| Age | Commit message (Collapse) | Author |
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Use the folio APIs where they exist. Saves several hidden calls to
compound_head(). Also removes a reference to page->mapping.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
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Convert f2fs_put_page() to f2fs_folio_put() and add a wrapper.
Replaces three calls to compound_head() with one.
[Jaegeuk Kim: fix missing null pointer check in f2fs_put_page]
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
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Convert f2fs_wait_on_page_writeback() to f2fs_folio_wait_writeback()
and add a compatibiility wrapper. Replaces five calls to
compound_head() with one.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
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User data is kept in a circular buffer backed by pages allocated as
needed. Only having space for one spare is still prone to having to
resort to allocation / freeing.
In my testing this decreases page allocs by 60% during a kernel build.
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://lore.kernel.org/r/20250303230409.452687-3-mjguzik@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
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The check operates on the stale value of 'head' and always loops back.
Just do it unconditionally. No functional changes.
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://lore.kernel.org/r/20250303230409.452687-2-mjguzik@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
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In commit ee2e3f50629f ("mount: fix mounting of detached mounts onto
targets that reside on shared mounts") I fixed a bug where propagating
the source mount tree of an anonymous mount namespace into a target
mount tree of a non-anonymous mount namespace could be used to trigger
an integer overflow in the non-anonymous mount namespace causing any new
mounts to fail.
The cause of this was that the propagation algorithm was unable to
recognize mounts from the source mount tree that were already propagated
into the target mount tree and then reappeared as propagation targets
when walking the destination propagation mount tree.
When fixing this I disabled mount propagation into anonymous mount
namespaces. Make it possible for anonymous mount namespace to receive
mount propagation events correctly. This is no also a correctness issue
now that we allow mounting detached mount trees onto detached mount
trees.
Mark the source anonymous mount namespace with MNTNS_PROPAGATING
indicating that all mounts belonging to this mount namespace are
currently in the process of being propagated and make the propagation
algorithm discard those if they appear as propagation targets.
Link: https://lore.kernel.org/r/20250225-work-mount-propagation-v1-1-e6e3724500eb@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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clang correctly notices that the 'uflags' variable initialization
only happens in some cases:
fs/namespace.c:4622:6: error: variable 'uflags' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
4622 | if (flags & MOVE_MOUNT_F_EMPTY_PATH) uflags = AT_EMPTY_PATH;
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fs/namespace.c:4623:48: note: uninitialized use occurs here
4623 | from_name = getname_maybe_null(from_pathname, uflags);
| ^~~~~~
fs/namespace.c:4622:2: note: remove the 'if' if its condition is always true
4622 | if (flags & MOVE_MOUNT_F_EMPTY_PATH) uflags = AT_EMPTY_PATH;
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Fixes: b1e9423d65e3 ("fs: support getname_maybe_null() in move_mount()")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20250226081201.1876195-1-arnd@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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The previous patch series only enabled the creation of detached mounts
from detached mounts that were created via open_tree(). In such cases we
know that the origin sequence number for the newly created anonymous
mount namespace will be set to the sequence number of the mount
namespace the source mount belonged to.
But fsmount() creates an anonymous mount namespace that does not have an
origin mount namespace as the anonymous mount namespace was derived from
a filesystem context created via fsopen().
Account for this case and allow the creation of detached mounts from
mounts created via fsmount(). Consequently, any such detached mount
created from an fsmount() mount will also have a zero origin sequence
number.
This allows to mount subdirectories without ever having to expose the
filesystem to a a non-anonymous mount namespace:
fd_context = sys_fsopen("tmpfs", 0);
sys_fsconfig(fd_context, FSCONFIG_CMD_CREATE, NULL, NULL, 0);
fd_tmpfs = sys_fsmount(fd_context, 0, 0);
mkdirat(fd_tmpfs, "subdir", 0755);
fd_tree = sys_open_tree(fd_tmpfs, "subdir", OPEN_TREE_CLONE);
sys_move_mount(fd_tree, "", -EBADF, "/mnt", MOVE_MOUNT_F_EMPTY_PATH);
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Currently, detached mounts can only be mounted onto attached mounts.
This limitation makes it impossible to assemble a new private rootfs and
move it into place. That's an extremely powerful concept for container
and service workloads that we should support.
Right now, a detached tree must be created, attached, then it can gain
additional mounts and then it can either be moved (if it doesn't reside
under a shared mount) or a detached mount created again. Lift this
restriction.
In order to allow mounting detached mounts onto other detached mounts
the same permission model used for creating detached mounts from
detached mounts can be used:
(1) Check that the caller is privileged over the owning user namespace
of it's current mount namespace.
(2) Check that the caller is located in the mount namespace of the mount
it wants to create a detached copy of.
The origin mount namespace of the anonymous mount namespace must be the
same as the caller's mount namespace. To establish this the sequence
number of the caller's mount namespace and the origin sequence number of
the anonymous mount namespace are compared.
The caller is always located in a non-anonymous mount namespace since
anonymous mount namespaces cannot be setns()ed into. The caller's mount
namespace will thus always have a valid sequence number.
The owning namespace of any mount namespace, anonymous or non-anonymous,
can never change. A mount attached to a non-anonymous mount namespace
can never change mount namespace.
If the sequence number of the non-anonymous mount namespace and the
origin sequence number of the anonymous mount namespace match, the
owning namespaces must match as well.
Hence, the capability check on the owning namespace of the caller's
mount namespace ensures that the caller has the ability to attach the
mount tree.
Link: https://lore.kernel.org/r/20250221-brauner-open_tree-v1-9-dbcfcb98c676@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Allow move_mount() to work with NULL path arguments.
Link: https://lore.kernel.org/r/20250221-brauner-open_tree-v1-8-dbcfcb98c676@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Add the ability to create detached mounts from detached mounts.
Currently, detached mounts can only be created from attached mounts.
This limitaton prevents various use-cases. For example, the ability to
mount a subdirectory without ever having to make the whole filesystem
visible first.
The current permission model for the OPEN_TREE_CLONE flag of the
open_tree() system call is:
(1) Check that the caller is privileged over the owning user namespace
of it's current mount namespace.
(2) Check that the caller is located in the mount namespace of the mount
it wants to create a detached copy of.
While it is not strictly necessary to do it this way it is consistently
applied in the new mount api. This model will also be used when allowing
the creation of detached mount from another detached mount.
The (1) requirement can simply be met by performing the same check as
for the non-detached case, i.e., verify that the caller is privileged
over its current mount namespace.
To meet the (2) requirement it must be possible to infer the origin
mount namespace that the anonymous mount namespace of the detached mount
was created from.
The origin mount namespace of an anonymous mount is the mount namespace
that the mounts that were copied into the anonymous mount namespace
originate from.
The origin mount namespace of the anonymous mount namespace must be the
same as the caller's mount namespace. To establish this the sequence
number of the caller's mount namespace and the origin sequence number of
the anonymous mount namespace are compared.
The caller is always located in a non-anonymous mount namespace since
anonymous mount namespaces cannot be setns()ed into. The caller's mount
namespace will thus always have a valid sequence number.
The owning namespace of any mount namespace, anonymous or non-anonymous,
can never change. A mount attached to a non-anonymous mount namespace
can never change mount namespace.
If the sequence number of the non-anonymous mount namespace and the
origin sequence number of the anonymous mount namespace match, the
owning namespaces must match as well.
Hence, the capability check on the owning namespace of the caller's
mount namespace ensures that the caller has the ability to copy the
mount tree.
Link: https://lore.kernel.org/r/20250221-brauner-open_tree-v1-6-dbcfcb98c676@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Add a helper that verifies whether a caller may copy a given mount tree.
Link: https://lore.kernel.org/r/20250221-brauner-open_tree-v1-5-dbcfcb98c676@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Instead of acquiring the namespace semaphore and the mount lock
everytime we close a file with FMODE_NEED_UNMOUNT set add a fastpath
that checks whether we need to at all. Most of the time the caller will
have attached the mount to the filesystem hierarchy and there's nothing
to do.
Link: https://lore.kernel.org/r/20250221-brauner-open_tree-v1-4-dbcfcb98c676@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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After we've attached a detached mount tree the anonymous mount namespace
must be empty. Add an assert and make this assumption explicit.
Link: https://lore.kernel.org/r/20250221-brauner-open_tree-v1-3-dbcfcb98c676@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Add a helper that checks whether a give mount namespace is empty instead
of open-coding the specific data structure check. This also be will be
used in follow-up patches.
Link: https://lore.kernel.org/r/20250221-brauner-open_tree-v1-2-dbcfcb98c676@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Store the sequence number of the mount namespace the anonymous mount
namespace has been created from. This information will be used in
follow-up patches.
Link: https://lore.kernel.org/r/20250221-brauner-open_tree-v1-1-dbcfcb98c676@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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syzbot reports an UBSAN issue as below:
------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in fs/f2fs/node.h:381:10
index 18446744073709550692 is out of range for type '__le32[5]' (aka 'unsigned int[5]')
CPU: 0 UID: 0 PID: 5318 Comm: syz.0.0 Not tainted 6.14.0-rc3-syzkaller-00060-g6537cfb395f3 #0
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
ubsan_epilogue lib/ubsan.c:231 [inline]
__ubsan_handle_out_of_bounds+0x121/0x150 lib/ubsan.c:429
get_nid fs/f2fs/node.h:381 [inline]
f2fs_truncate_inode_blocks+0xa5e/0xf60 fs/f2fs/node.c:1181
f2fs_do_truncate_blocks+0x782/0x1030 fs/f2fs/file.c:808
f2fs_truncate_blocks+0x10d/0x300 fs/f2fs/file.c:836
f2fs_truncate+0x417/0x720 fs/f2fs/file.c:886
f2fs_file_write_iter+0x1bdb/0x2550 fs/f2fs/file.c:5093
aio_write+0x56b/0x7c0 fs/aio.c:1633
io_submit_one+0x8a7/0x18a0 fs/aio.c:2052
__do_sys_io_submit fs/aio.c:2111 [inline]
__se_sys_io_submit+0x171/0x2e0 fs/aio.c:2081
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f238798cde9
index 18446744073709550692 (decimal, unsigned long long)
= 0xfffffffffffffc64 (hexadecimal, unsigned long long)
= -924 (decimal, long long)
In f2fs_truncate_inode_blocks(), UBSAN detects that get_nid() tries to
access .i_nid[-924], it means both offset[0] and level should zero.
The possible case should be in f2fs_do_truncate_blocks(), we try to
truncate inode size to zero, however, dn.ofs_in_node is zero and
dn.node_page is not an inode page, so it fails to truncate inode page,
and then pass zeroed free_from to f2fs_truncate_inode_blocks(), result
in this issue.
if (dn.ofs_in_node || IS_INODE(dn.node_page)) {
f2fs_truncate_data_blocks_range(&dn, count);
free_from += count;
}
I guess the reason why dn.node_page is not an inode page could be: there
are multiple nat entries share the same node block address, once the node
block address was reused, f2fs_get_node_page() may load a non-inode block.
Let's add a sanity check for such condition to avoid out-of-bounds access
issue.
Reported-by: syzbot+6653f10281a1badc749e@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/66fdcdf3.050a0220.40bef.0025.GAE@google.com
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
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f2fs_recover_quota_begin() and f2fs_recover_quota_end() should be called
in pair, there is some cases we may skip calling f2fs_recover_quota_end(),
fix it.
Fixes: e1bb7d3d9cbf ("f2fs: fix to recover quota data correctly")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
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Jan Prusakowski reported a kernel hang issue as below:
When running xfstests on linux-next kernel (6.14.0-rc3, 6.12) I
encountered a problem in generic/475 test where fsstress process
gets blocked in __f2fs_write_data_pages() and the test hangs.
The options I used are:
MKFS_OPTIONS -- -O compression -O extra_attr -O project_quota -O quota /dev/vdc
MOUNT_OPTIONS -- -o acl,user_xattr -o discard,compress_extension=* /dev/vdc /vdc
INFO: task kworker/u8:0:11 blocked for more than 122 seconds.
Not tainted 6.14.0-rc3-xfstests-lockdep #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:0 state:D stack:0 pid:11 tgid:11 ppid:2 task_flags:0x4208160 flags:0x00004000
Workqueue: writeback wb_workfn (flush-253:0)
Call Trace:
<TASK>
__schedule+0x309/0x8e0
schedule+0x3a/0x100
schedule_preempt_disabled+0x15/0x30
__mutex_lock+0x59a/0xdb0
__f2fs_write_data_pages+0x3ac/0x400
do_writepages+0xe8/0x290
__writeback_single_inode+0x5c/0x360
writeback_sb_inodes+0x22f/0x570
wb_writeback+0xb0/0x410
wb_do_writeback+0x47/0x2f0
wb_workfn+0x5a/0x1c0
process_one_work+0x223/0x5b0
worker_thread+0x1d5/0x3c0
kthread+0xfd/0x230
ret_from_fork+0x31/0x50
ret_from_fork_asm+0x1a/0x30
</TASK>
The root cause is: once generic/475 starts toload error table to dm
device, f2fs_prepare_compress_overwrite() will loop reading compressed
cluster pages due to IO error, meanwhile it has held .writepages lock,
it can block all other writeback tasks.
Let's fix this issue w/ below changes:
- add f2fs_handle_page_eio() in prepare_compress_overwrite() to
detect IO error.
- detect cp_error earler in f2fs_read_multi_pages().
Fixes: 4c8ff7095bef ("f2fs: support data compression")
Reported-by: Jan Prusakowski <jprusakowski@google.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull affs fixes from David Sterba:
"Two fixes from Simon Tatham. They're real bugfixes for problems with
OFS floppy disks created on linux and then read in the emulated
Workbench environment"
* tag 'affs-6.14-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
affs: don't write overlarge OFS data block size fields
affs: generate OFS sequence numbers starting at 1
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Pull xfs cleanups from Carlos Maiolino:
"Just a few cleanups"
* tag 'xfs-fixes-6.14-rc6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: remove the XBF_STALE check from xfs_buf_rele_cached
xfs: remove most in-flight buffer accounting
xfs: decouple buffer readahead from the normal buffer read path
xfs: reduce context switches for synchronous buffered I/O
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Add a zoned group with an attribute for the maximum number of open zones.
This allows querying the open zones for data placement tests, or also
for placement aware applications that are in control of the entire
file system.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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Extend the error sysfs initialization helper to include the neighbouring
attributes as well.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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Add the per-zone life time hint and the used block distribution
for fully written zones, grouping reclaimable zones in fixed-percentage
buckets spanning 0..9%, 10..19% and full zones as 100% used as well as a
few statistics about the zone allocator and open and reclaimable zones
in /proc/*/mountstats.
This gives good insight into data fragmentation and data placement
success rate.
Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com>
Co-developed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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The show_stats option allows a file system to dump plain text statistic
on a per-mount basis into /proc/*/mountstats. Wire up a no-op version
which will grow useful information for zoned file systems later.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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Add a file write life time data placement allocation scheme that aims to
minimize fragmentation and thereby to do two things:
a) separate file data to different zones when possible.
b) colocate file data of similar life times when feasible.
To get best results, average file sizes should align with the zone
capacity that is reported through the XFS_IOC_FSGEOMETRY ioctl.
This improvement in data placement efficiency reduces the number of
blocks requiring relocation by GC, and thus decreases overall write
amplification. The impact on performance varies depending on how full
the file system is.
For RocksDB using leveled compaction, the lifetime hints can improve
throughput for overwrite workloads at 80% file system utilization by
~10%, but for lower file system utilization there won't be as much
benefit in application performance as there is less need for garbage
collection to start with.
Lifetime hints can be disabled using the nolifetime mount option.
Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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Allow limiting the number of open zones used below that exported by the
device. This is required to tune the number of write streams when zoned
RT devices are used on conventional devices, and can be useful on zoned
devices that support a very large number of open zones.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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Zoned devices can have gaps beyond the usable capacity of a zone and the
end in the LBA/daddr address space. In other words, the hardware
equivalent to the RT groups already takes care of the power of 2
alignment for us. In this case the sparse FSB/RTB address space maps 1:1
to the device address space.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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Enable the zoned RT device directory feature. With this feature, RT
groups are written sequentially and always emptied before rewriting
the blocks. This perfectly maps to zoned devices, but can also be
used on conventional block devices.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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They'll need a little more work.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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While the zoned on-disk format supports reflinks, the GC code currently
always unshares reflinks when moving blocks to new zones, thus making the
feature unusuable. Disable reflinks until the GC code is refcount aware.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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File system with internal RT devices are a bit odd in that we need
to report AGs and RGs. To make this happen use separate synthetic
fmr_device values for the different sections instead of the dev_t
mapping used by other XFS configurations.
The data device is reported as file system metadata before the
start of the RGs for the synthetic RT fmr_device.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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Space usage is tracked by the rmap, which already is separately
cross-referenced. But on top of that we have the write pointer and can
do a basic sanity check here that the block is not beyond the write
pointer.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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Space usage is tracked by the rmap, which already is separately
cross-referenced. But on top of that we have the write pointer and can
do a basic sanity check here that the block is not beyond the write
pointer.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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Zoned file systems can have COW forks even without reflinks.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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Replace the inner loop growing one RT bitmap block at a time with
one just modifying the superblock counters for growing an entire
zone (aka RTG). The big restriction is just like at mkfs time only
a RT extent size of a single FSB is allowed, and the file system
capacity needs to be aligned to the zone size.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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File systems with a zoned RT device have a large number of reserved
blocks that are required for garbage collection, and which can't be
filled with user data. Exclude them from the available blocks reported
through stat(v)fs.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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Make xfs_rtextent_free_finish_item call into the zoned allocator to free
blocks on zoned RT devices.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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Direct writes to zoned RT devices are extremely simple. After taking the
block reservation before acquiring the iolock, the iomap direct I/O calls
into ->iomap_begin which will return a "fake" iomap for the entire
requested range. The actual block allocation is then done from the
submit_io handler using code shared with the buffered I/O path.
The iomap_dio_ops set the bio_set to the (iomap) ioend one and initialize
the embedded ioend, which allows reusing the existing ioend based buffered
I/O completion path.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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Implement buffered writes including page faults and block zeroing for
zoned RT devices. Buffered writes to zoned RT devices are split into
three phases:
1) a reservation for the worst case data block usage is taken before
acquiring the iolock. When there are enough free blocks but not
enough available one, garbage collection is kicked off to free the
space before continuing with the write. If there isn't enough
freeable space, the block reservation is reduced and a short write
will happen as expected by normal Linux write semantics.
2) with the iolock held, the generic iomap buffered write code is
called, which through the iomap_begin operation usually just inserts
delalloc extents for the range in a single iteration. Only for
overwrites of existing data that are not block aligned, or zeroing
operations the existing extent mapping is read to fill out the srcmap
and to figure out if zeroing is required.
3) the ->map_blocks callback to the generic iomap writeback code
calls into the zoned space allocator to actually allocate on-disk
space for the range before kicking of the writeback.
Note that because all writes are out of place, truncate or hole punches
that are not aligned to block size boundaries need to allocate space.
For block zeroing from truncate, ->setattr is called with the iolock
(aka i_rwsem) already held, so a hacky deviation from the above
scheme is needed. In this case the space reservations is called with
the iolock held, but is required not to block and can dip into the
reserved block pool. This can lead to -ENOSPC when truncating a
file, which is unfortunate. But fixing the calling conventions in
the VFS is probably much easier with code requiring it already in
mainline.
Similarly because all writes are out place, the zoned allocator can't
support unwritten extents and thus the FALLOC_FL_ALLOCATE_RANGE range
mode of fallocate. Other fallocate modes that would reserved space
but don't need to to provide proper semantics do work but do not
reserve space.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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RT groups on a zoned file system need to be completely empty before their
space can be reused. This means that partially empty groups need to be
emptied entirely to free up space if no entirely free groups are
available.
Add a garbage collection thread that moves all data out of the least used
zone when not enough free zones are available, and which resets all zones
that have been emptied. To find empty zone a simple set of 10 buckets
based on the amount of space used in the zone is used. To empty zones,
the rmap is walked to find the owners and the data is read and then
written to the new place.
To automatically defragment files the rmap records are sorted by inode
and logical offset. This means defragmentation of parallel writes into
a single zone happens automatically when performing garbage collection.
Because holding the iolock over the entire GC cycle would inject very
noticeable latency for other accesses to the inodes, the iolock is not
taken while performing I/O. Instead the I/O completion handler checks
that the mapping hasn't changed over the one recorded at the start of
the GC cycle and doesn't update the mapping if it change.
Co-developed-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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For zoned file systems garbage collection (GC) has to take the iolock
and mmaplock after moving data to a new place to synchronize with
readers. This means waiting for garbage collection with the iolock can
deadlock.
To avoid this, the worst case required blocks have to be reserved before
taking the iolock, which is done using a new RTAVAILABLE counter that
tracks blocks that are free to write into and don't require garbage
collection. The new helpers try to take these available blocks, and
if there aren't enough available it wakes and waits for GC. This is
done using a list of on-stack reservations to ensure fairness.
Co-developed-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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For zoned RT devices space is always allocated at the write pointer, that
is right after the last written block and only recorded on I/O completion.
Because the actual allocation algorithm is very simple and just involves
picking a good zone - preferably the one used for the last write to the
inode. As the number of zones that can written at the same time is
usually limited by the hardware, selecting a zone is done as late as
possible from the iomap dio and buffered writeback bio submissions
helpers just before submitting the bio.
Given that the writers already took a reservation before acquiring the
iolock, space will always be readily available if an open zone slot is
available. A new structure is used to track these open zones, and
pointed to by the xfs_rtgroup. Because zoned file systems don't have
a rsum cache the space for that pointer can be reused.
Allocations are only recorded at I/O completion time. The scheme used
for that is very similar to the reflink COW end I/O path.
Co-developed-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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Add support to validate and parse reported hardware zone state.
Co-developed-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Hans Holmberg <hans.holmberg@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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The zoned allocator never performs speculative preallocations, so don't
bother queueing up zoned inodes here.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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Zoned file systems require out of place writes and thus can't support
post-EOF speculative preallocations. Avoid the pointless ilock critical
section to find out that none can be freed.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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The zoned allocator unconditionally issues zone resets or discards after
emptying an entire zone, so supporting FITRIM for a zoned RT device is
not useful.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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Zoned file systems not only don't use the global frextents counter, but
for them the in-memory percpu counter also includes reservations taken
before even allocating delalloc extent records, so it will never match
the per-zone used information. Disable all updates and verification of
the sb counter for zoned file systems as it isn't useful for them.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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Export the zoned geometry information so that userspace can query it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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Allow creating an RT subvolume on the same device as the main data
device. This is mostly used for SMR HDDs where the conventional zones
are used for the data device and the sequential write required zones
for the zoned RT section.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
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