Since tree-checker has verified leaf when reading from disk, we don't
need the existing verify_dir_item() or btrfs_is_name_len_valid() checks.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Under some circumstances, an incremental send operation can issue wrong
paths for unlink commands related to files that have multiple hard links
and some (or all) of those links were renamed between the parent and send
snapshots. Consider the following example:
Parent snapshot
. (ino 256)
|---- a/ (ino 257)
| |---- b/ (ino 259)
| | |---- c/ (ino 260)
| | |---- f2 (ino 261)
| |
| |---- f2l1 (ino 261)
|
|---- d/ (ino 262)
|---- f1l1_2 (ino 258)
|---- f2l2 (ino 261)
|---- f1_2 (ino 258)
Send snapshot
. (ino 256)
|---- a/ (ino 257)
| |---- f2l1/ (ino 263)
| |---- b2/ (ino 259)
| |---- c/ (ino 260)
| | |---- d3 (ino 262)
| | |---- f1l1_2 (ino 258)
| | |---- f2l2_2 (ino 261)
| | |---- f1_2 (ino 258)
| |
| |---- f2 (ino 261)
| |---- f1l2 (ino 258)
|
|---- d (ino 261)
When computing the incremental send stream the following steps happen:
1) When processing inode 261, a rename operation is issued that renames
inode 262, which currently as a path of "d", to an orphan name of
"o262-7-0". This is done because in the send snapshot, inode 261 has
of its hard links with a path of "d" as well.
2) Two link operations are issued that create the new hard links for
inode 261, whose names are "d" and "f2l2_2", at paths "/" and
"o262-7-0/" respectively.
3) Still while processing inode 261, unlink operations are issued to
remove the old hard links of inode 261, with names "f2l1" and "f2l2",
at paths "a/" and "d/". However path "d/" does not correspond anymore
to the directory inode 262 but corresponds instead to a hard link of
inode 261 (link command issued in the previous step). This makes the
receiver fail with a ENOTDIR error when attempting the unlink
operation.
The problem happens because before sending the unlink operation, we failed
to detect that inode 262 was one of ancestors for inode 261 in the parent
snapshot, and therefore we didn't recompute the path for inode 262 before
issuing the unlink operation for the link named "f2l2" of inode 262. The
detection failed because the function "is_ancestor()" only follows the
first hard link it finds for an inode instead of all of its hard links
(as it was originally created for being used with directories only, for
which only one hard link exists). So fix this by making "is_ancestor()"
follow all hard links of the input inode.
A test case for fstests follows soon.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The LOGICAL_INO ioctl provides a backward mapping from extent bytenr and
offset (encoded as a single logical address) to a list of extent refs.
LOGICAL_INO complements TREE_SEARCH, which provides the forward mapping
(extent ref -> extent bytenr and offset, or logical address). These are
useful capabilities for programs that manipulate extents and extent
references from userspace (e.g. dedup and defrag utilities).
When the extents are uncompressed (and not encrypted and not other),
check_extent_in_eb performs filtering of the extent refs to remove any
extent refs which do not contain the same extent offset as the 'logical'
parameter's extent offset. This prevents LOGICAL_INO from returning
references to more than a single block.
To find the set of extent references to an uncompressed extent from [a, b),
userspace has to run a loop like this pseudocode:
for (i = a; i < b; ++i)
extent_ref_set += LOGICAL_INO(i);
At each iteration of the loop (up to 32768 iterations for a 128M extent),
data we are interested in is collected in the kernel, then deleted by
the filter in check_extent_in_eb.
When the extents are compressed (or encrypted or other), the 'logical'
parameter must be an extent bytenr (the 'a' parameter in the loop).
No filtering by extent offset is done (or possible?) so the result is
the complete set of extent refs for the entire extent. This removes
the need for the loop, since we get all the extent refs in one call.
Add an 'ignore_offset' argument to iterate_inodes_from_logical,
[...several levels of function call graph...], and check_extent_in_eb, so
that we can disable the extent offset filtering for uncompressed extents.
This flag can be set by an improved version of the LOGICAL_INO ioctl to
get either behavior as desired.
There is no functional change in this patch. The new flag is always
false.
Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor coding style fixes ]
Signed-off-by: David Sterba <dsterba@suse.com>
This code was first introduced in 31db9f7c23 ("Btrfs: introduce
BTRFS_IOC_SEND for btrfs send/receive") and it was not functional, then
it got slightly refactored in e938c8ad54 ("Btrfs: code cleanups for
send/receive"), alas it was still dead. So let's remove it for good!
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We pass in a pointer in our send arg struct, this means the struct size
doesn't match with 32bit user space and 64bit kernel space. Fix this by
adding a compat mode and doing the appropriate conversion.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ move structure to the beginning, next to receive 32bit compat ]
Signed-off-by: David Sterba <dsterba@suse.com>
By analyzing the perf on btrfs send, we found it take large amount of
cpu time on page_cache_sync_readahead. This effort can be reduced after
switching to asynchronous one. Overall performance gain on HDD and SSD
were 9 and 15 percent if simply send a large file.
Signed-off-by: Kuanling Huang <peterh@synology.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_changed_cb_t represents the signature of the callback being passed
to btrfs_compare_trees. Currently there is only one such callback,
namely changed_cb in send.c. This function doesn't really uses the first
2 parameters, i.e. the roots. Since there are not other functions
implementing the btrfs_changed_cb_t let's remove the unused parameters
from the prototype and implementation.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
iterate_dir_item:found_key - introduced in 31db9f7c23 ("Btrfs:
introduce BTRFS_IOC_SEND for btrfs send/receive"), yet never used.
record_ref:num - ditto
This is a first pass with the low-hanging fruit. There are still quite a
few unsued parameters in some function which have to abide by a callback
interface.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Pull btrfs fixes from David Sterba:
"We've collected a bunch of isolated fixes, for crashes, user-visible
behaviour or missing bits from other subsystem cleanups from the past.
The overall number is not small but I was not able to make it
significantly smaller. Most of the patches are supposed to go to
stable"
* 'for-4.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: log csums for all modified extents
Btrfs: fix unexpected result when dio reading corrupted blocks
btrfs: Report error on removing qgroup if del_qgroup_item fails
Btrfs: skip checksum when reading compressed data if some IO have failed
Btrfs: fix kernel oops while reading compressed data
Btrfs: use btrfs_op instead of bio_op in __btrfs_map_block
Btrfs: do not backup tree roots when fsync
btrfs: remove BTRFS_FS_QUOTA_DISABLING flag
btrfs: propagate error to btrfs_cmp_data_prepare caller
btrfs: prevent to set invalid default subvolid
Btrfs: send: fix error number for unknown inode types
btrfs: fix NULL pointer dereference from free_reloc_roots()
btrfs: finish ordered extent cleaning if no progress is found
btrfs: clear ordered flag on cleaning up ordered extents
Btrfs: fix incorrect {node,sector}size endianness from BTRFS_IOC_FS_INFO
Btrfs: do not reset bio->bi_ops while writing bio
Btrfs: use the new helper wbc_to_write_flags
ENOTSUPP should not be returned to the user program.
(cf. include/linux/errno.h)
Therefore, EOPNOTSUPP is used instead of ENOTSUPP.
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Pull more set_fs removal from Al Viro:
"Christoph's 'use kernel_read and friends rather than open-coding
set_fs()' series"
* 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs: unexport vfs_readv and vfs_writev
fs: unexport vfs_read and vfs_write
fs: unexport __vfs_read/__vfs_write
lustre: switch to kernel_write
gadget/f_mass_storage: stop messing with the address limit
mconsole: switch to kernel_read
btrfs: switch write_buf to kernel_write
net/9p: switch p9_fd_read to kernel_write
mm/nommu: switch do_mmap_private to kernel_read
serial2002: switch serial2002_tty_write to kernel_{read/write}
fs: make the buf argument to __kernel_write a void pointer
fs: fix kernel_write prototype
fs: fix kernel_read prototype
fs: move kernel_read to fs/read_write.c
fs: move kernel_write to fs/read_write.c
autofs4: switch autofs4_write to __kernel_write
ashmem: switch to ->read_iter
Instead of playing with the addressing limits.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
When doing an incremental send it's possible that the computed send stream
contains clone operations that will fail on the receiver if the receiver
has compression enabled and the clone operations target a sector sized
extent that starts at a zero file offset, is not compressed on the source
filesystem but ends up being compressed and inlined at the destination
filesystem.
Example scenario:
$ mkfs.btrfs -f /dev/sdb
$ mount -o compress /dev/sdb /mnt
# By doing a direct IO write, the data is not compressed.
$ xfs_io -f -d -c "pwrite -S 0xab 0 4K" /mnt/foobar
$ btrfs subvolume snapshot -r /mnt /mnt/mysnap1
$ xfs_io -c "reflink /mnt/foobar 0 8K 4K" /mnt/foobar
$ btrfs subvolume snapshot -r /mnt /mnt/mysnap2
$ btrfs send -f /tmp/1.snap /mnt/mysnap1
$ btrfs send -f /tmp/2.snap -p /mnt/mysnap1 /mnt/mysnap2
$ umount /mnt
$ mkfs.btrfs -f /dev/sdc
$ mount -o compress /dev/sdc /mnt
$ btrfs receive -f /tmp/1.snap /mnt
$ btrfs receive -f /tmp/2.snap /mnt
ERROR: failed to clone extents to foobar
Operation not supported
The same could be achieved by mounting the source filesystem without
compression and doing a buffered IO write instead of a direct IO one,
and mounting the destination filesystem with compression enabled.
So fix this by issuing regular write operations in the send stream
instead of clone operations when the source offset is zero and the
range has a length matching the sector size.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When doing an incremental send, while processing an extent that changed
between the parent and send snapshots and that extent was an inline extent
in the parent snapshot, it's possible to access a memory region beyond
the end of leaf if the inline extent is very small and it is the first
item in a leaf.
An example scenario is described below.
The send snapshot has the following leaf:
leaf 33865728 items 33 free space 773 generation 46 owner 5
fs uuid ab7090d8-dafd-4fb9-9246-723b6d2e2fb7
chunk uuid 2d16478c-c704-4ab9-b574-68bff2281b1f
(...)
item 14 key (335 EXTENT_DATA 0) itemoff 3052 itemsize 53
generation 36 type 1 (regular)
extent data disk byte 12791808 nr 4096
extent data offset 0 nr 4096 ram 4096
extent compression 0 (none)
item 15 key (335 EXTENT_DATA 8192) itemoff 2999 itemsize 53
generation 36 type 1 (regular)
extent data disk byte 138170368 nr 225280
extent data offset 0 nr 225280 ram 225280
extent compression 0 (none)
(...)
And the parent snapshot has the following leaf:
leaf 31272960 items 17 free space 17 generation 31 owner 5
fs uuid ab7090d8-dafd-4fb9-9246-723b6d2e2fb7
chunk uuid 2d16478c-c704-4ab9-b574-68bff2281b1f
item 0 key (335 EXTENT_DATA 0) itemoff 3951 itemsize 44
generation 31 type 0 (inline)
inline extent data size 23 ram_bytes 613 compression 1 (zlib)
(...)
When computing the send stream, it is detected that the extent of inode
335, at file offset 0, and at fs/btrfs/send.c:is_extent_unchanged() we
grab the leaf from the parent snapshot and access the inline extent item.
However, before jumping to the 'out' label, we access the 'offset' and
'disk_bytenr' fields of the extent item, which should not be done for
inline extents since the inlined data starts at the offset of the
'disk_bytenr' field and can be very small. For example accessing the
'offset' field of the file extent item results in the following trace:
[ 599.705368] general protection fault: 0000 [#1] PREEMPT SMP
[ 599.706296] Modules linked in: btrfs psmouse i2c_piix4 ppdev acpi_cpufreq serio_raw parport_pc i2c_core evdev tpm_tis tpm_tis_core sg pcspkr parport tpm button su$
[ 599.709340] CPU: 7 PID: 5283 Comm: btrfs Not tainted 4.10.0-rc8-btrfs-next-46+ #1
[ 599.709340] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014
[ 599.709340] task: ffff88023eedd040 task.stack: ffffc90006658000
[ 599.709340] RIP: 0010:read_extent_buffer+0xdb/0xf4 [btrfs]
[ 599.709340] RSP: 0018:ffffc9000665ba00 EFLAGS: 00010286
[ 599.709340] RAX: db73880000000000 RBX: 0000000000000000 RCX: 0000000000000001
[ 599.709340] RDX: ffffc9000665ba60 RSI: db73880000000000 RDI: ffffc9000665ba5f
[ 599.709340] RBP: ffffc9000665ba30 R08: 0000000000000001 R09: ffff88020dc5e098
[ 599.709340] R10: 0000000000001000 R11: 0000160000000000 R12: 6db6db6db6db6db7
[ 599.709340] R13: ffff880000000000 R14: 0000000000000000 R15: ffff88020dc5e088
[ 599.709340] FS: 00007f519555a8c0(0000) GS:ffff88023f3c0000(0000) knlGS:0000000000000000
[ 599.709340] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 599.709340] CR2: 00007f1411afd000 CR3: 0000000235f8e000 CR4: 00000000000006e0
[ 599.709340] Call Trace:
[ 599.709340] btrfs_get_token_64+0x93/0xce [btrfs]
[ 599.709340] ? printk+0x48/0x50
[ 599.709340] btrfs_get_64+0xb/0xd [btrfs]
[ 599.709340] process_extent+0x3a1/0x1106 [btrfs]
[ 599.709340] ? btree_read_extent_buffer_pages+0x5/0xef [btrfs]
[ 599.709340] changed_cb+0xb03/0xb3d [btrfs]
[ 599.709340] ? btrfs_get_token_32+0x7a/0xcc [btrfs]
[ 599.709340] btrfs_compare_trees+0x432/0x53d [btrfs]
[ 599.709340] ? process_extent+0x1106/0x1106 [btrfs]
[ 599.709340] btrfs_ioctl_send+0x960/0xe26 [btrfs]
[ 599.709340] btrfs_ioctl+0x181b/0x1fed [btrfs]
[ 599.709340] ? trace_hardirqs_on_caller+0x150/0x1ac
[ 599.709340] vfs_ioctl+0x21/0x38
[ 599.709340] ? vfs_ioctl+0x21/0x38
[ 599.709340] do_vfs_ioctl+0x611/0x645
[ 599.709340] ? rcu_read_unlock+0x5b/0x5d
[ 599.709340] ? __fget+0x6d/0x79
[ 599.709340] SyS_ioctl+0x57/0x7b
[ 599.709340] entry_SYSCALL_64_fastpath+0x18/0xad
[ 599.709340] RIP: 0033:0x7f51945eec47
[ 599.709340] RSP: 002b:00007ffc21c13e98 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
[ 599.709340] RAX: ffffffffffffffda RBX: ffffffff81096459 RCX: 00007f51945eec47
[ 599.709340] RDX: 00007ffc21c13f20 RSI: 0000000040489426 RDI: 0000000000000004
[ 599.709340] RBP: ffffc9000665bf98 R08: 00007f519450d700 R09: 00007f519450d700
[ 599.709340] R10: 00007f519450d9d0 R11: 0000000000000202 R12: 0000000000000046
[ 599.709340] R13: ffffc9000665bf78 R14: 0000000000000000 R15: 00007f5195574040
[ 599.709340] ? trace_hardirqs_off_caller+0x43/0xb1
[ 599.709340] Code: 29 f0 49 39 d8 4c 0f 47 c3 49 03 81 58 01 00 00 44 89 c1 4c 01 c2 4c 29 c3 48 c1 f8 03 49 0f af c4 48 c1 e0 0c 4c 01 e8 48 01 c6 <f3> a4 31 f6 4$
[ 599.709340] RIP: read_extent_buffer+0xdb/0xf4 [btrfs] RSP: ffffc9000665ba00
[ 599.762057] ---[ end trace fe00d7af61b9f49e ]---
This is because the 'offset' field starts at an offset of 37 bytes
(offsetof(struct btrfs_file_extent_item, offset)), has a length of 8
bytes and therefore attemping to read it causes a 1 byte access beyond
the end of the leaf, as the first item's content in a leaf is located
at the tail of the leaf, the item size is 44 bytes and the offset of
that field plus its length (37 + 8 = 45) goes beyond the item's size
by 1 byte.
So fix this by accessing the 'offset' and 'disk_bytenr' fields after
jumping to the 'out' label if we are processing an inline extent. We
move the reading operation of the 'disk_bytenr' field too because we
have the same problem as for the 'offset' field explained above when
the inline data is less then 8 bytes. The access to the 'generation'
field is also moved but just for the sake of grouping access to all
the fields.
Fixes: e1cbfd7bf6 ("Btrfs: send, fix file hole not being preserved due to inline extent")
Cc: <stable@vger.kernel.org> # v4.12+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
In some scenarios an incremental send stream can contain link commands
with an invalid target path. Such scenarios happen after moving some
directory inode A, renaming a regular file inode B into the old name of
inode A and finally creating a new hard link for inode B at directory
inode A.
Consider the following example scenario where this issue happens.
Parent snapshot:
. (ino 256)
|
|--- dir1/ (ino 257)
| |--- dir2/ (ino 258)
| |--- dir3/ (ino 259)
| |--- file1 (ino 261)
| |--- dir4/ (ino 262)
|
|--- dir5/ (ino 260)
Send snapshot:
. (ino 256)
|
|--- dir1/ (ino 257)
|--- dir2/ (ino 258)
| |--- dir3/ (ino 259)
| |--- dir4 (ino 261)
|
|--- dir6/ (ino 263)
|--- dir44/ (ino 262)
|--- file11 (ino 261)
|--- dir55/ (ino 260)
When attempting to apply the corresponding incremental send stream, a
link command contains an invalid target path which makes the receiver
fail. The following is the verbose output of the btrfs receive command:
receiving snapshot mysnap2 uuid=90076fe6-5ba6-e64a-9321-9279670ed16b (...)
utimes
utimes dir1
utimes dir1/dir2/dir3
utimes
rename dir1/dir2/dir3/dir4 -> o262-7-0
link dir1/dir2/dir3/dir4 -> dir1/dir2/dir3/file1
link dir1/dir2/dir3/dir4/file11 -> dir1/dir2/dir3/file1
ERROR: link dir1/dir2/dir3/dir4/file11 -> dir1/dir2/dir3/file1 failed: Not a directory
The following steps happen during the computation of the incremental send
stream the lead to this issue:
1) When processing inode 261, we orphanize inode 262 due to a name/location
collision with one of the new hard links for inode 261 (created in the
second step below).
2) We create one of the 2 new hard links for inode 261, the one whose
location is at "dir1/dir2/dir3/dir4".
3) We then attempt to create the other new hard link for inode 261, which
has inode 262 as its parent directory. Because the path for this new
hard link was computed before we started processing the new references
(hard links), it reflects the old name/location of inode 262, that is,
it does not account for the orphanization step that happened when
we started processing the new references for inode 261, whence it is
no longer valid, causing the receiver to fail.
So fix this issue by recomputing the full path of new references if we
ended up orphanizing other inodes which are directories.
A test case for fstests follows soon.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Since iterate_dir_item checks name_len in its own way,
so use btrfs_is_name_len_valid not 'verify_dir_item' to make more strict
name_len check.
Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ switched ENAMETOOLONG to EIO ]
Signed-off-by: David Sterba <dsterba@suse.com>
An incremental send can contain unlink operations with an invalid target
path when we rename some directory inode A, then rename some file inode B
to the old name of inode A and directory inode A is an ancestor of inode B
in the parent snapshot (but not anymore in the send snapshot).
Consider the following example scenario where this issue happens.
Parent snapshot:
. (ino 256)
|
|--- dir1/ (ino 257)
|--- dir2/ (ino 258)
| |--- file1 (ino 259)
| |--- file3 (ino 261)
|
|--- dir3/ (ino 262)
|--- file22 (ino 260)
|--- dir4/ (ino 263)
Send snapshot:
. (ino 256)
|
|--- dir1/ (ino 257)
|--- dir2/ (ino 258)
|--- dir3 (ino 260)
|--- file3/ (ino 262)
|--- dir4/ (ino 263)
|--- file11 (ino 269)
|--- file33 (ino 261)
When attempting to apply the corresponding incremental send stream, an
unlink operation contains an invalid path which makes the receiver fail.
The following is verbose output of the btrfs receive command:
receiving snapshot snap2 uuid=7d5450da-a573-e043-a451-ec85f4879f0f (...)
utimes
utimes dir1
utimes dir1/dir2
link dir1/dir3/dir4/file11 -> dir1/dir2/file1
unlink dir1/dir2/file1
utimes dir1/dir2
truncate dir1/dir3/dir4/file11 size=0
utimes dir1/dir3/dir4/file11
rename dir1/dir3 -> o262-7-0
link dir1/dir3 -> o262-7-0/file22
unlink dir1/dir3/file22
ERROR: unlink dir1/dir3/file22 failed. Not a directory
The following steps happen during the computation of the incremental send
stream the lead to this issue:
1) Before we start processing the new and deleted references for inode
260, we compute the full path of the deleted reference
("dir1/dir3/file22") and cache it in the list of deleted references
for our inode.
2) We then start processing the new references for inode 260, for which
there is only one new, located at "dir1/dir3". When processing this
new reference, we check that inode 262, which was not yet processed,
collides with the new reference and because of that we orphanize
inode 262 so its new full path becomes "o262-7-0".
3) After the orphanization of inode 262, we create the new reference for
inode 260 by issuing a link command with a target path of "dir1/dir3"
and a source path of "o262-7-0/file22".
4) We then start processing the deleted references for inode 260, for
which there is only one with the base name of "file22", and issue
an unlink operation containing the target path computed at step 1,
which is wrong because that path no longer exists and should be
replaced with "o262-7-0/file22".
So fix this issue by recomputing the full path of deleted references if
when we processed the new references for an inode we ended up orphanizing
any other inode that is an ancestor of our inode in the parent snapshot.
A test case for fstests follows soon.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
[ adjusted after prev patch removed fs_path::dir_path and dir_path_len ]
Signed-off-by: David Sterba <dsterba@suse.com>
Currently an incremental snapshot can generate link operations which
contain an invalid target path. Such case happens when in the send
snapshot a file was renamed, a new hard link added for it and some
other inode (with a lower number) got renamed to the former name of
that file. Example:
Parent snapshot
. (ino 256)
|
|--- f1 (ino 257)
|--- f2 (ino 258)
|--- f3 (ino 259)
Send snapshot
. (ino 256)
|
|--- f2 (ino 257)
|--- f3 (ino 258)
|--- f4 (ino 259)
|--- f5 (ino 258)
The following steps happen when computing the incremental send stream:
1) When processing inode 257, inode 258 is orphanized (renamed to
"o258-7-0"), because its current reference has the same name as the
new reference for inode 257;
2) When processing inode 258, we iterate over all its new references,
which have the names "f3" and "f5". The first iteration sees name
"f5" and renames the inode from its orphan name ("o258-7-0") to
"f5", while the second iteration sees the name "f3" and, incorrectly,
issues a link operation with a target name matching the orphan name,
which no longer exists. The first iteration had reset the current
valid path of the inode to "f5", but in the second iteration we lost
it because we found another inode, with a higher number of 259, which
has a reference named "f3" as well, so we orphanized inode 259 and
recomputed the current valid path of inode 258 to its old orphan
name because inode 259 could be an ancestor of inode 258 and therefore
the current valid path could contain the pre-orphanization name of
inode 259. However in this case inode 259 is not an ancestor of inode
258 so the current valid path should not be recomputed.
This makes the receiver fail with the following error:
ERROR: link f3 -> o258-7-0 failed: No such file or directory
So fix this by not recomputing the current valid path for an inode
whenever we find a colliding reference from some not yet processed inode
(inode number higher then the one currently being processed), unless
that other inode is an ancestor of the one we are currently processing.
A test case for fstests will follow soon.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We use a growing buffer for xattrs larger than a page size, at some
point vmalloc is unconditionally used for larger buffers. We can still
try to avoid it using the kvmalloc helper.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The logic of kmalloc and vmalloc fallback is opencoded in
several places, we can now use the existing helper.
Signed-off-by: David Sterba <dsterba@suse.com>
Pull btrfs updates from Chris Mason:
"This has fixes and cleanups Dave Sterba collected for the merge
window.
The biggest functional fixes are between btrfs raid5/6 and scrub, and
raid5/6 and device replacement. Some of our pending qgroup fixes are
included as well while I bash on the rest in testing.
We also have the usual set of cleanups, including one that makes
__btrfs_map_block() much more maintainable, and conversions from
atomic_t to refcount_t"
* 'for-linus-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (71 commits)
btrfs: fix the gfp_mask for the reada_zones radix tree
Btrfs: fix reported number of inode blocks
Btrfs: send, fix file hole not being preserved due to inline extent
Btrfs: fix extent map leak during fallocate error path
Btrfs: fix incorrect space accounting after failure to insert inline extent
Btrfs: fix invalid attempt to free reserved space on failure to cow range
btrfs: Handle delalloc error correctly to avoid ordered extent hang
btrfs: Fix metadata underflow caused by btrfs_reloc_clone_csum error
btrfs: check if the device is flush capable
btrfs: delete unused member nobarriers
btrfs: scrub: Fix RAID56 recovery race condition
btrfs: scrub: Introduce full stripe lock for RAID56
btrfs: Use ktime_get_real_ts for root ctime
Btrfs: handle only applicable errors returned by btrfs_get_extent
btrfs: qgroup: Fix qgroup corruption caused by inode_cache mount option
btrfs: use q which is already obtained from bdev_get_queue
Btrfs: switch to div64_u64 if with a u64 divisor
Btrfs: update scrub_parity to use u64 stripe_len
Btrfs: enable repair during read for raid56 profile
btrfs: use clear_page where appropriate
...
There are many code paths opencoding kvmalloc. Let's use the helper
instead. The main difference to kvmalloc is that those users are
usually not considering all the aspects of the memory allocator. E.g.
allocation requests <= 32kB (with 4kB pages) are basically never failing
and invoke OOM killer to satisfy the allocation. This sounds too
disruptive for something that has a reasonable fallback - the vmalloc.
On the other hand those requests might fallback to vmalloc even when the
memory allocator would succeed after several more reclaim/compaction
attempts previously. There is no guarantee something like that happens
though.
This patch converts many of those places to kv[mz]alloc* helpers because
they are more conservative.
Link: http://lkml.kernel.org/r/20170306103327.2766-2-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> # Xen bits
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Andreas Dilger <andreas.dilger@intel.com> # Lustre
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> # KVM/s390
Acked-by: Dan Williams <dan.j.williams@intel.com> # nvdim
Acked-by: David Sterba <dsterba@suse.com> # btrfs
Acked-by: Ilya Dryomov <idryomov@gmail.com> # Ceph
Acked-by: Tariq Toukan <tariqt@mellanox.com> # mlx4
Acked-by: Leon Romanovsky <leonro@mellanox.com> # mlx5
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Santosh Raspatur <santosh@chelsio.com>
Cc: Hariprasad S <hariprasad@chelsio.com>
Cc: Yishai Hadas <yishaih@mellanox.com>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: "Yan, Zheng" <zyan@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Normally we don't have inline extents followed by regular extents, but
there's currently at least one harmless case where this happens. For
example, when the page size is 4Kb and compression is enabled:
$ mkfs.btrfs -f /dev/sdb
$ mount -o compress /dev/sdb /mnt
$ xfs_io -f -c "pwrite -S 0xaa 0 4K" -c "fsync" /mnt/foobar
$ xfs_io -c "pwrite -S 0xbb 8K 4K" -c "fsync" /mnt/foobar
In this case we get a compressed inline extent, representing 4Kb of
data, followed by a hole extent and then a regular data extent. The
inline extent was not expanded/converted to a regular extent exactly
because it represents 4Kb of data. This does not cause any apparent
problem (such as the issue solved by commit e1699d2d7b
("btrfs: add missing memset while reading compressed inline extents"))
except trigger an unexpected case in the incremental send code path
that makes us issue an operation to write a hole when it's not needed,
resulting in more writes at the receiver and wasting space at the
receiver.
So teach the incremental send code to deal with this particular case.
The issue can be currently triggered by running fstests btrfs/137 with
compression enabled (MOUNT_OPTIONS="-o compress" ./check btrfs/137).
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
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: f5ecec3ce2 ("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>
When using the NO_HOLES feature, during an incremental send we often issue
write operations for holes when we should not, because that range is already
a hole in the destination snapshot. While that does not change the contents
of the file at the receiver, it avoids preservation of file holes, leading
to wasted disk space and extra IO during send/receive.
A couple examples where the holes are not preserved follows.
$ mkfs.btrfs -O no-holes -f /dev/sdb
$ mount /dev/sdb /mnt
$ xfs_io -f -c "pwrite -S 0xaa 0 4K" /mnt/foo
$ xfs_io -f -c "pwrite -S 0xaa 0 4K" -c "pwrite -S 0xbb 1028K 4K" /mnt/bar
$ btrfs subvolume snapshot -r /mnt /mnt/snap1
# Now add one new extent to our first test file, increasing its size and
# leaving a 1Mb hole between the first extent and this new extent.
$ xfs_io -c "pwrite -S 0xbb 1028K 4K" /mnt/foo
# Now overwrite the last extent of our second test file.
$ xfs_io -c "pwrite -S 0xcc 1028K 4K" /mnt/bar
$ btrfs subvolume snapshot -r /mnt /mnt/snap2
$ xfs_io -r -c "fiemap -v" /mnt/snap2/foo
/mnt/snap2/foo:
EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS
0: [0..7]: 25088..25095 8 0x2000
1: [8..2055]: hole 2048
2: [2056..2063]: 24576..24583 8 0x2001
$ xfs_io -r -c "fiemap -v" /mnt/snap2/bar
/mnt/snap2/bar:
EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS
0: [0..7]: 25096..25103 8 0x2000
1: [8..2055]: hole 2048
2: [2056..2063]: 24584..24591 8 0x2001
$ btrfs send /mnt/snap1 -f /tmp/1.snap
$ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/2.snap
$ umount /mnt
# It's not relevant to enable no-holes in the new filesystem.
$ mkfs.btrfs -O no-holes -f /dev/sdc
$ mount /dev/sdc /mnt
$ btrfs receive /mnt -f /tmp/1.snap
$ btrfs receive /mnt -f /tmp/2.snap
$ xfs_io -r -c "fiemap -v" /mnt/snap2/foo
/mnt/snap2/foo:
EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS
0: [0..7]: 24576..24583 8 0x2000
1: [8..2063]: 25624..27679 2056 0x1
$ xfs_io -r -c "fiemap -v" /mnt/snap2/bar
/mnt/snap2/bar:
EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS
0: [0..7]: 24584..24591 8 0x2000
1: [8..2063]: 27680..29735 2056 0x1
The holes do not exist in the second filesystem and they were replaced
with extents filled with the byte 0x00, making each file take 1032Kb of
space instead of 8Kb.
So fix this by not issuing the write operations consisting of buffers
filled with the byte 0x00 when the destination snapshot already has a
hole for the respective range.
A test case for fstests will follow soon.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
When both the parent and send snapshots have a directory inode with the
same number but different generations (therefore they are different
inodes) and both have an entry with the same name, an incremental send
stream will contain an invalid rmdir operation that refers to the
orphanized name of the inode from the parent snapshot.
The following example scenario shows how this happens.
Parent snapshot:
.
|---- d259_old/ (ino 259, gen 9)
| |---- d1/ (ino 258, gen 9)
|
|---- f (ino 257, gen 9)
Send snapshot:
.
|---- d258/ (ino 258, gen 7)
|---- d259/ (ino 259, gen 7)
|---- d1/ (ino 257, gen 7)
When the kernel is processing inode 258 it notices that in both snapshots
there is an inode numbered 259 that is a parent of an inode 258. However
it ignores the fact that the inodes numbered 259 have different generations
in both snapshots, which means they are effectively different inodes.
Then it checks that both inodes 259 have a dentry named "d1" and because
of that it issues a rmdir operation with orphanized name of the inode 258
from the parent snapshot. This happens at send.c:process_record_refs(),
which calls send.c:did_overwrite_first_ref() that returns true and because
of that later on at process_recorded_refs() such rmdir operation is issued
because the inode being currently processed (258) is a directory and it
was deleted in the send snapshot (and replaced with another inode that has
the same number and is a directory too).
Fix this issue by comparing the generations of parent directory inodes
that have the same number and make send.c:did_overwrite_first_ref() when
the generations are different.
The following steps reproduce the problem.
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ touch /mnt/f
$ mkdir /mnt/d1
$ mkdir /mnt/d259_old
$ mv /mnt/d1 /mnt/d259_old/d1
$ btrfs subvolume snapshot -r /mnt /mnt/snap1
$ btrfs send /mnt/snap1 -f /tmp/1.snap
$ umount /mnt
$ mkfs.btrfs -f /dev/sdc
$ mount /dev/sdc /mnt
$ mkdir /mnt/d1
$ mkdir /mnt/dir258
$ mkdir /mnt/dir259
$ mv /mnt/d1 /mnt/dir259/d1
$ btrfs subvolume snapshot -r /mnt /mnt/snap2
$ btrfs receive /mnt/ -f /tmp/1.snap
# Take note that once the filesystem is created, its current
# generation has value 7 so the inodes from the second snapshot all have
# a generation value of 7. And after receiving the first snapshot
# the filesystem is at a generation value of 10, because the call to
# create the second snapshot bumps the generation to 8 (the snapshot
# creation ioctl does a transaction commit), the receive command calls
# the snapshot creation ioctl to create the first snapshot, which bumps
# the filesystem's generation to 9, and finally when the receive
# operation finishes it calls an ioctl to transition the first snapshot
# (snap1) from RW mode to RO mode, which does another transaction commit
# and bumps the filesystem's generation to 10. This means all the inodes
# in the first snapshot (snap1) have a generation value of 9.
$ rm -f /tmp/1.snap
$ btrfs send /mnt/snap1 -f /tmp/1.snap
$ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/2.snap
$ umount /mnt
$ mkfs.btrfs -f /dev/sdd
$ mount /dev/sdd /mnt
$ btrfs receive /mnt -f /tmp/1.snap
$ btrfs receive -vv /mnt -f /tmp/2.snap
receiving snapshot mysnap2 uuid=9c03962f-f620-0047-9f98-32e5a87116d9, ctransid=7 parent_uuid=d17a6e3f-14e5-df4f-be39-a7951a5399aa, parent_ctransid=9
utimes
unlink f
mkdir o257-7-0
mkdir o259-7-0
rename o257-7-0 -> o259-7-0/d1
chown o259-7-0/d1 - uid=0, gid=0
chmod o259-7-0/d1 - mode=0755
utimes o259-7-0/d1
rmdir o258-9-0
ERROR: rmdir o258-9-0 failed: No such file or directory
Signed-off-by: Robbie Ko <robbieko@synology.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
[Rewrote changelog to be more precise and clear]
Signed-off-by: Filipe Manana <fdmanana@suse.com>
When we are checking if we need to delay the rename operation for an
inode we not checking if a parent inode that exists in the send and
parent snapshots is really the same inode or not, that is, we are not
comparing the generation number of the parent inode in the send and
parent snapshots. Not only this results in unnecessarily delaying a
rename operation but also can later on make us generate an incorrect
name for a new inode in the send snapshot that has the same number
as another inode in the parent snapshot but a different generation.
Here follows an example where this happens.
Parent snapshot:
. (ino 256, gen 3)
|--- dir258/ (ino 258, gen 7)
| |--- dir257/ (ino 257, gen 7)
|
|--- dir259/ (ino 259, gen 7)
Send snapshot:
. (ino 256, gen 3)
|--- file258 (ino 258, gen 10)
|
|--- new_dir259/ (ino 259, gen 10)
|--- dir257/ (ino 257, gen 7)
The following steps happen when computing the incremental send stream:
1) When processing inode 257, its new parent is created using its orphan
name (o257-21-0), and the rename operation for inode 257 is delayed
because its new parent (inode 259) was not yet processed - this
decision to delay the rename operation does not make much sense
because the inode 259 in the send snapshot is a new inode, it's not
the same as inode 259 in the parent snapshot.
2) When processing inode 258 we end up delaying its rmdir operation,
because inode 257 was not yet renamed (moved away from the directory
inode 258 represents). We also create the new inode 258 using its
orphan name "o258-10-0", then rename it to its final name of "file258"
and then issue a truncate operation for it. However this truncate
operation contains an incorrect name, which corresponds to the orphan
name and not to the final name, which makes the receiver fail. This
happens because when we attempt to compute the inode's current name
we verify that there's another inode with the same number (258) that
has its rmdir operation pending and because of that we generate an
orphan name for the new inode 258 (we do this in the function
get_cur_path()).
Fix this by not delayed the rename operation of an inode if it has parents
with the same number but different generations in both snapshots.
The following steps reproduce this example scenario.
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ mkdir /mnt/dir257
$ mkdir /mnt/dir258
$ mkdir /mnt/dir259
$ mv /mnt/dir257 /mnt/dir258/dir257
$ btrfs subvolume snapshot -r /mnt /mnt/snap1
$ mv /mnt/dir258/dir257 /mnt/dir257
$ rmdir /mnt/dir258
$ rmdir /mnt/dir259
# Remount the filesystem so that the next created inodes will have the
# numbers 258 and 259. This is because when a filesystem is mounted,
# btrfs sets the subvolume's inode counter to a value corresponding to
# the highest inode number in the subvolume plus 1. This inode counter
# is used to assign a unique number to each new inode and it's
# incremented by 1 after very inode creation.
# Note: we unmount and then mount instead of doing a mount with
# "-o remount" because otherwise the inode counter remains at value 260.
$ umount /mnt
$ mount /dev/sdb /mnt
$ touch /mnt/file258
$ mkdir /mnt/new_dir259
$ mv /mnt/dir257 /mnt/new_dir259/dir257
$ btrfs subvolume snapshot -r /mnt /mnt/snap2
$ btrfs send /mnt/snap1 -f /tmp/1.snap
$ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/2.snap
$ umount /mnt
$ mkfs.btrfs -f /dev/sdc
$ mount /dev/sdc /mnt
$ btrfs receive /mnt -f /tmo/1.snap
$ btrfs receive /mnt -f /tmo/2.snap -vv
receiving snapshot mysnap2 uuid=e059b6d1-7f55-f140-8d7c-9a3039d23c97, ctransid=10 parent_uuid=77e98cb6-8762-814f-9e05-e8ba877fc0b0, parent_ctransid=7
utimes
mkdir o259-10-0
rename dir258 -> o258-7-0
utimes
mkfile o258-10-0
rename o258-10-0 -> file258
utimes
truncate o258-10-0 size=0
ERROR: truncate o258-10-0 failed: No such file or directory
Reported-by: Robbie Ko <robbieko@synology.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Under certain situations, an incremental send operation can fail due to a
premature attempt to create a new top level inode (a direct child of the
subvolume/snapshot root) whose name collides with another inode that was
removed from the send snapshot.
Consider the following example scenario.
Parent snapshot:
. (ino 256, gen 8)
|---- a1/ (ino 257, gen 9)
|---- a2/ (ino 258, gen 9)
Send snapshot:
. (ino 256, gen 3)
|---- a2/ (ino 257, gen 7)
In this scenario, when receiving the incremental send stream, the btrfs
receive command fails like this (ran in verbose mode, -vv argument):
rmdir a1
mkfile o257-7-0
rename o257-7-0 -> a2
ERROR: rename o257-7-0 -> a2 failed: Is a directory
What happens when computing the incremental send stream is:
1) An operation to remove the directory with inode number 257 and
generation 9 is issued.
2) An operation to create the inode with number 257 and generation 7 is
issued. This creates the inode with an orphanized name of "o257-7-0".
3) An operation rename the new inode 257 to its final name, "a2", is
issued. This is incorrect because inode 258, which has the same name
and it's a child of the same parent (root inode 256), was not yet
processed and therefore no rmdir operation for it was yet issued.
The rename operation is issued because we fail to detect that the
name of the new inode 257 collides with inode 258, because their
parent, a subvolume/snapshot root (inode 256) has a different
generation in both snapshots.
So fix this by ignoring the generation value of a parent directory that
matches a root inode (number 256) when we are checking if the name of the
inode currently being processed collides with the name of some other
inode that was not yet processed.
We can achieve this scenario of different inodes with the same number but
different generation values either by mounting a filesystem with the inode
cache option (-o inode_cache) or by creating and sending snapshots across
different filesystems, like in the following example:
$ mkfs.btrfs -f /dev/sdb
$ mount /dev/sdb /mnt
$ mkdir /mnt/a1
$ mkdir /mnt/a2
$ btrfs subvolume snapshot -r /mnt /mnt/snap1
$ btrfs send /mnt/snap1 -f /tmp/1.snap
$ umount /mnt
$ mkfs.btrfs -f /dev/sdc
$ mount /dev/sdc /mnt
$ touch /mnt/a2
$ btrfs subvolume snapshot -r /mnt /mnt/snap2
$ btrfs receive /mnt -f /tmp/1.snap
# Take note that once the filesystem is created, its current
# generation has value 7 so the inode from the second snapshot has
# a generation value of 7. And after receiving the first snapshot
# the filesystem is at a generation value of 10, because the call to
# create the second snapshot bumps the generation to 8 (the snapshot
# creation ioctl does a transaction commit), the receive command calls
# the snapshot creation ioctl to create the first snapshot, which bumps
# the filesystem's generation to 9, and finally when the receive
# operation finishes it calls an ioctl to transition the first snapshot
# (snap1) from RW mode to RO mode, which does another transaction commit
# and bumps the filesystem's generation to 10.
$ rm -f /tmp/1.snap
$ btrfs send /mnt/snap1 -f /tmp/1.snap
$ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/2.snap
$ umount /mnt
$ mkfs.btrfs -f /dev/sdd
$ mount /dev/sdd /mnt
$ btrfs receive /mnt /tmp/1.snap
# Receive of snapshot snap2 used to fail.
$ btrfs receive /mnt /tmp/2.snap
Signed-off-by: Robbie Ko <robbieko@synology.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
[Rewrote changelog to be more precise and clear]
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Now we only use the root parameter to print the root objectid in
a tracepoint. We can use the root parameter from the transaction
handle for that. It's also used to join the transaction with
async commits, so we remove the comment that it's just for checking.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are loads of functions in btrfs that accept a root parameter
but only use it to obtain an fs_info pointer. Let's convert those to
just accept an fs_info pointer directly.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In routines where someptr->fs_info is referenced multiple times, we
introduce a convenience variable. This makes the code considerably
more readable.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We track the node sizes per-root, but they never vary from the values
in the superblock. This patch messes with the 80-column style a bit,
but subsequent patches to factor out root->fs_info into a convenience
variable fix it up again.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Pull btrfs fixes from Chris Mason:
"My patch fixes the btrfs list_head abuse that we tracked down during
Dave Jones' memory corruption investigation. With both Jens and my
patches in place, I'm no longer able to trigger problems.
Filipe is fixing a difficult old bug between snapshots, balance and
send. Dave is cooking a few more for the next rc, but these are tested
and ready"
* 'for-linus-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
btrfs: fix races on root_log_ctx lists
btrfs: fix incremental send failure caused by balance
Pull btrfs updates from Chris Mason:
"This is a big variety of fixes and cleanups.
Liu Bo continues to fixup fuzzer related problems, and some of Josef's
cleanups are prep for his bigger extent buffer changes (slated for
v4.10)"
* 'for-linus-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (39 commits)
Revert "btrfs: let btrfs_delete_unused_bgs() to clean relocated bgs"
Btrfs: remove unnecessary btrfs_mark_buffer_dirty in split_leaf
Btrfs: don't BUG() during drop snapshot
btrfs: fix btrfs_no_printk stub helper
Btrfs: memset to avoid stale content in btree leaf
btrfs: parent_start initialization cleanup
btrfs: Remove already completed TODO comment
btrfs: Do not reassign count in btrfs_run_delayed_refs
btrfs: fix a possible umount deadlock
Btrfs: fix memory leak in do_walk_down
btrfs: btrfs_debug should consume fs_info when DEBUG is not defined
btrfs: convert send's verbose_printk to btrfs_debug
btrfs: convert pr_* to btrfs_* where possible
btrfs: convert printk(KERN_* to use pr_* calls
btrfs: unsplit printed strings
btrfs: clean the old superblocks before freeing the device
Btrfs: kill BUG_ON in run_delayed_tree_ref
Btrfs: don't leak reloc root nodes on error
btrfs: squash lines for simple wrapper functions
Btrfs: improve check_node to avoid reading corrupted nodes
...
Remove the unnecessary typedefs and the zero-length a_entries array in
struct posix_acl_xattr_header.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This was basically an open-coded, less flexible dynamic printk. We can
just use btrfs_debug instead.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
CodingStyle chapter 2:
"[...] never break user-visible strings such as printk messages,
because that breaks the ability to grep for them."
This patch unsplits user-visible strings.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Suppose you have the following tree in snap1 on a file system mounted with -o
inode_cache so that inode numbers are recycled
└── [ 258] a
└── [ 257] b
and then you remove b, rename a to c, and then re-create b in c so you have the
following tree
└── [ 258] c
└── [ 257] b
and then you try to do an incremental send you will hit
ASSERT(pending_move == 0);
in process_all_refs(). This is because we assume that any recycling of inodes
will not have a pending change in our path, which isn't the case. This is the
case for the DELETE side, since we want to remove the old file using the old
path, but on the create side we could have a pending move and need to do the
normal pending rename dance. So remove this ASSERT() and put a comment about
why we ignore pending_move. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When doing an incremental send, if we find a new/modified/deleted extent,
reference or xattr without having previously processed the corresponding
inode item we end up exexuting a BUG_ON(). This is because whenever an
extent, xattr or reference is added, modified or deleted, we always expect
to have the corresponding inode item updated. However there are situations
where this will not happen due to transient -ENOMEM or -ENOSPC errors when
doing delayed inode updates.
For example, when punching holes we can succeed in deleting and modifying
(shrinking) extents but later fail to do the delayed inode update. So after
such failure we close our transaction handle and right after a snapshot of
the fs/subvol tree can be made and used later for a send operation. The
same thing can happen during truncate, link, unlink, and xattr related
operations.
So instead of executing a BUG_ON, make send return an -EIO error and print
an informative error message do dmesg/syslog.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
The caller of send_utimes() is supposed to be sure that the inode number
it passes to this function does actually exists in the send snapshot.
However due to logic/algorithm bugs (such as the one fixed by the patch
titled "Btrfs: send, fix invalid leaf accesses due to incorrect utimes
operations"), this might not be the case and when that happens it makes
send_utimes() access use an unrelated leaf item as the target inode item
or access beyond a leaf's boundaries (when the leaf is full and
path->slots[0] matches the number of items in the leaf).
So if the call to btrfs_search_slot() done by send_utimes() does not find
the inode item, just make sure send_utimes() returns -ENOENT and does not
silently accesses unrelated leaf items or does invalid leaf accesses, also
allowing us to easialy and deterministically catch such algorithmic/logic
bugs.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
During an incremental send, if we have delayed rename operations for inodes
that were children of directories which were removed in the send snapshot,
we can end up accessing incorrect items in a leaf or accessing beyond the
last item of the leaf due to issuing utimes operations for the removed
inodes. Consider the following example:
Parent snapshot:
. (ino 256)
|--- a/ (ino 257)
| |--- c/ (ino 262)
|
|--- b/ (ino 258)
| |--- d/ (ino 263)
|
|--- del/ (ino 261)
|--- x/ (ino 259)
|--- y/ (ino 260)
Send snapshot:
. (ino 256)
|--- a/ (ino 257)
|
|--- b/ (ino 258)
|
|--- c/ (ino 262)
| |--- y/ (ino 260)
|
|--- d/ (ino 263)
|--- x/ (ino 259)
1) When processing inodes 259 and 260, we end up delaying their rename
operations because their parents, inodes 263 and 262 respectively, were
not yet processed and therefore not yet renamed;
2) When processing inode 262, its rename operation is issued and right
after the rename operation for inode 260 is issued. However right after
issuing the rename operation for inode 260, at send.c:apply_dir_move(),
we issue utimes operations for all current and past parents of inode
260. This means we try to send a utimes operation for its old parent,
inode 261 (deleted in the send snapshot), which does not cause any
immediate and deterministic failure, because when the target inode is
not found in the send snapshot, the send.c:send_utimes() function
ignores it and uses the leaf region pointed to by path->slots[0],
which can be any unrelated item (belonging to other inode) or it can
be a region outside the leaf boundaries, if the leaf is full and
path->slots[0] matches the number of items in the leaf. So we end
up either successfully sending a utimes operation, which is fine
and irrelevant because the old parent (inode 261) will end up being
deleted later, or we end up doing an invalid memory access tha
crashes the kernel.
So fix this by making apply_dir_move() issue utimes operations only for
parents that still exist in the send snapshot. In a separate patch we
will make send_utimes() return an error (-ENOENT) if the given inode
does not exists in the send snapshot.
Signed-off-by: Robbie Ko <robbieko@synology.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
[Rewrote change log to be more detailed and better organized]
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Under certain situations, when doing an incremental send, we can end up
not freeing orphan_dir_info structures as soon as they are no longer
needed. Instead we end up freeing them only after finishing the send
stream, which causes a warning to be emitted:
[282735.229200] ------------[ cut here ]------------
[282735.229968] WARNING: CPU: 9 PID: 10588 at fs/btrfs/send.c:6298 btrfs_ioctl_send+0xe2f/0xe51 [btrfs]
[282735.231282] Modules linked in: btrfs crc32c_generic xor raid6_pq acpi_cpufreq tpm_tis ppdev tpm parport_pc psmouse parport sg pcspkr i2c_piix4 i2c_core evdev processor serio_raw button loop autofs4 ext4 crc16 jbd2 mbcache sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy [last unloaded: btrfs]
[282735.237130] CPU: 9 PID: 10588 Comm: btrfs Tainted: G W 4.6.0-rc7-btrfs-next-31+ #1
[282735.239309] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014
[282735.240160] 0000000000000000 ffff880224273ca8 ffffffff8126b42c 0000000000000000
[282735.240160] 0000000000000000 ffff880224273ce8 ffffffff81052b14 0000189a24273ac8
[282735.240160] ffff8802210c9800 0000000000000000 0000000000000001 0000000000000000
[282735.240160] Call Trace:
[282735.240160] [<ffffffff8126b42c>] dump_stack+0x67/0x90
[282735.240160] [<ffffffff81052b14>] __warn+0xc2/0xdd
[282735.240160] [<ffffffff81052beb>] warn_slowpath_null+0x1d/0x1f
[282735.240160] [<ffffffffa03c99d5>] btrfs_ioctl_send+0xe2f/0xe51 [btrfs]
[282735.240160] [<ffffffffa0398358>] btrfs_ioctl+0x14f/0x1f81 [btrfs]
[282735.240160] [<ffffffff8108e456>] ? arch_local_irq_save+0x9/0xc
[282735.240160] [<ffffffff8118da05>] vfs_ioctl+0x18/0x34
[282735.240160] [<ffffffff8118e00c>] do_vfs_ioctl+0x550/0x5be
[282735.240160] [<ffffffff81196f0c>] ? __fget+0x6b/0x77
[282735.240160] [<ffffffff81196fa1>] ? __fget_light+0x62/0x71
[282735.240160] [<ffffffff8118e0d1>] SyS_ioctl+0x57/0x79
[282735.240160] [<ffffffff8149e025>] entry_SYSCALL_64_fastpath+0x18/0xa8
[282735.240160] [<ffffffff81100c6b>] ? time_hardirqs_off+0x9/0x14
[282735.240160] [<ffffffff8108e87d>] ? trace_hardirqs_off_caller+0x1f/0xaa
[282735.256343] ---[ end trace a4539270c8056f93 ]---
Consider the following example:
Parent snapshot:
. (ino 256)
|--- a/ (ino 257)
| |--- c/ (ino 260)
|
|--- del/ (ino 259)
|--- tmp/ (ino 258)
|--- x/ (ino 261)
|--- y/ (ino 262)
Send snapshot:
. (ino 256)
|--- a/ (ino 257)
| |--- x/ (ino 261)
| |--- y/ (ino 262)
|
|--- c/ (ino 260)
|--- tmp/ (ino 258)
1) When processing inode 258, we end up delaying its rename operation
because it has an ancestor (in the send snapshot) that has a higher
inode number (inode 260) which was also renamed in the send snapshot,
therefore we delay the rename of inode 258 so that it happens after
inode 260 is renamed;
2) When processing inode 259, we end up delaying its deletion (rmdir
operation) because it has a child inode (258) that has its rename
operation delayed. At this point we allocate an orphan_dir_info
structure and tag inode 258 so that we later attempt to see if we
can delete (rmdir) inode 259 once inode 258 is renamed;
3) When we process inode 260, after renaming it we finally do the rename
operation for inode 258. Once we issue the rename operation for inode
258 we notice that this inode was tagged so that we attempt to see
if at this point we can delete (rmdir) inode 259. But at this point
we can not still delete inode 259 because it has 2 children, inodes
261 and 262, that were not yet processed and therefore not yet
moved (renamed) away from inode 259. We end up not freeing the
orphan_dir_info structure allocated in step 2;
4) We process inodes 261 and 262, and once we move/rename inode 262
we issue the rmdir operation for inode 260;
5) We finish the send stream and notice that red black tree that
contains orphan_dir_info structures is not empty, so we emit
a warning and then free any orphan_dir_structures left.
So fix this by freeing an orphan_dir_info structure once we try to
apply a pending rename operation if we can not delete yet the tagged
directory.
A test case for fstests follows soon.
Signed-off-by: Robbie Ko <robbieko@synology.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
[Modified changelog to be more detailed and easier to understand]
Under certain situations, an incremental send operation can contain
a rmdir operation that will make the receiving end fail when attempting
to execute it, because the target directory is not yet empty.
Consider the following example:
Parent snapshot:
. (ino 256)
|--- a/ (ino 257)
| |--- c/ (ino 260)
|
|--- del/ (ino 259)
|--- tmp/ (ino 258)
|--- x/ (ino 261)
Send snapshot:
. (ino 256)
|--- a/ (ino 257)
| |--- x/ (ino 261)
|
|--- c/ (ino 260)
|--- tmp/ (ino 258)
1) When processing inode 258, we delay its rename operation because inode
260 is its new parent in the send snapshot and it was not yet renamed
(since 260 > 258, that is, beyond the current progress);
2) When processing inode 259, we realize we can not yet send an rmdir
operation (against inode 259) because inode 258 was still not yet
renamed/moved away from inode 259. Therefore we update data structures
so that after inode 258 is renamed, we try again to see if we can
finally send an rmdir operation for inode 259;
3) When we process inode 260, we send a rename operation for it followed
by a rename operation for inode 258. Once we send the rename operation
for inode 258 we then check if we can finally issue an rmdir for its
previous parent, inode 259, by calling the can_rmdir() function with
a value of sctx->cur_ino + 1 (260 + 1 = 261) for its "progress"
argument. This makes can_rmdir() return true (value 1) because even
though there's still a child inode of inode 259 that was not yet
renamed/moved, which is inode 261, the given value of progress (261)
is not lower then 261 (that is, not lower than the inode number of
some child of inode 259). So we end up sending a rmdir operation for
inode 259 before its child inode 261 is processed and renamed.
So fix this by passing the correct progress value to the call to
can_rmdir() from within apply_dir_move() (where we issue delayed rename
operations), which should match stcx->cur_ino (the number of the inode
currently being processed) and not sctx->cur_ino + 1.
A test case for fstests follows soon.
Signed-off-by: Robbie Ko <robbieko@synology.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
[Rewrote change log to be more detailed, clear and well formatted]
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Example scenario:
Parent snapshot:
. (ino 277)
|---- tmp/ (ino 278)
|---- pre/ (ino 280)
| |---- wait_dir/ (ino 281)
|
|---- desc/ (ino 282)
|---- ance/ (ino 283)
| |---- below_ance/ (ino 279)
|
|---- other_dir/ (ino 284)
Send snapshot:
. (ino 277)
|---- tmp/ (ino 278)
|---- other_dir/ (ino 284)
|---- below_ance/ (ino 279)
| |---- pre/ (ino 280)
|
|---- wait_dir/ (ino 281)
|---- desc/ (ino 282)
|---- ance/ (ino 283)
While computing the send stream the following steps happen:
1) While processing inode 279 we end up delaying its rename operation
because its new parent in the send snapshot, inode 284, was not
yet processed and therefore not yet renamed;
2) Later when processing inode 280 we end up renaming it immediately to
"ance/below_once/pre" and not delay its rename operation because its
new parent (inode 279 in the send snapshot) has its rename operation
delayed and inode 280 is not an encestor of inode 279 (its parent in
the send snapshot) in the parent snapshot;
3) When processing inode 281 we end up delaying its rename operation
because its new parent in the send snapshot, inode 284, was not yet
processed and therefore not yet renamed;
4) When processing inode 282 we do not delay its rename operation because
its parent in the send snapshot, inode 281, already has its own rename
operation delayed and our current inode (282) is not an ancestor of
inode 281 in the parent snapshot. Therefore inode 282 is renamed to
"ance/below_ance/pre/wait_dir";
5) When processing inode 283 we realize that we can rename it because one
of its ancestors in the send snapshot, inode 281, has its rename
operation delayed and inode 283 is not an ancestor of inode 281 in the
parent snapshot. So a rename operation to rename inode 283 to
"ance/below_ance/pre/wait_dir/desc/ance" is issued. This path is
invalid due to a missing path building loop that was undetected by
the incremental send implementation, as inode 283 ends up getting
included twice in the path (once with its path in the parent snapshot).
Therefore its rename operation must wait before the ancestor inode 284
is renamed.
Fix this by not terminating the rename dependency checks when we find an
ancestor, in the send snapshot, that has its rename operation delayed. So
that we continue doing the same checks if the current inode is not an
ancestor, in the parent snapshot, of an ancestor in the send snapshot we
are processing in the loop.
The problem and reproducer were reported by Robbie Ko, as part of a patch
titled "Btrfs: incremental send, avoid ancestor rename to descendant".
However the fix was unnecessarily complicated and can be addressed with
much less code and effort.
Reported-by: Robbie Ko <robbieko@synology.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
The function path_loop() can return a negative integer, signaling an
error, 0 if there's no path loop and 1 if there's a path loop. We were
treating any non zero values as meaning that a path loop exists. Fix
this by explicitly checking for errors and gracefully return them to
user space.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
When doing an incremental send we can end up not moving directories that
have the same name. This happens when the same parent directory has
different child directories with the same name in the parent and send
snapshots.
For example, consider the following scenario:
Parent snapshot:
. (ino 256)
|---- d/ (ino 257)
| |--- p1/ (ino 258)
|
|---- p1/ (ino 259)
Send snapshot:
. (ino 256)
|--- d/ (ino 257)
|--- p1/ (ino 259)
|--- p1/ (ino 258)
The directory named "d" (inode 257) has in both snapshots an entry with
the name "p1" but it refers to different inodes in both snapshots (inode
258 in the parent snapshot and inode 259 in the send snapshot). When
attempting to move inode 258, the operation is delayed because its new
parent, inode 259, was not yet moved/renamed (as the stream is currently
processing inode 258). Then when processing inode 259, we also end up
delaying its move/rename operation so that it happens after inode 258 is
moved/renamed. This decision to delay the move/rename rename operation
of inode 259 is due to the fact that the new parent inode (257) still
has inode 258 as its child, which has the same name has inode 259. So
we end up with inode 258 move/rename operation waiting for inode's 259
move/rename operation, which in turn it waiting for inode's 258
move/rename. This results in ending the send stream without issuing
move/rename operations for inodes 258 and 259 and generating the
following warnings in syslog/dmesg:
[148402.979747] ------------[ cut here ]------------
[148402.980588] WARNING: CPU: 14 PID: 4117 at fs/btrfs/send.c:6177 btrfs_ioctl_send+0xe03/0xe51 [btrfs]
[148402.981928] Modules linked in: btrfs crc32c_generic xor raid6_pq acpi_cpufreq tpm_tis ppdev tpm parport_pc psmouse parport sg pcspkr i2c_piix4 i2c_core evdev processor serio_raw button loop autofs4 ext4 crc16 jbd2 mbcache sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy [last unloaded: btrfs]
[148402.986999] CPU: 14 PID: 4117 Comm: btrfs Tainted: G W 4.6.0-rc7-btrfs-next-31+ #1
[148402.988136] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014
[148402.988136] 0000000000000000 ffff88022139fca8 ffffffff8126b42c 0000000000000000
[148402.988136] 0000000000000000 ffff88022139fce8 ffffffff81052b14 000018212139fac8
[148402.988136] ffff88022b0db400 0000000000000000 0000000000000001 0000000000000000
[148402.988136] Call Trace:
[148402.988136] [<ffffffff8126b42c>] dump_stack+0x67/0x90
[148402.988136] [<ffffffff81052b14>] __warn+0xc2/0xdd
[148402.988136] [<ffffffff81052beb>] warn_slowpath_null+0x1d/0x1f
[148402.988136] [<ffffffffa04bc831>] btrfs_ioctl_send+0xe03/0xe51 [btrfs]
[148402.988136] [<ffffffffa048b358>] btrfs_ioctl+0x14f/0x1f81 [btrfs]
[148402.988136] [<ffffffff8108e456>] ? arch_local_irq_save+0x9/0xc
[148402.988136] [<ffffffff8108eb51>] ? __lock_is_held+0x3c/0x57
[148402.988136] [<ffffffff8118da05>] vfs_ioctl+0x18/0x34
[148402.988136] [<ffffffff8118e00c>] do_vfs_ioctl+0x550/0x5be
[148402.988136] [<ffffffff81196f0c>] ? __fget+0x6b/0x77
[148402.988136] [<ffffffff81196fa1>] ? __fget_light+0x62/0x71
[148402.988136] [<ffffffff8118e0d1>] SyS_ioctl+0x57/0x79
[148402.988136] [<ffffffff8149e025>] entry_SYSCALL_64_fastpath+0x18/0xa8
[148402.988136] [<ffffffff8108e89d>] ? trace_hardirqs_off_caller+0x3f/0xaa
[148403.011373] ---[ end trace a4539270c8056f8b ]---
[148403.012296] ------------[ cut here ]------------
[148403.013071] WARNING: CPU: 14 PID: 4117 at fs/btrfs/send.c:6194 btrfs_ioctl_send+0xe19/0xe51 [btrfs]
[148403.014447] Modules linked in: btrfs crc32c_generic xor raid6_pq acpi_cpufreq tpm_tis ppdev tpm parport_pc psmouse parport sg pcspkr i2c_piix4 i2c_core evdev processor serio_raw button loop autofs4 ext4 crc16 jbd2 mbcache sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy [last unloaded: btrfs]
[148403.019708] CPU: 14 PID: 4117 Comm: btrfs Tainted: G W 4.6.0-rc7-btrfs-next-31+ #1
[148403.020104] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014
[148403.020104] 0000000000000000 ffff88022139fca8 ffffffff8126b42c 0000000000000000
[148403.020104] 0000000000000000 ffff88022139fce8 ffffffff81052b14 000018322139fac8
[148403.020104] ffff88022b0db400 0000000000000000 0000000000000001 0000000000000000
[148403.020104] Call Trace:
[148403.020104] [<ffffffff8126b42c>] dump_stack+0x67/0x90
[148403.020104] [<ffffffff81052b14>] __warn+0xc2/0xdd
[148403.020104] [<ffffffff81052beb>] warn_slowpath_null+0x1d/0x1f
[148403.020104] [<ffffffffa04bc847>] btrfs_ioctl_send+0xe19/0xe51 [btrfs]
[148403.020104] [<ffffffffa048b358>] btrfs_ioctl+0x14f/0x1f81 [btrfs]
[148403.020104] [<ffffffff8108e456>] ? arch_local_irq_save+0x9/0xc
[148403.020104] [<ffffffff8108eb51>] ? __lock_is_held+0x3c/0x57
[148403.020104] [<ffffffff8118da05>] vfs_ioctl+0x18/0x34
[148403.020104] [<ffffffff8118e00c>] do_vfs_ioctl+0x550/0x5be
[148403.020104] [<ffffffff81196f0c>] ? __fget+0x6b/0x77
[148403.020104] [<ffffffff81196fa1>] ? __fget_light+0x62/0x71
[148403.020104] [<ffffffff8118e0d1>] SyS_ioctl+0x57/0x79
[148403.020104] [<ffffffff8149e025>] entry_SYSCALL_64_fastpath+0x18/0xa8
[148403.020104] [<ffffffff8108e89d>] ? trace_hardirqs_off_caller+0x3f/0xaa
[148403.038981] ---[ end trace a4539270c8056f8c ]---
There's another issue caused by similar (but more complex) changes in the
directory hierarchy that makes move/rename operations fail, described with
the following example:
Parent snapshot:
.
|---- a/ (ino 262)
| |---- c/ (ino 268)
|
|---- d/ (ino 263)
|---- ance/ (ino 267)
|---- e/ (ino 264)
|---- f/ (ino 265)
|---- ance/ (ino 266)
Send snapshot:
.
|---- a/ (ino 262)
|---- c/ (ino 268)
| |---- ance/ (ino 267)
|
|---- d/ (ino 263)
| |---- ance/ (ino 266)
|
|---- f/ (ino 265)
|---- e/ (ino 264)
When the inode 265 is processed, the path for inode 267 is computed, which
at that time corresponds to "d/ance", and it's stored in the names cache.
Later on when processing inode 266, we end up orphanizing (renaming to a
name matching the pattern o<ino>-<gen>-<seq>) inode 267 because it has
the same name as inode 266 and it's currently a child of the new parent
directory (inode 263) for inode 266. After the orphanization and while we
are still processing inode 266, a rename operation for inode 266 is
generated. However the source path for that rename operation is incorrect
because it ends up using the old, pre-orphanization, name of inode 267.
The no longer valid name for inode 267 was previously cached when
processing inode 265 and it remains usable and considered valid until
the inode currently being processed has a number greater than 267.
This resulted in the receiving side failing with the following error:
ERROR: rename d/ance/ance -> d/ance failed: No such file or directory
So fix these issues by detecting such circular dependencies for rename
operations and by clearing the cached name of an inode once the inode
is orphanized.
A test case for fstests will follow soon.
Signed-off-by: Robbie Ko <robbieko@synology.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
[Rewrote change log to be more detailed and organized, and improved
comments]
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Qu Wenruo
Filipe Manana
Zygo Blaxell
Nikolay Borisov
Josef Bacik
Kuanling Huang
Linus Torvalds
Tsutomu Itoh
Christoph Hellwig
David Sterba
Su Yue
Michal Hocko
Dan Carpenter
Robbie Ko
Jeff Mahoney
Andreas Gruenbacher
Masahiro Yamada
Josef Bacik