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* Btrfs: make free space cache write out functions more readableMiao Xie2014-06-191-66/+93
| | | | | | | | | This patch makes the free space cache write out functions more readable, and beisdes that, it also reduces the stack space that the function -- __btrfs_write_out_cache uses from 194bytes to 144bytes. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: remove unused wait queue in struct extent_bufferFilipe Manana2014-06-191-1/+0Star
| | | | | | | | | | The lock_wq wait queue is not used anywhere, therefore just remove it. On a x86_64 system, this reduced sizeof(struct extent_buffer) from 320 bytes down to 296 bytes, which means a 4Kb page can now be used for 13 extent buffers instead of 12. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: fix deadlocks with trylock on tree nodesChris Mason2014-06-191-34/+46
| | | | | | | | | | | | | The Btrfs tree trylock function is poorly named. It always takes the spinlock and backs off if the blocking lock is held. This can lead to surprising lockups because people expect it to really be a trylock. This commit makes it a pure trylock, both for the spinlock and the blocking lock. It also reworks the nested lock handling slightly to avoid taking the read lock while a spinning write lock might be held. Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: fix error handling in create_pending_snapshotEric Sandeen2014-06-131-5/+7
| | | | | | | | | | fcebe456 cut and pasted some code to a later point in create_pending_snapshot(), but didn't switch to the appropriate error handling for this stage of the function. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: fix use of uninit "ret" in end_extent_writepage()Eric Sandeen2014-06-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | If this condition in end_extent_writepage() is false: if (tree->ops && tree->ops->writepage_end_io_hook) we will then test an uninitialized "ret" at: ret = ret < 0 ? ret : -EIO; The test for ret is for the case where ->writepage_end_io_hook failed, and we'd choose that ret as the error; but if there is no ->writepage_end_io_hook, nothing sets ret. Initializing ret to 0 should be sufficient; if writepage_end_io_hook wasn't set, (!uptodate) means non-zero err was passed in, so we choose -EIO in that case. Signed-of-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: free ulist in qgroup_shared_accounting() error pathEric Sandeen2014-06-131-1/+3
| | | | | | | | | If tmp = ulist_alloc(GFP_NOFS) fails, we return without freeing the previously allocated qgroups = ulist_alloc(GFP_NOFS) and cause a memory leak. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: fix qgroups sanity test crash or hangFilipe Manana2014-06-131-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Often when running the qgroups sanity test, a crash or a hang happened. This is because the extent buffer the test uses for the root node doesn't have an header level explicitly set, making it have a random level value. This is a problem when it's not zero for the btrfs_search_slot() calls the test ends up doing, resulting in crashes or hangs such as the following: [ 6454.127192] Btrfs loaded, debug=on, assert=on, integrity-checker=on (...) [ 6454.127760] BTRFS: selftest: Running qgroup tests [ 6454.127964] BTRFS: selftest: Running test_test_no_shared_qgroup [ 6454.127966] BTRFS: selftest: Qgroup basic add [ 6480.152005] BUG: soft lockup - CPU#0 stuck for 23s! [modprobe:5383] [ 6480.152005] Modules linked in: btrfs(+) xor raid6_pq binfmt_misc nfsd auth_rpcgss oid_registry nfs_acl nfs lockd fscache sunrpc i2c_piix4 i2c_core pcspkr evbug psmouse serio_raw e1000 [last unloaded: btrfs] [ 6480.152005] irq event stamp: 188448 [ 6480.152005] hardirqs last enabled at (188447): [<ffffffff8168ef5c>] restore_args+0x0/0x30 [ 6480.152005] hardirqs last disabled at (188448): [<ffffffff81698e6a>] apic_timer_interrupt+0x6a/0x80 [ 6480.152005] softirqs last enabled at (188446): [<ffffffff810516cf>] __do_softirq+0x1cf/0x450 [ 6480.152005] softirqs last disabled at (188441): [<ffffffff81051c25>] irq_exit+0xb5/0xc0 [ 6480.152005] CPU: 0 PID: 5383 Comm: modprobe Not tainted 3.15.0-rc8-fdm-btrfs-next-33+ #4 [ 6480.152005] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 6480.152005] task: ffff8802146125a0 ti: ffff8800d0d00000 task.ti: ffff8800d0d00000 [ 6480.152005] RIP: 0010:[<ffffffff81349a63>] [<ffffffff81349a63>] __write_lock_failed+0x13/0x20 [ 6480.152005] RSP: 0018:ffff8800d0d038e8 EFLAGS: 00000287 [ 6480.152005] RAX: 0000000000000000 RBX: ffffffff8168ef5c RCX: 000005deb8525852 [ 6480.152005] RDX: 0000000000000000 RSI: 0000000000001d45 RDI: ffff8802105000b8 [ 6480.152005] RBP: ffff8800d0d038e8 R08: fffffe12710f63db R09: ffffffffa03196fb [ 6480.152005] R10: ffff8802146125a0 R11: ffff880214612e28 R12: ffff8800d0d03858 [ 6480.152005] R13: 0000000000000000 R14: ffff8800d0d00000 R15: ffff8802146125a0 [ 6480.152005] FS: 00007f14ff804700(0000) GS:ffff880215e00000(0000) knlGS:0000000000000000 [ 6480.152005] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 6480.152005] CR2: 00007fff4df0dac8 CR3: 00000000d1796000 CR4: 00000000000006f0 [ 6480.152005] Stack: [ 6480.152005] ffff8800d0d03908 ffffffff810ae967 0000000000000001 ffff8802105000b8 [ 6480.152005] ffff8800d0d03938 ffffffff8168e57e ffffffffa0319c16 0000000000000007 [ 6480.152005] ffff880210500000 ffff880210500100 ffff8800d0d039b8 ffffffffa0319c16 [ 6480.152005] Call Trace: [ 6480.152005] [<ffffffff810ae967>] do_raw_write_lock+0x47/0xa0 [ 6480.152005] [<ffffffff8168e57e>] _raw_write_lock+0x5e/0x80 [ 6480.152005] [<ffffffffa0319c16>] ? btrfs_tree_lock+0x116/0x270 [btrfs] [ 6480.152005] [<ffffffffa0319c16>] btrfs_tree_lock+0x116/0x270 [btrfs] [ 6480.152005] [<ffffffffa02b2acb>] btrfs_lock_root_node+0x3b/0x50 [btrfs] [ 6480.152005] [<ffffffffa02b81a6>] btrfs_search_slot+0x916/0xa20 [btrfs] [ 6480.152005] [<ffffffff811a727f>] ? create_object+0x23f/0x300 [ 6480.152005] [<ffffffffa02b9958>] btrfs_insert_empty_items+0x78/0xd0 [btrfs] [ 6480.152005] [<ffffffffa036041a>] insert_normal_tree_ref.constprop.4+0xa2/0x19a [btrfs] [ 6480.152005] [<ffffffffa03605c3>] test_no_shared_qgroup+0xb1/0x1ca [btrfs] [ 6480.152005] [<ffffffff8108cad6>] ? local_clock+0x16/0x30 [ 6480.152005] [<ffffffffa035ef8e>] btrfs_test_qgroups+0x1ae/0x1d7 [btrfs] [ 6480.152005] [<ffffffffa03a69d2>] ? ftrace_define_fields_btrfs_space_reservation+0xfd/0xfd [btrfs] [ 6480.152005] [<ffffffffa03a6a86>] init_btrfs_fs+0xb4/0x153 [btrfs] [ 6480.152005] [<ffffffff81000352>] do_one_initcall+0x102/0x150 [ 6480.152005] [<ffffffff8103d223>] ? set_memory_nx+0x43/0x50 [ 6480.152005] [<ffffffff81682668>] ? set_section_ro_nx+0x6d/0x74 [ 6480.152005] [<ffffffff810d91cc>] load_module+0x1cdc/0x2630 (...) Therefore initialize the extent buffer as an empty leaf (level 0). Issue easy to reproduce when btrfs is built as a module via: $ for ((i = 1; i <= 1000000; i++)); do rmmod btrfs; modprobe btrfs; done Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: prevent RCU warning when dereferencing radix tree slotSasha Levin2014-06-131-1/+1
| | | | | | | | Mark the dereference as protected by lock. Not doing so triggers an RCU warning since the radix tree assumed that RCU is in use. Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: fix unfinished readahead thread for raid5/6 degraded mountingWang Shilong2014-06-131-2/+7
| | | | | | | | | | | | | | | | | | | | | Steps to reproduce: # mkfs.btrfs -f /dev/sd[b-f] -m raid5 -d raid5 # mkfs.ext4 /dev/sdc --->corrupt one of btrfs device # mount /dev/sdb /mnt -o degraded # btrfs scrub start -BRd /mnt This is because readahead would skip missing device, this is not true for RAID5/6, because REQ_GET_READ_MIRRORS return 1 for RAID5/6 block mapping. If expected data locates in missing device, readahead thread would not call __readahead_hook() which makes event @rc->elems=0 wait forever. Fix this problem by checking return value of btrfs_map_block(),we can only skip missing device safely if there are several mirrors. Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: new ioctl TREE_SEARCH_V2Gerhard Heift2014-06-132-0/+51
| | | | | | | | | | | | This new ioctl call allows the user to supply a buffer of varying size in which a tree search can store its results. This is much more flexible if you want to receive items which are larger than the current fixed buffer of 3992 bytes or if you want to fetch more items at once. Items larger than this buffer are for example some of the type EXTENT_CSUM. Signed-off-by: Gerhard Heift <Gerhard@Heift.Name> Signed-off-by: Chris Mason <clm@fb.com> Acked-by: David Sterba <dsterba@suse.cz>
* btrfs: tree_search, search_ioctl: direct copy to userspaceGerhard Heift2014-06-131-15/+33
| | | | | | | | | By copying each found item seperatly to userspace, we do not need extra buffer in the kernel. Signed-off-by: Gerhard Heift <Gerhard@Heift.Name> Signed-off-by: Chris Mason <clm@fb.com> Acked-by: David Sterba <dsterba@suse.cz>
* btrfs: new function read_extent_buffer_to_userGerhard Heift2014-06-132-0/+40
| | | | | | | | This new function reads the content of an extent directly to user memory. Signed-off-by: Gerhard Heift <Gerhard@Heift.Name> Signed-off-by: Chris Mason <clm@fb.com> Acked-by: David Sterba <dsterba@suse.cz>
* btrfs: tree_search, copy_to_sk: return needed size on EOVERFLOWGerhard Heift2014-06-131-9/+15
| | | | | | | | | If an item in tree_search is too large to be stored in the given buffer, return the needed size (including the header). Signed-off-by: Gerhard Heift <Gerhard@Heift.Name> Signed-off-by: Chris Mason <clm@fb.com> Acked-by: David Sterba <dsterba@suse.cz>
* btrfs: tree_search, copy_to_sk: return EOVERFLOW for too small bufferGerhard Heift2014-06-131-2/+26
| | | | | | | | | | | | | | In copy_to_sk, if an item is too large for the given buffer, it now returns -EOVERFLOW instead of copying a search_header with len = 0. For backward compatibility for the first item it still copies such a header to the buffer, but not any other following items, which could have fitted. tree_search changes -EOVERFLOW back to 0 to behave similiar to the way it behaved before this patch. Signed-off-by: Gerhard Heift <Gerhard@Heift.Name> Signed-off-by: Chris Mason <clm@fb.com> Acked-by: David Sterba <dsterba@suse.cz>
* btrfs: tree_search, search_ioctl: accept varying bufferGerhard Heift2014-06-131-7/+11
| | | | | | | | rewrite search_ioctl to accept a buffer with varying size Signed-off-by: Gerhard Heift <Gerhard@Heift.Name> Signed-off-by: Chris Mason <clm@fb.com> Acked-by: David Sterba <dsterba@suse.cz>
* btrfs: tree_search: eliminate redundant nr_items checkGerhard Heift2014-06-131-5/+7
| | | | | | | | | | If the amount of items reached the given limit of nr_items, we can leave copy_to_sk without updating the key. Also by returning 1 we leave the loop in search_ioctl without rechecking if we reached the given limit. Signed-off-by: Gerhard Heift <Gerhard@Heift.Name> Signed-off-by: Chris Mason <clm@fb.com> Acked-by: David Sterba <dsterba@suse.cz>
* Btrfs: convert smp_mb__{before,after}_clear_bitChris Mason2014-06-101-2/+2
| | | | | | | The new call is smp_mb__{before,after}_atomic. The __ gives us extra protection from the atomic rays. Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: fix scrub_print_warning to handle skinny metadata extentsLiu Bo2014-06-103-15/+24
| | | | | | | | | The skinny extents are intepreted incorrectly in scrub_print_warning(), and end up hitting the BUG() in btrfs_extent_inline_ref_size. Reported-by: Konstantinos Skarlatos <k.skarlatos@gmail.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: make fsync work after cloning into a fileFilipe Manana2014-06-104-38/+155
| | | | | | | | | | | | | | | | When cloning into a file, we were correctly replacing the extent items in the target range and removing the extent maps. However we weren't replacing the extent maps with new ones that point to the new extents - as a consequence, an incremental fsync (when the inode doesn't have the full sync flag) was a NOOP, since it relies on the existence of extent maps in the modified list of the inode's extent map tree, which was empty. Therefore add new extent maps to reflect the target clone range. A test case for xfstests follows. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: use right type to get real comparisonLiu Bo2014-06-101-1/+1
| | | | | | | | We want to make sure the point is still within the extent item, not to verify the memory it's pointing to. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: don't check nodes for extent itemsJosef Bacik2014-06-101-2/+3
| | | | | | | | | | | The backref code was looking at nodes as well as leaves when we tried to populate extent item entries. This is not good, and although we go away with it for the most part because we'd skip where disk_bytenr != random_memory, sometimes random_memory would match and suddenly boom. This fixes that problem. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: don't release invalid page in btrfs_page_exists_in_range()Filipe Manana2014-06-101-0/+1
| | | | | | | | | | | In inode.c:btrfs_page_exists_in_range(), if the page we got from the radix tree is an exception entry, which can't be retried, we exit the loop with a non-NULL page and then call page_cache_release against it, which is not ok since it's not a valid page. This could also make us return true when we shouldn't. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: make sure we retry if page is a retriable exceptionFilipe Manana2014-06-101-1/+3
| | | | | | | | | | | | | In inode.c:btrfs_page_exists_in_range(), if the page we get from the radix tree is an exception which should make us retry, set page to NULL in order to really retry, because otherwise we don't get another loop iteration executed (page != NULL makes the while loop exit). This also was making us call page_cache_release after exiting the loop, which isn't correct because page doesn't point to a valid page, and possibly return true from the function when we shouldn't. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: make sure we retry if we couldn't get the pageFilipe Manana2014-06-101-1/+3
| | | | | | | | | | | | In inode.c:btrfs_page_exists_in_range(), if we can't get the page we need to retry. However we weren't retrying because we weren't setting page to NULL, which makes the while loop exit immediately and will make us call page_cache_release after exiting the loop which is incorrect because our page get didn't succeed. This could also make us return true when we shouldn't. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: replace EINVAL with EOPNOTSUPP for dev_replace raid56Gui Hecheng2014-06-101-1/+1
| | | | | | | | | | To return EOPNOTSUPP is more user friendly than to return EINVAL, and then user-space tool will show that the dev_replace operation for raid56 is not currently supported rather than showing that there is an invalid argument. Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
* trivial: fs/btrfs/ioctl.c: fix typo s/substract/subtract/Antonio Ospite2014-06-101-2/+2
| | | | | | | | Signed-off-by: Antonio Ospite <ao2@ao2.it> Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <jbacik@fb.com> Cc: linux-btrfs@vger.kernel.org Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: fix leaf corruption after __btrfs_drop_extentsLiu Bo2014-06-101-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Several reports about leaf corruption has been floating on the list, one of them points to __btrfs_drop_extents(), and we find that the leaf becomes corrupted after __btrfs_drop_extents(), it's really a rare case but it does exist. The problem turns out to be btrfs_next_leaf() called in __btrfs_drop_extents(). So in btrfs_next_leaf(), we release the current path to re-search the last key of the leaf for locating next leaf, and we've taken it into account that there might be balance operations between leafs during this 'unlock and re-lock' dance, so we check the path again and advance it if there are now more items available. But things are a bit different if that last key happens to be removed and balance gets a bigger key as the last one, and btrfs_search_slot will return it with ret > 0, IOW, nothing change in this leaf except the new last key, then we think we're okay because there is no more item balanced in, fine, we thinks we can go to the next leaf. However, we should return that bigger key, otherwise we deserve leaf corruption, for example, in endio, skipping that key means that __btrfs_drop_extents() thinks it has dropped all extent matched the required range and finish_ordered_io can safely insert a new extent, but it actually doesn't and ends up a leaf corruption. One may be asking that why our locking on extent io tree doesn't work as expected, ie. it should avoid this kind of race situation. But in __btrfs_drop_extents(), we don't always find extents which are included within our locking range, IOW, extents can start before our searching start, in this case locking on extent io tree doesn't protect us from the race. This takes the special case into account. Reviewed-by: Filipe Manana <fdmanana@gmail.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: ensure btrfs_prev_leaf doesn't miss 1 itemFilipe Manana2014-06-101-1/+11
| | | | | | | | | | | | | | We might have had an item with the previous key in the tree right before we released our path. And after we released our path, that item might have been pushed to the first slot (0) of the leaf we were holding due to a tree balance. Alternatively, an item with the previous key can exist as the only element of a leaf (big fat item). Therefore account for these 2 cases, so that our callers (like btrfs_previous_item) don't miss an existing item with a key matching the previous key we computed above. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: fix clone to deal with holes when NO_HOLES feature is enabledFilipe Manana2014-06-101-25/+83
| | | | | | | | | | | | | | If the NO_HOLES feature is enabled holes don't have file extent items in the btree that represent them anymore. This made the clone operation ignore the gaps that exist between consecutive file extent items and therefore not create the holes at the destination. When not using the NO_HOLES feature, the holes were created at the destination. A test case for xfstests follows. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: free delayed node outside of root->inode_lockJeff Mahoney2014-06-101-2/+5
| | | | | | | | | | On heavy workloads, we're seeing soft lockup warnings on root->inode_lock in __btrfs_release_delayed_node. The low hanging fruit is to reduce the size of the critical section. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: replace EINVAL with ERANGE for resize when ULLONG_MAXGui Hecheng2014-06-101-1/+1
| | | | | | | | To be accurate about the error case, if the new size is beyond ULLONG_MAX, return ERANGE instead of EINVAL. Signed-off-by: Gui Hecheng <guihc.fnst@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: fix transaction leak during fsync callFilipe Manana2014-06-101-1/+3
| | | | | | | | | | | | If btrfs_log_dentry_safe() returns an error, we set ret to 1 and fall through with the goal of committing the transaction. However, in the case where the inode doesn't need a full sync, we would call btrfs_wait_ordered_range() against the target range for our inode, and if it returned an error, we would return without commiting or ending the transaction. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: Avoid trucating page or punching hole in a already existed hole.Qu Wenruo2014-06-101-14/+98
| | | | | | | | | | | | | btrfs_punch_hole() will truncate unaligned pages or punch hole on a already existed hole. This will cause unneeded zero page or holes splitting the original huge hole. This patch will skip already existed holes before any page truncating or hole punching. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: update commit root on snapshot creation after orphan cleanupFilipe Manana2014-06-101-0/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On snapshot creation (either writable or read-only), we do orphan cleanup against the root of the snapshot. If the cleanup did remove any orphans, then the current root node will be different from the commit root node until the next transaction commit happens. A send operation always uses the commit root of a snapshot - this means it will see the orphans if it starts computing the send stream before the next transaction commit happens (triggered by a timer or sync() for .e.g), which is when the commit root gets assigned a reference to current root, where the orphans are not visible anymore. The consequence of send seeing the orphans is explained below. For example: mkfs.btrfs -f /dev/sdd mount -o commit=999 /dev/sdd /mnt # open a file with O_TMPFILE and leave it open # write some data to the file btrfs subvolume snapshot -r /mnt /mnt/snap1 btrfs send /mnt/snap1 -f /tmp/send.data The send operation will fail with the following error: ERROR: send ioctl failed with -116: Stale file handle What happens here is that our snapshot has an orphan inode still visible through the commit root, that corresponds to the tmpfile. However send will attempt to call inode.c:btrfs_iget(), with the goal of reading the file's data, which will return -ESTALE because it will use the current root (and not the commit root) of the snapshot. Of course, there are other cases where we can get orphans, but this example using a tmpfile makes it much easier to reproduce the issue. Therefore on snapshot creation, after calling btrfs_orphan_cleanup, if the commit root is different from the current root, just commit the transaction associated with the snapshot's root (if it exists), so that a send will not see any orphans that don't exist anymore. This also guarantees a send will always see the same content regardless of whether a transaction commit happened already before the send was requested and after the orphan cleanup (meaning the commit root and current roots are the same) or it hasn't happened yet (commit and current roots are different). Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: ioctl, don't re-lock extent range when not necessaryFilipe Manana2014-06-101-2/+7
| | | | | | | | | | | | | | | | | In ioctl.c:lock_extent_range(), after locking our target range, the ordered extent that btrfs_lookup_first_ordered_extent() returns us may not overlap our target range at all. In this case we would just unlock our target range, wait for any new ordered extents that overlap the range to complete, lock again the range and repeat all these steps until we don't get any ordered extent and the delalloc flag isn't set in the io tree for our target range. Therefore just stop if we get an ordered extent that doesn't overlap our target range and the dealalloc flag isn't set for the range in the inode's io tree. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: avoid visiting all extent items when cloning a rangeFilipe Manana2014-06-101-4/+22
| | | | | | | | | | | When cloning a range of a file, we were visiting all the extent items in the btree that belong to our source inode. We don't need to visit those extent items that don't overlap the range we are cloning, as doing so only makes us waste time and do unnecessary btree navigations (btrfs_next_leaf) for inodes that have a large number of file extent items in the btree. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: set dead flag on the right root when destroying snapshotFilipe Manana2014-06-101-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | We were setting the BTRFS_ROOT_SUBVOL_DEAD flag on the root of the parent of our target snapshot, instead of setting it in the target snapshot's root. This is easy to observe by running the following scenario: mkfs.btrfs -f /dev/sdd mount /dev/sdd /mnt btrfs subvolume create /mnt/first_subvol btrfs subvolume snapshot -r /mnt /mnt/mysnap1 btrfs subvolume delete /mnt/first_subvol btrfs subvolume snapshot -r /mnt /mnt/mysnap2 btrfs send -p /mnt/mysnap1 /mnt/mysnap2 -f /tmp/send.data The send command failed because the send ioctl returned -EPERM. A test case for xfstests follows. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: ensure readers see new data after a clone operationFilipe Manana2014-06-101-5/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We were cleaning the clone target file range from the page cache before we did replace the file extent items in the fs tree. This was racy, as right after cleaning the relevant range from the page cache and before replacing the file extent items, a read against that range could be performed by another task and populate again the page cache with stale data (stale after the cloning finishes). This would result in reads after the clone operation successfully finishes to get old data (and potentially for a very long time). Therefore evict the pages after replacing the file extent items, so that subsequent reads will always get the new data. Similarly, we were prone to races while cloning the file extent items because we weren't locking the target range and wait for any existing ordered extents against that range to complete. It was possible that after cloning the extent items, a write operation that was performed before the clone operation and overlaps the same range, would end up undoing all or part of the work the clone operation did (a worker task running inode.c:btrfs_finish_ordered_io). Therefore lock the target range in the io tree, wait for all pending ordered extents against that range to finish and then safely perform the cloning. The issue of reading stale data after the clone operation is easy to reproduce by running the following C program in a loop until it exits with return value 1. #include <unistd.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <errno.h> #include <pthread.h> #include <fcntl.h> #include <assert.h> #include <asm/types.h> #include <linux/ioctl.h> #include <sys/stat.h> #include <sys/types.h> #include <sys/ioctl.h> #define SRC_FILE "/mnt/sdd/foo" #define DST_FILE "/mnt/sdd/bar" #define FILE_SIZE (16 * 1024) #define PATTERN_SRC 'X' #define PATTERN_DST 'Y' struct btrfs_ioctl_clone_range_args { __s64 src_fd; __u64 src_offset, src_length; __u64 dest_offset; }; #define BTRFS_IOCTL_MAGIC 0x94 #define BTRFS_IOC_CLONE_RANGE _IOW(BTRFS_IOCTL_MAGIC, 13, \ struct btrfs_ioctl_clone_range_args) static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER; static int clone_done = 0; static int reader_ready = 0; static int stale_data = 0; static void *reader_loop(void *arg) { char buf[4096], want_buf[4096]; memset(want_buf, PATTERN_SRC, 4096); pthread_mutex_lock(&mutex); reader_ready = 1; pthread_mutex_unlock(&mutex); while (1) { int done, fd, ret; fd = open(DST_FILE, O_RDONLY); assert(fd != -1); pthread_mutex_lock(&mutex); done = clone_done; pthread_mutex_unlock(&mutex); ret = read(fd, buf, 4096); assert(ret == 4096); close(fd); if (done) { ret = memcmp(buf, want_buf, 4096); if (ret == 0) { printf("Found new content\n"); } else { printf("Found old content\n"); pthread_mutex_lock(&mutex); stale_data = 1; pthread_mutex_unlock(&mutex); } break; } } return NULL; } int main(int argc, char *argv[]) { pthread_t reader; int ret, i, fd; struct btrfs_ioctl_clone_range_args clone_args; int fd1, fd2; ret = remove(SRC_FILE); if (ret == -1 && errno != ENOENT) { fprintf(stderr, "Error deleting src file: %s\n", strerror(errno)); return 1; } ret = remove(DST_FILE); if (ret == -1 && errno != ENOENT) { fprintf(stderr, "Error deleting dst file: %s\n", strerror(errno)); return 1; } fd = open(SRC_FILE, O_CREAT | O_WRONLY | O_TRUNC, S_IRWXU); assert(fd != -1); for (i = 0; i < FILE_SIZE; i++) { char c = PATTERN_SRC; ret = write(fd, &c, 1); assert(ret == 1); } close(fd); fd = open(DST_FILE, O_CREAT | O_WRONLY | O_TRUNC, S_IRWXU); assert(fd != -1); for (i = 0; i < FILE_SIZE; i++) { char c = PATTERN_DST; ret = write(fd, &c, 1); assert(ret == 1); } close(fd); sync(); ret = pthread_create(&reader, NULL, reader_loop, NULL); assert(ret == 0); while (1) { int r; pthread_mutex_lock(&mutex); r = reader_ready; pthread_mutex_unlock(&mutex); if (r) break; } fd1 = open(SRC_FILE, O_RDONLY); if (fd1 < 0) { fprintf(stderr, "Error open src file: %s\n", strerror(errno)); return 1; } fd2 = open(DST_FILE, O_RDWR); if (fd2 < 0) { fprintf(stderr, "Error open dst file: %s\n", strerror(errno)); return 1; } clone_args.src_fd = fd1; clone_args.src_offset = 0; clone_args.src_length = 4096; clone_args.dest_offset = 0; ret = ioctl(fd2, BTRFS_IOC_CLONE_RANGE, &clone_args); assert(ret == 0); close(fd1); close(fd2); pthread_mutex_lock(&mutex); clone_done = 1; pthread_mutex_unlock(&mutex); ret = pthread_join(reader, NULL); assert(ret == 0); pthread_mutex_lock(&mutex); ret = stale_data ? 1 : 0; pthread_mutex_unlock(&mutex); return ret; } Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Chris Mason <clm@fb.com>
* fs: btrfs: volumes.c: Fix for possible null pointer dereferenceRickard Strandqvist2014-06-101-2/+3
| | | | | | | | | There is otherwise a risk of a possible null pointer dereference. Was largely found by using a static code analysis program called cppcheck. Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: allocate raid type kobjects dynamicallyJeff Mahoney2014-06-103-16/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | We are currently allocating space_info objects in an array when we allocate space_info. When a user does something like: # btrfs balance start -mconvert=raid1 -dconvert=raid1 /mnt # btrfs balance start -mconvert=single -dconvert=single /mnt -f # btrfs balance start -mconvert=raid1 -dconvert=raid1 / We can end up with memory corruption since the kobject hasn't been reinitialized properly and the name pointer was left set. The rationale behind allocating them statically was to avoid creating a separate kobject container that just contained the raid type. It used the index in the array to determine the index. Ultimately, though, this wastes more memory than it saves in all but the most complex scenarios and introduces kobject lifetime questions. This patch allocates the kobjects dynamically instead. Note that we also remove the kobject_get/put of the parent kobject since kobject_add and kobject_del do that internally. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reported-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: send, use the right limits for xattr names and valuesFilipe Manana2014-06-101-7/+23
| | | | | | | | | | | | | | | | We were limiting the sum of the xattr name and value lengths to PATH_MAX, which is not correct, specially on filesystems created with btrfs-progs v3.12 or higher, where the default leaf size is max(16384, PAGE_SIZE), or systems with page sizes larger than 4096 bytes. Xattrs have their own specific maximum name and value lengths, which depend on the leaf size, therefore use these limits to be able to send xattrs with sizes larger than PATH_MAX. A test case for xfstests follows. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: send, don't error in the presence of subvols/snapshotsFilipe Manana2014-06-101-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we are doing an incremental send and the base snapshot has a directory with name X that doesn't exist anymore in the second snapshot and a new subvolume/snapshot exists in the second snapshot that has the same name as the directory (name X), the incremental send would fail with -ENOENT error. This is because it attempts to lookup for an inode with a number matching the objectid of a root, which doesn't exist. Steps to reproduce: mkfs.btrfs -f /dev/sdd mount /dev/sdd /mnt mkdir /mnt/testdir btrfs subvolume snapshot -r /mnt /mnt/mysnap1 rmdir /mnt/testdir btrfs subvolume create /mnt/testdir btrfs subvolume snapshot -r /mnt /mnt/mysnap2 btrfs send -p /mnt/mysnap1 /mnt/mysnap2 -f /tmp/send.data A test case for xfstests follows. Reported-by: Robert White <rwhite@pobox.com> Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: async delayed refsChris Mason2014-06-105-3/+107
| | | | | | | | | | | | Delayed extent operations are triggered during transaction commits. The goal is to queue up a healthly batch of changes to the extent allocation tree and run through them in bulk. This farms them off to async helper threads. The goal is to have the bulk of the delayed operations being done in the background, but this is also important to limit our stack footprint. Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: split up __extent_writepage to lower stack usageChris Mason2014-06-102-138/+194
| | | | | | | | | | | __extent_writepage has two unrelated parts. First it does the delayed allocation dance and second it does the mapping and IO for the page we're actually writing. This splits it up into those two parts so the stack from one doesn't impact the stack from the other. Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: Drop EXTENT_UPTODATE check in hole punching and direct lockingAlex Gartrell2014-06-103-7/+71
| | | | | | | | | | | | | | | In these instances, we are trying to determine if a page has been accessed since we began the operation for the sake of retry. This is easily accomplished by doing a gang lookup in the page mapping radix tree, and it saves us the dependency on the flag (so that we might eventually delete it). btrfs_page_exists_in_range borrows heavily from find_get_page, replacing the radix tree look up with a gang lookup of 1, so that we can find the next highest page >= index and see if it falls into our lock range. Signed-off-by: Chris Mason <clm@fb.com> Signed-off-by: Alex Gartrell <agartrell@fb.com>
* Btrfs: cut down stack usage in btree_write_cache_pagesChris Mason2014-06-101-4/+5
| | | | | | | | This adds noinline_for_stack to two helpers used by btree_write_cache_pages. It shaves us down from 424 bytes on the stack to 280. Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: break up __btrfs_write_out_cache to cut down stack usageChris Mason2014-06-101-117/+191
| | | | | | | __btrfs_write_out_cache was one of our stack pigs. This breaks it up into helper functions and slims it down to 194 bytes. Signed-off-by: Chris Mason <clm@fb.com>
* Btrfs: free tmp ulist for qgroup rescanJosef Bacik2014-06-101-0/+1
| | | | | | | Memory leaks are bad mmkay? Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: usage error should not be logged into system logAnand Jain2014-06-101-4/+1Star
| | | | | | | | | | | | | I have an opinion that system logs /var/log/messages are valuable info to investigate the real system issues at the data center. People handling data center issues do spend a lot time and efforts analyzing messages files. Having usage error logged into /var/log/messages is something we should avoid. Signed-off-by: Anand Jain <Anand.Jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
* btrfs: remove newline from inode cache kthread nameDavid Sterba2014-06-101-1/+1
| | | | | Signed-off-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>