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2016-06-10Merge branch 'for-linus-4.7' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fixes from Chris Mason: "Has some fixes and some new self tests for btrfs. The self tests are usually disabled in the .config file (unless you're doing btrfs dev work), and this bunch is meant to find problems with the 64K page size patches. Jeff has a patch to help people see if they are using the hardware assist crc32c module, which really helps us nail down problems when people ask why crcs are using so much CPU. Otherwise, it's small fixes" * 'for-linus-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: self-tests: Fix extent buffer bitmap test fail on BE system Btrfs: self-tests: Fix test_bitmaps fail on 64k sectorsize Btrfs: self-tests: Use macros instead of constants and add missing newline Btrfs: self-tests: Support testing all possible sectorsizes and nodesizes Btrfs: self-tests: Execute page straddling test only when nodesize < PAGE_SIZE btrfs: advertise which crc32c implementation is being used at module load Btrfs: add validadtion checks for chunk loading Btrfs: add more validation checks for superblock Btrfs: clear uptodate flags of pages in sys_array eb Btrfs: self-tests: Support non-4k page size Btrfs: Fix integer overflow when calculating bytes_per_bitmap Btrfs: test_check_exists: Fix infinite loop when searching for free space entries Btrfs: end transaction if we abort when creating uuid root btrfs: Use __u64 in exported linux/btrfs.h.
2016-06-10Merge branch 'stacking-fixes' (vfs stacking fixes from Jann)Linus Torvalds
Merge filesystem stacking fixes from Jann Horn. * emailed patches from Jann Horn <jannh@google.com>: sched: panic on corrupted stack end ecryptfs: forbid opening files without mmap handler proc: prevent stacking filesystems on top
2016-06-10ecryptfs: forbid opening files without mmap handlerJann Horn
This prevents users from triggering a stack overflow through a recursive invocation of pagefault handling that involves mapping procfs files into virtual memory. Signed-off-by: Jann Horn <jannh@google.com> Acked-by: Tyler Hicks <tyhicks@canonical.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-10proc: prevent stacking filesystems on topJann Horn
This prevents stacking filesystems (ecryptfs and overlayfs) from using procfs as lower filesystem. There is too much magic going on inside procfs, and there is no good reason to stack stuff on top of procfs. (For example, procfs does access checks in VFS open handlers, and ecryptfs by design calls open handlers from a kernel thread that doesn't drop privileges or so.) Signed-off-by: Jann Horn <jannh@google.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-08Merge branch 'misc-fixes-4.7' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.7
2016-06-08Merge branch 'for-chris' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.7
2016-06-08Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs fixes from Al Viro: "Fixes for crap of assorted ages: EOPENSTALE one is 4.2+, autofs one is 4.6, d_walk - 3.2+. The atomic_open() and coredump ones are regressions from this window" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: coredump: fix dumping through pipes fix a regression in atomic_open() fix d_walk()/non-delayed __d_free() race autofs braino fix for do_last() fix EOPENSTALE bug in do_last()
2016-06-08coredump: fix dumping through pipesMateusz Guzik
The offset in the core file used to be tracked with ->written field of the coredump_params structure. The field was retired in favour of file->f_pos. However, ->f_pos is not maintained for pipes which leads to breakage. Restore explicit tracking of the offset in coredump_params. Introduce ->pos field for this purpose since ->written was already reused. Fixes: a00839395103 ("get rid of coredump_params->written"). Reported-by: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> Signed-off-by: Mateusz Guzik <mguzik@redhat.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-06-08fix a regression in atomic_open()Al Viro
open("/foo/no_such_file", O_RDONLY | O_CREAT) on should fail with EACCES when /foo is not writable; failing with ENOENT is obviously wrong. That got broken by a braino introduced when moving the creat_error logics from atomic_open() to lookup_open(). Easy to fix, fortunately. Spotted-by: "Yan, Zheng" <ukernel@gmail.com> Tested-by: "Yan, Zheng" <ukernel@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-06-08fix d_walk()/non-delayed __d_free() raceAl Viro
Ascend-to-parent logics in d_walk() depends on all encountered child dentries not getting freed without an RCU delay. Unfortunately, in quite a few cases it is not true, with hard-to-hit oopsable race as the result. Fortunately, the fix is simiple; right now the rule is "if it ever been hashed, freeing must be delayed" and changing it to "if it ever had a parent, freeing must be delayed" closes that hole and covers all cases the old rule used to cover. Moreover, pipes and sockets remain _not_ covered, so we do not introduce RCU delay in the cases which are the reason for having that delay conditional in the first place. Cc: stable@vger.kernel.org # v3.2+ (and watch out for __d_materialise_dentry()) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-06-07mnt: fs_fully_visible test the proper mount for MNT_LOCKEDEric W. Biederman
MNT_LOCKED implies on a child mount implies the child is locked to the parent. So while looping through the children the children should be tested (not their parent). Typically an unshare of a mount namespace locks all mounts together making both the parent and the slave as locked but there are a few corner cases where other things work. Cc: stable@vger.kernel.org Fixes: ceeb0e5d39fc ("vfs: Ignore unlocked mounts in fs_fully_visible") Reported-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-06-07mnt: If fs_fully_visible fails call put_filesystem.Eric W. Biederman
Add this trivial missing error handling. Cc: stable@vger.kernel.org Fixes: 1b852bceb0d1 ("mnt: Refactor the logic for mounting sysfs and proc in a user namespace") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-06-06Btrfs: self-tests: Fix extent buffer bitmap test fail on BE systemFeifei Xu
In __test_eb_bitmaps(), we write random data to a bitmap. Then copy the bitmap to another bitmap that resides inside an extent buffer. Later we verify the values of corresponding bits in the bitmap and the bitmap inside the extent buffer. However, extent_buffer_test_bit() reads in byte granularity while test_bit() reads in unsigned long granularity. Hence we end up comparing wrong bits on big-endian systems such as ppc64. This commit fixes the issue by reading the bitmap in byte granularity. Reviewed-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Feifei Xu <xufeifei@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-06-06Btrfs: self-tests: Fix test_bitmaps fail on 64k sectorsizeFeifei Xu
With 64K sectorsize, 1G sized block group cannot span across bitmaps. To execute test_bitmaps() function, this commit allocates "BITS_PER_BITMAP * sectorsize + PAGE_SIZE" sized block group. Reviewed-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Feifei Xu <xufeifei@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-06-06Btrfs: self-tests: Use macros instead of constants and add missing newlineFeifei Xu
This commit replaces numerical constants with appropriate preprocessor macros. Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Feifei Xu <xufeifei@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-06-06Btrfs: self-tests: Support testing all possible sectorsizes and nodesizesFeifei Xu
To test all possible sectorsizes, this commit adds a sectorsize array. This commit executes the tests for all possible sectorsizes and nodesizes. Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Feifei Xu <xufeifei@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-06-06Btrfs: self-tests: Execute page straddling test only when nodesize < PAGE_SIZEFeifei Xu
On ppc64, PAGE_SIZE is 64k which is same as BTRFS_MAX_METADATA_BLOCKSIZE. In such a scenario, we will never be able to have an extent buffer containing more than one page. Hence in such cases this commit does not execute the page straddling tests. Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Feifei Xu <xufeifei@linux.vnet.ibm.com> Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-06-06btrfs: advertise which crc32c implementation is being used at module loadJeff Mahoney
Since several architectures support hardware-accelerated crc32c calculation, it would be nice to confirm that btrfs is actually using it. We can see an elevated use count for the module, but it doesn't actually show who the users are. This patch simply prints the name of the driver after successfully initializing the shash. Signed-off-by: Jeff Mahoney <jeffm@suse.com> [ added a helper and used in module load-time message ] Signed-off-by: David Sterba <dsterba@suse.com>
2016-06-06Btrfs: add validadtion checks for chunk loadingLiu Bo
To prevent fuzzed filesystem images from panic the whole system, we need various validation checks to refuse to mount such an image if btrfs finds any invalid value during loading chunks, including both sys_array and regular chunks. Note that these checks may not be sufficient to cover all corner cases, feel free to add more checks. Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Reported-by: Quentin Casasnovas <quentin.casasnovas@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-06-06Btrfs: add more validation checks for superblockLiu Bo
This adds validation checks for super_total_bytes, super_bytes_used and super_stripesize, super_num_devices. Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Reported-by: Quentin Casasnovas <quentin.casasnovas@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-06-06Btrfs: clear uptodate flags of pages in sys_array ebLiu Bo
We set uptodate flag to pages in the temporary sys_array eb, but do not clear the flag after free eb. As the special btree inode may still hold a reference on those pages, the uptodate flag can remain alive in them. If btrfs_super_chunk_root has been intentionally changed to the offset of this sys_array eb, reading chunk_root will read content of sys_array and it will skip our beautiful checks in btree_readpage_end_io_hook() because of "pages of eb are uptodate => eb is uptodate" This adds the 'clear uptodate' part to force it to read from disk. Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-06-05devpts: Make each mount of devpts an independent filesystem.Eric W. Biederman
The /dev/ptmx device node is changed to lookup the directory entry "pts" in the same directory as the /dev/ptmx device node was opened in. If there is a "pts" entry and that entry is a devpts filesystem /dev/ptmx uses that filesystem. Otherwise the open of /dev/ptmx fails. The DEVPTS_MULTIPLE_INSTANCES configuration option is removed, so that userspace can now safely depend on each mount of devpts creating a new instance of the filesystem. Each mount of devpts is now a separate and equal filesystem. Reserved ttys are now available to all instances of devpts where the mounter is in the initial mount namespace. A new vfs helper path_pts is introduced that finds a directory entry named "pts" in the directory of the passed in path, and changes the passed in path to point to it. The helper path_pts uses a function path_parent_directory that was factored out of follow_dotdot. In the implementation of devpts: - devpts_mnt is killed as it is no longer meaningful if all mounts of devpts are equal. - pts_sb_from_inode is replaced by just inode->i_sb as all cached inodes in the tty layer are now from the devpts filesystem. - devpts_add_ref is rolled into the new function devpts_ptmx. And the unnecessary inode hold is removed. - devpts_del_ref is renamed devpts_release and reduced to just a deacrivate_super. - The newinstance mount option continues to be accepted but is now ignored. In devpts_fs.h definitions for when !CONFIG_UNIX98_PTYS are removed as they are never used. Documentation/filesystems/devices.txt is updated to describe the current situation. This has been verified to work properly on openwrt-15.05, centos5, centos6, centos7, debian-6.0.2, debian-7.9, debian-8.2, ubuntu-14.04.3, ubuntu-15.10, fedora23, magia-5, mint-17.3, opensuse-42.1, slackware-14.1, gentoo-20151225 (13.0?), archlinux-2015-12-01. With the caveat that on centos6 and on slackware-14.1 that there wind up being two instances of the devpts filesystem mounted on /dev/pts, the lower copy does not end up getting used. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Greg KH <greg@kroah.com> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Peter Anvin <hpa@zytor.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Serge Hallyn <serge.hallyn@ubuntu.com> Cc: Willy Tarreau <w@1wt.eu> Cc: Aurelien Jarno <aurelien@aurel32.net> Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> Cc: Jann Horn <jann@thejh.net> Cc: Jiri Slaby <jslaby@suse.com> Cc: Florian Weimer <fw@deneb.enyo.de> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-05autofs braino fix for do_last()Al Viro
It's an analogue of commit 7500c38a (fix the braino in "namei: massage lookup_slow() to be usable by lookup_one_len_unlocked()"). The same problem (->lookup()-returned unhashed negative dentry just might be an autofs one with ->d_manage() that would wait until the daemon makes it positive) applies in do_last() - we need to do follow_managed() first. Fortunately, remaining callers of follow_managed() are OK - only autofs has that weirdness (negative dentry that does not mean an instant -ENOENT)) and autofs never has its negative dentries hashed, so we can't pick one from a dcache lookup. ->d_manage() is a bloody mess ;-/ Cc: stable@vger.kernel.org # v4.6 Spotted-by: Ian Kent <raven@themaw.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-06-04Merge branch 'for-linus-4.7' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fixes from Chris Mason: "The important part of this pull is Filipe's set of fixes for btrfs device replacement. Filipe fixed a few issues seen on the list and a number he found on his own" * 'for-linus-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: deal with duplciates during extent_map insertion in btrfs_get_extent Btrfs: fix race between device replace and read repair Btrfs: fix race between device replace and discard Btrfs: fix race between device replace and chunk allocation Btrfs: fix race setting block group back to RW mode during device replace Btrfs: fix unprotected assignment of the left cursor for device replace Btrfs: fix race setting block group readonly during device replace Btrfs: fix race between device replace and block group removal Btrfs: fix race between readahead and device replace/removal
2016-06-04fix EOPENSTALE bug in do_last()Al Viro
EOPENSTALE occuring at the last component of a trailing symlink ends up with do_last() retrying its lookup. After the symlink body has been discarded. The thing is, all this retry_lookup logics in there is not needed at all - the upper layers will do the right thing if we simply return that -EOPENSTALE as we would with any other error. Trying to microoptimize in do_last() is a lot of headache for no good reason. Cc: stable@vger.kernel.org # v4.2+ Tested-by: Oleg Drokin <green@linuxhacker.ru> Reviewed-and-Tested-by: Jeff Layton <jlayton@poochiereds.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-06-03Btrfs: deal with duplciates during extent_map insertion in btrfs_get_extentChris Mason
When dealing with inline extents, btrfs_get_extent will incorrectly try to insert a duplicate extent_map. The dup hits -EEXIST from add_extent_map, but then we try to merge with the existing one and end up trying to insert a zero length extent_map. This actually works most of the time, except when there are extent maps past the end of the inline extent. rocksdb will trigger this sometimes because it preallocates an extent and then truncates down. Josef made a script to trigger with xfs_io: #!/bin/bash xfs_io -f -c "pwrite 0 1000" inline xfs_io -c "falloc -k 4k 1M" inline xfs_io -c "pread 0 1000" -c "fadvise -d 0 1000" -c "pread 0 1000" inline xfs_io -c "fadvise -d 0 1000" inline cat inline You'll get EIOs trying to read inline after this because add_extent_map is returning EEXIST Signed-off-by: Chris Mason <clm@fb.com>
2016-06-02Btrfs: self-tests: Support non-4k page sizeFeifei Xu
self-tests code assumes 4k as the sectorsize and nodesize. This commit fix hardcoded 4K. Enables the self-tests code to be executed on non-4k page sized systems (e.g. ppc64). Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Feifei Xu <xufeifei@linux.vnet.ibm.com> Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-06-02Btrfs: Fix integer overflow when calculating bytes_per_bitmapFeifei Xu
On ppc64, bytes_per_bitmap will be (65536*8*65536). Hence append UL to fix integer overflow. Reviewed-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Feifei Xu <xufeifei@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-06-02Btrfs: test_check_exists: Fix infinite loop when searching for free space ↵Feifei Xu
entries On a ppc64 machine using 64K as the block size, assume that the RB tree at btrfs_free_space_ctl->free_space_offset contains following two entries: 1. A bitmap entry having an offset value of 0 and having the bits corresponding to the address range [128M+512K, 128M+768K] set. 2. An extent entry corresponding to the address range [128M-256K, 128M-128K] In such a scenario, test_check_exists() invoked for checking the existence of address range [128M+768K, 256M] can lead to an infinite loop as explained below: - Checking for the extent entry fails. - Checking for a bitmap entry results in the free space info in range [128M+512K, 128M+768K] beng returned. - rb_prev(info) returns NULL because the bitmap entry starting from offset 0 comes first in the RB tree. - current_node = bitmap node. - while (current_node) tmp = rb_next(bitmap_node);/*tmp is extent based free space entry*/ Since extent based free space entry's last address is smaller than the address being searched for (i.e. 128M+768K) we incorrectly again obtain the extent node as the "next right node" of the RB tree and thus end up looping infinitely. This patch fixes the issue by checking the "tmp" variable which point to the most recently searched free space node. Reviewed-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Feifei Xu <xufeifei@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-06-01ceph: use i_version to check validity of fscacheYan, Zheng
Signed-off-by: Yan, Zheng <zyan@redhat.com>
2016-06-01ceph: improve fscache revalidationYan, Zheng
There are several issues in fscache revalidation code. - In ceph_revalidate_work(), fscache_invalidate() is called when fscache_check_consistency() return 0. This is complete wrong because 0 means cache is valid. - Handle_cap_grant() calls ceph_queue_revalidate() if client already has CAP_FILE_CACHE. This code is confusing. Client should revalidate the cache each time it got CAP_FILE_CACHE anew. - In Handle_cap_grant(), fscache_invalidate() is called if MDS revokes CAP_FILE_CACHE. This is inconsistency with the case that inode get evicted. In the later case, the cache is not discarded. Client may use the cache when inode is reloaded. This patch moves the fscache revalidation into ceph_get_caps(). Client revalidates the cache after it gets CAP_FILE_CACHE. i_rdcache_gen should keep constance while CAP_FILE_CACHE is used. If i_fscache_gen is not equal to i_rdcache_gen, client needs to check cache's consistency. Signed-off-by: Yan, Zheng <zyan@redhat.com>
2016-06-01ceph: disable fscache when inode is opened for writeYan, Zheng
All other filesystems do not add dirty pages to fscache. They all disable fscache when inode is opened for write. Only ceph adds dirty pages to fscache, but the code is buggy. Signed-off-by: Yan, Zheng <zyan@redhat.com>
2016-06-01ceph: avoid unnecessary fscache invalidation/revlidationYan, Zheng
ceph_fill_file_size() has already called ceph_fscache_invalidate() if it return true. Signed-off-by: Yan, Zheng <zyan@redhat.com>
2016-06-01ceph: call __fscache_uncache_page() if readpages failsYan, Zheng
If readpages fails, fscache needs to cleanup its internal state. Signed-off-by: Yan, Zheng <zyan@redhat.com>
2016-06-01FS-Cache: make check_consistency callback return intYan, Zheng
__fscache_check_consistency() calls check_consistency() callback and return the callback's return value. But the return type of check_consistency() is bool. So __fscache_check_consistency() return 1 if the cache is inconsistent. This is inconsistent with the document. Signed-off-by: Yan, Zheng <zyan@redhat.com> Acked-by: David Howells <dhowells@redhat.com>
2016-06-01FS-Cache: wake write waiter after invalidating writesYan, Zheng
Signed-off-by: Yan, Zheng <zyan@redhat.com> Acked-by: David Howells <dhowells@redhat.com>
2016-05-31Btrfs: end transaction if we abort when creating uuid rootJosef Bacik
We still need to call btrfs_end_transaction if we call btrfs_abort_transaction, otherwise we hang and make me super grumpy. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-31Btrfs: fix race between device replace and read repairFilipe Manana
While we are finishing a device replace operation we can have a concurrent task trying to do a read repair operation, in which case it will call btrfs_map_block() to get a struct btrfs_bio which can have a stripe that points to the source device of the device replace operation. This allows for the read repair task to dereference the stripe's device pointer after the device replace operation has freed the source device, resulting in an invalid memory access. This is similar to the problem solved by my previous patch in the same series and named "Btrfs: fix race between device replace and discard". So fix this by surrounding the call to btrfs_map_block() and the code that uses the returned struct btrfs_bio with calls to btrfs_bio_counter_inc_blocked() and btrfs_bio_counter_dec(), giving the proper serialization with the finishing phase of the device replace operation. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com>
2016-05-30Btrfs: fix race between device replace and discardFilipe Manana
While we are finishing a device replace operation, we can make a discard operation (fs mounted with -o discard) do an invalid memory access like the one reported by the following trace: [ 3206.384654] general protection fault: 0000 [#1] PREEMPT SMP [ 3206.387520] Modules linked in: dm_mod btrfs crc32c_generic xor raid6_pq acpi_cpufreq tpm_tis psmouse tpm ppdev sg parport_pc evdev i2c_piix4 parport processor serio_raw i2c_core pcspkr button loop autofs4 ext4 crc16 jbd2 mbcache sr_mod cdrom ata_generic sd_mod virtio_scsi ata_piix libata virtio_pci virtio_ring scsi_mod e1000 virtio floppy [last unloaded: btrfs] [ 3206.388595] CPU: 14 PID: 29194 Comm: fsstress Not tainted 4.6.0-rc7-btrfs-next-29+ #1 [ 3206.388595] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [ 3206.388595] task: ffff88017ace0100 ti: ffff880171b98000 task.ti: ffff880171b98000 [ 3206.388595] RIP: 0010:[<ffffffff8124d233>] [<ffffffff8124d233>] blkdev_issue_discard+0x5c/0x2a7 [ 3206.388595] RSP: 0018:ffff880171b9bb80 EFLAGS: 00010246 [ 3206.388595] RAX: ffff880171b9bc28 RBX: 000000000090d000 RCX: 0000000000000000 [ 3206.388595] RDX: ffffffff82fa1b48 RSI: ffffffff8179f46c RDI: ffffffff82fa1b48 [ 3206.388595] RBP: ffff880171b9bcc0 R08: 0000000000000000 R09: 0000000000000001 [ 3206.388595] R10: ffff880171b9bce0 R11: 000000000090f000 R12: ffff880171b9bbe8 [ 3206.388595] R13: 0000000000000010 R14: 0000000000004868 R15: 6b6b6b6b6b6b6b6b [ 3206.388595] FS: 00007f6182e4e700(0000) GS:ffff88023fdc0000(0000) knlGS:0000000000000000 [ 3206.388595] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 3206.388595] CR2: 00007f617c2bbb18 CR3: 000000017ad9c000 CR4: 00000000000006e0 [ 3206.388595] Stack: [ 3206.388595] 0000000000004878 0000000000000000 0000000002400040 0000000000000000 [ 3206.388595] 0000000000000000 ffff880171b9bbe8 ffff880171b9bbb0 ffff880171b9bbb0 [ 3206.388595] ffff880171b9bbc0 ffff880171b9bbc0 ffff880171b9bbd0 ffff880171b9bbd0 [ 3206.388595] Call Trace: [ 3206.388595] [<ffffffffa042899e>] btrfs_issue_discard+0x12f/0x143 [btrfs] [ 3206.388595] [<ffffffffa042899e>] ? btrfs_issue_discard+0x12f/0x143 [btrfs] [ 3206.388595] [<ffffffffa042e862>] btrfs_discard_extent+0x87/0xde [btrfs] [ 3206.388595] [<ffffffffa04303b5>] btrfs_finish_extent_commit+0xb2/0x1df [btrfs] [ 3206.388595] [<ffffffff8149c246>] ? __mutex_unlock_slowpath+0x150/0x15b [ 3206.388595] [<ffffffffa04464c4>] btrfs_commit_transaction+0x7fc/0x980 [btrfs] [ 3206.388595] [<ffffffff8149c246>] ? __mutex_unlock_slowpath+0x150/0x15b [ 3206.388595] [<ffffffffa0459af6>] btrfs_sync_file+0x38f/0x428 [btrfs] [ 3206.388595] [<ffffffff811a8292>] vfs_fsync_range+0x8c/0x9e [ 3206.388595] [<ffffffff811a82c0>] vfs_fsync+0x1c/0x1e [ 3206.388595] [<ffffffff811a8417>] do_fsync+0x31/0x4a [ 3206.388595] [<ffffffff811a8637>] SyS_fsync+0x10/0x14 [ 3206.388595] [<ffffffff8149e025>] entry_SYSCALL_64_fastpath+0x18/0xa8 [ 3206.388595] [<ffffffff81100c6b>] ? time_hardirqs_off+0x9/0x14 [ 3206.388595] [<ffffffff8108e87d>] ? trace_hardirqs_off_caller+0x1f/0xaa This happens because when we call btrfs_map_block() from btrfs_discard_extent() to get a btrfs_bio structure, the device replace operation has not finished yet, but before we use the device of one of the stripes from the returned btrfs_bio structure, the device object is freed. This is illustrated by the following diagram. CPU 1 CPU 2 btrfs_dev_replace_start() (...) btrfs_dev_replace_finishing() btrfs_start_transaction() btrfs_commit_transaction() (...) btrfs_sync_file() btrfs_start_transaction() (...) btrfs_commit_transaction() btrfs_finish_extent_commit() btrfs_discard_extent() btrfs_map_block() --> returns a struct btrfs_bio with a stripe that has a device field pointing to source device of the replace operation (the device that is being replaced) mutex_lock(&uuid_mutex) mutex_lock(&fs_info->fs_devices->device_list_mutex) mutex_lock(&fs_info->chunk_mutex) btrfs_dev_replace_update_device_in_mapping_tree() --> iterates the mapping tree and for each extent map that has a stripe pointing to the source device, it updates the stripe to point to the target device instead btrfs_rm_dev_replace_blocked() --> waits for fs_info->bio_counter to go down to 0 btrfs_rm_dev_replace_remove_srcdev() --> removes source device from the list of devices mutex_unlock(&fs_info->chunk_mutex) mutex_unlock(&fs_info->fs_devices->device_list_mutex) mutex_unlock(&uuid_mutex) btrfs_rm_dev_replace_free_srcdev() --> frees the source device --> iterates over all stripes of the returned struct btrfs_bio --> for each stripe it dereferences its device pointer --> it ends up finding a pointer to the device used as the source device for the replace operation and that was already freed So fix this by surrounding the call to btrfs_map_block(), and the code that uses the returned struct btrfs_bio, with calls to btrfs_bio_counter_inc_blocked() and btrfs_bio_counter_dec(), so that the finishing phase of the device replace operation blocks until the the bio counter decreases to zero before it frees the source device. This is the same approach we do at btrfs_map_bio() for example. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com>
2016-05-30libceph: change ceph_osdmap_flag() to take osdcIlya Dryomov
For the benefit of every single caller, take osdc instead of map. Also, now that osdc->osdmap can't ever be NULL, drop the check. Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2016-05-30Btrfs: fix race between device replace and chunk allocationFilipe Manana
While iterating and copying extents from the source device, the device replace code keeps adjusting a left cursor that is used to make sure that once we finish processing a device extent, any future writes to extents from the corresponding block group will get into both the source and target devices. This left cursor is also used for resuming the device replace operation at mount time. However using this left cursor to decide whether writes go into both devices or only the source device is not enough to guarantee we don't miss copying extents into the target device. There are two cases where the current approach fails. The first one is related to when there are holes in the device and they get allocated for new block groups while the device replace operation is iterating the device extents (more on this explained below). The second one is that when that loop over the device extents finishes, we start dellaloc, wait for all ordered extents and then commit the current transaction, we might have got new block groups allocated that are now using a device extent that has an offset greater then or equals to the value of the left cursor, in which case writes to extents belonging to these new block groups will get issued only to the source device. For the first case where the current approach of using a left cursor fails, consider the source device currently has the following layout: [ extent bg A ] [ hole, unallocated space ] [extent bg B ] 3Gb 4Gb 5Gb While we are iterating the device extents from the source device using the commit root of the device tree, the following happens: CPU 1 CPU 2 <we are at transaction N> scrub_enumerate_chunks() --> searches the device tree for extents belonging to the source device using the device tree's commit root --> 1st iteration finds extent belonging to block group A --> sets block group A to RO mode (btrfs_inc_block_group_ro) --> sets cursor left to found_key.offset which is 3Gb --> scrub_chunk() starts copies all allocated extents from block group's A stripe at source device into target device btrfs_alloc_chunk() --> allocates device extent in the range [4Gb, 5Gb[ from the source device for a new block group C extent allocated from block group C for a direct IO, buffered write or btree node/leaf extent is written to, perhaps in response to a writepages() call from the VM or directly through direct IO the write is made only against the source device and not against the target device because the extent's offset is in the interval [4Gb, 5Gb[ which is larger then the value of cursor_left (3Gb) --> scrub_chunks() finishes --> updates left cursor from 3Gb to 4Gb --> btrfs_dec_block_group_ro() sets block group A back to RW mode <we are still at transaction N> --> 2nd iteration finds extent belonging to block group B - it did not find the new extent in the range [4Gb, 5Gb[ for block group C because we are using the device tree's commit root or even because the block group's items are not all yet inserted in the respective btrees, that is, the block group is still attached to some transaction handle's new_bgs list and btrfs_create_pending_block_groups() was not called yet against that transaction handle, so the device extent items were not yet inserted into the devices tree <we are still at transaction N> --> so we end not copying anything from the newly allocated device extent from the source device to the target device So fix this by making __btrfs_map_block() always redirect writes to the target device as well, independently of the left cursor's value. With this change the left cursor is now used only for the purpose of tracking progress and allow a mount operation to resume a device replace. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com>
2016-05-30Btrfs: fix race setting block group back to RW mode during device replaceFilipe Manana
After it finishes processing a device extent, the device replace code sets back the block group to RW mode and then after that it sets the left cursor to match the logical end address of the block group, so that future writes into extents belonging to the block group go both the source (old) and target (new) devices. However from the moment we turn the block group back to RW mode we have a short time window, that lasts until we update the left cursor's value, where extents can be allocated from the block group and written to, in which case they will not be copied/written to the target (new) device. Fix this by updating the left cursor's value before turning the block group back to RW mode. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com>
2016-05-30Btrfs: fix unprotected assignment of the left cursor for device replaceFilipe Manana
We were assigning new values to fields of the device replace object without holding the respective lock after processing each device extent. This is important for the left cursor field which can be accessed by a concurrent task running __btrfs_map_block (which, correctly, takes the device replace lock). So change these fields while holding the device replace lock. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com>
2016-05-30Btrfs: fix race setting block group readonly during device replaceFilipe Manana
When we do a device replace, for each device extent we find from the source device, we set the corresponding block group to readonly mode to prevent writes into it from happening while we are copying the device extent from the source to the target device. However just before we set the block group to readonly mode some concurrent task might have already allocated an extent from it or decided it could perform a nocow write into one of its extents, which can make the device replace process to miss copying an extent since it uses the extent tree's commit root to search for extents and only once it finishes searching for all extents belonging to the block group it does set the left cursor to the logical end address of the block group - this is a problem if the respective ordered extents finish while we are searching for extents using the extent tree's commit root and no transaction commit happens while we are iterating the tree, since it's the delayed references created by the ordered extents (when they complete) that insert the extent items into the extent tree (using the non-commit root of course). Example: CPU 1 CPU 2 btrfs_dev_replace_start() btrfs_scrub_dev() scrub_enumerate_chunks() --> finds device extent belonging to block group X <transaction N starts> starts buffered write against some inode writepages is run against that inode forcing dellaloc to run btrfs_writepages() extent_writepages() extent_write_cache_pages() __extent_writepage() writepage_delalloc() run_delalloc_range() cow_file_range() btrfs_reserve_extent() --> allocates an extent from block group X (which is not yet in RO mode) btrfs_add_ordered_extent() --> creates ordered extent Y flush_epd_write_bio() --> bio against the extent from block group X is submitted btrfs_inc_block_group_ro(bg X) --> sets block group X to readonly scrub_chunk(bg X) scrub_stripe(device extent from srcdev) --> keeps searching for extent items belonging to the block group using the extent tree's commit root --> it never blocks due to fs_info->scrub_pause_req as no one tries to commit transaction N --> copies all extents found from the source device into the target device --> finishes search loop bio completes ordered extent Y completes and creates delayed data reference which will add an extent item to the extent tree when run (typically at transaction commit time) --> so the task doing the scrub/device replace at CPU 1 misses this and does not copy this extent into the new/target device btrfs_dec_block_group_ro(bg X) --> turns block group X back to RW mode dev_replace->cursor_left is set to the logical end offset of block group X So fix this by waiting for all cow and nocow writes after setting a block group to readonly mode. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com>
2016-05-30Btrfs: fix race between device replace and block group removalFilipe Manana
When it's finishing, the device replace code iterates all extent maps representing block group and for each one that has a stripe that refers to the source device, it replaces its device with the target device. However when it replaces the source device with the target device it, the target device still has an ID of 0ULL (BTRFS_DEV_REPLACE_DEVID), only after its ID is changed to match the one from the source device. This leads to races with the chunk removal code that can temporarly see a device with an ID of 0ULL and then attempt to use that ID to remove items from the device tree and fail, causing a transaction abort: [ 9238.594364] BTRFS info (device sdf): dev_replace from /dev/sdf (devid 3) to /dev/sde finished [ 9238.594377] ------------[ cut here ]------------ [ 9238.594402] WARNING: CPU: 14 PID: 21566 at fs/btrfs/volumes.c:2771 btrfs_remove_chunk+0x2e5/0x793 [btrfs] [ 9238.594403] BTRFS: Transaction aborted (error 1) [ 9238.594416] Modules linked in: btrfs crc32c_generic acpi_cpufreq xor tpm_tis tpm raid6_pq ppdev parport_pc processor psmouse parport i2c_piix4 evdev sg i2c_core se rio_raw pcspkr button loop autofs4 ext4 crc16 jbd2 mbcache sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix virtio_pci libata virtio_ring virtio e1000 scsi_mod fl oppy [last unloaded: btrfs] [ 9238.594418] CPU: 14 PID: 21566 Comm: btrfs-cleaner Not tainted 4.6.0-rc7-btrfs-next-29+ #1 [ 9238.594419] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [ 9238.594421] 0000000000000000 ffff88017f1dbc60 ffffffff8126b42c ffff88017f1dbcb0 [ 9238.594422] 0000000000000000 ffff88017f1dbca0 ffffffff81052b14 00000ad37f1dbd18 [ 9238.594423] 0000000000000001 ffff88018068a558 ffff88005c4b9c00 ffff880233f60db0 [ 9238.594424] Call Trace: [ 9238.594428] [<ffffffff8126b42c>] dump_stack+0x67/0x90 [ 9238.594430] [<ffffffff81052b14>] __warn+0xc2/0xdd [ 9238.594432] [<ffffffff81052b7a>] warn_slowpath_fmt+0x4b/0x53 [ 9238.594434] [<ffffffff8116c311>] ? kmem_cache_free+0x128/0x188 [ 9238.594450] [<ffffffffa04d43f5>] btrfs_remove_chunk+0x2e5/0x793 [btrfs] [ 9238.594452] [<ffffffff8108e456>] ? arch_local_irq_save+0x9/0xc [ 9238.594464] [<ffffffffa04a26fa>] btrfs_delete_unused_bgs+0x317/0x382 [btrfs] [ 9238.594476] [<ffffffffa04a961d>] cleaner_kthread+0x1ad/0x1c7 [btrfs] [ 9238.594489] [<ffffffffa04a9470>] ? btree_invalidatepage+0x8e/0x8e [btrfs] [ 9238.594490] [<ffffffff8106f403>] kthread+0xd4/0xdc [ 9238.594494] [<ffffffff8149e242>] ret_from_fork+0x22/0x40 [ 9238.594495] [<ffffffff8106f32f>] ? kthread_stop+0x286/0x286 [ 9238.594496] ---[ end trace 183efbe50275f059 ]--- The sequence of steps leading to this is like the following: CPU 1 CPU 2 btrfs_dev_replace_finishing() at this point dev_replace->tgtdev->devid == BTRFS_DEV_REPLACE_DEVID (0ULL) ... btrfs_start_transaction() btrfs_commit_transaction() btrfs_delete_unused_bgs() btrfs_remove_chunk() looks up for the extent map corresponding to the chunk lock_chunks() (chunk_mutex) check_system_chunk() unlock_chunks() (chunk_mutex) locks fs_info->chunk_mutex btrfs_dev_replace_update_device_in_mapping_tree() --> iterates fs_info->mapping_tree and replaces the device in every extent map's map->stripes[] with dev_replace->tgtdev, which still has an id of 0ULL (BTRFS_DEV_REPLACE_DEVID) iterates over all stripes from the extent map --> calls btrfs_free_dev_extent() passing it the target device that still has an ID of 0ULL --> btrfs_free_dev_extent() fails --> aborts current transaction finishes setting up the target device, namely it sets tgtdev->devid to the value of srcdev->devid (which is necessarily > 0) frees the srcdev unlocks fs_info->chunk_mutex So fix this by taking the device list mutex while processing the stripes for the chunk's extent map. This is similar to the race between device replace and block group creation that was fixed by commit 50460e37186a ("Btrfs: fix race when finishing dev replace leading to transaction abort"). Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com>
2016-05-30Btrfs: fix race between readahead and device replace/removalFilipe Manana
The list of devices is protected by the device_list_mutex and the device replace code, in its finishing phase correctly takes that mutex before removing the source device from that list. However the readahead code was iterating that list without acquiring the respective mutex leading to crashes later on due to invalid memory accesses: [125671.831036] general protection fault: 0000 [#1] PREEMPT SMP [125671.832129] Modules linked in: btrfs dm_flakey dm_mod crc32c_generic xor raid6_pq acpi_cpufreq tpm_tis tpm ppdev evdev parport_pc psmouse sg parport processor ser [125671.834973] CPU: 10 PID: 19603 Comm: kworker/u32:19 Tainted: G W 4.6.0-rc7-btrfs-next-29+ #1 [125671.834973] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [125671.834973] Workqueue: btrfs-readahead btrfs_readahead_helper [btrfs] [125671.834973] task: ffff8801ac520540 ti: ffff8801ac918000 task.ti: ffff8801ac918000 [125671.834973] RIP: 0010:[<ffffffff81270479>] [<ffffffff81270479>] __radix_tree_lookup+0x6a/0x105 [125671.834973] RSP: 0018:ffff8801ac91bc28 EFLAGS: 00010206 [125671.834973] RAX: 0000000000000000 RBX: 6b6b6b6b6b6b6b6a RCX: 0000000000000000 [125671.834973] RDX: 0000000000000000 RSI: 00000000000c1bff RDI: ffff88002ebd62a8 [125671.834973] RBP: ffff8801ac91bc70 R08: 0000000000000001 R09: 0000000000000000 [125671.834973] R10: ffff8801ac91bc70 R11: 0000000000000000 R12: ffff88002ebd62a8 [125671.834973] R13: 0000000000000000 R14: 0000000000000000 R15: 00000000000c1bff [125671.834973] FS: 0000000000000000(0000) GS:ffff88023fd40000(0000) knlGS:0000000000000000 [125671.834973] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [125671.834973] CR2: 000000000073cae4 CR3: 00000000b7723000 CR4: 00000000000006e0 [125671.834973] Stack: [125671.834973] 0000000000000000 ffff8801422d5600 ffff8802286bbc00 0000000000000000 [125671.834973] 0000000000000001 ffff8802286bbc00 00000000000c1bff 0000000000000000 [125671.834973] ffff88002e639eb8 ffff8801ac91bc80 ffffffff81270541 ffff8801ac91bcb0 [125671.834973] Call Trace: [125671.834973] [<ffffffff81270541>] radix_tree_lookup+0xd/0xf [125671.834973] [<ffffffffa04ae6a6>] reada_peer_zones_set_lock+0x3e/0x60 [btrfs] [125671.834973] [<ffffffffa04ae8b9>] reada_pick_zone+0x29/0x103 [btrfs] [125671.834973] [<ffffffffa04af42f>] reada_start_machine_worker+0x129/0x2d3 [btrfs] [125671.834973] [<ffffffffa04880be>] btrfs_scrubparity_helper+0x185/0x3aa [btrfs] [125671.834973] [<ffffffffa0488341>] btrfs_readahead_helper+0xe/0x10 [btrfs] [125671.834973] [<ffffffff81069691>] process_one_work+0x271/0x4e9 [125671.834973] [<ffffffff81069dda>] worker_thread+0x1eb/0x2c9 [125671.834973] [<ffffffff81069bef>] ? rescuer_thread+0x2b3/0x2b3 [125671.834973] [<ffffffff8106f403>] kthread+0xd4/0xdc [125671.834973] [<ffffffff8149e242>] ret_from_fork+0x22/0x40 [125671.834973] [<ffffffff8106f32f>] ? kthread_stop+0x286/0x286 So fix this by taking the device_list_mutex in the readahead code. We can't use here the lighter approach of using a rcu_read_lock() and rcu_read_unlock() pair together with a list_for_each_entry_rcu() call because we end up doing calls to sleeping functions (kzalloc()) in the respective code path. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com>
2016-05-29hash_string: Fix zero-length case for !DCACHE_WORD_ACCESSGeorge Spelvin
The self-test was updated to cover zero-length strings; the function needs to be updated, too. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: George Spelvin <linux@sciencehorizons.net> Fixes: fcfd2fbf22d2 ("fs/namei.c: Add hashlen_string() function") Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-29Rename other copy of hash_string to hashlen_stringGeorge Spelvin
The original name was simply hash_string(), but that conflicted with a function with that name in drivers/base/power/trace.c, and I decided that calling it "hashlen_" was better anyway. But you have to do it in two places. [ This caused build errors for architectures that don't define CONFIG_DCACHE_WORD_ACCESS - Linus ] Signed-off-by: George Spelvin <linux@sciencehorizons.net> Reported-by: Guenter Roeck <linux@roeck-us.net> Fixes: fcfd2fbf22d2 ("fs/namei.c: Add hashlen_string() function") Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-28hpfs: implement the show_options methodMikulas Patocka
The HPFS filesystem used generic_show_options to produce string that is displayed in /proc/mounts. However, there is a problem that the options may disappear after remount. If we mount the filesystem with option1 and then remount it with option2, /proc/mounts should show both option1 and option2, however it only shows option2 because the whole option string is replaced with replace_mount_options in hpfs_remount_fs. To fix this bug, implement the hpfs_show_options function that prints options that are currently selected. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-28affs: fix remount failure when there are no options changedMikulas Patocka
Commit c8f33d0bec99 ("affs: kstrdup() memory handling") checks if the kstrdup function returns NULL due to out-of-memory condition. However, if we are remounting a filesystem with no change to filesystem-specific options, the parameter data is NULL. In this case, kstrdup returns NULL (because it was passed NULL parameter), although no out of memory condition exists. The mount syscall then fails with ENOMEM. This patch fixes the bug. We fail with ENOMEM only if data is non-NULL. The patch also changes the call to replace_mount_options - if we didn't pass any filesystem-specific options, we don't call replace_mount_options (thus we don't erase existing reported options). Fixes: c8f33d0bec99 ("affs: kstrdup() memory handling") Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org # v4.1+ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>