- 07 1月, 2011 29 次提交
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由 Nick Piggin 提交于
Use RCU to simplify locking in dget_parent. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
dget_locked was a shortcut to avoid the lazy lru manipulation when we already held dcache_lock (lru manipulation was relatively cheap at that point). However, how that the lru lock is an innermost one, we never hold it at any caller, so the lock cost can now be avoided. We already have well working lazy dcache LRU, so it should be fine to defer LRU manipulations to scan time. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
dcache_inode_lock can be avoided in d_delete() and d_materialise_unique() in cases where it is not required. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
It is possible to run dput without taking data structure locks up-front. In many cases where we don't kill the dentry anyway, these locks are not required. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
Long lived dcache "multi-step" operations which retry on rename seq can be starved with a lot of rename activity. If they fail after the 1st pass, take the rename_lock for writing to avoid further starvation. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
dcache_lock no longer protects anything. remove it. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
The remaining usages for dcache_lock is to allow atomic, multi-step read-side operations over the directory tree by excluding modifications to the tree. Also, to walk in the leaf->root direction in the tree where we don't have a natural d_lock ordering. This could be accomplished by taking every d_lock, but this would mean a huge number of locks and actually gets very tricky. Solve this instead by using the rename seqlock for multi-step read-side operations, retry in case of a rename so we don't walk up the wrong parent. Concurrent dentry insertions are not serialised against. Concurrent deletes are tricky when walking up the directory: our parent might have been deleted when dropping locks so also need to check and retry for that. We can also use the rename lock in cases where livelock is a worry (and it is introduced in subsequent patch). Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
Cover d_name with d_lock in more cases, where there may be concurrent modification to it. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
Add a new lock, dcache_inode_lock, to protect the inode's i_dentry list from concurrent modification. d_alias is also protected by d_lock. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
Protect d_subdirs and d_child with d_lock, except in filesystems that aren't using dcache_lock for these anyway (eg. using i_mutex). Note: if we change the locking rule in future so that ->d_child protection is provided only with ->d_parent->d_lock, it may allow us to reduce some locking. But it would be an exception to an otherwise regular locking scheme, so we'd have to see some good results. Probably not worthwhile. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
Protect d_unhashed(dentry) condition with d_lock. This means keeping DCACHE_UNHASHED bit in synch with hash manipulations. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
Make d_count non-atomic and protect it with d_lock. This allows us to ensure a 0 refcount dentry remains 0 without dcache_lock. It is also fairly natural when we start protecting many other dentry members with d_lock. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
Add a new lock, dcache_lru_lock, to protect the dcache LRU list from concurrent modification. d_lru is also protected by d_lock, which allows LRU lists to be accessed without the lru lock, using RCU in future patches. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
Add a new lock, dcache_hash_lock, to protect the dcache hash table from concurrent modification. d_hash is also protected by d_lock. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
Remove dcache_lock locking from hostfs filesystem, and move it into dcache helpers. All that is required is a coherent path name. Protection from concurrent modification of the namespace after path name generation is not provided in current code, because dcache_lock is dropped before the path is used. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
Change d_hash so it may be called from lock-free RCU lookups. See similar patch for d_compare for details. For in-tree filesystems, this is just a mechanical change. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
Change d_compare so it may be called from lock-free RCU lookups. This does put significant restrictions on what may be done from the callback, however there don't seem to have been any problems with in-tree fses. If some strange use case pops up that _really_ cannot cope with the rcu-walk rules, we can just add new rcu-unaware callbacks, which would cause name lookup to drop out of rcu-walk mode. For in-tree filesystems, this is just a mechanical change. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
smpfs and ncpfs want to update a live dentry name in-place. Rather than have them open code the locking, provide a documented dcache API. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
Use vfat's method for dealing with negative dentries to preserve case, rather than overwrite dentry name in d_revalidate, which is a bit ugly and also gets in the way of doing lock-free path walking. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
Use vfat's method for dealing with negative dentries to preserve case, rather than overwrite dentry name in d_revalidate, which is a bit ugly and also gets in the way of doing lock-free path walking. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
Change d_delete from a dentry deletion notification to a dentry caching advise, more like ->drop_inode. Require it to be constant and idempotent, and not take d_lock. This is how all existing filesystems use the callback anyway. This makes fine grained dentry locking of dput and dentry lru scanning much simpler. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
Remove redundant (and incorrect, since dcache RCU lookup) dentry locking documentation and point to the canonical document. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
Switching d_op on a live dentry is racy in general, so avoid it. In this case it is a negative dentry, which is safer, but there are still concurrent ops which may be called on d_op in that case (eg. d_revalidate). So in general a filesystem may not do this. Fix configfs so as not to do this. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
Switching d_op on a live dentry is racy in general, so avoid it. In this case it is a negative dentry, which is safer, but there are still concurrent ops which may be called on d_op in that case (eg. d_revalidate). So in general a filesystem may not do this. Fix cgroupfs so as not to do this. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
percpu_counter library generates quite nasty code, so unless you need to dynamically allocate counters or take fast approximate value, a simple per cpu set of counters is much better. The percpu_counter can never be made to work as well, because it has an indirection from pointer to percpu memory, and it can't use direct this_cpu_inc interfaces because it doesn't use static PER_CPU data, so code will always be worse. In the fastpath, it is the difference between this: incl %gs:nr_dentry # nr_dentry and this: movl percpu_counter_batch(%rip), %edx # percpu_counter_batch, movl $1, %esi #, movq $nr_dentry, %rdi #, call __percpu_counter_add # (plus I clobber registers) __percpu_counter_add: pushq %rbp # movq %rsp, %rbp #, subq $32, %rsp #, movq %rbx, -24(%rbp) #, movq %r12, -16(%rbp) #, movq %r13, -8(%rbp) #, movq %rdi, %rbx # fbc, fbc #APP # 216 "/home/npiggin/usr/src/linux-2.6/arch/x86/include/asm/thread_info.h" 1 movq %gs:kernel_stack,%rax #, pfo_ret__ # 0 "" 2 #NO_APP incl -8124(%rax) # <variable>.preempt_count movq 32(%rdi), %r12 # <variable>.counters, tcp_ptr__ #APP # 78 "lib/percpu_counter.c" 1 add %gs:this_cpu_off, %r12 # this_cpu_off, tcp_ptr__ # 0 "" 2 #NO_APP movslq (%r12),%r13 #* tcp_ptr__, tmp73 movslq %edx,%rax # batch, batch addq %rsi, %r13 # amount, count cmpq %rax, %r13 # batch, count jge .L27 #, negl %edx # tmp76 movslq %edx,%rdx # tmp76, tmp77 cmpq %rdx, %r13 # tmp77, count jg .L28 #, .L27: movq %rbx, %rdi # fbc, call _raw_spin_lock # addq %r13, 8(%rbx) # count, <variable>.count movq %rbx, %rdi # fbc, movl $0, (%r12) #,* tcp_ptr__ call _raw_spin_unlock # .L29: #APP # 216 "/home/npiggin/usr/src/linux-2.6/arch/x86/include/asm/thread_info.h" 1 movq %gs:kernel_stack,%rax #, pfo_ret__ # 0 "" 2 #NO_APP decl -8124(%rax) # <variable>.preempt_count movq -8136(%rax), %rax #, D.14625 testb $8, %al #, D.14625 jne .L32 #, .L31: movq -24(%rbp), %rbx #, movq -16(%rbp), %r12 #, movq -8(%rbp), %r13 #, leave ret .p2align 4,,10 .p2align 3 .L28: movl %r13d, (%r12) # count,* jmp .L29 # .L32: call preempt_schedule # .p2align 4,,6 jmp .L31 # .size __percpu_counter_add, .-__percpu_counter_add .p2align 4,,15 Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
The nr_unused counters count the number of objects on an LRU, and as such they are synchronized with LRU object insertion and removal and scanning, and protected under the LRU lock. Making it per-cpu does not actually get any concurrency improvements because of this lock, and summing the counter is much slower, and incrementing/decrementing it costs more code size and is slower too. These counters should stay per-LRU, which currently means global. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
This is a nasty and error prone API. It is no longer used, remove it. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Nick Piggin 提交于
d_validate has been broken for a long time. kmem_ptr_validate does not guarantee that a pointer can be dereferenced if it can go away at any time. Even rcu_read_lock doesn't help, because the pointer might be queued in RCU callbacks but not executed yet. So the parent cannot be checked, nor the name hashed. The dentry pointer can not be touched until it can be verified under lock. Hashing simply cannot be used. Instead, verify the parent/child relationship by traversing parent's d_child list. It's slow, but only ncpfs and the destaged smbfs care about it, at this point. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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- 05 1月, 2011 5 次提交
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由 Nick Piggin 提交于
This reverts commit 3825bdb7. You cannot dget() a dentry without having a reference, or holding a lock that guarantees it remains valid. Signed-off-by: NNick Piggin <npiggin@kernel.dk>
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由 Linus Torvalds 提交于
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git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6由 Linus Torvalds 提交于
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: ipv4/route.c: respect prefsrc for local routes bridge: stp: ensure mac header is set bridge: fix br_multicast_ipv6_rcv for paged skbs atl1: fix oops when changing tx/rx ring params drivers/atm/atmtcp.c: add missing atm_dev_put starfire: Fix dma_addr_t size test for MIPS tg3: fix return value check in tg3_read_vpd() Broadcom CNIC core network driver: fix mem leak on allocation failures in cnic_alloc_uio_rings() ISDN, Gigaset: Fix memory leak in do_disconnect_req() CAN: Use inode instead of kernel address for /proc file skfp: testing the wrong variable in skfp_driver_init() ppp: allow disabling multilink protocol ID compression ehea: Avoid changing vlan flags ueagle-atm: fix PHY signal initialization race
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由 Joel Sing 提交于
The preferred source address is currently ignored for local routes, which results in all local connections having a src address that is the same as the local dst address. Fix this by respecting the preferred source address when it is provided for local routes. This bug can be demonstrated as follows: # ifconfig dummy0 192.168.0.1 # ip route show table local | grep local.*dummy0 local 192.168.0.1 dev dummy0 proto kernel scope host src 192.168.0.1 # ip route change table local local 192.168.0.1 dev dummy0 \ proto kernel scope host src 127.0.0.1 # ip route show table local | grep local.*dummy0 local 192.168.0.1 dev dummy0 proto kernel scope host src 127.0.0.1 We now establish a local connection and verify the source IP address selection: # nc -l 192.168.0.1 3128 & # nc 192.168.0.1 3128 & # netstat -ant | grep 192.168.0.1:3128.*EST tcp 0 0 192.168.0.1:3128 192.168.0.1:33228 ESTABLISHED tcp 0 0 192.168.0.1:33228 192.168.0.1:3128 ESTABLISHED Signed-off-by: NJoel Sing <jsing@google.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Christoph Hellwig 提交于
The ->trim_fs has been removed meanwhile, so remove it from the documentation as well. Signed-off-by: NChristoph Hellwig <hch@lst.de> Reported-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 04 1月, 2011 6 次提交
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由 Linus Torvalds 提交于
* master.kernel.org:/home/rmk/linux-2.6-arm: ARM: pxa: fix page table corruption on resume ARM: it8152: add IT8152_LAST_IRQ definition to fix build error ARM: pxa: PXA_ESERIES depends on FB_W100. ARM: 6605/1: Add missing include "asm/memory.h" ARM: 6540/1: Stop irqsoff trace on return to user ARM: 6537/1: update Nomadik, U300 and Ux500 maintainers ARM: 6536/1: Add missing SZ_{32,64,128} ARM: fix cache-feroceon-l2 after stack based kmap_atomic() ARM: fix cache-xsc3l2 after stack based kmap_atomic() ARM: get rid of kmap_high_l1_vipt() ARM: smp: avoid incrementing mm_users on CPU startup ARM: pxa: PXA_ESERIES depends on FB_W100.
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由 Andrew Morton 提交于
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=25702Reported-by: NMartin Ettl <ettl.martin@gmx.de> Cc: David Howells <dhowells@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Mimi Zohar 提交于
If security_filter_rule_init() doesn't return a rule, then not everything is as fine as the return code implies. This bug only occurs when the LSM (eg. SELinux) is disabled at runtime. Adding an empty LSM rule causes ima_match_rules() to always succeed, ignoring any remaining rules. default IMA TCB policy: # PROC_SUPER_MAGIC dont_measure fsmagic=0x9fa0 # SYSFS_MAGIC dont_measure fsmagic=0x62656572 # DEBUGFS_MAGIC dont_measure fsmagic=0x64626720 # TMPFS_MAGIC dont_measure fsmagic=0x01021994 # SECURITYFS_MAGIC dont_measure fsmagic=0x73636673 < LSM specific rule > dont_measure obj_type=var_log_t measure func=BPRM_CHECK measure func=FILE_MMAP mask=MAY_EXEC measure func=FILE_CHECK mask=MAY_READ uid=0 Thus without the patch, with the boot parameters 'tcb selinux=0', adding the above 'dont_measure obj_type=var_log_t' rule to the default IMA TCB measurement policy, would result in nothing being measured. The patch prevents the default TCB policy from being replaced. Signed-off-by: NMimi Zohar <zohar@us.ibm.com> Cc: James Morris <jmorris@namei.org> Acked-by: NSerge Hallyn <serge.hallyn@canonical.com> Cc: David Safford <safford@watson.ibm.com> Cc: <stable@kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Florian Westphal 提交于
commit bf9ae538 (llc: use dev_hard_header) removed the skb_reset_mac_header call from llc_mac_hdr_init. This seems fine itself, but br_send_bpdu() invokes ebtables LOCAL_OUT. We oops in ebt_basic_match() because it assumes eth_hdr(skb) returns a meaningful result. Cc: acme@ghostprotocols.net References: https://bugzilla.kernel.org/show_bug.cgi?id=24532Signed-off-by: NFlorian Westphal <fw@strlen.de> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Linus Torvalds 提交于
Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf: Fix callchain hit bad cast on ascii display arch/x86/oprofile/op_model_amd.c: Perform initialisation on a single CPU watchdog: Improve initialisation error message and documentation
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