year ago, Wengang Wang tried some first steps
to add tracepoints to ocfs2. Hiss original patch is here:
http://oss.oracle.com/pipermail/ocfs2-devel/2009-November/005512.html

But as Steven Rostedt indicated in his article
http://lwn.net/Articles/383362/, we'd better have our trace
files resides in fs/ocfs2, so I rewrited the patch using the
method Steven mentioned in that article.

Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-21 11:13:14 +08:00
Tao Ma c1e8d35ef5 ocfs2: Remove EXIT from masklog.
mlog_exit is used to record the exit status of a function.
But because it is added in so many functions, if we enable it,
the system logs get filled up quickly and cause too much I/O.
So actually no one can open it for a production system or even
for a test.

This patch just try to remove it or change it. So:
1. if all the error paths already use mlog_errno, it is just removed.
   Otherwise, it will be replaced by mlog_errno.
2. if it is used to print some return value, it is replaced with
   mlog(0,...).
mlog_exit_ptr is changed to mlog(0.
All those mlog(0,...) will be replaced with trace events later.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-03-07 16:43:21 +08:00
Tao Ma ef6b689b63 ocfs2: Remove ENTRY from masklog.
ENTRY is used to record the entry of a function.
But because it is added in so many functions, if we enable it,
the system logs get filled up quickly and cause too much I/O.
So actually no one can open it for a production system or even
for a test.

So for mlog_entry_void, we just remove it.
for mlog_entry(...), we replace it with mlog(0,...), and they
will be replace by trace event later.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
2011-02-21 11:10:44 +08:00
Linus Torvalds 422e6c4bc4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (57 commits)
  tidy the trailing symlinks traversal up
  Turn resolution of trailing symlinks iterative everywhere
  simplify link_path_walk() tail
  Make trailing symlink resolution in path_lookupat() iterative
  update nd->inode in __do_follow_link() instead of after do_follow_link()
  pull handling of one pathname component into a helper
  fs: allow AT_EMPTY_PATH in linkat(), limit that to CAP_DAC_READ_SEARCH
  Allow passing O_PATH descriptors via SCM_RIGHTS datagrams
  readlinkat(), fchownat() and fstatat() with empty relative pathnames
  Allow O_PATH for symlinks
  New kind of open files - "location only".
  ext4: Copy fs UUID to superblock
  ext3: Copy fs UUID to superblock.
  vfs: Export file system uuid via /proc/<pid>/mountinfo
  unistd.h: Add new syscalls numbers to asm-generic
  x86: Add new syscalls for x86_64
  x86: Add new syscalls for x86_32
  fs: Remove i_nlink check from file system link callback
  fs: Don't allow to create hardlink for deleted file
  vfs: Add open by file handle support
  ...
2011-03-15 15:48:13 -07:00
Trond Myklebust c83ce989cb VFS: Fix the nfs sillyrename regression in kernel 2.6.38
The new vfs locking scheme introduced in 2.6.38 breaks NFS sillyrename
because the latter relies on being able to determine the parent
directory of the dentry in the ->iput() callback in order to send the
appropriate unlink rpc call.

Looking at the code that cares about races with dput(), there doesn't
seem to be anything that specifically uses d_parent as a test for
whether or not there is a race:
  - __d_lookup_rcu(), __d_lookup() all test for d_hashed() after d_parent
  - shrink_dcache_for_umount() is safe since nothing else can rearrange
    the dentries in that super block.
  - have_submount(), select_parent() and d_genocide() can test for a
    deletion if we set the DCACHE_DISCONNECTED flag when the dentry
    is removed from the parent's d_subdirs list.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org (2.6.38, needs commit c826cb7dfc "dcache.c:
	create helper function for duplicated functionality" )
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-15 15:46:11 -07:00
Linus Torvalds c826cb7dfc dcache.c: create helper function for duplicated functionality
This creates a helper function for he "try to ascend into the parent
directory" case, which was written out in triplicate before.  With all
the locking and subtle sequence number stuff, we really don't want to
duplicate that kind of code.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-15 15:29:21 -07:00
Al Viro 574197e0de tidy the trailing symlinks traversal up
* pull the handling of current->total_link_count into
__do_follow_link()
* put the common "do ->put_link() if needed and path_put() the link"
  stuff into a helper (put_link(nd, link, cookie))
* rename __do_follow_link() to follow_link(), while we are at it

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15 17:16:25 -04:00
Al Viro b356379a02 Turn resolution of trailing symlinks iterative everywhere
The last remaining place (resolution of nested symlink) converted
to the loop of the same kind we have in path_lookupat() and
path_openat().

Note that we still *do* have a recursion in pathname resolution;
can't avoid it, really.  However, it's strictly for nested symlinks
now - i.e. ones in the middle of a pathname.

link_path_walk() has lost the tail now - it always walks everything
except the last component.

do_follow_link() renamed to nested_symlink() and moved down.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15 17:16:25 -04:00
Al Viro ce0525449d simplify link_path_walk() tail
Now that link_path_walk() is called without LOOKUP_PARENT
only from do_follow_link(), we can simplify the checks in
last component handling.  First of all, checking if we'd
arrived to a directory is not needed - the caller will check
it anyway.  And LOOKUP_FOLLOW is guaranteed to be there,
since we only get to that place with nd->depth > 0.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15 17:16:25 -04:00
Al Viro bd92d7fed8 Make trailing symlink resolution in path_lookupat() iterative
Now the only caller of link_path_walk() that does *not* pass
LOOKUP_PARENT is do_follow_link()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15 17:16:25 -04:00
Al Viro b21041d0f7 update nd->inode in __do_follow_link() instead of after do_follow_link()
... and note that we only need to do it for LAST_BIND symlinks

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15 17:16:25 -04:00
Al Viro ce57dfc179 pull handling of one pathname component into a helper
new helper: walk_component().  Handles everything except symlinks;
returns negative on error, 0 on success and 1 on symlinks we decided
to follow.  Drops out of RCU mode on such symlinks.

link_path_walk() and do_last() switched to using that.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15 17:16:20 -04:00
Aneesh Kumar K.V 11a7b371b6 fs: allow AT_EMPTY_PATH in linkat(), limit that to CAP_DAC_READ_SEARCH
We don't want to allow creation of private hardlinks by different application
using the fd passed to them via SCM_RIGHTS. So limit the null relative name
usage in linkat syscall to CAP_DAC_READ_SEARCH

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2011-03-15 17:16:05 -04:00
Linus Torvalds 76ca078328 Merge branch 'for-linus' of git://xenbits.xen.org/people/sstabellini/linux-pvhvm
* 'for-linus' of git://xenbits.xen.org/people/sstabellini/linux-pvhvm:
  xen: suspend: remove xen_hvm_suspend
  xen: suspend: pull pre/post suspend hooks out into suspend_info
  xen: suspend: move arch specific pre/post suspend hooks into generic hooks
  xen: suspend: refactor non-arch specific pre/post suspend hooks
  xen: suspend: add "arch" to pre/post suspend hooks
  xen: suspend: pass extra hypercall argument via suspend_info struct
  xen: suspend: refactor cancellation flag into a structure
  xen: suspend: use HYPERVISOR_suspend for PVHVM case instead of open coding
  xen: switch to new schedop hypercall by default.
  xen: use new schedop interface for suspend
  xen: do not respond to unknown xenstore control requests
  xen: fix compile issue if XEN is enabled but XEN_PVHVM is disabled
  xen: PV on HVM: support PV spinlocks and IPIs
  xen: make the ballon driver work for hvm domains
  xen-blkfront: handle Xen major numbers other than XENVBD
  xen: do not use xen_info on HVM, set pv_info name to "Xen HVM"
  xen: no need to delay xen_setup_shutdown_event for hvm guests anymore
2011-03-15 10:59:09 -07:00
Linus Torvalds 27d2a8b97e Merge branches 'stable/ia64', 'stable/blkfront-cleanup' and 'stable/cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/ia64' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen: ia64 build broken due to "xen: switch to new schedop hypercall by default."

* 'stable/blkfront-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen: Union the blkif_request request specific fields

* 'stable/cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen: annotate functions which only call into __init at start of day
  xen p2m: annotate variable which appears unused
  xen: events: mark cpu_evtchn_mask_p as __refdata
2011-03-15 10:49:16 -07:00
Linus Torvalds 010b8f4e26 Merge branch 'stable/irq.cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/irq.cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen: events: remove dom0 specific xen_create_msi_irq
  xen: events: use xen_bind_pirq_msi_to_irq from xen_create_msi_irq
  xen: events: push set_irq_msi down into xen_create_msi_irq
  xen: events: update pirq_to_irq in xen_create_msi_irq
  xen: events: refactor xen_create_msi_irq slightly
  xen: events: separate MSI PIRQ allocation from PIRQ binding to IRQ
  xen: events: assume PHYSDEVOP_get_free_pirq exists
  xen: pci: collapse apic_register_gsi_xen_hvm and xen_hvm_register_pirq
  xen: events: return irq from xen_allocate_pirq_msi
  xen: events: drop XEN_ALLOC_IRQ flag to xen_allocate_pirq_msi
  xen: events: do not leak IRQ from xen_allocate_pirq_msi when no pirq available.
  xen: pci: only define xen_initdom_setup_msi_irqs if CONFIG_XEN_DOM0
2011-03-15 10:47:56 -07:00
Linus Torvalds 397fae0818 Merge branches 'stable/irq.rework' and 'stable/pcifront-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/irq.rework' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/irq: Cleanup up the pirq_to_irq for DomU PV PCI passthrough guests as well.
  xen: Use IRQF_FORCE_RESUME
  xen/timer: Missing IRQF_NO_SUSPEND in timer code broke suspend.
  xen: Fix compile error introduced by "switch to new irq_chip functions"
  xen: Switch to new irq_chip functions
  xen: Remove stale irq_chip.end
  xen: events: do not free legacy IRQs
  xen: events: allocate GSIs and dynamic IRQs from separate IRQ ranges.
  xen: events: add xen_allocate_irq_{dynamic, gsi} and xen_free_irq
  xen:events: move find_unbound_irq inside CONFIG_PCI_MSI
  xen: handled remapped IRQs when enabling a pcifront PCI device.
  genirq: Add IRQF_FORCE_RESUME

* 'stable/pcifront-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  pci/xen: When free-ing MSI-X/MSI irq->desc also use generic code.
  pci/xen: Cleanup: convert int** to int[]
  pci/xen: Use xen_allocate_pirq_msi instead of xen_allocate_pirq
  xen-pcifront: Sanity check the MSI/MSI-X values
  xen-pcifront: don't use flush_scheduled_work()
2011-03-15 10:47:16 -07:00
Linus Torvalds c7146dd009 Merge branches 'stable/p2m-identity.v4.9.1' and 'stable/e820' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
* 'stable/p2m-identity.v4.9.1' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/m2p: Check whether the MFN has IDENTITY_FRAME bit set..
  xen/m2p: No need to catch exceptions when we know that there is no RAM
  xen/debug: WARN_ON when identity PFN has no _PAGE_IOMAP flag set.
  xen/debugfs: Add 'p2m' file for printing out the P2M layout.
  xen/setup: Set identity mapping for non-RAM E820 and E820 gaps.
  xen/mmu: WARN_ON when racing to swap middle leaf.
  xen/mmu: Set _PAGE_IOMAP if PFN is an identity PFN.
  xen/mmu: Add the notion of identity (1-1) mapping.
  xen: Mark all initial reserved pages for the balloon as INVALID_P2M_ENTRY.

* 'stable/e820' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/e820: Don't mark balloon memory as E820_UNUSABLE when running as guest and fix overflow.
  xen/setup: Inhibit resource API from using System RAM E820 gaps as PCI mem gaps.
2011-03-15 10:32:15 -07:00
Al Viro 326be7b484 Allow passing O_PATH descriptors via SCM_RIGHTS datagrams
Just need to make sure that AF_UNIX garbage collector won't
confuse O_PATHed socket on filesystem for real AF_UNIX opened
socket.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15 02:21:45 -04:00
Al Viro 65cfc67223 readlinkat(), fchownat() and fstatat() with empty relative pathnames
For readlinkat() we simply allow empty pathname; it will fail unless
we have dfd equal to O_PATH-opened symlink, so we are outside of
POSIX scope here.  For fchownat() and fstatat() we allow AT_EMPTY_PATH;
let the caller explicitly ask for such behaviour.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15 02:21:45 -04:00
Al Viro bcda76524c Allow O_PATH for symlinks
At that point we can't do almost nothing with them.  They can be opened
with O_PATH, we can manipulate such descriptors with dup(), etc. and
we can see them in /proc/*/{fd,fdinfo}/*.

We can't (and won't be able to) follow /proc/*/fd/* symlinks for those;
there's simply not enough information for pathname resolution to go on
from such point - to resolve a symlink we need to know which directory
does it live in.

We will be able to do useful things with them after the next commit, though -
readlinkat() and fchownat() will be possible to use with dfd being an
O_PATH-opened symlink and empty relative pathname.  Combined with
open_by_handle() it'll give us a way to do realink-by-handle and
lchown-by-handle without messing with more redundant syscalls.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15 02:21:45 -04:00
Al Viro 1abf0c718f New kind of open files - "location only".
New flag for open(2) - O_PATH.  Semantics:
	* pathname is resolved, but the file itself is _NOT_ opened
as far as filesystem is concerned.
	* almost all operations on the resulting descriptors shall
fail with -EBADF.  Exceptions are:
	1) operations on descriptors themselves (i.e.
		close(), dup(), dup2(), dup3(), fcntl(fd, F_DUPFD),
		fcntl(fd, F_DUPFD_CLOEXEC, ...), fcntl(fd, F_GETFD),
		fcntl(fd, F_SETFD, ...))
	2) fcntl(fd, F_GETFL), for a common non-destructive way to
		check if descriptor is open
	3) "dfd" arguments of ...at(2) syscalls, i.e. the starting
		points of pathname resolution
	* closing such descriptor does *NOT* affect dnotify or
posix locks.
	* permissions are checked as usual along the way to file;
no permission checks are applied to the file itself.  Of course,
giving such thing to syscall will result in permission checks (at
the moment it means checking that starting point of ....at() is
a directory and caller has exec permissions on it).

fget() and fget_light() return NULL on such descriptors; use of
fget_raw() and fget_raw_light() is needed to get them.  That protects
existing code from dealing with those things.

There are two things still missing (they come in the next commits):
one is handling of symlinks (right now we refuse to open them that
way; see the next commit for semantics related to those) and another
is descriptor passing via SCM_RIGHTS datagrams.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15 02:21:45 -04:00
Aneesh Kumar K.V f2fa2ffc20 ext4: Copy fs UUID to superblock
File system UUID is made available to application
via  /proc/<pid>/mountinfo

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15 02:21:45 -04:00
Aneesh Kumar K.V 03cb5f03dc ext3: Copy fs UUID to superblock.
File system UUID is made available to application
via  /proc/<pid>/mountinfo

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15 02:21:45 -04:00
Aneesh Kumar K.V 93f1c20bc8 vfs: Export file system uuid via /proc/<pid>/mountinfo
We add a per superblock uuid field. File systems should
update the uuid in the fill_super callback

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15 02:21:45 -04:00
Aneesh Kumar K.V a51571ccb8 unistd.h: Add new syscalls numbers to asm-generic
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-15 02:21:45 -04:00