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* Merge branch 'cpus4096-for-linus-3' of ↵Linus Torvalds2009-01-031-1/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'cpus4096-for-linus-3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (77 commits) x86: setup_per_cpu_areas() cleanup cpumask: fix compile error when CONFIG_NR_CPUS is not defined cpumask: use alloc_cpumask_var_node where appropriate cpumask: convert shared_cpu_map in acpi_processor* structs to cpumask_var_t x86: use cpumask_var_t in acpi/boot.c x86: cleanup some remaining usages of NR_CPUS where s/b nr_cpu_ids sched: put back some stack hog changes that were undone in kernel/sched.c x86: enable cpus display of kernel_max and offlined cpus ia64: cpumask fix for is_affinity_mask_valid() cpumask: convert RCU implementations, fix xtensa: define __fls mn10300: define __fls m32r: define __fls h8300: define __fls frv: define __fls cris: define __fls cpumask: CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS cpumask: zero extra bits in alloc_cpumask_var_node cpumask: replace for_each_cpu_mask_nr with for_each_cpu in kernel/time/ cpumask: convert mm/ ...
| * Merge branch 'master' of ↵Rusty Russell2008-12-31139-14278/+12319
| |\ | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 Conflicts: arch/x86/kernel/io_apic.c
| * | bitmap: fix seq_bitmap and seq_cpumask to take const pointerRusty Russell2008-12-301-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | Impact: cleanup seq_bitmap just calls bitmap_scnprintf on the bits: that arg can be const. Similarly, seq_cpumask just calls seq_bitmap. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* | | get rid of special-casing the /sbin/loader on alphaAl Viro2009-01-031-39/+0
| | | | | | | | | | | | | | | | | | | | | ... just make it a binfmt handler like #! one. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | sanitize ifdefs in binfmt_aoutAl Viro2009-01-031-9/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | They are actually alpha vs. i386/arm/m68k i.e. ecoff vs. aout. In the only place where we actually tried to handle arm and i386/m68k in different ways (START_DATA() in coredump handling), the arm variant works for all of them (i386 and m68k have u.start_code set to 0). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | remove the rudiment of a.out for sparcAl Viro2009-01-031-64/+1
| | | | | | | | | | | | | | | | | | | | | it's been used only in sunos compat Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge branch 'linux-next' of git://git.infradead.org/ubifs-2.6Linus Torvalds2009-01-0220-474/+924
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'linux-next' of git://git.infradead.org/ubifs-2.6: (33 commits) UBIFS: add more useful debugging prints UBIFS: print debugging messages properly UBIFS: fix numerous spelling mistakes UBIFS: allow mounting when short of space UBIFS: fix writing uncompressed files UBIFS: fix checkpatch.pl warnings UBIFS: fix sparse warnings UBIFS: simplify make_free_space UBIFS: do not lie about used blocks UBIFS: restore budg_uncommitted_idx UBIFS: always commit on unmount UBIFS: use ubi_sync UBIFS: always commit in sync_fs UBIFS: fix file-system synchronization UBIFS: fix constants initialization UBIFS: avoid unnecessary calculations UBIFS: re-calculate min_idx_size after the commit UBIFS: use nicer 64-bit math UBIFS: fix available blocks count UBIFS: various comment improvements and fixes ...
| * | | UBIFS: add more useful debugging printsArtem Bityutskiy2008-12-311-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | Print node sizes and maximum node sizes. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: print debugging messages properlyArtem Bityutskiy2008-12-311-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We cannot use ubifs_err() macro with DBGKEY() and DBGKEY1(), because this is racy and holding dbg_lock is needed. Use dbg_err() instead, which does have the lock held. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: fix numerous spelling mistakesArtem Bityutskiy2008-12-313-12/+11
| | | | | | | | | | | | | | | | Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: allow mounting when short of spaceArtem Bityutskiy2008-12-311-11/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is fine if there is not free space - we should still allow mounting this FS. This patch relaxes the free space requirements and adds info dumps. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: fix writing uncompressed filesArtem Bityutskiy2008-12-312-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | UBIFS does not disable compression if ui->flags is non-zero, e.g. if the file has "sync" flag. This is because of the typo which is fixed by this patch. The patch also adds a couple of useful debugging prints. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: fix checkpatch.pl warningsArtem Bityutskiy2008-12-316-25/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These are mostly long lines and wrong indentation warning fixes. But also there are two volatile variables and checkpatch.pl complains about them: WARNING: Use of volatile is usually wrong: see Documentation/volatile-considered-harmful.txt + volatile int gc_seq; WARNING: Use of volatile is usually wrong: see Documentation/volatile-considered-harmful.txt + volatile int gced_lnum; Well, we anyway use smp_wmb() for c->gc_seq and c->gced_lnum, so these 'volatile' modifiers can be just dropped. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: fix sparse warningsArtem Bityutskiy2008-12-311-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fs/ubifs/compress.c:111:8: warning: incorrect type in argument 5 (different signedness) fs/ubifs/compress.c:111:8: expected unsigned int *dlen fs/ubifs/compress.c:111:8: got int *out_len fs/ubifs/compress.c:175:10: warning: incorrect type in argument 5 (different signedness) fs/ubifs/compress.c:175:10: expected unsigned int *dlen fs/ubifs/compress.c:175:10: got int *out_len Fix this by adding a cast to (unsigned int *). We guarantee that our lengths are small and no overflow is possible. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: simplify make_free_spaceArtem Bityutskiy2008-12-311-102/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The 'make_free_space()' function was too complex and this patch simplifies it. It also fixes a bug - the freespace test failed straight away on UBI volumes with 512 bytes LEB size. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: do not lie about used blocksArtem Bityutskiy2008-12-311-10/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Do not force UBIFS return 0 used space when it is empty. It leads to a situation when creating any file immediately produces tens of used blocks, which looks very weird. It is better to be honest and say that some blocks are used even if the FS is empty. And ext2 does the same. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: restore budg_uncommitted_idxArtem Bityutskiy2008-12-311-3/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | UBIFS stores uncommitted index size in c->budg_uncommitted_idx, and this affect budgeting calculations. When mounting and replaying, this variable is not updated, so we may end up with "over-budgeting". This patch fixes the issue. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: always commit on unmountArtem Bityutskiy2008-12-311-11/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | UBIFS commits on unmount to make the next mount faster. Currently, it commits only if there is more than LEB size bytes in the journal. This is not very good, because journal size may be large (512KiB). And there may be few deletions in the journal which do not take much journal space, but which do introduce a lot of TNC changes and make mount slow. Thus, jurt remove this condition and always commit. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: use ubi_syncArtem Bityutskiy2008-12-311-6/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | UBI now has (fake for now, though) synchronization call - use it. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: always commit in sync_fsArtem Bityutskiy2008-12-311-20/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Always run commit in sync_fs, because even if the journal seems to be almost empty, there may be a deletion which removes a large file, which affects the index greatly. And because we want better free space predictions after 'sync_fs()', we have to commit. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: fix file-system synchronizationArtem Bityutskiy2008-12-311-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Argh. The ->sync_fs call is called _before_ all inodes are flushed. This means we first sync write buffers and commit, then all inodes are synced, and we end up with unflushed write buffers! Fix this by forcing synching all indoes from 'ubifs_sync_fs()'. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: fix constants initializationArtem Bityutskiy2008-12-311-5/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The c->min_idx_lebs constant depends on c->old_idx_sz, which is read from the master node. This means that we have to initialize c->min_idx_lebs only after we have read the master node. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: avoid unnecessary calculationsArtem Bityutskiy2008-12-231-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Do not calculate min_idx_lebs, because it is available in c->min_idx_lebs Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: re-calculate min_idx_size after the commitArtem Bityutskiy2008-12-231-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we commit, but before we try to write anything to the flash media, @c->min_idx_size is inaccurate, because we do not re-calculate it after the commit. Do not forget to do this. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: use nicer 64-bit mathArtem Bityutskiy2008-12-236-35/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of using do_div(), use better primitives from linux/math64.h. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: fix available blocks countArtem Bityutskiy2008-12-233-9/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Take into account that 2 eraseblocks are never available because they are reserved for the index. This gives more realistic count of FS blocks. To avoid future confusions like this, introduce a constant. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: various comment improvements and fixesArtem Bityutskiy2008-12-232-22/+24
| | | | | | | | | | | | | | | | Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: improve budgeting dumpArtem Bityutskiy2008-12-233-3/+16
| | | | | | | | | | | | | | | | | | | | | | | | Dump available space calculated by budgeting subsystem. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: fix tnc dumpingArtem Bityutskiy2008-12-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | debugfs tnc dumping was broken because of an obvious typo. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: use PAGE_CACHE_MASK correctlyArtem Bityutskiy2008-12-231-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | It has high bits set, not low bits set as the UBIFS code assumed. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: fix section mismatchAlexey Dobriyan2008-12-042-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes the following section mismatch: WARNING: fs/ubifs/ubifs.o(.init.text+0xec): Section mismatch in reference from the function init_module() to the function .exit.text:ubifs_compressors_exit() Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: introduce LPT dump functionArtem Bityutskiy2008-12-035-48/+186
| | | | | | | | | | | | | | | | Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: dump stack in LPT check functionsArtem Bityutskiy2008-12-031-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | It is useful to know how we got to the checking function when hunting the bugs. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: run debugging checks only if they are enabledArtem Bityutskiy2008-12-032-2/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Do not forget to check whether lpt debugging is enabled before running the check functions. This commit also makes some spelling fixes. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: add debugfs supportArtem Bityutskiy2008-12-034-20/+193
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We need to have a possibility to see various UBIFS variables and ask UBIFS to dump various information. Debugfs is what we need. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: separate debugging fields outArtem Bityutskiy2008-12-039-113/+156
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce a new data structure which contains all debugging stuff inside. This is cleaner than having debugging stuff directly in 'c'. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: avoid unnecessary checksKukkonen Mika2008-12-031-14/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I have a habit of compiling kernel with EXTRA_CFLAGS="-Wextra -Wno-unused -Wno-sign-compare -Wno-missing-field-initializers" and so fs/ubifs/key.h give lots (~10) of these every time: CC fs/ubifs/tnc_misc.o In file included from fs/ubifs/ubifs.h:1725, from fs/ubifs/tnc_misc.c:30: fs/ubifs/key.h: In function 'key_r5_hash': fs/ubifs/key.h:64: warning: comparison of unsigned expression >= 0 is always true fs/ubifs/key.h: In function 'key_test_hash': fs/ubifs/key.h:81: warning: comparison of unsigned expression >= 0 is always true This patch fixes the warnings. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: introduce compression mount optionsArtem Bityutskiy2008-12-034-16/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is very handy to be able to change default UBIFS compressor via mount options. Introduce -o compr=<name> mount option support. Currently only "none", "lzo" and "zlib" compressors are supported. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: use bit-fields to store compression typeArtem Bityutskiy2008-12-032-3/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Save a 4 bytes of RAM per 'struct inode' by stroring inode compression type in bit-filed, instead of using 'int'. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
| * | | UBIFS: slight compression optimizationArtem Bityutskiy2008-12-032-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If data does not compress, it is better to leave it uncompressed because we'll read it faster then. So do not compress data if we save less than 64 bytes. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
* | | | Merge branch 'kvm-updates/2.6.29' of ↵Linus Torvalds2009-01-021-1/+6
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm * 'kvm-updates/2.6.29' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm: (140 commits) KVM: MMU: handle large host sptes on invlpg/resync KVM: Add locking to virtual i8259 interrupt controller KVM: MMU: Don't treat a global pte as such if cr4.pge is cleared MAINTAINERS: Maintainership changes for kvm/ia64 KVM: ia64: Fix kvm_arch_vcpu_ioctl_[gs]et_regs() KVM: x86: Rework user space NMI injection as KVM_CAP_USER_NMI KVM: VMX: Fix pending NMI-vs.-IRQ race for user space irqchip KVM: fix handling of ACK from shared guest IRQ KVM: MMU: check for present pdptr shadow page in walk_shadow KVM: Consolidate userspace memory capability reporting into common code KVM: Advertise the bug in memory region destruction as fixed KVM: use cpumask_var_t for cpus_hardware_enabled KVM: use modern cpumask primitives, no cpumask_t on stack KVM: Extract core of kvm_flush_remote_tlbs/kvm_reload_remote_mmus KVM: set owner of cpu and vm file operations anon_inodes: use fops->owner for module refcount x86: KVM guest: kvm_get_tsc_khz: return khz, not lpj KVM: MMU: prepopulate the shadow on invlpg KVM: MMU: skip global pgtables on sync due to cr3 switch KVM: MMU: collapse remote TLB flushes on root sync ...
| * | | | anon_inodes: use fops->owner for module refcountChristian Borntraeger2008-12-311-1/+6
| | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | | | CRED: Wrap task credential accesses in the devpts filesystemDavid Howells2009-01-021-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | devpts: fix unused function warningAndrew Morton2009-01-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fs/devpts/inode.c:324: warning: 'compare_init_pts_sb' defined but not used Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | devpts: Coding style clean upAlan Cox2009-01-021-27/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Just nail the oddments now while this code is being touched Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | Enable multiple instances of devptsSukadev Bhattiprolu2009-01-021-7/+163
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To support containers, allow multiple instances of devpts filesystem, such that indices of ptys allocated in one instance are independent of ptys allocated in other instances of devpts. But to preserve backward compatibility, enable this support for multiple instances only if: - CONFIG_DEVPTS_MULTIPLE_INSTANCES is set to Y, and - '-o newinstance' mount option is specified while mounting devpts To use multi-instance mount, a container startup script could: $ ns_exec -cm /bin/bash $ umount /dev/pts $ mount -t devpts -o newinstance lxcpts /dev/pts $ mount -o bind /dev/pts/ptmx /dev/ptmx $ /usr/sbin/sshd -p 1234 where 'ns_exec -cm /bin/bash' is calls clone() with CLONE_NEWNS flag and execs /bin/bash in the child process. A pty created by the sshd is not visible in the original mount of /dev/pts. USER-SPACE-IMPACT: - See Documentation/fs/devpts.txt (included in next patch) for user- space impact in multi-instance and mixed-mode operation. TODO: - Update mount(8), pts(4) man pages. Highlight impact of not redirecting /dev/ptmx to /dev/pts/ptmx after a multi-instance mount. Changelog[v6]: - [Dave Hansen] Use new get_init_pts_sb() interface - [Serge Hallyn] Don't bother displaying 'newinstance' in show_options - [Serge Hallyn] Use macros (PARSE_REMOUNT/PARSE_MOUNT) instead of 0/1. - [Serge Hallyn] Check error return from get_sb_single() (now get_init_pts_sb()) - devpts_pty_kill(): don't dput error dentries Changelog[v5]: - Move get_sb_ref() definition to earlier patch - Move usage info to Documentation/filesystems/devpts.txt (next patch) - Make ptmx node even in init_pts_ns, now that default mode is 0000 (defined in earlier patch, enabled here). - Cache ptmx dentry and use to update mode during remount (defined in earlier patch, enabled here). - Bugfix: explicitly ignore newinstance on remount (if newinstance was specified on remount of initial mount, it would be ignored but /proc/mounts would imply that the option was set) Changelog[v4]: - Update patch description to address H. Peter Anvin's comments - Consolidate multi-instance mode code under new config token, CONFIG_DEVPTS_MULTIPLE_INSTANCE. - Move usage-details from patch description to Documentation/fs/devpts.txt Changelog[v3]: - Rename new mount option to 'newinstance' - Create ptmx nodes only in 'newinstance' mounts - Bugfix: parse_mount_options() modifies @data but since we need to parse the @data twice (once in devpts_get_sb() and once during do_remount_sb()), parse a local copy of @data in devpts_get_sb(). (restructured code in devpts_get_sb() to fix this) Changelog[v2]: - Support both single-mount and multiple-mount semantics and provide '-onewmnt' option to select the semantics. Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | Define get_init_pts_sb()Sukadev Bhattiprolu2009-01-021-1/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | See comments in the function header for details. The new interface will be used in a follow-on patch. Changelog [v2]: [Dave Hansen] Replace get_sb_ref() in fs/super.c with get_init_pts_sb() and make the new interface private to devpts Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | Define mknod_ptmx()Sukadev Bhattiprolu2009-01-021-5/+110
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | /dev/ptmx is closely tied to the devpts filesystem. An open of /dev/ptmx, allocates the next pty index and the associated device shows up in the devpts fs as /dev/pts/n. Wih multiple instancs of devpts filesystem, during an open of /dev/ptmx we would be unable to determine which instance of the devpts is being accessed. So we move the 'ptmx' node into /dev/pts and use the inode of the 'ptmx' node to identify the superblock and hence the devpts instance. This patch adds ability for the kernel to internally create the [ptmx, c, 5:2] device when mounting devpts filesystem. Since the ptmx node in devpts is new and may surprise some userspace scripts, the default permissions for the new node is 0000. These permissions can be changed either using chmod or by remounting with the new '-o ptmxmode=0666' mount option. Changelog[v5]: - [Serge Hallyn bugfix]: Letting new_inode() assign inode number to ptmx can collide with hand-assigning inode numbers to ptys. So, hand-assign specific inode number to ptmx node also. - [Serge Hallyn]: Maybe safer to grab root dentry mutex while creating ptmx node - [Bugfix with Serge Hallyn] Replace lookup_one_len() in mknod_ptmx() wih d_alloc_name() (lookup during ->get_sb() locks up system). To simplify patchset, fold the ptmx_dentry patch into this. Changelog[v4]: - Change default permissions of pts/ptmx node to 0000. - Move code for ptmxmode under #ifdef CONFIG_DEVPTS_MULTIPLE_INSTANCES. Changelog[v3]: - Rename ptmx_mode to ptmxmode (for consistency with 'newinstance') Changelog[v2]: - [H. Peter Anvin] Remove mknod() system call support and create the ptmx node internally. Changelog[v1]: - Earlier version of this patch enabled creating /dev/pts/tty as well. As pointed out by Al Viro and H. Peter Anvin, that is not really necessary. Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | Extract option parsing to new functionSukadev Bhattiprolu2009-01-021-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move code to parse mount options into a separate function so it can (later) be shared between mount and remount operations. Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | Per-mount 'config' objectSukadev Bhattiprolu2009-01-021-18/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With support for multiple mounts of devpts, the 'config' structure really represents per-mount options rather than config parameters. Rename 'config' structure to 'pts_mount_opts' and store it in the super-block. Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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