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* | | | Merge branch 'for-linus' of ↵Linus Torvalds2018-04-204-7/+12
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs fixes from Al Viro: "Assorted fixes. Some of that is only a matter with fault injection (broken handling of small allocation failure in various mount-related places), but the last one is a root-triggerable stack overflow, and combined with userns it gets really nasty ;-/" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: Don't leak MNT_INTERNAL away from internal mounts mm,vmscan: Allow preallocating memory for register_shrinker(). rpc_pipefs: fix double-dput() orangefs_kill_sb(): deal with allocation failures jffs2_kill_sb(): deal with failed allocations hypfs_kill_super(): deal with failed allocations
| * | | | Don't leak MNT_INTERNAL away from internal mountsAl Viro2018-04-191-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We want it only for the stuff created by SB_KERNMOUNT mounts, *not* for their copies. As it is, creating a deep stack of bindings of /proc/*/ns/* somewhere in a new namespace and exiting yields a stack overflow. Cc: stable@kernel.org Reported-by: Alexander Aring <aring@mojatatu.com> Bisected-by: Kirill Tkhai <ktkhai@virtuozzo.com> Tested-by: Kirill Tkhai <ktkhai@virtuozzo.com> Tested-by: Alexander Aring <aring@mojatatu.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | | mm,vmscan: Allow preallocating memory for register_shrinker().Tetsuo Handa2018-04-161-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | syzbot is catching so many bugs triggered by commit 9ee332d99e4d5a97 ("sget(): handle failures of register_shrinker()"). That commit expected that calling kill_sb() from deactivate_locked_super() without successful fill_super() is safe, but the reality was different; some callers assign attributes which are needed for kill_sb() after sget() succeeds. For example, [1] is a report where sb->s_mode (which seems to be either FMODE_READ | FMODE_EXCL | FMODE_WRITE or FMODE_READ | FMODE_EXCL) is not assigned unless sget() succeeds. But it does not worth complicate sget() so that register_shrinker() failure path can safely call kill_block_super() via kill_sb(). Making alloc_super() fail if memory allocation for register_shrinker() failed is much simpler. Let's avoid calling deactivate_locked_super() from sget_userns() by preallocating memory for the shrinker and making register_shrinker() in sget_userns() never fail. [1] https://syzkaller.appspot.com/bug?id=588996a25a2587be2e3a54e8646728fb9cae44e7 Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reported-by: syzbot <syzbot+5a170e19c963a2e0df79@syzkaller.appspotmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | | orangefs_kill_sb(): deal with allocation failuresAl Viro2018-04-151-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | orangefs_fill_sb() might've failed to allocate ORANGEFS_SB(s); don't oops in that case. Cc: stable@kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | | jffs2_kill_sb(): deal with failed allocationsAl Viro2018-04-151-1/+1
| | |/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | jffs2_fill_super() might fail to allocate jffs2_sb_info; jffs2_kill_sb() must survive that. Cc: stable@kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | | Merge tag 'ecryptfs-4.17-rc2-fixes' of ↵Linus Torvalds2018-04-204-21/+46
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs Pull eCryptfs fixes from Tyler Hicks: "Minor cleanups and a bug fix to completely ignore unencrypted filenames in the lower filesystem when filename encryption is enabled at the eCryptfs layer" * tag 'ecryptfs-4.17-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs: eCryptfs: don't pass up plaintext names when using filename encryption ecryptfs: fix spelling mistake: "cadidate" -> "candidate" ecryptfs: lookup: Don't check if mount_crypt_stat is NULL
| * | | | eCryptfs: don't pass up plaintext names when using filename encryptionTyler Hicks2018-04-162-18/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Both ecryptfs_filldir() and ecryptfs_readlink_lower() use ecryptfs_decode_and_decrypt_filename() to translate lower filenames to upper filenames. The function correctly passes up lower filenames, unchanged, when filename encryption isn't in use. However, it was also passing up lower filenames when the filename wasn't encrypted or when decryption failed. Since 88ae4ab9802e, eCryptfs refuses to lookup lower plaintext names when filename encryption is enabled so this resulted in a situation where userspace would see lower plaintext filenames in calls to getdents(2) but then not be able to lookup those filenames. An example of this can be seen when enabling filename encryption on an eCryptfs mount at the root directory of an Ext4 filesystem: $ ls -1i /lower 12 ECRYPTFS_FNEK_ENCRYPTED.FWYZD8TcW.5FV-TKTEYOHsheiHX9a-w.NURCCYIMjI8pn5BDB9-h3fXwrE-- 11 lost+found $ ls -1i /upper ls: cannot access '/upper/lost+found': No such file or directory ? lost+found 12 test With this change, the lower lost+found dentry is ignored: $ ls -1i /lower 12 ECRYPTFS_FNEK_ENCRYPTED.FWYZD8TcW.5FV-TKTEYOHsheiHX9a-w.NURCCYIMjI8pn5BDB9-h3fXwrE-- 11 lost+found $ ls -1i /upper 12 test Additionally, some potentially noisy error/info messages in the related code paths are turned into debug messages so that the logs can't be easily filled. Fixes: 88ae4ab9802e ("ecryptfs_lookup(): try either only encrypted or plaintext name") Reported-by: Guenter Roeck <linux@roeck-us.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
| * | | | ecryptfs: fix spelling mistake: "cadidate" -> "candidate"Colin Ian King2018-03-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Trivial fix to spelling mistake in debug message text. Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
| * | | | ecryptfs: lookup: Don't check if mount_crypt_stat is NULLGuenter Roeck2018-03-291-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mount_crypt_stat is assigned to &ecryptfs_superblock_to_private(ecryptfs_dentry->d_sb)->mount_crypt_stat, and mount_crypt_stat is not the first object in struct ecryptfs_sb_info. mount_crypt_stat is therefore never NULL. At the same time, no crash in ecryptfs_lookup() has been reported, and the lookup functions in other file systems don't check if d_sb is NULL either. Given that, remove the NULL check. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
* | | | | Merge tag 'for_v4.17-rc2' of ↵Linus Torvalds2018-04-207-39/+54
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs - isofs memory leak fix - two fsnotify fixes of event mask handling - udf fix of UTF-16 handling - couple other smaller cleanups * tag 'for_v4.17-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: udf: Fix leak of UTF-16 surrogates into encoded strings fs: ext2: Adding new return type vm_fault_t isofs: fix potential memory leak in mount option parsing MAINTAINERS: add an entry for FSNOTIFY infrastructure fsnotify: fix typo in a comment about mark->g_list fsnotify: fix ignore mask logic in send_to_group() isofs compress: Remove VLA usage fs: quota: Replace GFP_ATOMIC with GFP_KERNEL in dquot_init fanotify: fix logic of events on child
| * | | | | udf: Fix leak of UTF-16 surrogates into encoded stringsJan Kara2018-04-181-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | OSTA UDF specification does not mention whether the CS0 charset in case of two bytes per character encoding should be treated in UTF-16 or UCS-2. The sample code in the standard does not treat UTF-16 surrogates in any special way but on systems such as Windows which work in UTF-16 internally, filenames would be treated as being in UTF-16 effectively. In Linux it is more difficult to handle characters outside of Base Multilingual plane (beyond 0xffff) as NLS framework works with 2-byte characters only. Just make sure we don't leak UTF-16 surrogates into the resulting string when loading names from the filesystem for now. CC: stable@vger.kernel.org # >= v4.6 Reported-by: Mingye Wang <arthur200126@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
| * | | | | fs: ext2: Adding new return type vm_fault_tSouptick Joarder2018-04-161-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use new return type vm_fault_t for page_mkwrite, pfn_mkwrite and fault handler. Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Jan Kara <jack@suse.cz>
| * | | | | isofs: fix potential memory leak in mount option parsingChengguang Xu2018-04-161-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When specifying string type mount option (e.g., iocharset) several times in a mount, current option parsing may cause memory leak. Hence, call kfree for previous one in this case. Meanwhile, check memory allocation result for it. Signed-off-by: Chengguang Xu <cgxu519@gmx.com> Signed-off-by: Jan Kara <jack@suse.cz>
| * | | | | fsnotify: fix ignore mask logic in send_to_group()Amir Goldstein2018-04-131-14/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ignore mask logic in send_to_group() does not match the logic in fanotify_should_send_event(). In the latter, a vfsmount mark ignore mask precedes an inode mark mask and in the former, it does not. That difference may cause events to be sent to fanotify backend for no reason. Fix the logic in send_to_group() to match that of fanotify_should_send_event(). Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
| * | | | | isofs compress: Remove VLA usageKyle Spiers2018-04-111-3/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As part of the effort to remove VLAs from the kernel[1], this changes the allocation of the bhs and pages arrays from being on the stack to being kcalloc()ed. This also allows for the removal of the explicit zeroing of bhs. https://lkml.org/lkml/2018/3/7/621 Signed-off-by: Kyle Spiers <ksspiers@google.com> Signed-off-by: Jan Kara <jack@suse.cz>
| * | | | | fs: quota: Replace GFP_ATOMIC with GFP_KERNEL in dquot_initJia-Ju Bai2018-04-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | dquot_init() is never called in atomic context. This function is only set as a parameter of fs_initcall(). Despite never getting called from atomic context, dquot_init() calls __get_free_pages() with GFP_ATOMIC, which waits busily for allocation. GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL, to avoid busy waiting and improve the possibility of sucessful allocation. This is found by a static analysis tool named DCNS written by myself. And I also manually check it. Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
| * | | | | fanotify: fix logic of events on childAmir Goldstein2018-04-091-19/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When event on child inodes are sent to the parent inode mark and parent inode mark was not marked with FAN_EVENT_ON_CHILD, the event will not be delivered to the listener process. However, if the same process also has a mount mark, the event to the parent inode will be delivered regadless of the mount mark mask. This behavior is incorrect in the case where the mount mark mask does not contain the specific event type. For example, the process adds a mark on a directory with mask FAN_MODIFY (without FAN_EVENT_ON_CHILD) and a mount mark with mask FAN_CLOSE_NOWRITE (without FAN_ONDIR). A modify event on a file inside that directory (and inside that mount) should not create a FAN_MODIFY event, because neither of the marks requested to get that event on the file. Fixes: 1968f5eed54c ("fanotify: use both marks when possible") Cc: stable <stable@vger.kernel.org> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
* | | | | | ceph: always update atime/mtime/ctime for new inodeYan, Zheng2018-04-161-3/+7
| |_|/ / / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For new inode, atime/mtime/ctime are uninitialized. Don't compare against them. Cc: stable@kernel.org Signed-off-by: "Yan, Zheng" <zyan@redhat.com> Reviewed-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
* | | | | Merge tag 'for-4.17-part2-tag' of ↵Linus Torvalds2018-04-1594-1234/+277
|\ \ \ \ \ | | |_|/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull more btrfs updates from David Sterba: "We have queued a few more fixes (error handling, log replay, softlockup) and the rest is SPDX updates that touche almost all files so the diffstat is long" * tag 'for-4.17-part2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: Only check first key for committed tree blocks btrfs: add SPDX header to Kconfig btrfs: replace GPL boilerplate by SPDX -- sources btrfs: replace GPL boilerplate by SPDX -- headers Btrfs: fix loss of prealloc extents past i_size after fsync log replay Btrfs: clean up resources during umount after trans is aborted btrfs: Fix possible softlock on single core machines Btrfs: bail out on error during replay_dir_deletes Btrfs: fix NULL pointer dereference in log_dir_items
| * | | | btrfs: Only check first key for committed tree blocksQu Wenruo2018-04-131-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When looping btrfs/074 with many cpus (>= 8), it's possible to trigger kernel warning due to first key verification: [ 4239.523446] WARNING: CPU: 5 PID: 2381 at fs/btrfs/disk-io.c:460 btree_read_extent_buffer_pages+0x1ad/0x210 [ 4239.523830] Modules linked in: [ 4239.524630] RIP: 0010:btree_read_extent_buffer_pages+0x1ad/0x210 [ 4239.527101] Call Trace: [ 4239.527251] read_tree_block+0x42/0x70 [ 4239.527434] read_node_slot+0xd2/0x110 [ 4239.527632] push_leaf_right+0xad/0x1b0 [ 4239.527809] split_leaf+0x4ea/0x700 [ 4239.527988] ? leaf_space_used+0xbc/0xe0 [ 4239.528192] ? btrfs_set_lock_blocking_rw+0x99/0xb0 [ 4239.528416] btrfs_search_slot+0x8cc/0xa40 [ 4239.528605] btrfs_insert_empty_items+0x71/0xc0 [ 4239.528798] __btrfs_run_delayed_refs+0xa98/0x1680 [ 4239.529013] btrfs_run_delayed_refs+0x10b/0x1b0 [ 4239.529205] btrfs_commit_transaction+0x33/0xaf0 [ 4239.529445] ? start_transaction+0xa8/0x4f0 [ 4239.529630] btrfs_alloc_data_chunk_ondemand+0x1b0/0x4e0 [ 4239.529833] btrfs_check_data_free_space+0x54/0xa0 [ 4239.530045] btrfs_delalloc_reserve_space+0x25/0x70 [ 4239.531907] btrfs_direct_IO+0x233/0x3d0 [ 4239.532098] generic_file_direct_write+0xcb/0x170 [ 4239.532296] btrfs_file_write_iter+0x2bb/0x5f4 [ 4239.532491] aio_write+0xe2/0x180 [ 4239.532669] ? lock_acquire+0xac/0x1e0 [ 4239.532839] ? __might_fault+0x3e/0x90 [ 4239.533032] do_io_submit+0x594/0x860 [ 4239.533223] ? do_io_submit+0x594/0x860 [ 4239.533398] SyS_io_submit+0x10/0x20 [ 4239.533560] ? SyS_io_submit+0x10/0x20 [ 4239.533729] do_syscall_64+0x75/0x1d0 [ 4239.533979] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 4239.534182] RIP: 0033:0x7f8519741697 The problem here is, at btree_read_extent_buffer_pages() we don't have acquired read/write lock on that extent buffer, only basic info like level/bytenr is reliable. So race condition leads to such false alert. However in current call site, it's impossible to acquire proper lock without race window. To fix the problem, we only verify first key for committed tree blocks (whose generation is no larger than fs_info->last_trans_committed), so the content of such tree blocks will not change and there is no need to get read/write lock. Reported-by: Nikolay Borisov <nborisov@suse.com> Fixes: 581c1760415c ("btrfs: Validate child tree block's level and first key") Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
| * | | | btrfs: add SPDX header to KconfigDavid Sterba2018-04-121-0/+2
| | | | | | | | | | | | | | | | | | | | Signed-off-by: David Sterba <dsterba@suse.com>
| * | | | btrfs: replace GPL boilerplate by SPDX -- sourcesDavid Sterba2018-04-1258-750/+65
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove GPL boilerplate text (long, short, one-line) and keep the rest, ie. personal, company or original source copyright statements. Add the SPDX header. Signed-off-by: David Sterba <dsterba@suse.com>
| * | | | btrfs: replace GPL boilerplate by SPDX -- headersDavid Sterba2018-04-1235-475/+133
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove GPL boilerplate text (long, short, one-line) and keep the rest, ie. personal, company or original source copyright statements. Add the SPDX header. Unify the include protection macros to match the file names. Signed-off-by: David Sterba <dsterba@suse.com>
| * | | | Btrfs: fix loss of prealloc extents past i_size after fsync log replayFilipe Manana2018-04-121-5/+58
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently if we allocate extents beyond an inode's i_size (through the fallocate system call) and then fsync the file, we log the extents but after a power failure we replay them and then immediately drop them. This behaviour happens since about 2009, commit c71bf099abdd ("Btrfs: Avoid orphan inodes cleanup while replaying log"), because it marks the inode as an orphan instead of dropping any extents beyond i_size before replaying logged extents, so after the log replay, and while the mount operation is still ongoing, we find the inode marked as an orphan and then perform a truncation (drop extents beyond the inode's i_size). Because the processing of orphan inodes is still done right after replaying the log and before the mount operation finishes, the intention of that commit does not make any sense (at least as of today). However reverting that behaviour is not enough, because we can not simply discard all extents beyond i_size and then replay logged extents, because we risk dropping extents beyond i_size created in past transactions, for example: add prealloc extent beyond i_size fsync - clears the flag BTRFS_INODE_NEEDS_FULL_SYNC from the inode transaction commit add another prealloc extent beyond i_size fsync - triggers the fast fsync path power failure In that scenario, we would drop the first extent and then replay the second one. To fix this just make sure that all prealloc extents beyond i_size are logged, and if we find too many (which is far from a common case), fallback to a full transaction commit (like we do when logging regular extents in the fast fsync path). Trivial reproducer: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ xfs_io -f -c "pwrite -S 0xab 0 256K" /mnt/foo $ sync $ xfs_io -c "falloc -k 256K 1M" /mnt/foo $ xfs_io -c "fsync" /mnt/foo <power failure> # mount to replay log $ mount /dev/sdb /mnt # at this point the file only has one extent, at offset 0, size 256K A test case for fstests follows soon, covering multiple scenarios that involve adding prealloc extents with previous shrinking truncates and without such truncates. Fixes: c71bf099abdd ("Btrfs: Avoid orphan inodes cleanup while replaying log") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
| * | | | Btrfs: clean up resources during umount after trans is abortedLiu Bo2018-04-121-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently if some fatal errors occur, like all IO get -EIO, resources would be cleaned up when a) transaction is being committed or b) BTRFS_FS_STATE_ERROR is set However, in some rare cases, resources may be left alone after transaction gets aborted and umount may run into some ASSERT(), e.g. ASSERT(list_empty(&block_group->dirty_list)); For case a), in btrfs_commit_transaciton(), there're several places at the beginning where we just call btrfs_end_transaction() without cleaning up resources. For case b), it is possible that the trans handle doesn't have any dirty stuff, then only trans hanlde is marked as aborted while BTRFS_FS_STATE_ERROR is not set, so resources remain in memory. This makes btrfs also check BTRFS_FS_STATE_TRANS_ABORTED to make sure that all resources won't stay in memory after umount. Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com> Signed-off-by: David Sterba <dsterba@suse.com>
| * | | | btrfs: Fix possible softlock on single core machinesNikolay Borisov2018-04-051-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | do_chunk_alloc implements a loop checking whether there is a pending chunk allocation and if so causes the caller do loop. Generally this loop is executed only once, however testing with btrfs/072 on a single core vm machines uncovered an extreme case where the system could loop indefinitely. This is due to a missing cond_resched when loop which doesn't give a chance to the previous chunk allocator finish its job. The fix is to simply add the missing cond_resched. Fixes: 6d74119f1a3e ("Btrfs: avoid taking the chunk_mutex in do_chunk_alloc") Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
| * | | | Btrfs: bail out on error during replay_dir_deletesLiu Bo2018-04-051-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If errors were returned by btrfs_next_leaf(), replay_dir_deletes needs to bail out, otherwise @ret would be forced to be 0 after 'break;' and the caller won't be aware of it. Fixes: e02119d5a7b4 ("Btrfs: Add a write ahead tree log to optimize synchronous operations") Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com> Signed-off-by: David Sterba <dsterba@suse.com>
| * | | | Btrfs: fix NULL pointer dereference in log_dir_itemsLiu Bo2018-04-051-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 0, 1 and <0 can be returned by btrfs_next_leaf(), and when <0 is returned, path->nodes[0] could be NULL, log_dir_items lacks such a check for <0 and we may run into a null pointer dereference panic. Fixes: e02119d5a7b4 ("Btrfs: Add a write ahead tree log to optimize synchronous operations") Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com> Signed-off-by: David Sterba <dsterba@suse.com>
* | | | | Merge tag '4.17-rc1SMB3-Fixes' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds2018-04-1513-71/+240
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull cifs fixes from Steve French: "SMB3 fixes, a few for stable, and some important cleanup work from Ronnie of the smb3 transport code" * tag '4.17-rc1SMB3-Fixes' of git://git.samba.org/sfrench/cifs-2.6: cifs: change validate_buf to validate_iov cifs: remove rfc1002 hardcoded constants from cifs_discard_remaining_data() cifs: Change SMB2_open to return an iov for the error parameter cifs: add resp_buf_size to the mid_q_entry structure smb3.11: replace a 4 with server->vals->header_preamble_size cifs: replace a 4 with server->vals->header_preamble_size cifs: add pdu_size to the TCP_Server_Info structure SMB311: Improve checking of negotiate security contexts SMB3: Fix length checking of SMB3.11 negotiate request CIFS: add ONCE flag for cifs_dbg type cifs: Use ULL suffix for 64-bit constant SMB3: Log at least once if tree connect fails during reconnect cifs: smb2pdu: Fix potential NULL pointer dereference
| * | | | | cifs: change validate_buf to validate_iovRonnie Sahlberg2018-04-121-18/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
| * | | | | cifs: remove rfc1002 hardcoded constants from cifs_discard_remaining_data()Ronnie Sahlberg2018-04-121-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
| * | | | | cifs: Change SMB2_open to return an iov for the error parameterRonnie Sahlberg2018-04-123-9/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
| * | | | | cifs: add resp_buf_size to the mid_q_entry structureRonnie Sahlberg2018-04-124-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | and get rid of some more calls to get_rfc1002_length() Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
| * | | | | smb3.11: replace a 4 with server->vals->header_preamble_sizeSteve French2018-04-122-5/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | More cleanup of use of hardcoded 4 byte RFC1001 field size Signed-off-by: Steve French <smfrench@gmail.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
| * | | | | cifs: replace a 4 with server->vals->header_preamble_sizeRonnie Sahlberg2018-04-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
| * | | | | cifs: add pdu_size to the TCP_Server_Info structureRonnie Sahlberg2018-04-124-6/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | and get rid of some get_rfc1002_length() in smb2 Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
| * | | | | SMB311: Improve checking of negotiate security contextsSteve French2018-04-123-0/+106
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SMB3.11 crypto and hash contexts were not being checked strictly enough. Add parsing and validity checking for the security contexts in the SMB3.11 negotiate response. Signed-off-by: Steve French <smfrench@gmail.com> CC: Stable <stable@vger.kernel.org> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
| * | | | | SMB3: Fix length checking of SMB3.11 negotiate requestSteve French2018-04-122-0/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The length checking for SMB3.11 negotiate request includes "negotiate contexts" which caused a buffer validation problem and a confusing warning message on SMB3.11 mount e.g.: SMB2 server sent bad RFC1001 len 236 not 170 Fix the length checking for SMB3.11 negotiate to account for the new negotiate context so that we don't log a warning on SMB3.11 mount by default but do log warnings if lengths returned by the server are incorrect. CC: Stable <stable@vger.kernel.org> Signed-off-by: Steve French <smfrench@gmail.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
| * | | | | CIFS: add ONCE flag for cifs_dbg typeAurelien Aptel2018-04-112-29/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * Since cifs_vfs_error was just using pr_debug_ratelimited like the rest of cifs_dbg, move it there too * Add a ONCE type flag to call the pr_xxx_once() debug function instead of the ratelimited ones. To convert existing printk_once() calls to this we can run: perl -i -pE \ 's/printk_once\s*\(([^" \n]+)(.*)/cifs_dbg(VFS|ONCE,$2/g' \ fs/cifs/*.c Signed-off-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
| * | | | | cifs: Use ULL suffix for 64-bit constantGeert Uytterhoeven2018-04-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On 32-bit (e.g. with m68k-linux-gnu-gcc-4.1): fs/cifs/inode.c: In function ‘simple_hashstr’: fs/cifs/inode.c:713: warning: integer constant is too large for ‘long’ type Fixes: 7ea884c77e5c97f1 ("smb3: Fix root directory when server returns inode number of zero") Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com>
| * | | | | SMB3: Log at least once if tree connect fails during reconnectSteve French2018-04-112-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adding an extra debug message to show if a tree connect failure during reconnect (and made it a log once so it doesn't spam the logs). Saw a case recently where tree connect repeatedly returned access denied on reconnect and it wasn't as easy to spot as it should have been. Signed-off-by: Steve French <smfrench@gmail.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com>
| * | | | | cifs: smb2pdu: Fix potential NULL pointer dereferenceGustavo A. R. Silva2018-04-111-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | tcon->ses is being dereferenced before it is null checked, hence there is a potential null pointer dereference. Fix this by moving the pointer dereference after tcon->ses has been properly null checked. Addresses-Coverity-ID: 1467426 ("Dereference before null check") Fixes: 93012bf98416 ("cifs: add server->vals->header_preamble_size") Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
* | | | | | Merge branch 'akpm' (patches from Andrew)Linus Torvalds2018-04-141-1/+22
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge yet more updates from Andrew Morton: - various hotfixes - kexec_file updates and feature work * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (27 commits) kernel/kexec_file.c: move purgatories sha256 to common code kernel/kexec_file.c: allow archs to set purgatory load address kernel/kexec_file.c: remove mis-use of sh_offset field during purgatory load kernel/kexec_file.c: remove unneeded variables in kexec_purgatory_setup_sechdrs kernel/kexec_file.c: remove unneeded for-loop in kexec_purgatory_setup_sechdrs kernel/kexec_file.c: split up __kexec_load_puragory kernel/kexec_file.c: use read-only sections in arch_kexec_apply_relocations* kernel/kexec_file.c: search symbols in read-only kexec_purgatory kernel/kexec_file.c: make purgatory_info->ehdr const kernel/kexec_file.c: remove checks in kexec_purgatory_load include/linux/kexec.h: silence compile warnings kexec_file, x86: move re-factored code to generic side x86: kexec_file: clean up prepare_elf64_headers() x86: kexec_file: lift CRASH_MAX_RANGES limit on crash_mem buffer x86: kexec_file: remove X86_64 dependency from prepare_elf64_headers() x86: kexec_file: purge system-ram walking from prepare_elf64_headers() kexec_file,x86,powerpc: factor out kexec_file_ops functions kexec_file: make use of purgatory optional proc: revalidate misc dentries mm, slab: reschedule cache_reap() on the same CPU ...
| * | | | | | proc: revalidate misc dentriesAlexey Dobriyan2018-04-131-1/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If module removes proc directory while another process pins it by chdir'ing to it, then subsequent recreation of proc entry and all entries down the tree will not be visible to any process until pinning process unchdir from directory and unpins everything. Steps to reproduce: proc_mkdir("aaa", NULL); proc_create("aaa/bbb", ...); chdir("/proc/aaa"); remove_proc_entry("aaa/bbb", NULL); remove_proc_entry("aaa", NULL); proc_mkdir("aaa", NULL); # inaccessible because "aaa" dentry still points # to the original "aaa". proc_create("aaa/bbb", ...); Fix is to implement ->d_revalidate and ->d_delete. Link: http://lkml.kernel.org/r/20180312201938.GA4871@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | | Merge branch 'overlayfs-linus' of ↵Linus Torvalds2018-04-1311-166/+477
|\ \ \ \ \ \ \ | |/ / / / / / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull overlayfs updates from Miklos Szeredi: "In addition to bug fixes and cleanups there are two new features from Amir: - Consistent inode number support for the case when layers are not all on the same filesystem (feature is dubbed "xino"). - Optimize overlayfs file handle decoding. This one touches the exportfs interface to allow detecting the disconnected directory case" * 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: update documentation w.r.t "xino" feature ovl: add support for "xino" mount and config options ovl: consistent d_ino for non-samefs with xino ovl: consistent i_ino for non-samefs with xino ovl: constant st_ino for non-samefs with xino ovl: allocate anon bdev per unique lower fs ovl: factor out ovl_map_dev_ino() helper ovl: cleanup ovl_update_time() ovl: add WARN_ON() for non-dir redirect cases ovl: cleanup setting OVL_INDEX ovl: set d->is_dir and d->opaque for last path element ovl: Do not check for redirect if this is last layer ovl: lookup in inode cache first when decoding lower file handle ovl: do not try to reconnect a disconnected origin dentry ovl: disambiguate ovl_encode_fh() ovl: set lower layer st_dev only if setting lower st_ino ovl: fix lookup with middle layer opaque dir and absolute path redirects ovl: Set d->last properly during lookup ovl: set i_ino to the value of st_ino for NFS export
| * | | | | | ovl: add support for "xino" mount and config optionsAmir Goldstein2018-04-123-3/+88
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With mount option "xino=on", mounter declares that there are enough free high bits in underlying fs to hold the layer fsid. If overlayfs does encounter underlying inodes using the high xino bits reserved for layer fsid, a warning will be emitted and the original inode number will be used. The mount option name "xino" goes after a similar meaning mount option of aufs, but in overlayfs case, the mapping is stateless. An example for a use case of "xino=on" is when upper/lower is on an xfs filesystem. xfs uses 64bit inode numbers, but it currently never uses the upper 8bit for inode numbers exposed via stat(2) and that is not likely to change in the future without user opting-in for a new xfs feature. The actual number of unused upper bit is much larger and determined by the xfs filesystem geometry (64 - agno_log - agblklog - inopblog). That means that for all practical purpose, there are enough unused bits in xfs inode numbers for more than OVL_MAX_STACK unique fsid's. Another use case of "xino=on" is when upper/lower is on tmpfs. tmpfs inode numbers are allocated sequentially since boot, so they will practially never use the high inode number bits. For compatibility with applications that expect 32bit inodes, the feature can be disabled with "xino=off". The option "xino=auto" automatically detects underlying filesystem that use 32bit inodes and enables the feature. The Kconfig option OVERLAY_FS_XINO_AUTO and module parameter of the same name, determine if the default mode for overlayfs mount is "xino=auto" or "xino=off". Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * | | | | | ovl: consistent d_ino for non-samefs with xinoAmir Goldstein2018-04-121-6/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When overlay layers are not all on the same fs, but all inode numbers of underlying fs do not use the high 'xino' bits, overlay st_ino values are constant and persistent. In that case, relax non-samefs constraint for consistent d_ino and always iterate non-merge dir using ovl_fill_real() actor so we can remap lower inode numbers to unique lower fs range. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * | | | | | ovl: consistent i_ino for non-samefs with xinoAmir Goldstein2018-04-124-14/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When overlay layers are not all on the same fs, but all inode numbers of underlying fs do not use the high 'xino' bits, overlay st_ino values are constant and persistent. In that case, set i_ino value to the same value as st_ino for nfsd readdirplus validator. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * | | | | | ovl: constant st_ino for non-samefs with xinoAmir Goldstein2018-04-125-10/+75
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On 64bit systems, when overlay layers are not all on the same fs, but all inode numbers of underlying fs are not using the high bits, use the high bits to partition the overlay st_ino address space. The high bits hold the fsid (upper fsid is 0). This way overlay inode numbers are unique and all inodes use overlay st_dev. Inode numbers are also persistent for a given layer configuration. Currently, our only indication for available high ino bits is from a filesystem that supports file handles and uses the default encode_fh() operation, which encodes a 32bit inode number. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * | | | | | ovl: allocate anon bdev per unique lower fsAmir Goldstein2018-04-124-28/+72
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of allocating an anonymous bdev per lower layer, allocate one anonymous bdev per every unique lower fs that is different than upper fs. Every unique lower fs is assigned an fsid > 0 and the number of unique lower fs are stored in ofs->numlowerfs. The assigned fsid is stored in the lower layer struct and will be used also for inode number multiplexing. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>