summaryrefslogtreecommitdiffstats
path: root/fs
Commit message (Collapse)AuthorAgeFilesLines
* fs: Use rename lock and RCU for multi-step operationsNick Piggin2011-01-073-27/+139
| | | | | | | | | | | | | | | | | | | | | 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: Nick Piggin <npiggin@kernel.dk>
* fs: increase d_name lock coverageNick Piggin2011-01-071-2/+12
| | | | | | | Cover d_name with d_lock in more cases, where there may be concurrent modification to it. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
* fs: scale inode alias listNick Piggin2011-01-078-9/+77
| | | | | | | 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: Nick Piggin <npiggin@kernel.dk>
* fs: dcache scale subdirsNick Piggin2011-01-0711-153/+302
| | | | | | | | | | | | 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: Nick Piggin <npiggin@kernel.dk>
* fs: dcache scale d_unhashedNick Piggin2011-01-077-54/+95
| | | | | | | Protect d_unhashed(dentry) condition with d_lock. This means keeping DCACHE_UNHASHED bit in synch with hash manipulations. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
* fs: dcache scale dentry refcountNick Piggin2011-01-0716-50/+108
| | | | | | | | 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: Nick Piggin <npiggin@kernel.dk>
* fs: dcache scale lruNick Piggin2011-01-071-28/+84
| | | | | | | | 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: Nick Piggin <npiggin@kernel.dk>
* fs: dcache scale hashNick Piggin2011-01-071-11/+62
| | | | | | | 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: Nick Piggin <npiggin@kernel.dk>
* hostfs: simplify lockingNick Piggin2011-01-072-16/+23
| | | | | | | | | | 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: Nick Piggin <npiggin@kernel.dk>
* fs: change d_hash for rcu-walkNick Piggin2011-01-0719-43/+71
| | | | | | | | | 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: Nick Piggin <npiggin@kernel.dk>
* fs: change d_compare for rcu-walkNick Piggin2011-01-0717-139/+191
| | | | | | | | | | | | | 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: Nick Piggin <npiggin@kernel.dk>
* fs: name case update methodNick Piggin2011-01-072-29/+33
| | | | | | | 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: Nick Piggin <npiggin@kernel.dk>
* jfs: dont overwrite dentry name in d_revalidateNick Piggin2011-01-071-8/+35
| | | | | | | | 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: Nick Piggin <npiggin@kernel.dk>
* cifs: dont overwrite dentry name in d_revalidateNick Piggin2011-01-071-19/+24
| | | | | | | | 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: Nick Piggin <npiggin@kernel.dk>
* fs: change d_delete semanticsNick Piggin2011-01-0715-20/+18
| | | | | | | | | | | | 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: Nick Piggin <npiggin@kernel.dk>
* config fs: avoid switching ->d_op on live dentryNick Piggin2011-01-071-8/+9
| | | | | | | | | 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: Nick Piggin <npiggin@kernel.dk>
* fs: use fast counters for vfs cachesNick Piggin2011-01-072-13/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Nick Piggin <npiggin@kernel.dk>
* vfs: revert per-cpu nr_unused counters for dentry and inodesNick Piggin2011-01-072-21/+12
| | | | | | | | | | | | | | 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: Nick Piggin <npiggin@kernel.dk>
* fs: d_validate fixesNick Piggin2011-01-071-18/+7
| | | | | | | | | | | | | | | | | | 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: Nick Piggin <npiggin@kernel.dk>
* Revert "fs: use RCU read side protection in d_validate"Nick Piggin2011-01-051-12/+19
| | | | | | | | | This reverts commit 3825bdb7ed920845961f32f364454bee5f469abb. You cannot dget() a dentry without having a reference, or holding a lock that guarantees it remains valid. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
* Merge branch 'upstream-linus' of ↵Linus Torvalds2010-12-238-28/+81
|\ | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2 * 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2: ocfs2: Fix system inodes cache overflow. ocfs2: Hold ip_lock when set/clear flags for indexed dir. ocfs2: Adjust masklog flag values Ocfs2: Teach 'coherency=full' O_DIRECT writes to correctly up_read i_alloc_sem. ocfs2/dlm: Migrate lockres with no locks if it has a reference
| * ocfs2: Fix system inodes cache overflow.Tao Ma2010-12-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we store system inodes cache in ocfs2_super, we use a array for global system inodes. But unfortunately, the range is calculated wrongly which makes it overflow and pollute ocfs2_super->local_system_inodes. This patch fix it by setting the range properly. The corresponding bug is ossbug1303. http://oss.oracle.com/bugzilla/show_bug.cgi?id=1303 Cc: stable@kernel.org Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>
| * ocfs2: Hold ip_lock when set/clear flags for indexed dir.Tao Ma2010-12-161-0/+4
| | | | | | | | | | | | | | | | When we set/clear the dyn_features for an inode we hold the ip_lock. So do it when we set/clear OCFS2_INDEXED_DIR_FL also. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>
| * ocfs2: Adjust masklog flag valuesSunil Mushran2010-12-162-8/+10
| | | | | | | | | | | | | | Two masklogs had the same flag value. Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>
| * Ocfs2: Teach 'coherency=full' O_DIRECT writes to correctly up_read i_alloc_sem.Tristan Ye2010-12-093-6/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Due to newly-introduced 'coherency=full' O_DIRECT writes also takes the EX rw_lock like buffered writes did(rw_level == 1), it turns out messing the usage of 'level' in ocfs2_dio_end_io() up, which caused i_alloc_sem being failed to get up_read'd correctly. This patch tries to teach ocfs2_dio_end_io to understand well on all locking stuffs by explicitly introducing a new bit for i_alloc_sem in iocb's private data, just like what we did for rw_lock. Signed-off-by: Tristan Ye <tristan.ye@oracle.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>
| * ocfs2/dlm: Migrate lockres with no locks if it has a referenceSunil Mushran2010-12-091-13/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | o2dlm was not migrating resources with zero locks because it assumed that that resource would get purged by dlm_thread. However, some usage patterns involve creating and dropping locks at a high rate leading to the migrate thread seeing zero locks but the purge thread seeing an active reference. When this happens, the dlm_thread cannot purge the resource and the migrate thread sees no reason to migrate that resource. The spell is broken when the migrate thread catches the resource with a lock. The fix is to make the migrate thread also consider the reference map. This usage pattern can be triggered by userspace on userdlm locks and flocks. Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>
* | Merge branch 'linus-hot-fix' of ↵Linus Torvalds2010-12-231-0/+5
|\ \ | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 * 'linus-hot-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: fix on-line resizing regression
| * | ext4: fix on-line resizing regressionTheodore Ts'o2010-12-231-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | https://bugzilla.kernel.org/show_bug.cgi?id=25352 This regression was caused by commit a31437b85: "ext4: use sb_issue_zeroout in setup_new_group_blocks", by accidentally dropping the code which reserved the block group descriptor and inode table blocks. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* | | logfs: fix "Kernel BUG at readwrite.c:1193"Prasad Joshi2010-12-221-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This happens when __logfs_create() tries to write a new inode to the disk which is full. __logfs_create() associates the transaction pointer with inode. During the logfs_write_inode() function call chain this transaction pointer is moved from inode to page->private using function move_inode_to_page (do_write_inode() -> inode_to_page() -> move_inode_to_page) When the write inode fails, the transaction is aborted and iput is called on the failed inode. During delete_inode the same transaction pointer associated with the page is getting used. Thus causing kernel BUG. The patch checks for error in write_inode() and restores the page->private to NULL. Addresses https://bugzilla.kernel.org/show_bug.cgi?id=20162 Signed-off-by: Prasad Joshi <prasadjoshi124@gmail.com> Cc: Joern Engel <joern@logfs.org> Cc: Florian Mickler <florian@mickler.org> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Maciej Rutecki <maciej.rutecki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | logfs: fix deadlock in logfs_get_wblocks, hold and wait on super->s_write_mutexPrasad Joshi2010-12-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | do_logfs_journal_wl_pass() should use GFP_NOFS for memory allocation GC code calls btree_insert32 with GFP_KERNEL while holding a mutex super->s_write_mutex. The same mutex is used in address_space_operations->writepage(), and a call to writepage() could be triggered as a result of memory allocation in btree_insert32, causing a deadlock. Addresses https://bugzilla.kernel.org/show_bug.cgi?id=20342 Signed-off-by: Prasad Joshi <prasadjoshi124@gmail.com> Cc: Joern Engel <joern@logfs.org> Cc: Florian Mickler <florian@mickler.org> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Maciej Rutecki <maciej.rutecki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge branch 'for-linus' of ↵Linus Torvalds2010-12-202-17/+25
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: ceph: handle partial result from get_user_pages ceph: mark user pages dirty on direct-io reads ceph: fix null pointer dereference in ceph_init_dentry for nfs reexport ceph: fix direct-io on non-page-aligned buffers ceph: fix msgr_init error path
| * | | ceph: mark user pages dirty on direct-io readsHenry C Chang2010-12-171-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For read operation, we have to set the argument _write_ of get_user_pages to 1 since we will write data to pages. Also, we need to SetPageDirty before releasing these pages. Signed-off-by: Henry C Chang <henry_c_chang@tcloudcomputing.com> Signed-off-by: Sage Weil <sage@newdream.net>
| * | | ceph: fix null pointer dereference in ceph_init_dentry for nfs reexportSage Weil2010-12-171-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The fh_to_dentry etc. methods use ceph_init_dentry(), which assumes that d_parent is defined. It isn't for those callers, so check! Signed-off-by: Sage Weil <sage@newdream.net>
| * | | ceph: fix direct-io on non-page-aligned buffersHenry C Chang2010-12-151-12/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The user buffer may be 512-byte aligned, not page-aligned. We were assuming the buffer was page-aligned and only accounting for non-page-aligned io offsets. Signed-off-by: Henry C Chang <henry_c_chang@tcloudcomputing.com> Signed-off-by: Sage Weil <sage@newdream.net>
* | | | Fix btrfs b0rkageAl Viro2010-12-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Buggered-in: 76dda93c6ae2 ("Btrfs: add snapshot/subvolume destroy ioctl") Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Chris Mason <chris.mason@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | Merge branch 'for-linus' of git://git.infradead.org/users/eparis/notifyLinus Torvalds2010-12-164-31/+60
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://git.infradead.org/users/eparis/notify: fanotify: fill in the metadata_len field on struct fanotify_event_metadata fanotify: split version into version and metadata_len fanotify: Dont try to open a file descriptor for the overflow event fanotify: Introduce FAN_NOFD fanotify: do not leak user reference on allocation failure inotify: stop kernel memory leak on file creation failure fanotify: on group destroy allow all waiters to bypass permission check fanotify: Dont allow a mask of 0 if setting or removing a mark fanotify: correct broken ref counting in case adding a mark failed fanotify: if set by user unset FMODE_NONOTIFY before fsnotify_perm() is called fanotify: remove packed from access response message fanotify: deny permissions when no event was sent
| * | | | fanotify: fill in the metadata_len field on struct fanotify_event_metadataEric Paris2010-12-151-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The fanotify_event_metadata now has a field which is supposed to indicate the length of the metadata portion of the event. Fill in that field as well. Based-in-part-on-patch-by: Alexey Zaytsev <alexey.zaytsev@gmail.com> Signed-off-by: Eric Paris <eparis@redhat.com>
| * | | | fanotify: Dont try to open a file descriptor for the overflow eventLino Sanfilippo2010-12-071-4/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We should not try to open a file descriptor for the overflow event since this will always fail. Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Signed-off-by: Eric Paris <eparis@redhat.com>
| * | | | fanotify: do not leak user reference on allocation failureEric Paris2010-12-071-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If fanotify_init is unable to allocate a new fsnotify group it will return but will not drop its reference on the associated user struct. Drop that reference on error. Reported-by: Vegard Nossum <vegard.nossum@gmail.com> Signed-off-by: Eric Paris <eparis@redhat.com>
| * | | | inotify: stop kernel memory leak on file creation failureEric Paris2010-12-071-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If inotify_init is unable to allocate a new file for the new inotify group we leak the new group. This patch drops the reference on the group on file allocation failure. Reported-by: Vegard Nossum <vegard.nossum@gmail.com> cc: stable@kernel.org Signed-off-by: Eric Paris <eparis@redhat.com>
| * | | | fanotify: on group destroy allow all waiters to bypass permission checkLino Sanfilippo2010-12-072-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When fanotify_release() is called, there may still be processes waiting for access permission. Currently only processes for which an event has already been queued into the groups access list will be woken up. Processes for which no event has been queued will continue to sleep and thus cause a deadlock when fsnotify_put_group() is called. Furthermore there is a race allowing further processes to be waiting on the access wait queue after wake_up (if they arrive before clear_marks_by_group() is called). This patch corrects this by setting a flag to inform processes that the group is about to be destroyed and thus not to wait for access permission. [additional changelog from eparis] Lets think about the 4 relevant code paths from the PoV of the 'operator' 'listener' 'responder' and 'closer'. Where operator is the process doing an action (like open/read) which could require permission. Listener is the task (or in this case thread) slated with reading from the fanotify file descriptor. The 'responder' is the thread responsible for responding to access requests. 'Closer' is the thread attempting to close the fanotify file descriptor. The 'operator' is going to end up in: fanotify_handle_event() get_response_from_access() (THIS BLOCKS WAITING ON USERSPACE) The 'listener' interesting code path fanotify_read() copy_event_to_user() prepare_for_access_response() (THIS CREATES AN fanotify_response_event) The 'responder' code path: fanotify_write() process_access_response() (REMOVE A fanotify_response_event, SET RESPONSE, WAKE UP 'operator') The 'closer': fanotify_release() (SUPPOSED TO CLEAN UP THE REST OF THIS MESS) What we have today is that in the closer we remove all of the fanotify_response_events and set a bit so no more response events are ever created in prepare_for_access_response(). The bug is that we never wake all of the operators up and tell them to move along. You fix that in fanotify_get_response_from_access(). You also fix other operators which haven't gotten there yet. So I agree that's a good fix. [/additional changelog from eparis] [remove additional changes to minimize patch size] [move initialization so it was inside CONFIG_FANOTIFY_PERMISSION] Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Signed-off-by: Eric Paris <eparis@redhat.com>
| * | | | fanotify: Dont allow a mask of 0 if setting or removing a markLino Sanfilippo2010-12-071-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In mark_remove_from_mask() we destroy marks that have their event mask cleared. Thus we should not allow the creation of those marks in the first place. With this patch we check if the mask given from user is 0 in case of FAN_MARK_ADD. If so we return an error. Same for FAN_MARK_REMOVE since this does not have any effect. Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Signed-off-by: Eric Paris <eparis@redhat.com>
| * | | | fanotify: correct broken ref counting in case adding a mark failedLino Sanfilippo2010-12-071-17/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If adding a mount or inode mark failed fanotify_free_mark() is called explicitly. But at this time the mark has already been put into the destroy list of the fsnotify_mark kernel thread. If the thread is too slow it will try to decrease the reference of a mark, that has already been freed by fanotify_free_mark(). (If its fast enough it will only decrease the marks ref counter from 2 to 1 - note that the counter has been increased to 2 in add_mark() - which has practically no effect.) This patch fixes the ref counting by not calling free_mark() explicitly, but decreasing the ref counter and rely on the fsnotify_mark thread to cleanup in case adding the mark has failed. Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Signed-off-by: Eric Paris <eparis@redhat.com>
| * | | | fanotify: if set by user unset FMODE_NONOTIFY before fsnotify_perm() is calledLino Sanfilippo2010-12-071-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Unsetting FMODE_NONOTIFY in fsnotify_open() is too late, since fsnotify_perm() is called before. If FMODE_NONOTIFY is set fsnotify_perm() will skip permission checks, so a user can still disable permission checks by setting this flag in an open() call. This patch corrects this by unsetting the flag before fsnotify_perm is called. Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de> Signed-off-by: Eric Paris <eparis@redhat.com>
| * | | | fanotify: deny permissions when no event was sentEric Paris2010-12-071-4/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If no event was sent to userspace we cannot expect userspace to respond to permissions requests. Today such requests just hang forever. This patch will deny any permissions event which was unable to be sent to userspace. Reported-by: Tvrtko Ursulin <tvrtko.ursulin@sophos.com> Signed-off-by: Eric Paris <eparis@redhat.com>
* | | | | nilfs2: fix regression of garbage collection ioctlRyusuke Konishi2010-12-162-9/+12
| |_|/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On 2.6.37-rc1, garbage collection ioctl of nilfs was broken due to the commit 263d90cefc7d82a0 ("nilfs2: remove own inode hash used for GC"), and leading to filesystem corruption. The patch doesn't queue gc-inodes for log writer if they are reused through the vfs inode cache. Here, gc-inode is the inode which buffers blocks to be relocated on GC. That patch queues gc-inodes in nilfs_init_gcinode() function, but this function is not called when they don't have I_NEW flag. Thus, some of live blocks are wrongly overrode without being moved to new logs. This resolves the problem by moving the gc-inode queueing to an outer function to ensure it's done right. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
* | | | Merge branch 'for_linus' of ↵Linus Torvalds2010-12-154-4/+18
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: fix typo which broke '..' detection in ext4_find_entry() ext4: Turn off multiple page-io submission by default
| * | | | ext4: fix typo which broke '..' detection in ext4_find_entry()Aaro Koskinen2010-12-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There should be a check for the NUL character instead of '0'. Fortunately the only thing that cares about this is NFS serving, which is why we didn't notice this in the merge window testing. Reported-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
| * | | | ext4: Turn off multiple page-io submission by defaultTheodore Ts'o2010-12-143-3/+17
| |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Jon Nelson has found a test case which causes postgresql to fail with the error: psql:t.sql:4: ERROR: invalid page header in block 38269 of relation base/16384/16581 Under memory pressure, it looks like part of a file can end up getting replaced by zero's. Until we can figure out the cause, we'll roll back the change and use block_write_full_page() instead of ext4_bio_write_page(). The new, more efficient writing function can be used via the mount option mblk_io_submit, so we can test and fix the new page I/O code. To reproduce the problem, install postgres 8.4 or 9.0, and pin enough memory such that the system just at the end of triggering writeback before running the following sql script: begin; create temporary table foo as select x as a, ARRAY[x] as b FROM generate_series(1, 10000000 ) AS x; create index foo_a_idx on foo (a); create index foo_b_idx on foo USING GIN (b); rollback; If the temporary table is created on a hard drive partition which is encrypted using dm_crypt, then under memory pressure, approximately 30-40% of the time, pgsql will issue the above failure. This patch should fix this problem, and the problem will come back if the file system is mounted with the mblk_io_submit mount option. Reported-by: Jon Nelson <jnelson@jamponi.net> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* | | | install_special_mapping skips security_file_mmap check.Tavis Ormandy2010-12-151-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The install_special_mapping routine (used, for example, to setup the vdso) skips the security check before insert_vm_struct, allowing a local attacker to bypass the mmap_min_addr security restriction by limiting the available pages for special mappings. bprm_mm_init() also skips the check, and although I don't think this can be used to bypass any restrictions, I don't see any reason not to have the security check. $ uname -m x86_64 $ cat /proc/sys/vm/mmap_min_addr 65536 $ cat install_special_mapping.s section .bss resb BSS_SIZE section .text global _start _start: mov eax, __NR_pause int 0x80 $ nasm -D__NR_pause=29 -DBSS_SIZE=0xfffed000 -f elf -o install_special_mapping.o install_special_mapping.s $ ld -m elf_i386 -Ttext=0x10000 -Tbss=0x11000 -o install_special_mapping install_special_mapping.o $ ./install_special_mapping & [1] 14303 $ cat /proc/14303/maps 0000f000-00010000 r-xp 00000000 00:00 0 [vdso] 00010000-00011000 r-xp 00001000 00:19 2453665 /home/taviso/install_special_mapping 00011000-ffffe000 rwxp 00000000 00:00 0 [stack] It's worth noting that Red Hat are shipping with mmap_min_addr set to 4096. Signed-off-by: Tavis Ormandy <taviso@google.com> Acked-by: Kees Cook <kees@ubuntu.com> Acked-by: Robert Swiecki <swiecki@google.com> [ Changed to not drop the error code - akpm ] Reviewed-by: James Morris <jmorris@namei.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-20 04:19:14 +0000