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2017-04-18Btrfs: update comments in cache_save_setupLiu Bo1-1/+2
We also don't bother to flush free space cache while with free space tree. Cc: David Sterba <dsterba@suse.cz> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18Btrfs: convert BUG_ON to WARN_ONLiu Bo1-2/+2
These two BUG_ON()s would never be true, ensured by callers' logic. Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18Btrfs: helper for ops that requires full stripeLiu Bo1-8/+10
This adds a helper to show directly whether ops require full stripe. Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18Btrfs: do not add extra mirror when dev_replace target dev is not availableLiu Bo1-3/+4
With this, we can avoid allocating memory for dev replace copies if the target dev is not available. Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18Btrfs: handle operations for device replace separatelyLiu Bo1-81/+98
Since this part is mostly independent, this moves it to a separate function. Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18Btrfs: introduce a function to get extra mirror from replaceLiu Bo1-72/+89
As the part of getting extra mirror in __btrfs_map_block is independent, this puts it into a separate function. Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18Btrfs: separate DISCARD from __btrfs_map_blockLiu Bo1-114/+175
Since DISCARD is not as important as an operation like write, we don't copy it to target device during replace, and it makes __btrfs_map_block less complex. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18Btrfs: create a helper for getting chunk mapLiu Bo3-111/+57
We have similar code here and there, this merges them into a helper. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18Btrfs: add file item tracepointsLiu Bo1-0/+15
While debugging truncate problems, I found that these tracepoints could help us quickly know what went wrong. Two sets of tracepoints are created to track regular/prealloc file item and inline file item respectively, I put inline as a separate one since what inline file items cares about are way less than the regular one. This adds four tracepoints: - btrfs_get_extent_show_fi_regular - btrfs_get_extent_show_fi_inline - btrfs_truncate_show_fi_regular - btrfs_truncate_show_fi_inline Cc: David Sterba <dsterba@suse.cz> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> [ formatting adjustments ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18btrfs: convert btrfs_raid_bio.refs from atomic_t to refcount_tElena Reshetova1-10/+9
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18btrfs: convert scrub_ctx.refs from atomic_t to refcount_tElena Reshetova1-5/+5
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18btrfs: convert scrub_parity.refs from atomic_t to refcount_tElena Reshetova1-4/+4
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18btrfs: convert scrub_block.refs from atomic_t to refcount_tElena Reshetova1-5/+5
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18btrfs: convert scrub_recover.refs from atomic_t to refcount_tElena Reshetova1-4/+4
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18btrfs: convert compressed_bio.pending_bios from atomic_t to refcount_tElena Reshetova1-9/+9
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18btrfs: convert extent_state.refs from atomic_t to refcount_tElena Reshetova2-8/+9
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18btrfs: convert btrfs_root.refs from atomic_t to refcount_tElena Reshetova3-4/+4
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18btrfs: convert btrfs_delayed_item.refs from atomic_t to refcount_tElena Reshetova2-10/+10
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18btrfs: convert btrfs_delayed_node.refs from atomic_t to refcount_tElena Reshetova2-16/+16
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18btrfs: convert btrfs_delayed_ref_node.refs from atomic_t to refcount_tElena Reshetova5-12/+14
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18btrfs: convert btrfs_caching_control.count from atomic_t to refcount_tElena Reshetova2-7/+8
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18btrfs: convert btrfs_ordered_extent.refs from atomic_t to refcount_tElena Reshetova2-10/+10
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18btrfs: convert extent_map.refs from atomic_t to refcount_tElena Reshetova5-10/+11
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18btrfs: convert btrfs_transaction.use_count from atomic_t to refcount_tElena Reshetova5-14/+16
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18btrfs: convert btrfs_bio.refs from atomic_t to refcount_tElena Reshetova2-5/+5
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18Btrfs: remove ASSERT in btrfs_truncate_inode_itemsLiu Bo1-7/+0
After 76b42abbf748 ("Btrfs: fix data loss after truncate when using the no-holes feature"), For either NO_HOLES or inline extents, we've set last_size to newsize to avoid data loss after remount or inode got evicted and read again, thus, we don't need this check anymore. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18btrfs: fix a bogus warning when converting only data or metadataAdam Borowski1-3/+9
If your filesystem has, eg, data:raid0 metadata:raid1, and you run "btrfs balance -dconvert=raid1", the meta.target field will be uninitialized. That's otherwise ok, as it's unused except for this warning. Thus, let's use the existing set of raid levels for the comparison. As a side effect, non-convert balances will now nag about data>metadata. Signed-off-by: Adam Borowski <kilobyte@angband.pl> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-14Merge branch 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfsLinus Torvalds3-13/+14
Pull btrfs fixes from Chris Mason: "Dave Sterba collected a few more fixes for the last rc. These aren't marked for stable, but I'm putting them in with a batch were testing/sending by hand for this release" * 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: fix potential use-after-free for cloned bio Btrfs: fix segmentation fault when doing dio read Btrfs: fix invalid dereference in btrfs_retry_endio btrfs: drop the nossd flag when remounting with -o ssd
2017-04-11Btrfs: fix potential use-after-free for cloned bioLiu Bo1-1/+1
KASAN reports that there is a use-after-free case of bio in btrfs_map_bio. If we need to submit IOs to several disks at a time, the original bio would get cloned and mapped to the destination disk, but we really should use the original bio instead of a cloned bio to do the sanity check because cloned bios are likely to be freed by its endio. Reported-by: Diego <diegocg@gmail.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-11Btrfs: fix segmentation fault when doing dio readLiu Bo1-2/+6
Commit 2dabb3248453 ("Btrfs: Direct I/O read: Work on sectorsized blocks") introduced this bug during iterating bio pages in dio read's endio hook, and it could end up with segment fault of the dio reading task. So the reason is 'if (nr_sectors--)', and it makes the code assume that there is one more block in the same page, so page offset is increased and the bio which is created to repair the bad block then has an incorrect bvec.bv_offset, and a later access of the page content would throw a segmentation fault. This also adds ASSERT to check page offset against page size. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-11Btrfs: fix invalid dereference in btrfs_retry_endioLiu Bo1-10/+4
When doing directIO repair, we have this oops: [ 1458.532816] general protection fault: 0000 [#1] SMP ... [ 1458.536291] Workqueue: btrfs-endio-repair btrfs_endio_repair_helper [btrfs] [ 1458.536893] task: ffff88082a42d100 task.stack: ffffc90002b3c000 [ 1458.537499] RIP: 0010:btrfs_retry_endio+0x7e/0x1a0 [btrfs] ... [ 1458.543261] Call Trace: [ 1458.543958] ? rcu_read_lock_sched_held+0xc4/0xd0 [ 1458.544374] bio_endio+0xed/0x100 [ 1458.544750] end_workqueue_fn+0x3c/0x40 [btrfs] [ 1458.545257] normal_work_helper+0x9f/0x900 [btrfs] [ 1458.545762] btrfs_endio_repair_helper+0x12/0x20 [btrfs] [ 1458.546224] process_one_work+0x34d/0xb70 [ 1458.546570] ? process_one_work+0x29e/0xb70 [ 1458.546938] worker_thread+0x1cf/0x960 [ 1458.547263] ? process_one_work+0xb70/0xb70 [ 1458.547624] kthread+0x17d/0x180 [ 1458.547909] ? kthread_create_on_node+0x70/0x70 [ 1458.548300] ret_from_fork+0x31/0x40 It turns out that btrfs_retry_endio is trying to get inode from a directIO page. This fixes the problem by using the saved inode pointer, done->inode. btrfs_retry_endio_nocsum has the same problem, and it's fixed as well. Also cleanup unused @start (which is too trivial for a separate patch). Cc: David Sterba <dsterba@suse.cz> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-11btrfs: drop the nossd flag when remounting with -o ssdAdam Borowski1-0/+3
The opposite case was already handled right in the very next switch entry. And also when turning on nossd, drop ssd_spread. Reported-by: Hans van Kranenburg <hans.van.kranenburg@mendix.com> Signed-off-by: Adam Borowski <kilobyte@angband.pl> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-03-31Merge branch 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfsLinus Torvalds6-29/+44
Pull btrfs fixes from Chris Mason: "We have three small fixes queued up in my for-linus-4.11 branch" * 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: fix an integer overflow check btrfs: Change qgroup_meta_rsv to 64bit Btrfs: bring back repair during read
2017-03-29Btrfs: fix an integer overflow checkDan Carpenter1-1/+6
This isn't super serious because you need CAP_ADMIN to run this code. I added this integer overflow check last year but apparently I am rubbish at writing integer overflow checks... There are two issues. First, access_ok() works on unsigned long type and not u64 so on 32 bit systems the access_ok() could be checking a truncated size. The other issue is that we should be using a stricter limit so we don't overflow the kzalloc() setting ctx->clone_roots later in the function after the access_ok(): alloc_size = sizeof(struct clone_root) * (arg->clone_sources_count + 1); sctx->clone_roots = kzalloc(alloc_size, GFP_KERNEL | __GFP_NOWARN); Fixes: f5ecec3ce21f ("btrfs: send: silence an integer overflow warning") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> [ added comment ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-03-29btrfs: Change qgroup_meta_rsv to 64bitGoldwyn Rodrigues3-7/+7
Using an int value is causing qg->reserved to become negative and exclusive -EDQUOT to be reached prematurely. This affects exclusive qgroups only. TEST CASE: DEVICE=/dev/vdb MOUNTPOINT=/mnt SUBVOL=$MOUNTPOINT/tmp umount $SUBVOL umount $MOUNTPOINT mkfs.btrfs -f $DEVICE mount /dev/vdb $MOUNTPOINT btrfs quota enable $MOUNTPOINT btrfs subvol create $SUBVOL umount $MOUNTPOINT mount /dev/vdb $MOUNTPOINT mount -o subvol=tmp $DEVICE $SUBVOL btrfs qgroup limit -e 3G $SUBVOL btrfs quota rescan /mnt -w for i in `seq 1 44000`; do dd if=/dev/zero of=/mnt/tmp/test_$i bs=10k count=1 if [[ $? > 0 ]]; then btrfs qgroup show -pcref $SUBVOL exit 1 fi done Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> [ add reproducer to changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-03-29Btrfs: bring back repair during readLiu Bo2-21/+31
Commit 20a7db8ab3f2 ("btrfs: add dummy callback for readpage_io_failed and drop checks") made a cleanup around readpage_io_failed_hook, and it was supposed to keep the original sematics, but it also unexpectedly disabled repair during read for dup, raid1 and raid10. This fixes the problem by letting data's inode call the generic readpage_io_failed callback by returning -EAGAIN from its readpage_io_failed_hook in order to notify end_bio_extent_readpage to do the rest. We don't call it directly because the generic one takes an offset from end_bio_extent_readpage() to calculate the index in the checksum array and inode's readpage_io_failed_hook doesn't offer that offset. Cc: David Sterba <dsterba@suse.cz> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> [ keep the const function attribute ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-03-23Merge branch 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfsLinus Torvalds2-1/+16
Pull btrfs fixes from Chris Mason: "Zygo tracked down a very old bug with inline compressed extents. I didn't tag this one for stable because I want to do individual tested backports. It's a little tricky and I'd rather do some extra testing on it along the way" * 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: btrfs: add missing memset while reading compressed inline extents Btrfs: fix regression in lock_delalloc_pages btrfs: remove btrfs_err_str function from uapi/linux/btrfs.h
2017-03-17btrfs: add missing memset while reading compressed inline extentsZygo Blaxell1-0/+14
This is a story about 4 distinct (and very old) btrfs bugs. Commit c8b978188c ("Btrfs: Add zlib compression support") added three data corruption bugs for inline extents (bugs #1-3). Commit 93c82d5750 ("Btrfs: zero page past end of inline file items") fixed bug #1: uncompressed inline extents followed by a hole and more extents could get non-zero data in the hole as they were read. The fix was to add a memset in btrfs_get_extent to zero out the hole. Commit 166ae5a418 ("btrfs: fix inline compressed read err corruption") fixed bug #2: compressed inline extents which contained non-zero bytes might be replaced with zero bytes in some cases. This patch removed an unhelpful memset from uncompress_inline, but the case where memset is required was missed. There is also a memset in the decompression code, but this only covers decompressed data that is shorter than the ram_bytes from the extent ref record. This memset doesn't cover the region between the end of the decompressed data and the end of the page. It has also moved around a few times over the years, so there's no single patch to refer to. This patch fixes bug #3: compressed inline extents followed by a hole and more extents could get non-zero data in the hole as they were read (i.e. bug #3 is the same as bug #1, but s/uncompressed/compressed/). The fix is the same: zero out the hole in the compressed case too, by putting a memset back in uncompress_inline, but this time with correct parameters. The last and oldest bug, bug #0, is the cause of the offending inline extent/hole/extent pattern. Bug #0 is a subtle and mostly-harmless quirk of behavior somewhere in the btrfs write code. In a few special cases, an inline extent and hole are allowed to persist where they normally would be combined with later extents in the file. A fast reproducer for bug #0 is presented below. A few offending extents are also created in the wild during large rsync transfers with the -S flag. A Linux kernel build (git checkout; make allyesconfig; make -j8) will produce a handful of offending files as well. Once an offending file is created, it can present different content to userspace each time it is read. Bug #0 is at least 4 and possibly 8 years old. I verified every vX.Y kernel back to v3.5 has this behavior. There are fossil records of this bug's effects in commits all the way back to v2.6.32. I have no reason to believe bug #0 wasn't present at the beginning of btrfs compression support in v2.6.29, but I can't easily test kernels that old to be sure. It is not clear whether bug #0 is worth fixing. A fix would likely require injecting extra reads into currently write-only paths, and most of the exceptional cases caused by bug #0 are already handled now. Whether we like them or not, bug #0's inline extents followed by holes are part of the btrfs de-facto disk format now, and we need to be able to read them without data corruption or an infoleak. So enough about bug #0, let's get back to bug #3 (this patch). An example of on-disk structure leading to data corruption found in the wild: item 61 key (606890 INODE_ITEM 0) itemoff 9662 itemsize 160 inode generation 50 transid 50 size 47424 nbytes 49141 block group 0 mode 100644 links 1 uid 0 gid 0 rdev 0 flags 0x0(none) item 62 key (606890 INODE_REF 603050) itemoff 9642 itemsize 20 inode ref index 3 namelen 10 name: DB_File.so item 63 key (606890 EXTENT_DATA 0) itemoff 8280 itemsize 1362 inline extent data size 1341 ram 4085 compress(zlib) item 64 key (606890 EXTENT_DATA 4096) itemoff 8227 itemsize 53 extent data disk byte 5367308288 nr 20480 extent data offset 0 nr 45056 ram 45056 extent compression(zlib) Different data appears in userspace during each read of the 11 bytes between 4085 and 4096. The extent in item 63 is not long enough to fill the first page of the file, so a memset is required to fill the space between item 63 (ending at 4085) and item 64 (beginning at 4096) with zero. Here is a reproducer from Liu Bo, which demonstrates another method of creating the same inline extent and hole pattern: Using 'page_poison=on' kernel command line (or enable CONFIG_PAGE_POISONING) run the following: # touch foo # chattr +c foo # xfs_io -f -c "pwrite -W 0 1000" foo # xfs_io -f -c "falloc 4 8188" foo # od -x foo # echo 3 >/proc/sys/vm/drop_caches # od -x foo This produce the following on my box: Correct output: file contains 1000 data bytes followed by zeros: 0000000 cdcd cdcd cdcd cdcd cdcd cdcd cdcd cdcd * 0001740 cdcd cdcd cdcd cdcd 0000 0000 0000 0000 0001760 0000 0000 0000 0000 0000 0000 0000 0000 * 0020000 Actual output: the data after the first 1000 bytes will be different each run: 0000000 cdcd cdcd cdcd cdcd cdcd cdcd cdcd cdcd * 0001740 cdcd cdcd cdcd cdcd 6c63 7400 635f 006d 0001760 5f74 6f43 7400 435f 0053 5f74 7363 7400 0002000 435f 0056 5f74 6164 7400 645f 0062 5f74 (...) Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: Chris Mason <clm@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2017-03-17Btrfs: fix regression in lock_delalloc_pagesLiu Bo1-1/+2
The bug is a regression after commit (da2c7009f6ca "btrfs: teach __process_pages_contig about PAGE_LOCK operation") and commit (76c0021db8fd "Btrfs: use helper to simplify lock/unlock pages"). So if the dirty pages which are under writeback got truncated partially before we lock the dirty pages, we couldn't find all pages mapping to the delalloc range, and the bug didn't return an error so it kept going on and found that the delalloc range got truncated and got to unlock the dirty pages, and then the ASSERT could caught the error, and showed ----------------------------------------------------------------------------- assertion failed: page_ops & PAGE_LOCK, file: fs/btrfs/extent_io.c, line: 1716 ----------------------------------------------------------------------------- This fixes the bug by returning the proper -EAGAIN. Cc: David Sterba <dsterba@suse.com> Reported-by: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-03-03Merge branch 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds1-3/+3
Pull vfs 'statx()' update from Al Viro. This adds the new extended stat() interface that internally subsumes our previous stat interfaces, and allows user mode to specify in more detail what kind of information it wants. It also allows for some explicit synchronization information to be passed to the filesystem, which can be relevant for network filesystems: is the cached value ok, or do you need open/close consistency, or what? From David Howells. Andreas Dilger points out that the first version of the extended statx interface was posted June 29, 2010: https://www.spinics.net/lists/linux-fsdevel/msg33831.html * 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: statx: Add a system call to make enhanced file info available
2017-03-03Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds3-0/+3
Pull sched.h split-up from Ingo Molnar: "The point of these changes is to significantly reduce the <linux/sched.h> header footprint, to speed up the kernel build and to have a cleaner header structure. After these changes the new <linux/sched.h>'s typical preprocessed size goes down from a previous ~0.68 MB (~22K lines) to ~0.45 MB (~15K lines), which is around 40% faster to build on typical configs. Not much changed from the last version (-v2) posted three weeks ago: I eliminated quirks, backmerged fixes plus I rebased it to an upstream SHA1 from yesterday that includes most changes queued up in -next plus all sched.h changes that were pending from Andrew. I've re-tested the series both on x86 and on cross-arch defconfigs, and did a bisectability test at a number of random points. I tried to test as many build configurations as possible, but some build breakage is probably still left - but it should be mostly limited to architectures that have no cross-compiler binaries available on kernel.org, and non-default configurations" * 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (146 commits) sched/headers: Clean up <linux/sched.h> sched/headers: Remove #ifdefs from <linux/sched.h> sched/headers: Remove the <linux/topology.h> include from <linux/sched.h> sched/headers, hrtimer: Remove the <linux/wait.h> include from <linux/hrtimer.h> sched/headers, x86/apic: Remove the <linux/pm.h> header inclusion from <asm/apic.h> sched/headers, timers: Remove the <linux/sysctl.h> include from <linux/timer.h> sched/headers: Remove <linux/magic.h> from <linux/sched/task_stack.h> sched/headers: Remove <linux/sched.h> from <linux/sched/init.h> sched/core: Remove unused prefetch_stack() sched/headers: Remove <linux/rculist.h> from <linux/sched.h> sched/headers: Remove the 'init_pid_ns' prototype from <linux/sched.h> sched/headers: Remove <linux/signal.h> from <linux/sched.h> sched/headers: Remove <linux/rwsem.h> from <linux/sched.h> sched/headers: Remove the runqueue_is_locked() prototype sched/headers: Remove <linux/sched.h> from <linux/sched/hotplug.h> sched/headers: Remove <linux/sched.h> from <linux/sched/debug.h> sched/headers: Remove <linux/sched.h> from <linux/sched/nohz.h> sched/headers: Remove <linux/sched.h> from <linux/sched/stat.h> sched/headers: Remove the <linux/gfp.h> include from <linux/sched.h> sched/headers: Remove <linux/rtmutex.h> from <linux/sched.h> ...
2017-03-02statx: Add a system call to make enhanced file info availableDavid Howells1-3/+3
Add a system call to make extended file information available, including file creation and some attribute flags where available through the underlying filesystem. The getattr inode operation is altered to take two additional arguments: a u32 request_mask and an unsigned int flags that indicate the synchronisation mode. This change is propagated to the vfs_getattr*() function. Functions like vfs_stat() are now inline wrappers around new functions vfs_statx() and vfs_statx_fd() to reduce stack usage. ======== OVERVIEW ======== The idea was initially proposed as a set of xattrs that could be retrieved with getxattr(), but the general preference proved to be for a new syscall with an extended stat structure. A number of requests were gathered for features to be included. The following have been included: (1) Make the fields a consistent size on all arches and make them large. (2) Spare space, request flags and information flags are provided for future expansion. (3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an __s64). (4) Creation time: The SMB protocol carries the creation time, which could be exported by Samba, which will in turn help CIFS make use of FS-Cache as that can be used for coherency data (stx_btime). This is also specified in NFSv4 as a recommended attribute and could be exported by NFSD [Steve French]. (5) Lightweight stat: Ask for just those details of interest, and allow a netfs (such as NFS) to approximate anything not of interest, possibly without going to the server [Trond Myklebust, Ulrich Drepper, Andreas Dilger] (AT_STATX_DONT_SYNC). (6) Heavyweight stat: Force a netfs to go to the server, even if it thinks its cached attributes are up to date [Trond Myklebust] (AT_STATX_FORCE_SYNC). And the following have been left out for future extension: (7) Data version number: Could be used by userspace NFS servers [Aneesh Kumar]. Can also be used to modify fill_post_wcc() in NFSD which retrieves i_version directly, but has just called vfs_getattr(). It could get it from the kstat struct if it used vfs_xgetattr() instead. (There's disagreement on the exact semantics of a single field, since not all filesystems do this the same way). (8) BSD stat compatibility: Including more fields from the BSD stat such as creation time (st_btime) and inode generation number (st_gen) [Jeremy Allison, Bernd Schubert]. (9) Inode generation number: Useful for FUSE and userspace NFS servers [Bernd Schubert]. (This was asked for but later deemed unnecessary with the open-by-handle capability available and caused disagreement as to whether it's a security hole or not). (10) Extra coherency data may be useful in making backups [Andreas Dilger]. (No particular data were offered, but things like last backup timestamp, the data version number and the DOS archive bit would come into this category). (11) Allow the filesystem to indicate what it can/cannot provide: A filesystem can now say it doesn't support a standard stat feature if that isn't available, so if, for instance, inode numbers or UIDs don't exist or are fabricated locally... (This requires a separate system call - I have an fsinfo() call idea for this). (12) Store a 16-byte volume ID in the superblock that can be returned in struct xstat [Steve French]. (Deferred to fsinfo). (13) Include granularity fields in the time data to indicate the granularity of each of the times (NFSv4 time_delta) [Steve French]. (Deferred to fsinfo). (14) FS_IOC_GETFLAGS value. These could be translated to BSD's st_flags. Note that the Linux IOC flags are a mess and filesystems such as Ext4 define flags that aren't in linux/fs.h, so translation in the kernel may be a necessity (or, possibly, we provide the filesystem type too). (Some attributes are made available in stx_attributes, but the general feeling was that the IOC flags were to ext[234]-specific and shouldn't be exposed through statx this way). (15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer, Michael Kerrisk]. (Deferred, probably to fsinfo. Finding out if there's an ACL or seclabal might require extra filesystem operations). (16) Femtosecond-resolution timestamps [Dave Chinner]. (A __reserved field has been left in the statx_timestamp struct for this - if there proves to be a need). (17) A set multiple attributes syscall to go with this. =============== NEW SYSTEM CALL =============== The new system call is: int ret = statx(int dfd, const char *filename, unsigned int flags, unsigned int mask, struct statx *buffer); The dfd, filename and flags parameters indicate the file to query, in a similar way to fstatat(). There is no equivalent of lstat() as that can be emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags. There is also no equivalent of fstat() as that can be emulated by passing a NULL filename to statx() with the fd of interest in dfd. Whether or not statx() synchronises the attributes with the backing store can be controlled by OR'ing a value into the flags argument (this typically only affects network filesystems): (1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this respect. (2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise its attributes with the server - which might require data writeback to occur to get the timestamps correct. (3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a network filesystem. The resulting values should be considered approximate. mask is a bitmask indicating the fields in struct statx that are of interest to the caller. The user should set this to STATX_BASIC_STATS to get the basic set returned by stat(). It should be noted that asking for more information may entail extra I/O operations. buffer points to the destination for the data. This must be 256 bytes in size. ====================== MAIN ATTRIBUTES RECORD ====================== The following structures are defined in which to return the main attribute set: struct statx_timestamp { __s64 tv_sec; __s32 tv_nsec; __s32 __reserved; }; struct statx { __u32 stx_mask; __u32 stx_blksize; __u64 stx_attributes; __u32 stx_nlink; __u32 stx_uid; __u32 stx_gid; __u16 stx_mode; __u16 __spare0[1]; __u64 stx_ino; __u64 stx_size; __u64 stx_blocks; __u64 __spare1[1]; struct statx_timestamp stx_atime; struct statx_timestamp stx_btime; struct statx_timestamp stx_ctime; struct statx_timestamp stx_mtime; __u32 stx_rdev_major; __u32 stx_rdev_minor; __u32 stx_dev_major; __u32 stx_dev_minor; __u64 __spare2[14]; }; The defined bits in request_mask and stx_mask are: STATX_TYPE Want/got stx_mode & S_IFMT STATX_MODE Want/got stx_mode & ~S_IFMT STATX_NLINK Want/got stx_nlink STATX_UID Want/got stx_uid STATX_GID Want/got stx_gid STATX_ATIME Want/got stx_atime{,_ns} STATX_MTIME Want/got stx_mtime{,_ns} STATX_CTIME Want/got stx_ctime{,_ns} STATX_INO Want/got stx_ino STATX_SIZE Want/got stx_size STATX_BLOCKS Want/got stx_blocks STATX_BASIC_STATS [The stuff in the normal stat struct] STATX_BTIME Want/got stx_btime{,_ns} STATX_ALL [All currently available stuff] stx_btime is the file creation time, stx_mask is a bitmask indicating the data provided and __spares*[] are where as-yet undefined fields can be placed. Time fields are structures with separate seconds and nanoseconds fields plus a reserved field in case we want to add even finer resolution. Note that times will be negative if before 1970; in such a case, the nanosecond fields will also be negative if not zero. The bits defined in the stx_attributes field convey information about a file, how it is accessed, where it is and what it does. The following attributes map to FS_*_FL flags and are the same numerical value: STATX_ATTR_COMPRESSED File is compressed by the fs STATX_ATTR_IMMUTABLE File is marked immutable STATX_ATTR_APPEND File is append-only STATX_ATTR_NODUMP File is not to be dumped STATX_ATTR_ENCRYPTED File requires key to decrypt in fs Within the kernel, the supported flags are listed by: KSTAT_ATTR_FS_IOC_FLAGS [Are any other IOC flags of sufficient general interest to be exposed through this interface?] New flags include: STATX_ATTR_AUTOMOUNT Object is an automount trigger These are for the use of GUI tools that might want to mark files specially, depending on what they are. Fields in struct statx come in a number of classes: (0) stx_dev_*, stx_blksize. These are local system information and are always available. (1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino, stx_size, stx_blocks. These will be returned whether the caller asks for them or not. The corresponding bits in stx_mask will be set to indicate whether they actually have valid values. If the caller didn't ask for them, then they may be approximated. For example, NFS won't waste any time updating them from the server, unless as a byproduct of updating something requested. If the values don't actually exist for the underlying object (such as UID or GID on a DOS file), then the bit won't be set in the stx_mask, even if the caller asked for the value. In such a case, the returned value will be a fabrication. Note that there are instances where the type might not be valid, for instance Windows reparse points. (2) stx_rdev_*. This will be set only if stx_mode indicates we're looking at a blockdev or a chardev, otherwise will be 0. (3) stx_btime. Similar to (1), except this will be set to 0 if it doesn't exist. ======= TESTING ======= The following test program can be used to test the statx system call: samples/statx/test-statx.c Just compile and run, passing it paths to the files you want to examine. The file is built automatically if CONFIG_SAMPLES is enabled. Here's some example output. Firstly, an NFS directory that crosses to another FSID. Note that the AUTOMOUNT attribute is set because transiting this directory will cause d_automount to be invoked by the VFS. [root@andromeda ~]# /tmp/test-statx -A /warthog/data statx(/warthog/data) = 0 results=7ff Size: 4096 Blocks: 8 IO Block: 1048576 directory Device: 00:26 Inode: 1703937 Links: 125 Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041 Access: 2016-11-24 09:02:12.219699527+0000 Modify: 2016-11-17 10:44:36.225653653+0000 Change: 2016-11-17 10:44:36.225653653+0000 Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------) Secondly, the result of automounting on that directory. [root@andromeda ~]# /tmp/test-statx /warthog/data statx(/warthog/data) = 0 results=7ff Size: 4096 Blocks: 8 IO Block: 1048576 directory Device: 00:27 Inode: 2 Links: 125 Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041 Access: 2016-11-24 09:02:12.219699527+0000 Modify: 2016-11-17 10:44:36.225653653+0000 Change: 2016-11-17 10:44:36.225653653+0000 Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-02Merge branch 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfsLinus Torvalds32-656/+861
Pull more btrfs updates from Chris Mason: "Btrfs round two. These are mostly a continuation of Dave Sterba's collection of cleanups, but Filipe also has some bug fixes and performance improvements" * 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (69 commits) btrfs: add dummy callback for readpage_io_failed and drop checks btrfs: drop checks for mandatory extent_io_ops callbacks btrfs: document existence of extent_io ops callbacks btrfs: let writepage_end_io_hook return void btrfs: do proper error handling in btrfs_insert_xattr_item btrfs: handle allocation error in update_dev_stat_item btrfs: remove BUG_ON from __tree_mod_log_insert btrfs: derive maximum output size in the compression implementation btrfs: use predefined limits for calculating maximum number of pages for compression btrfs: export compression buffer limits in a header btrfs: merge nr_pages input and output parameter in compress_pages btrfs: merge length input and output parameter in compress_pages btrfs: constify name of subvolume in creation helpers btrfs: constify buffers used by compression helpers btrfs: constify input buffer of btrfs_csum_data btrfs: constify device path passed to relevant helpers btrfs: make btrfs_inode_resume_unlocked_dio take btrfs_inode btrfs: make btrfs_inode_block_unlocked_dio take btrfs_inode btrfs: Make btrfs_add_nondir take btrfs_inode btrfs: Make btrfs_add_link take btrfs_inode ...
2017-03-02sched/headers: Prepare for the reduction of <linux/sched.h>'s signal API dependencyIngo Molnar2-0/+2
Instead of including the full <linux/signal.h>, we are going to include the types-only <linux/signal_types.h> header in <linux/sched.h>, to further decouple the scheduler header from the signal headers. This means that various files which relied on the full <linux/signal.h> need to be updated to gain an explicit dependency on it. Update the code that relies on sched.h's inclusion of the <linux/signal.h> header. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h>Ingo Molnar1-0/+1
Fix up affected files that include this signal functionality via sched.h. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-28Merge branch 'for-chris-4.11-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.11Chris Mason31-626/+673
2017-02-28btrfs: add dummy callback for readpage_io_failed and drop checksDavid Sterba4-3/+10
Make extent_io_ops::readpage_io_failed_hook callback mandatory and define a dummy function for btrfs_extent_io_ops. As the failed IO callback is not performance critical, the branch vs extra trade off does not hurt. Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28btrfs: drop checks for mandatory extent_io_ops callbacksDavid Sterba1-4/+3
We know that eadpage_end_io_hook, submit_bio_hook and merge_bio_hook are always defined so we can drop the checks before we call them. Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28btrfs: document existence of extent_io ops callbacksDavid Sterba3-11/+26
Some of the callbacks defined in btree_extent_io_ops and btrfs_extent_io_ops do always exist so we don't need to check the existence before each call. This patch just reorders the definition and documents which are mandatory/optional. Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28btrfs: let writepage_end_io_hook return voidDavid Sterba3-11/+6
There's no error path in any of the instances, always return 0. Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>