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path: root/fs/anon_inodes.c
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2010-03-12anon_inodes: mark the anon inode privateEric Paris
Inotify was switched to use anon_inode instead of its own private filesystem which only had one inode in commit c44dcc56d2b5c7 "switch inotify_user to anon_inode" The problem with this is that now the inotify inode is not a distinct inode which can be managed by LSMs. userspace tools which use inotify were allowed to use the inotify inode but may not have had permission to do read/write type operations on the anon_inode. After looking at the anon_inode and its users it looks like the best solution is to just mark the anon_inode as S_PRIVATE so the security system will ignore it. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: James Morris <jmorris@namei.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-22Sanitize f_flags helpersAl Viro
* pull ACC_MODE to fs.h; we have several copies all over the place * nightmarish expression calculating f_mode by f_flags deserves a helper too (OPEN_FMODE(flags)) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-22anonfd: Allow making anon files read-onlyRoland Dreier
It seems a couple places such as arch/ia64/kernel/perfmon.c and drivers/infiniband/core/uverbs_main.c could use anon_inode_getfile() instead of a private pseudo-fs + alloc_file(), if only there were a way to get a read-only file. So provide this by having anon_inode_getfile() create a read-only file if we pass O_RDONLY in flags. Signed-off-by: Roland Dreier <rolandd@cisco.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-17fs: no games with DCACHE_UNHASHEDNick Piggin
Filesystems outside the regular namespace do not have to clear DCACHE_UNHASHED in order to have a working /proc/$pid/fd/XXX. Nothing in proc prevents the fd link from being used if its dentry is not in the hash. Also, it does not get put into the dcache hash if DCACHE_UNHASHED is clear; that depends on the filesystem calling d_add or d_rehash. So delete the misleading comments and needless code. Acked-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-17fs: anon_inodes implement dnameNick Piggin
Add a d_dname method for anon_inodes filesystem, the same way pipefs and sockfs pseudo filesystems. This allows us to remove the DCACHE_UNHASHED hack from anon_inodes.c (see next patch). [AV: inumber is useless here, dropped from anon_inodefs_dname()] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Miklos Szeredi <mszeredi@suse.cz> Cc: Davide Libenzi <davidel@xmailserver.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-16switch alloc_file() to passing struct pathAl Viro
... and have the caller grab both mnt and dentry; kill leak in infiniband, while we are at it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-10-04headers: remove sched.h from poll.hAlexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-23anonfd: split interface into file creation and installDavide Libenzi
Split the anonfd interface into a bare file pointer creation one, and a file pointer creation plus install one. There are cases, like the usage of eventfds inside other kernel interfaces, where the file pointer created by anonfd needs to be used inside the initialization of other structures. As it is right now, as soon as anon_inode_getfd() returns, the kenrle can race with userspace closing the newly installed file descriptor. This patch, while keeping the old anon_inode_getfd(), introduces a new anon_inode_getfile() (whose services are reused in anon_inode_getfd()) that allows to split the file creation phase and the fd install one. Once all the kernel structures are initialized, the code can call the proper fd_install(). Gregory manifested the need for something like this inside KVM. Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: James Morris <jmorris@namei.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Gregory Haskins <ghaskins@novell.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Roland Dreier <rolandd@cisco.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18fs: Provide empty .set_page_dirty() aop for anon inodesPeter Zijlstra
.set_page_dirty() is one of those a_ops that defaults to the buffer implementation when not set. Therefore provide a dummy function to make it do nothing. (Uncovered by perfcounters fd's which can now be writable-mmap-ed.) Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Davide Libenzi <davidel@xmailserver.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-27constify dentry_operations: restAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-12-31anon_inodes: use fops->owner for module refcountChristian Borntraeger
There is an imbalance for anonymous inodes. If the fops->owner field is set, the module reference count of owner is decreases on release. ("filp_close" --> "__fput" ---> "fops_put") On the other hand, anon_inode_getfd does not increase the module reference count of owner. This causes two problems: - if owner is set, the module refcount goes negative - if owner is not set, the module can be unloaded while code is running This patch changes anon_inode_getfd to be symmetric regarding fops->owner handling. I have checked all existing users of anon_inode_getfd. Noone sets fops->owner, thats why nobody has seen the module refcount negative. The refcounting was tested with a patched and unpatched KVM module.(see patch 2/2) I also did an epoll_open/close test. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Avi Kivity <avi@redhat.com>
2008-11-14CRED: Wrap task credential accesses in the filesystem subsystemDavid Howells
Wrap access to task credentials so that they can be separated more easily from the task_struct during the introduction of COW creds. Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id(). Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more sense to use RCU directly rather than a convenient wrapper; these will be addressed by later patches. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: James Morris <jmorris@namei.org>
2008-07-24flag parameters: NONBLOCK in anon_inode_getfdUlrich Drepper
Building on the previous change to anon_inode_getfd, this patch introduces support for handling of O_NONBLOCK in addition to the already supported O_CLOEXEC. Following patches will take advantage of this support. As can be seen, the additional support for supporting this functionality is minimal. Signed-off-by: Ulrich Drepper <drepper@redhat.com> Acked-by: Davide Libenzi <davidel@xmailserver.org> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24flag parameters: anon_inode_getfd extensionUlrich Drepper
This patch just extends the anon_inode_getfd interface to take an additional parameter with a flag value. The flag value is passed on to get_unused_fd_flags in anticipation for a use with the O_CLOEXEC flag. No actual semantic changes here, the changed callers all pass 0 for now. [akpm@linux-foundation.org: KVM fix] Signed-off-by: Ulrich Drepper <drepper@redhat.com> Acked-by: Davide Libenzi <davidel@xmailserver.org> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-01[PATCH] sanitize anon_inode_getfd()Al Viro
a) none of the callers even looks at inode or file returned by anon_inode_getfd() b) any caller that would try to look at those would be racy, since by the time it returns we might have raced with close() from another thread and that file would be pining for fjords. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-03-19[PATCH] fix up new filp allocatorsDave Hansen
Some new uses of get_empty_filp() have crept in; switched to alloc_file() to make sure that pieces of initialization won't be missing. We really need to kill get_empty_filp(). [AV] fixed dentry leak on failure exit in anon_inode_getfd() Cc: Erez Zadok <ezk@cs.sunysb.edu> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: "J Bruce Fields" <bfields@fieldses.org> Acked-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2007-10-17anon-inodes use open coded atomic_inc for the shared inodeDavide Libenzi
Since we know the shared inode count is always >0, we can avoid igrab() and use an open coded atomic_inc(). This also fixes a bug noticed by Yan Zheng <yanzheng@21cn.com>: were checking for an IS_ERR() return from igrab(), but it actually returns NULL on error. Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Cc: Yan Zheng <yanzheng@21cn.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm: (80 commits) KVM: Use CPU_DYING for disabling virtualization KVM: Tune hotplug/suspend IPIs KVM: Keep track of which cpus have virtualization enabled SMP: Allow smp_call_function_single() to current cpu i386: Allow smp_call_function_single() to current cpu x86_64: Allow smp_call_function_single() to current cpu HOTPLUG: Adapt thermal throttle to CPU_DYING HOTPLUG: Adapt cpuset hotplug callback to CPU_DYING HOTPLUG: Add CPU_DYING notifier KVM: Clean up #includes KVM: Remove kvmfs in favor of the anonymous inodes source KVM: SVM: Reliably detect if SVM was disabled by BIOS KVM: VMX: Remove unnecessary code in vmx_tlb_flush() KVM: MMU: Fix Wrong tlb flush order KVM: VMX: Reinitialize the real-mode tss when entering real mode KVM: Avoid useless memory write when possible KVM: Fix x86 emulator writeback KVM: Add support for in-kernel pio handlers KVM: VMX: Fix interrupt checking on lightweight exit KVM: Adds support for in-kernel mmio handlers ...
2007-07-16Fix trivial typos in anon_inodes.c commentsJ. Bruce Fields
Trivial typo and grammar fixes. Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu> Cc: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16KVM: Remove kvmfs in favor of the anonymous inodes sourceAvi Kivity
kvm uses a pseudo filesystem, kvmfs, to generate inodes, a job that the new anonymous inodes source does much better. Cc: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Avi Kivity <avi@qumranet.com>
2007-05-11signal/timer/event fds: anonymous inode sourceDavide Libenzi
This patch add an anonymous inode source, to be used for files that need and inode only in order to create a file*. We do not care of having an inode for each file, and we do not even care of having different names in the associated dentries (dentry names will be same for classes of file*). This allow code reuse, and will be used by epoll, signalfd and timerfd (and whatever else there'll be). Signed-off-by: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>