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2014-11-26debugfs: add helper function to create device related seq_fileArend van Spriel
This patch adds a helper function that simplifies adding a so-called single_open sequence file for device drivers. The calling device driver needs to provide a read function and a device pointer. The field struct seq_file::private will reference the device pointer upon call to the read function so the driver can obtain his data from it and do its task of providing the file content using seq_printf() calls and alike. Using this helper function also gets rid of the need to specify file operations per debugfs file. Signed-off-by: Arend van Spriel <arend@broadcom.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-07sysfs/kernfs: make read requests on pre-alloc files use the buffer.NeilBrown
To match the previous patch which used the pre-alloc buffer for writes, this patch causes reads to use the same buffer. This is not strictly necessary as the current seq_read() will allocate on first read, so user-space can trigger the required pre-alloc. But consistency is valuable. The read function is somewhat simpler than seq_read() and, for example, does not support reading from an offset into the file: reads must be at the start of the file. As seq_read() does not use the prealloc buffer, ->seq_show is incompatible with ->prealloc and caused an EINVAL return from open(). sysfs code which calls into kernfs always chooses the correct function. As the buffer is shared with writes and other reads, the mutex is extended to cover the copy_to_user. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-07sysfs/kernfs: allow attributes to request write buffer be pre-allocated.NeilBrown
md/raid allows metadata management to be performed in user-space. A various times, particularly on device failure, the metadata needs to be updated before further writes can be permitted. This means that the user-space program which updates metadata much not block on writeout, and so must not allocate memory. mlockall(MCL_CURRENT|MCL_FUTURE) and pre-allocation can avoid all memory allocation issues for user-memory, but that does not help kernel memory. Several kernel objects can be pre-allocated. e.g. files opened before any writes to the array are permitted. However some kernel allocation happens in places that cannot be pre-allocated. In particular, writes to sysfs files (to tell md that it can now allow writes to the array) allocate a buffer using GFP_KERNEL. This patch allows attributes to be marked as "PREALLOC". In that case the maximal buffer is allocated when the file is opened, and then used on each write instead of allocating a new buffer. As the same buffer is now shared for all writes on the same file description, the mutex is extended to cover full use of the buffer including the copy_from_user(). The new __ATTR_PREALLOC() 'or's a new flag in to the 'mode', which is inspected by sysfs_add_file_mode_ns() to determine if the file should be marked as requiring prealloc. Despite the comment, we *do* use ->seq_show together with ->prealloc in this patch. The next patch fixes that. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-07fs: sysfs: return EGBIG on write if offset is larger than file sizeVladimir Zapolskiy
According to the user expectations common utilities like dd or sh redirection operator > should work correctly over binary files from sysfs. At the moment doing excessive write can not be completed: write(1, "\0\0\0\0\0\0\0\0", 8) = 4 write(1, "\0\0\0\0", 4) = 0 write(1, "\0\0\0\0", 4) = 0 write(1, "\0\0\0\0", 4) = 0 ... Fix the problem by returning EFBIG described in man 2 write. Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-03Merge branch 'platform/remove_owner' of ↵Greg Kroah-Hartman
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux into driver-core-next Remove all .owner fields from platform drivers
2014-11-02Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull VFS fixes from Al Viro: "A bunch of assorted fixes, most of them followups to overlayfs merge" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: ovl: initialize ->is_cursor Return short read or 0 at end of a raw device, not EIO isofs: don't bother with ->d_op for normal case isofs_cmp(): we'll never see a dentry for . or .. overlayfs: fix lockdep misannotation ovl: fix check for cursor overlayfs: barriers for opening upper-layer directory rcu: Provide counterpart to rcu_dereference() for non-RCU situations staging: android: logger: Fix log corruption regression
2014-11-01Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fixes from Chris Mason: "Filipe is nailing down some problems with our skinny extent variation, and Dave's patch fixes endian problems in the new super block checks" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: fix race that makes btrfs_lookup_extent_info miss skinny extent items Btrfs: properly clean up btrfs_end_io_wq_cache Btrfs: fix invalid leaf slot access in btrfs_lookup_extent() btrfs: use macro accessors in superblock validation checks
2014-10-31Merge tag 'ext4_for_linus_stable' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 bugfixes from Ted Ts'o: "A set of miscellaneous ext4 bug fixes for 3.18" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: make ext4_ext_convert_to_initialized() return proper number of blocks ext4: bail early when clearing inode journal flag fails ext4: bail out from make_indexed_dir() on first error jbd2: use a better hash function for the revoke table ext4: prevent bugon on race between write/fcntl ext4: remove extent status procfs files if journal load fails ext4: disallow changing journal_csum option during remount ext4: enable journal checksum when metadata checksum feature enabled ext4: fix oops when loading block bitmap failed ext4: fix overflow when updating superblock backups after resize
2014-10-31Merge branch 'for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull quota and ext3 fixes from Jan Kara. * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: fs, jbd: use a more generic hash function quota: Properly return errors from dquot_writeback_dquots() ext3: Don't check quota format when there are no quota files
2014-10-31ovl: initialize ->is_cursorMiklos Szeredi
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-31Return short read or 0 at end of a raw device, not EIODavid Jeffery
Author: David Jeffery <djeffery@redhat.com> Changes to the basic direct I/O code have broken the raw driver when reading to the end of a raw device. Instead of returning a short read for a read that extends partially beyond the device's end or 0 when at the end of the device, these reads now return EIO. The raw driver needs the same end of device handling as was added for normal block devices. Using blkdev_read_iter, which has the needed size checks, prevents the EIO conditions at the end of the device. Signed-off-by: David Jeffery <djeffery@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-31isofs: don't bother with ->d_op for normal caseAl Viro
we only need it for joliet and case-insensitive mounts Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-30fs: allow open(dir, O_TMPFILE|..., 0) with mode 0Eric Rannaud
The man page for open(2) indicates that when O_CREAT is specified, the 'mode' argument applies only to future accesses to the file: Note that this mode applies only to future accesses of the newly created file; the open() call that creates a read-only file may well return a read/write file descriptor. The man page for open(2) implies that 'mode' is treated identically by O_CREAT and O_TMPFILE. O_TMPFILE, however, behaves differently: int fd = open("/tmp", O_TMPFILE | O_RDWR, 0); assert(fd == -1); assert(errno == EACCES); int fd = open("/tmp", O_TMPFILE | O_RDWR, 0600); assert(fd > 0); For O_CREAT, do_last() sets acc_mode to MAY_OPEN only: if (*opened & FILE_CREATED) { /* Don't check for write permission, don't truncate */ open_flag &= ~O_TRUNC; will_truncate = false; acc_mode = MAY_OPEN; path_to_nameidata(path, nd); goto finish_open_created; } But for O_TMPFILE, do_tmpfile() passes the full op->acc_mode to may_open(). This patch lines up the behavior of O_TMPFILE with O_CREAT. After the inode is created, may_open() is called with acc_mode = MAY_OPEN, in do_tmpfile(). A different, but related glibc bug revealed the discrepancy: https://sourceware.org/bugzilla/show_bug.cgi?id=17523 The glibc lazily loads the 'mode' argument of open() and openat() using va_arg() only if O_CREAT is present in 'flags' (to support both the 2 argument and the 3 argument forms of open; same idea for openat()). However, the glibc ignores the 'mode' argument if O_TMPFILE is in 'flags'. On x86_64, for open(), it magically works anyway, as 'mode' is in RDX when entering open(), and is still in RDX on SYSCALL, which is where the kernel looks for the 3rd argument of a syscall. But openat() is not quite so lucky: 'mode' is in RCX when entering the glibc wrapper for openat(), while the kernel looks for the 4th argument of a syscall in R10. Indeed, the syscall calling convention differs from the regular calling convention in this respect on x86_64. So the kernel sees mode = 0 when trying to use glibc openat() with O_TMPFILE, and fails with EACCES. Signed-off-by: Eric Rannaud <e@nanocritical.com> Acked-by: Andy Lutomirski <luto@amacapital.net> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-30ext4: make ext4_ext_convert_to_initialized() return proper number of blocksJan Kara
ext4_ext_convert_to_initialized() can return more blocks than are actually allocated from map->m_lblk in case where initial part of the on-disk extent is zeroed out. Luckily this doesn't have serious consequences because the caller currently uses the return value only to unmap metadata buffers. Anyway this is a data corruption/exposure problem waiting to happen so fix it. Coverity-id: 1226848 Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-10-30ext4: bail early when clearing inode journal flag failsJan Kara
When clearing inode journal flag, we call jbd2_journal_flush() to force all the journalled data to their final locations. Currently we ignore when this fails and continue clearing inode journal flag. This isn't a big problem because when jbd2_journal_flush() fails, journal is likely aborted anyway. But it can still lead to somewhat confusing results so rather bail out early. Coverity-id: 989044 Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-10-30ext4: bail out from make_indexed_dir() on first errorJan Kara
When ext4_handle_dirty_dx_node() or ext4_handle_dirty_dirent_node() fail, there's really something wrong with the fs and there's no point in continuing further. Just return error from make_indexed_dir() in that case. Also initialize frames array so that if we return early due to error, dx_release() doesn't try to dereference uninitialized memory (which could happen also due to error in do_split()). Coverity-id: 741300 Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org
2014-10-30jbd2: use a better hash function for the revoke tableTheodore Ts'o
The old hash function didn't work well for 64-bit block numbers, and used undefined (negative) shift right behavior. Use the generic 64-bit hash function instead. Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reported-by: Andrey Ryabinin <a.ryabinin@samsung.com>
2014-10-30ext4: prevent bugon on race between write/fcntlDmitry Monakhov
O_DIRECT flags can be toggeled via fcntl(F_SETFL). But this value checked twice inside ext4_file_write_iter() and __generic_file_write() which result in BUG_ON inside ext4_direct_IO. Let's initialize iocb->private unconditionally. TESTCASE: xfstest:generic/036 https://patchwork.ozlabs.org/patch/402445/ #TYPICAL STACK TRACE: kernel BUG at fs/ext4/inode.c:2960! invalid opcode: 0000 [#1] SMP Modules linked in: brd iTCO_wdt lpc_ich mfd_core igb ptp dm_mirror dm_region_hash dm_log dm_mod CPU: 6 PID: 5505 Comm: aio-dio-fcntl-r Not tainted 3.17.0-rc2-00176-gff5c017 #161 Hardware name: Intel Corporation W2600CR/W2600CR, BIOS SE5C600.86B.99.99.x028.061320111235 06/13/2011 task: ffff88080e95a7c0 ti: ffff88080f908000 task.ti: ffff88080f908000 RIP: 0010:[<ffffffff811fabf2>] [<ffffffff811fabf2>] ext4_direct_IO+0x162/0x3d0 RSP: 0018:ffff88080f90bb58 EFLAGS: 00010246 RAX: 0000000000000400 RBX: ffff88080fdb2a28 RCX: 00000000a802c818 RDX: 0000040000080000 RSI: ffff88080d8aeb80 RDI: 0000000000000001 RBP: ffff88080f90bbc8 R08: 0000000000000000 R09: 0000000000001581 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88080d8aeb80 R13: ffff88080f90bbf8 R14: ffff88080fdb28c8 R15: ffff88080fdb2a28 FS: 00007f23b2055700(0000) GS:ffff880818400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f23b2045000 CR3: 000000080cedf000 CR4: 00000000000407e0 Stack: ffff88080f90bb98 0000000000000000 7ffffffffffffffe ffff88080fdb2c30 0000000000000200 0000000000000200 0000000000000001 0000000000000200 ffff88080f90bbc8 ffff88080fdb2c30 ffff88080f90be08 0000000000000200 Call Trace: [<ffffffff8112ca9d>] generic_file_direct_write+0xed/0x180 [<ffffffff8112f2b2>] __generic_file_write_iter+0x222/0x370 [<ffffffff811f495b>] ext4_file_write_iter+0x34b/0x400 [<ffffffff811bd709>] ? aio_run_iocb+0x239/0x410 [<ffffffff811bd709>] ? aio_run_iocb+0x239/0x410 [<ffffffff810990e5>] ? local_clock+0x25/0x30 [<ffffffff810abd94>] ? __lock_acquire+0x274/0x700 [<ffffffff811f4610>] ? ext4_unwritten_wait+0xb0/0xb0 [<ffffffff811bd756>] aio_run_iocb+0x286/0x410 [<ffffffff810990e5>] ? local_clock+0x25/0x30 [<ffffffff810ac359>] ? lock_release_holdtime+0x29/0x190 [<ffffffff811bc05b>] ? lookup_ioctx+0x4b/0xf0 [<ffffffff811bde3b>] do_io_submit+0x55b/0x740 [<ffffffff811bdcaa>] ? do_io_submit+0x3ca/0x740 [<ffffffff811be030>] SyS_io_submit+0x10/0x20 [<ffffffff815ce192>] system_call_fastpath+0x16/0x1b Code: 01 48 8b 80 f0 01 00 00 48 8b 18 49 8b 45 10 0f 85 f1 01 00 00 48 03 45 c8 48 3b 43 48 0f 8f e3 01 00 00 49 83 7c 24 18 00 75 04 <0f> 0b eb fe f0 ff 83 ec 01 00 00 49 8b 44 24 18 8b 00 85 c0 89 RIP [<ffffffff811fabf2>] ext4_direct_IO+0x162/0x3d0 RSP <ffff88080f90bb58> Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Cc: stable@vger.kernel.org
2014-10-30ext4: remove extent status procfs files if journal load failsDarrick J. Wong
If we can't load the journal, remove the procfs files for the extent status information file to avoid leaking resources. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org
2014-10-30ext4: disallow changing journal_csum option during remountDarrick J. Wong
ext4 does not permit changing the metadata or journal checksum feature flag while mounted. Until we decide to support that, don't allow a remount to change the journal_csum flag (right now we silently fail to change anything). Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-10-30ext4: enable journal checksum when metadata checksum feature enabledDarrick J. Wong
If metadata checksumming is turned on for the FS, we need to tell the journal to use checksumming too. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org
2014-10-30ext4: fix oops when loading block bitmap failedJan Kara
When we fail to load block bitmap in __ext4_new_inode() we will dereference NULL pointer in ext4_journal_get_write_access(). So check for error from ext4_read_block_bitmap(). Coverity-id: 989065 Cc: stable@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-10-30ext4: fix overflow when updating superblock backups after resizeJan Kara
When there are no meta block groups update_backups() will compute the backup block in 32-bit arithmetics thus possibly overflowing the block number and corrupting the filesystem. OTOH filesystems without meta block groups larger than 16 TB should be rare. Fix the problem by doing the counting in 64-bit arithmetics. Coverity-id: 741252 CC: stable@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Lukas Czerner <lczerner@redhat.com>
2014-10-29Merge branch 'akpm' (incoming from Andrew Morton)Linus Torvalds
Merge misc fixes from Andrew Morton: "21 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (21 commits) mm/balloon_compaction: fix deflation when compaction is disabled sh: fix sh770x SCIF memory regions zram: avoid NULL pointer access in concurrent situation mm/slab_common: don't check for duplicate cache names ocfs2: fix d_splice_alias() return code checking mm: rmap: split out page_remove_file_rmap() mm: memcontrol: fix missed end-writeback page accounting mm: page-writeback: inline account_page_dirtied() into single caller lib/bitmap.c: fix undefined shift in __bitmap_shift_{left|right}() drivers/rtc/rtc-bq32k.c: fix register value memory-hotplug: clear pgdat which is allocated by bootmem in try_offline_node() drivers/rtc/rtc-s3c.c: fix initialization failure without rtc source clock kernel/kmod: fix use-after-free of the sub_info structure drivers/rtc/rtc-pm8xxx.c: rework to support pm8941 rtc mm, thp: fix collapsing of hugepages on madvise drivers: of: add return value to of_reserved_mem_device_init() mm: free compound page with correct order gcov: add ARM64 to GCOV_PROFILE_ALL fsnotify: next_i is freed during fsnotify_unmount_inodes. mm/compaction.c: avoid premature range skip in isolate_migratepages_range ...
2014-10-29ocfs2: fix d_splice_alias() return code checkingRichard Weinberger
d_splice_alias() can return a valid dentry, NULL or an ERR_PTR. Currently the code checks not for ERR_PTR and will cuase an oops in ocfs2_dentry_attach_lock(). Fix this by using IS_ERR_OR_NULL(). Signed-off-by: Richard Weinberger <richard@nod.at> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-29fsnotify: next_i is freed during fsnotify_unmount_inodes.Jerry Hoemann
During file system stress testing on 3.10 and 3.12 based kernels, the umount command occasionally hung in fsnotify_unmount_inodes in the section of code: spin_lock(&inode->i_lock); if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) { spin_unlock(&inode->i_lock); continue; } As this section of code holds the global inode_sb_list_lock, eventually the system hangs trying to acquire the lock. Multiple crash dumps showed: The inode->i_state == 0x60 and i_count == 0 and i_sb_list would point back at itself. As this is not the value of list upon entry to the function, the kernel never exits the loop. To help narrow down problem, the call to list_del_init in inode_sb_list_del was changed to list_del. This poisons the pointers in the i_sb_list and causes a kernel to panic if it transverse a freed inode. Subsequent stress testing paniced in fsnotify_unmount_inodes at the bottom of the list_for_each_entry_safe loop showing next_i had become free. We believe the root cause of the problem is that next_i is being freed during the window of time that the list_for_each_entry_safe loop temporarily releases inode_sb_list_lock to call fsnotify and fsnotify_inode_delete. The code in fsnotify_unmount_inodes attempts to prevent the freeing of inode and next_i by calling __iget. However, the code doesn't do the __iget call on next_i if i_count == 0 or if i_state & (I_FREEING | I_WILL_FREE) The patch addresses this issue by advancing next_i in the above two cases until we either find a next_i which we can __iget or we reach the end of the list. This makes the handling of next_i more closely match the handling of the variable "inode." The time to reproduce the hang is highly variable (from hours to days.) We ran the stress test on a 3.10 kernel with the proposed patch for a week without failure. During list_for_each_entry_safe, next_i is becoming free causing the loop to never terminate. Advance next_i in those cases where __iget is not done. Signed-off-by: Jerry Hoemann <jerry.hoemann@hp.com> Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com> Cc: Ken Helias <kenhelias@firemail.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-29Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block layer fixes from Jens Axboe: "A small collection of fixes for the current kernel. This contains: - Two error handling fixes from Jan Kara. One for null_blk on failure to add a device, and the other for the block/scsi_ioctl SCSI_IOCTL_SEND_COMMAND fixing up the error jump point. - A commit added in the merge window for the bio integrity bits unfortunately disabled merging for all requests if CONFIG_BLK_DEV_INTEGRITY wasn't set. Reverse the logic, so that integrity checking wont disallow merges when not enabled. - A fix from Ming Lei for merging and generating too many segments. This caused a BUG in virtio_blk. - Two error handling printk() fixups from Robert Elliott, improving the information given when we rate limit. - Error handling fixup on elevator_init() failure from Sudip Mukherjee. - A fix from Tony Battersby, fixing up a memory leak in the scatterlist handling with scsi-mq" * 'for-linus' of git://git.kernel.dk/linux-block: block: Fix merge logic when CONFIG_BLK_DEV_INTEGRITY is not defined lib/scatterlist: fix memory leak with scsi-mq block: fix wrong error return in elevator_init() scsi: Fix error handling in SCSI_IOCTL_SEND_COMMAND null_blk: Cleanup error recovery in null_add_dev() blk-merge: recaculate segment if it isn't less than max segments fs: clarify rate limit suppressed buffer I/O errors fs: merge I/O error prints into one line
2014-10-28isofs_cmp(): we'll never see a dentry for . or ..Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-28overlayfs: fix lockdep misannotationMiklos Szeredi
In an overlay directory that shadows an empty lower directory, say /mnt/a/empty102, do: touch /mnt/a/empty102/x unlink /mnt/a/empty102/x rmdir /mnt/a/empty102 It's actually harmless, but needs another level of nesting between I_MUTEX_CHILD and I_MUTEX_NORMAL. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Tested-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-28ovl: fix check for cursorMiklos Szeredi
ovl_cache_entry.name is now an array not a pointer, so it makes no sense test for it being NULL. Detected by coverity. From: Miklos Szeredi <mszeredi@suse.cz> Fixes: 68bf8611076a ("overlayfs: make ovl_cache_entry->name an array instead of +pointer") Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-28overlayfs: barriers for opening upper-layer directoryAl Viro
make sure that a) all stores done by opening struct file don't leak past storing the reference in od->upperfile b) the lockless side has read dependency barrier Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-28Btrfs: fix race that makes btrfs_lookup_extent_info miss skinny extent itemsFilipe Manana
We have a race that can lead us to miss skinny extent items in the function btrfs_lookup_extent_info() when the skinny metadata feature is enabled. So basically the sequence of steps is: 1) We search in the extent tree for the skinny extent, which returns > 0 (not found); 2) We check the previous item in the returned leaf for a non-skinny extent, and we don't find it; 3) Because we didn't find the non-skinny extent in step 2), we release our path to search the extent tree again, but this time for a non-skinny extent key; 4) Right after we released our path in step 3), a skinny extent was inserted in the extent tree (delayed refs were run) - our second extent tree search will miss it, because it's not looking for a skinny extent; 5) After the second search returned (with ret > 0), we look for any delayed ref for our extent's bytenr (and we do it while holding a read lock on the leaf), but we won't find any, as such delayed ref had just run and completed after we released out path in step 3) before doing the second search. Fix this by removing completely the path release and re-search logic. This is safe, because if we seach for a metadata item and we don't find it, we have the guarantee that the returned leaf is the one where the item would be inserted, and so path->slots[0] > 0 and path->slots[0] - 1 must be the slot where the non-skinny extent item is if it exists. The only case where path->slots[0] is zero is when there are no smaller keys in the tree (i.e. no left siblings for our leaf), in which case the re-search logic isn't needed as well. This race has been present since the introduction of skinny metadata (change 3173a18f70554fe7880bb2d85c7da566e364eb3c). Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-10-28Merge branch 'for-3.18' of git://linux-nfs.org/~bfields/linuxLinus Torvalds
Pull two nfsd fixes from Bruce Fields: "One regression from the 3.16 xdr rewrite, one an older bug exposed by a separate bug in the client's new SEEK code" * 'for-3.18' of git://linux-nfs.org/~bfields/linux: nfsd4: fix crash on unknown operation number nfsd4: fix response size estimation for OP_SEQUENCE
2014-10-27Btrfs: properly clean up btrfs_end_io_wq_cacheJosef Bacik
In one of Dave's cleanup commits he forgot to call btrfs_end_io_wq_exit on unload, which makes us unable to unload and then re-load the btrfs module. This fixes the problem. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: David Sterba <dsterba@suse.cz> Reviewed-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-10-27Btrfs: fix invalid leaf slot access in btrfs_lookup_extent()Filipe Manana
If we couldn't find our extent item, we accessed the current slot (path->slots[0]) to check if it corresponds to an equivalent skinny metadata item. However this slot could be beyond our last item in the leaf (i.e. path->slots[0] >= btrfs_header_nritems(leaf)), in which case we shouldn't process it. Since btrfs_lookup_extent() is only used to find extent items for data extents, fix this by removing completely the logic that looks up for an equivalent skinny metadata item, since it can not exist. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-10-27btrfs: use macro accessors in superblock validation checksDavid Sterba
The initial patch c926093ec516f5d316 (btrfs: add more superblock checks) did not properly use the macro accessors that wrap endianness and the code would not work correctly on big endian machines. Reported-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
2014-10-26Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "overlayfs merge + leak fix for d_splice_alias() failure exits" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: overlayfs: embed middle into overlay_readdir_data overlayfs: embed root into overlay_readdir_data overlayfs: make ovl_cache_entry->name an array instead of pointer overlayfs: don't hold ->i_mutex over opening the real directory fix inode leaks on d_splice_alias() failure exits fs: limit filesystem stacking depth overlay: overlay filesystem documentation overlayfs: implement show_options overlayfs: add statfs support overlay filesystem shmem: support RENAME_WHITEOUT ext4: support RENAME_WHITEOUT vfs: add RENAME_WHITEOUT vfs: add whiteout support vfs: export check_sticky() vfs: introduce clone_private_mount() vfs: export __inode_permission() to modules vfs: export do_splice_direct() to modules vfs: add i_op->dentry_open()
2014-10-24overlayfs: embed middle into overlay_readdir_dataAl Viro
same story... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-24overlayfs: embed root into overlay_readdir_dataAl Viro
no sense having it a pointer - all instances have it pointing to local variable in the same stack frame Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-24overlayfs: make ovl_cache_entry->name an array instead of pointerAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-24overlayfs: don't hold ->i_mutex over opening the real directoryAl Viro
just use it to serialize the assignment Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-23Merge branch 'overlayfs.v25' of ↵Al Viro
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs into for-linus
2014-10-23fix inode leaks on d_splice_alias() failure exitsAl Viro
d_splice_alias() callers expect it to either stash the inode reference into a new alias, or drop the inode reference. That makes it possible to just return d_splice_alias() result from ->lookup() instance, without any extra housekeeping required. Unfortunately, that should include the failure exits. If d_splice_alias() returns an error, it leaves the dentry it has been given negative and thus it *must* drop the inode reference. Easily fixed, but it goes way back and will need backporting. Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-24fs: limit filesystem stacking depthMiklos Szeredi
Add a simple read-only counter to super_block that indicates how deep this is in the stack of filesystems. Previously ecryptfs was the only stackable filesystem and it explicitly disallowed multiple layers of itself. Overlayfs, however, can be stacked recursively and also may be stacked on top of ecryptfs or vice versa. To limit the kernel stack usage we must limit the depth of the filesystem stack. Initially the limit is set to 2. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24overlayfs: implement show_optionsErez Zadok
This is useful because of the stacking nature of overlayfs. Users like to find out (via /proc/mounts) which lower/upper directory were used at mount time. AV: even failing ovl_parse_opt() could've done some kstrdup() AV: failure of ovl_alloc_entry() should end up with ENOMEM, not EINVAL Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24overlayfs: add statfs supportAndy Whitcroft
Add support for statfs to the overlayfs filesystem. As the upper layer is the target of all write operations assume that the space in that filesystem is the space in the overlayfs. There will be some inaccuracy as overwriting a file will copy it up and consume space we were not expecting, but it is better than nothing. Use the upper layer dentry and mount from the overlayfs root inode, passing the statfs call to that filesystem. Signed-off-by: Andy Whitcroft <apw@canonical.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24overlay filesystemMiklos Szeredi
Overlayfs allows one, usually read-write, directory tree to be overlaid onto another, read-only directory tree. All modifications go to the upper, writable layer. This type of mechanism is most often used for live CDs but there's a wide variety of other uses. The implementation differs from other "union filesystem" implementations in that after a file is opened all operations go directly to the underlying, lower or upper, filesystems. This simplifies the implementation and allows native performance in these cases. The dentry tree is duplicated from the underlying filesystems, this enables fast cached lookups without adding special support into the VFS. This uses slightly more memory than union mounts, but dentries are relatively small. Currently inodes are duplicated as well, but it is a possible optimization to share inodes for non-directories. Opening non directories results in the open forwarded to the underlying filesystem. This makes the behavior very similar to union mounts (with the same limitations vs. fchmod/fchown on O_RDONLY file descriptors). Usage: mount -t overlayfs overlayfs -olowerdir=/lower,upperdir=/upper/upper,workdir=/upper/work /overlay The following cotributions have been folded into this patch: Neil Brown <neilb@suse.de>: - minimal remount support - use correct seek function for directories - initialise is_real before use - rename ovl_fill_cache to ovl_dir_read Felix Fietkau <nbd@openwrt.org>: - fix a deadlock in ovl_dir_read_merged - fix a deadlock in ovl_remove_whiteouts Erez Zadok <ezk@fsl.cs.sunysb.edu> - fix cleanup after WARN_ON Sedat Dilek <sedat.dilek@googlemail.com> - fix up permission to confirm to new API Robin Dong <hao.bigrat@gmail.com> - fix possible leak in ovl_new_inode - create new inode in ovl_link Andy Whitcroft <apw@canonical.com> - switch to __inode_permission() - copy up i_uid/i_gid from the underlying inode AV: - ovl_copy_up_locked() - dput(ERR_PTR(...)) on two failure exits - ovl_clear_empty() - one failure exit forgetting to do unlock_rename(), lack of check for udir being the parent of upper, dropping and regaining the lock on udir (which would require _another_ check for parent being right). - bogus d_drop() in copyup and rename [fix from your mail] - copyup/remove and copyup/rename races [fix from your mail] - ovl_dir_fsync() leaving ERR_PTR() in ->realfile - ovl_entry_free() is pointless - it's just a kfree_rcu() - fold ovl_do_lookup() into ovl_lookup() - manually assigning ->d_op is wrong. Just use ->s_d_op. [patches picked from Miklos]: * copyup/remove and copyup/rename races * bogus d_drop() in copyup and rename Also thanks to the following people for testing and reporting bugs: Jordi Pujol <jordipujolp@gmail.com> Andy Whitcroft <apw@canonical.com> Michal Suchanek <hramrach@centrum.cz> Felix Fietkau <nbd@openwrt.org> Erez Zadok <ezk@fsl.cs.sunysb.edu> Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24ext4: support RENAME_WHITEOUTMiklos Szeredi
Add whiteout support to ext4_rename(). A whiteout inode (chrdev/0,0) is created before the rename takes place. The whiteout inode is added to the old entry instead of deleting it. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24vfs: add RENAME_WHITEOUTMiklos Szeredi
This adds a new RENAME_WHITEOUT flag. This flag makes rename() create a whiteout of source. The whiteout creation is atomic relative to the rename. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24vfs: add whiteout supportMiklos Szeredi
Whiteout isn't actually a new file type, but is represented as a char device (Linus's idea) with 0/0 device number. This has several advantages compared to introducing a new whiteout file type: - no userspace API changes (e.g. trivial to make backups of upper layer filesystem, without losing whiteouts) - no fs image format changes (you can boot an old kernel/fsck without whiteout support and things won't break) - implementation is trivial Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>