On sparc, if we have an alloca() like situation, as is the case with
SHASH_DESC_ON_STACK(), we can end up referencing deallocated stack
memory. The result can be that the value is clobbered if a trap
or interrupt arrives at just the right instruction.
It only occurs if the function ends returning a value from that
alloca() area and that value can be placed into the return value
register using a single instruction.
For example, in lib/libcrc32c.c:crc32c() we end up with a return
sequence like:
return %i7+8
lduw [%o5+16], %o0 ! MEM[(u32 *)__shash_desc.1_10 + 16B],
%o5 holds the base of the on-stack area allocated for the shash
descriptor. But the return released the stack frame and the
register window.
So if an intererupt arrives between 'return' and 'lduw', then
the value read at %o5+16 can be corrupted.
Add a data compiler barrier to work around this problem. This is
exactly what the gcc fix will end up doing as well, and it absolutely
should not change the code generated for other cpus (unless gcc
on them has the same bug :-)
With crucial insight from Eric Sandeen.
Cc: <stable@vger.kernel.org>
Reported-by: Anatoly Pugachev <matorola@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Merge more updates from Andrew Morton:
- the rest of MM
- various misc things
- procfs updates
- lib/ updates
- checkpatch updates
- kdump/kexec updates
- add kvmalloc helpers, use them
- time helper updates for Y2038 issues. We're almost ready to remove
current_fs_time() but that awaits a btrfs merge.
- add tracepoints to DAX
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (114 commits)
drivers/staging/ccree/ssi_hash.c: fix build with gcc-4.4.4
selftests/vm: add a test for virtual address range mapping
dax: add tracepoint to dax_insert_mapping()
dax: add tracepoint to dax_writeback_one()
dax: add tracepoints to dax_writeback_mapping_range()
dax: add tracepoints to dax_load_hole()
dax: add tracepoints to dax_pfn_mkwrite()
dax: add tracepoints to dax_iomap_pte_fault()
mtd: nand: nandsim: convert to memalloc_noreclaim_*()
treewide: convert PF_MEMALLOC manipulations to new helpers
mm: introduce memalloc_noreclaim_{save,restore}
mm: prevent potential recursive reclaim due to clearing PF_MEMALLOC
mm/huge_memory.c: deposit a pgtable for DAX PMD faults when required
mm/huge_memory.c: use zap_deposited_table() more
time: delete CURRENT_TIME_SEC and CURRENT_TIME
gfs2: replace CURRENT_TIME with current_time
apparmorfs: replace CURRENT_TIME with current_time()
lustre: replace CURRENT_TIME macro
fs: ubifs: replace CURRENT_TIME_SEC with current_time
fs: ufs: use ktime_get_real_ts64() for birthtime
...
Patch series "kvmalloc", v5.
There are many open coded kmalloc with vmalloc fallback instances in the
tree. Most of them are not careful enough or simply do not care about
the underlying semantic of the kmalloc/page allocator which means that
a) some vmalloc fallbacks are basically unreachable because the kmalloc
part will keep retrying until it succeeds b) the page allocator can
invoke a really disruptive steps like the OOM killer to move forward
which doesn't sound appropriate when we consider that the vmalloc
fallback is available.
As it can be seen implementing kvmalloc requires quite an intimate
knowledge if the page allocator and the memory reclaim internals which
strongly suggests that a helper should be implemented in the memory
subsystem proper.
Most callers, I could find, have been converted to use the helper
instead. This is patch 6. There are some more relying on __GFP_REPEAT
in the networking stack which I have converted as well and Eric Dumazet
was not opposed [2] to convert them as well.
[1] http://lkml.kernel.org/r/20170130094940.13546-1-mhocko@kernel.org
[2] http://lkml.kernel.org/r/1485273626.16328.301.camel@edumazet-glaptop3.roam.corp.google.com
This patch (of 9):
Using kmalloc with the vmalloc fallback for larger allocations is a
common pattern in the kernel code. Yet we do not have any common helper
for that and so users have invented their own helpers. Some of them are
really creative when doing so. Let's just add kv[mz]alloc and make sure
it is implemented properly. This implementation makes sure to not make
a large memory pressure for > PAGE_SZE requests (__GFP_NORETRY) and also
to not warn about allocation failures. This also rules out the OOM
killer as the vmalloc is a more approapriate fallback than a disruptive
user visible action.
This patch also changes some existing users and removes helpers which
are specific for them. In some cases this is not possible (e.g.
ext4_kvmalloc, libcfs_kvzalloc) because those seems to be broken and
require GFP_NO{FS,IO} context which is not vmalloc compatible in general
(note that the page table allocation is GFP_KERNEL). Those need to be
fixed separately.
While we are at it, document that __vmalloc{_node} about unsupported gfp
mask because there seems to be a lot of confusion out there.
kvmalloc_node will warn about GFP_KERNEL incompatible (which are not
superset) flags to catch new abusers. Existing ones would have to die
slowly.
[sfr@canb.auug.org.au: f2fs fixup]
Link: http://lkml.kernel.org/r/20170320163735.332e64b7@canb.auug.org.au
Link: http://lkml.kernel.org/r/20170306103032.2540-2-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Andreas Dilger <adilger@dilger.ca> [ext4 part]
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: John Hubbard <jhubbard@nvidia.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>
In this round, we've focused on enhancing performance with regards to block
allocation, GC, and discard/in-place-update IO controls. There are a bunch
of clean-ups as well as minor bug fixes.
= Enhancement
- disable heap-based allocation by default
- issue small-sized discard commands by default
- change the policy of data hotness for logging
- distinguish IOs in terms of size and wbc type
- start SSR earlier to avoid foreground GC
- enhance data structures managing discard commands
- enhance in-place update flow
- add some more fault injection routines
- secure one more xattr entry
= Bug fix
- calculate victim cost for GC correctly
- remain correct victim segment number for GC
- race condition in nid allocator and initializer
- stale pointer produced by atomic_writes
- fix missing REQ_SYNC for flush commands
- handle missing errors in more corner cases
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Merge tag 'for-f2fs-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs
Pull f2fs updates from Jaegeuk Kim:
"In this round, we've focused on enhancing performance with regards to
block allocation, GC, and discard/in-place-update IO controls. There
are a bunch of clean-ups as well as minor bug fixes.
Enhancements:
- disable heap-based allocation by default
- issue small-sized discard commands by default
- change the policy of data hotness for logging
- distinguish IOs in terms of size and wbc type
- start SSR earlier to avoid foreground GC
- enhance data structures managing discard commands
- enhance in-place update flow
- add some more fault injection routines
- secure one more xattr entry
Bug fixes:
- calculate victim cost for GC correctly
- remain correct victim segment number for GC
- race condition in nid allocator and initializer
- stale pointer produced by atomic_writes
- fix missing REQ_SYNC for flush commands
- handle missing errors in more corner cases"
* tag 'for-f2fs-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (111 commits)
f2fs: fix a mount fail for wrong next_scan_nid
f2fs: enhance scalability of trace macro
f2fs: relocate inode_{,un}lock in F2FS_IOC_SETFLAGS
f2fs: Make flush bios explicitely sync
f2fs: show available_nids in f2fs/status
f2fs: flush dirty nats periodically
f2fs: introduce CP_TRIMMED_FLAG to avoid unneeded discard
f2fs: allow cpc->reason to indicate more than one reason
f2fs: release cp and dnode lock before IPU
f2fs: shrink size of struct discard_cmd
f2fs: don't hold cmd_lock during waiting discard command
f2fs: nullify fio->encrypted_page for each writes
f2fs: sanity check segment count
f2fs: introduce valid_ipu_blkaddr to clean up
f2fs: lookup extent cache first under IPU scenario
f2fs: reconstruct code to write a data page
f2fs: introduce __wait_discard_cmd
f2fs: introduce __issue_discard_cmd
f2fs: enable small discard by default
f2fs: delay awaking discard thread
...
If user has no key under an encrypted dir, fscrypt gives digested dentries.
Previously, when looking up a dentry, f2fs only checks its hash value with
first 4 bytes of the digested dentry, which didn't handle hash collisions fully.
This patch enhances to check entire dentry bytes likewise ext4.
Eric reported how to reproduce this issue by:
# seq -f "edir/abcdefghijklmnopqrstuvwxyz012345%.0f" 100000 | xargs touch
# find edir -type f | xargs stat -c %i | sort | uniq | wc -l
100000
# sync
# echo 3 > /proc/sys/vm/drop_caches
# keyctl new_session
# find edir -type f | xargs stat -c %i | sort | uniq | wc -l
99999
Cc: <stable@vger.kernel.org>
Reported-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
(fixed f2fs_dentry_hash() to work even when the hash is 0)
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Introduce CP_TRIMMED_FLAG to indicate all invalid block were trimmed
before umount, so once we do mount with image which contain the flag,
we don't record invalid blocks as undiscard one, when fstrim is being
triggered, we can avoid issuing redundant discard commands.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Change to use different bits of cpc->reason to indicate different status,
so cpc->reason can indicate more than one reason.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
We don't need to rewrite the page under cp_rwsem and dnode locks.
Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
In order to shrink size of struct discard_cmd, change variable type of
@state in struct discard_cmd from int to unsigned char.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Previously, with protection of cmd_lock, we will wait for end io of
discard command which potentially may lead long latency, making worse
concurrency.
So, in this patch, we try to add reference into discard entry to prevent
the entry being released by other thread, then we can avoid holding
global cmd_lock during waiting discard to finish.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch start to enable 4K granularity small discard by default
when realtime discard is on, so, in seriously fragmented space,
small size discard can be issued in time to avoid useless storage
space occupying of invalid filesystem's data, then performance of
flash storage can be recovered.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
With a recent addition of f2fs_lookup_extent_tree(), we get a warning about
the use of empty macros:
fs/f2fs/extent_cache.c: In function 'f2fs_lookup_extent_tree':
fs/f2fs/extent_cache.c:358:32: error: suggest braces around empty body in an 'else' statement [-Werror=empty-body]
stat_inc_rbtree_node_hit(sbi);
A good way to avoid the warning and make the code more robust is to define
all no-op macros as 'do { } while (0)'.
Fixes: 54c2258cd6 ("f2fs: extract rb-tree operation infrastructure")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reivewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch adds an ioctl to flush data in faster device to cold area. User can
give device number and number of segments to move. It doesn't move it if there
is only one device.
The parameter looks like:
struct f2fs_flush_device {
u32 dev_num; /* device number to flush */
u32 segments; /* # of segments to flush */
};
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
For IPU writes, there won't be any udpates in dnode page since we
will reuse old block address instead of allocating new one, so we
don't need to lock cp_rwsem during IPU IO submitting.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Introduce __check_rb_tree_consistence to check consistence of rb-tree
based discard cache in runtime.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Keep issuing big size discard in prior instead of the one with random
size, so that we expect that it will help to:
- be quick to recycle unused large space in flash storage device.
- give a chance for
a) wait to merge small piece discards into bigger one, or
b) avoid issuing discards while they have being reallocated by SSR.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Avoid long variable name in discard_cmd_control structure, no logic
change.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Introduce rb-tree based discard cache infrastructure to speed up lookup and
merge operation of discard entry.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
[Jaegeuk Kim: initialize dc to avoid build warning]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
rb-tree lookup/update functions are deeply coupled into extent cache
codes, it's very hard to reuse these basic functions, this patch
extracts common rb-tree operation infrastructure for latter reusing.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Add braces around variables used within macros for those make sense
to do it. Many of the macros in f2fs already do this. What this commit
doesn't do is anything that changes line# as a result of adding braces,
which usually affects the binary via __LINE__.
Confirmed no diff in fs/f2fs/f2fs.ko before/after this commit on x86_64,
to make sure this has no functional change as well as there's been no
unexpected side effect due to callers' arithmetics within the existing
code.
Signed-off-by: Tomohiro Kusumi <tkusumi@tuxera.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Split f2fs_wait_discard_bios from f2fs_wait_discard_bio, just for cleanup,
no logic change.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Split discard_cmd_list to discard_{pend,wait}_list, so while sending/waiting
discard command, we can avoid traversing unneeded entries in original list.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Since callers statically know which type to use, make_dentry_ptr()
can simply be splitted into two inline functions. This way, the code
has less inlined, fewer arguments, and no cast.
Signed-off-by: Tomohiro Kusumi <tkusumi@tuxera.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch tries to split in-place-update bios from sequential bios.
Suggested-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
If two threads try to flush dirty pages in different inodes respectively,
f2fs_write_data_pages() will produce WRITE and WRITE_SYNC one at a time,
resulting in a lot of 4KB seperated IOs.
So, this patch gives higher priority to WB_SYNC_ALL IOs and gathers write
IOs with a big WRITE_SYNC'ed bio.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
It would better split small and large IOs separately in order to get more
consecutive big writes.
The default threshold is set to 64KB, but configurable by sysfs/min_hot_blocks.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch changes to use bitmap instead of extent in struct discard_entry
to indicate discard range in one segment, for fragmented space, this
implementation can save memory footprint.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Adds to count discard command entry and show the number in debugfs,
also fix to add cost of discard command cache into total comsumed
memory footprint.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Show historical count of flush command and discard command.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch allow write data to normal file when writting
new checkpoint.
We relax three limitations for write_begin path:
1. data allocation
2. node allocation
3. variables in checkpoint
Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch adds to show the max number of volatile operations which are
conducting concurrently.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
As discuss with Jaegeuk and Chao,
"Once checkpoint is done, f2fs doesn't need to update there-in filename at all."
The disk-level filename is used only one case,
1. create a file A under a dir
2. sync A
3. godown
4. umount
5. mount (roll_forward)
Only the rename/cross_rename changes the filename, if it happens,
a. between step 1 and 2, the sync A will caused checkpoint, so that,
the roll_forward at step 5 never happens.
b. after step 2, the roll_forward happens, file A will roll forward
to the result as after step 1.
So that, any updating the disk filename is useless, just cleanup it.
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
free_nid_bitmap and free_nid_count in update_free_nid_bitmap should be
updated atomically, use nid_list_lock cover them to avoid race in
concurrent scenario.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Reviewed-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Clear FI_DATA_EXIST flag atomically in truncate_inline_inode, and
the return value from truncate_inline_inode isn't used, remove it.
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Fixes: 3cf4574705 ("f2fs: introduce get_next_page_offset to speed up SEEK_DATA")
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patch adds to account free nids for each NAT blocks, and while
scanning all free nid bitmap, do check count and skip lookuping in
full NAT block.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Add a system call to make extended file information available, including
file creation and some attribute flags where available through the
underlying filesystem.
The getattr inode operation is altered to take two additional arguments: a
u32 request_mask and an unsigned int flags that indicate the
synchronisation mode. This change is propagated to the vfs_getattr*()
function.
Functions like vfs_stat() are now inline wrappers around new functions
vfs_statx() and vfs_statx_fd() to reduce stack usage.
========
OVERVIEW
========
The idea was initially proposed as a set of xattrs that could be retrieved
with getxattr(), but the general preference proved to be for a new syscall
with an extended stat structure.
A number of requests were gathered for features to be included. The
following have been included:
(1) Make the fields a consistent size on all arches and make them large.
(2) Spare space, request flags and information flags are provided for
future expansion.
(3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an
__s64).
(4) Creation time: The SMB protocol carries the creation time, which could
be exported by Samba, which will in turn help CIFS make use of
FS-Cache as that can be used for coherency data (stx_btime).
This is also specified in NFSv4 as a recommended attribute and could
be exported by NFSD [Steve French].
(5) Lightweight stat: Ask for just those details of interest, and allow a
netfs (such as NFS) to approximate anything not of interest, possibly
without going to the server [Trond Myklebust, Ulrich Drepper, Andreas
Dilger] (AT_STATX_DONT_SYNC).
(6) Heavyweight stat: Force a netfs to go to the server, even if it thinks
its cached attributes are up to date [Trond Myklebust]
(AT_STATX_FORCE_SYNC).
And the following have been left out for future extension:
(7) Data version number: Could be used by userspace NFS servers [Aneesh
Kumar].
Can also be used to modify fill_post_wcc() in NFSD which retrieves
i_version directly, but has just called vfs_getattr(). It could get
it from the kstat struct if it used vfs_xgetattr() instead.
(There's disagreement on the exact semantics of a single field, since
not all filesystems do this the same way).
(8) BSD stat compatibility: Including more fields from the BSD stat such
as creation time (st_btime) and inode generation number (st_gen)
[Jeremy Allison, Bernd Schubert].
(9) Inode generation number: Useful for FUSE and userspace NFS servers
[Bernd Schubert].
(This was asked for but later deemed unnecessary with the
open-by-handle capability available and caused disagreement as to
whether it's a security hole or not).
(10) Extra coherency data may be useful in making backups [Andreas Dilger].
(No particular data were offered, but things like last backup
timestamp, the data version number and the DOS archive bit would come
into this category).
(11) Allow the filesystem to indicate what it can/cannot provide: A
filesystem can now say it doesn't support a standard stat feature if
that isn't available, so if, for instance, inode numbers or UIDs don't
exist or are fabricated locally...
(This requires a separate system call - I have an fsinfo() call idea
for this).
(12) Store a 16-byte volume ID in the superblock that can be returned in
struct xstat [Steve French].
(Deferred to fsinfo).
(13) Include granularity fields in the time data to indicate the
granularity of each of the times (NFSv4 time_delta) [Steve French].
(Deferred to fsinfo).
(14) FS_IOC_GETFLAGS value. These could be translated to BSD's st_flags.
Note that the Linux IOC flags are a mess and filesystems such as Ext4
define flags that aren't in linux/fs.h, so translation in the kernel
may be a necessity (or, possibly, we provide the filesystem type too).
(Some attributes are made available in stx_attributes, but the general
feeling was that the IOC flags were to ext[234]-specific and shouldn't
be exposed through statx this way).
(15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer,
Michael Kerrisk].
(Deferred, probably to fsinfo. Finding out if there's an ACL or
seclabal might require extra filesystem operations).
(16) Femtosecond-resolution timestamps [Dave Chinner].
(A __reserved field has been left in the statx_timestamp struct for
this - if there proves to be a need).
(17) A set multiple attributes syscall to go with this.
===============
NEW SYSTEM CALL
===============
The new system call is:
int ret = statx(int dfd,
const char *filename,
unsigned int flags,
unsigned int mask,
struct statx *buffer);
The dfd, filename and flags parameters indicate the file to query, in a
similar way to fstatat(). There is no equivalent of lstat() as that can be
emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags. There is
also no equivalent of fstat() as that can be emulated by passing a NULL
filename to statx() with the fd of interest in dfd.
Whether or not statx() synchronises the attributes with the backing store
can be controlled by OR'ing a value into the flags argument (this typically
only affects network filesystems):
(1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this
respect.
(2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise
its attributes with the server - which might require data writeback to
occur to get the timestamps correct.
(3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a
network filesystem. The resulting values should be considered
approximate.
mask is a bitmask indicating the fields in struct statx that are of
interest to the caller. The user should set this to STATX_BASIC_STATS to
get the basic set returned by stat(). It should be noted that asking for
more information may entail extra I/O operations.
buffer points to the destination for the data. This must be 256 bytes in
size.
======================
MAIN ATTRIBUTES RECORD
======================
The following structures are defined in which to return the main attribute
set:
struct statx_timestamp {
__s64 tv_sec;
__s32 tv_nsec;
__s32 __reserved;
};
struct statx {
__u32 stx_mask;
__u32 stx_blksize;
__u64 stx_attributes;
__u32 stx_nlink;
__u32 stx_uid;
__u32 stx_gid;
__u16 stx_mode;
__u16 __spare0[1];
__u64 stx_ino;
__u64 stx_size;
__u64 stx_blocks;
__u64 __spare1[1];
struct statx_timestamp stx_atime;
struct statx_timestamp stx_btime;
struct statx_timestamp stx_ctime;
struct statx_timestamp stx_mtime;
__u32 stx_rdev_major;
__u32 stx_rdev_minor;
__u32 stx_dev_major;
__u32 stx_dev_minor;
__u64 __spare2[14];
};
The defined bits in request_mask and stx_mask are:
STATX_TYPE Want/got stx_mode & S_IFMT
STATX_MODE Want/got stx_mode & ~S_IFMT
STATX_NLINK Want/got stx_nlink
STATX_UID Want/got stx_uid
STATX_GID Want/got stx_gid
STATX_ATIME Want/got stx_atime{,_ns}
STATX_MTIME Want/got stx_mtime{,_ns}
STATX_CTIME Want/got stx_ctime{,_ns}
STATX_INO Want/got stx_ino
STATX_SIZE Want/got stx_size
STATX_BLOCKS Want/got stx_blocks
STATX_BASIC_STATS [The stuff in the normal stat struct]
STATX_BTIME Want/got stx_btime{,_ns}
STATX_ALL [All currently available stuff]
stx_btime is the file creation time, stx_mask is a bitmask indicating the
data provided and __spares*[] are where as-yet undefined fields can be
placed.
Time fields are structures with separate seconds and nanoseconds fields
plus a reserved field in case we want to add even finer resolution. Note
that times will be negative if before 1970; in such a case, the nanosecond
fields will also be negative if not zero.
The bits defined in the stx_attributes field convey information about a
file, how it is accessed, where it is and what it does. The following
attributes map to FS_*_FL flags and are the same numerical value:
STATX_ATTR_COMPRESSED File is compressed by the fs
STATX_ATTR_IMMUTABLE File is marked immutable
STATX_ATTR_APPEND File is append-only
STATX_ATTR_NODUMP File is not to be dumped
STATX_ATTR_ENCRYPTED File requires key to decrypt in fs
Within the kernel, the supported flags are listed by:
KSTAT_ATTR_FS_IOC_FLAGS
[Are any other IOC flags of sufficient general interest to be exposed
through this interface?]
New flags include:
STATX_ATTR_AUTOMOUNT Object is an automount trigger
These are for the use of GUI tools that might want to mark files specially,
depending on what they are.
Fields in struct statx come in a number of classes:
(0) stx_dev_*, stx_blksize.
These are local system information and are always available.
(1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino,
stx_size, stx_blocks.
These will be returned whether the caller asks for them or not. The
corresponding bits in stx_mask will be set to indicate whether they
actually have valid values.
If the caller didn't ask for them, then they may be approximated. For
example, NFS won't waste any time updating them from the server,
unless as a byproduct of updating something requested.
If the values don't actually exist for the underlying object (such as
UID or GID on a DOS file), then the bit won't be set in the stx_mask,
even if the caller asked for the value. In such a case, the returned
value will be a fabrication.
Note that there are instances where the type might not be valid, for
instance Windows reparse points.
(2) stx_rdev_*.
This will be set only if stx_mode indicates we're looking at a
blockdev or a chardev, otherwise will be 0.
(3) stx_btime.
Similar to (1), except this will be set to 0 if it doesn't exist.
=======
TESTING
=======
The following test program can be used to test the statx system call:
samples/statx/test-statx.c
Just compile and run, passing it paths to the files you want to examine.
The file is built automatically if CONFIG_SAMPLES is enabled.
Here's some example output. Firstly, an NFS directory that crosses to
another FSID. Note that the AUTOMOUNT attribute is set because transiting
this directory will cause d_automount to be invoked by the VFS.
[root@andromeda ~]# /tmp/test-statx -A /warthog/data
statx(/warthog/data) = 0
results=7ff
Size: 4096 Blocks: 8 IO Block: 1048576 directory
Device: 00:26 Inode: 1703937 Links: 125
Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
Access: 2016-11-24 09:02:12.219699527+0000
Modify: 2016-11-17 10:44:36.225653653+0000
Change: 2016-11-17 10:44:36.225653653+0000
Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------)
Secondly, the result of automounting on that directory.
[root@andromeda ~]# /tmp/test-statx /warthog/data
statx(/warthog/data) = 0
results=7ff
Size: 4096 Blocks: 8 IO Block: 1048576 directory
Device: 00:27 Inode: 2 Links: 125
Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041
Access: 2016-11-24 09:02:12.219699527+0000
Modify: 2016-11-17 10:44:36.225653653+0000
Change: 2016-11-17 10:44:36.225653653+0000
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This round introduces several interesting features such as on-disk NAT bitmaps,
IO alignment, and a discard thread. And it includes a couple of major bug fixes
as below.
== Enhancement ==
- introduce on-disk bitmaps to avoid scanning NAT blocks when getting free nids
- support IO alignment to prepare open-channel SSD integration in future
- introduce a discard thread to avoid long latency during checkpoint and fstrim
- use SSR for warm node and enable inline_xattr by default
- introduce in-memory bitmaps to check FS consistency for debugging
- improve write_begin by avoiding needless read IO
== Bug fix ==
- fix broken zone_reset behavior for SMR drive
- fix wrong victim selection policy during GC
- fix missing behavior when preparing discard commands
- fix bugs in atomic write support and fiemap
- workaround to handle multiple f2fs_add_link calls having same name
And it includes a bunch of clean-up patches as well.
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Merge tag 'for-f2fs-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs
Pull f2fs updates from Jaegeuk Kim:
"This round introduces several interesting features such as on-disk NAT
bitmaps, IO alignment, and a discard thread. And it includes a couple
of major bug fixes as below.
Enhancements:
- introduce on-disk bitmaps to avoid scanning NAT blocks when getting
free nids
- support IO alignment to prepare open-channel SSD integration in
future
- introduce a discard thread to avoid long latency during checkpoint
and fstrim
- use SSR for warm node and enable inline_xattr by default
- introduce in-memory bitmaps to check FS consistency for debugging
- improve write_begin by avoiding needless read IO
Bug fixes:
- fix broken zone_reset behavior for SMR drive
- fix wrong victim selection policy during GC
- fix missing behavior when preparing discard commands
- fix bugs in atomic write support and fiemap
- workaround to handle multiple f2fs_add_link calls having same name
... and it includes a bunch of clean-up patches as well"
* tag 'for-f2fs-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (97 commits)
f2fs: avoid to flush nat journal entries
f2fs: avoid to issue redundant discard commands
f2fs: fix a plint compile warning
f2fs: add f2fs_drop_inode tracepoint
f2fs: Fix zoned block device support
f2fs: remove redundant set_page_dirty()
f2fs: fix to enlarge size of write_io_dummy mempool
f2fs: fix memory leak of write_io_dummy mempool during umount
f2fs: fix to update F2FS_{CP_}WB_DATA count correctly
f2fs: use MAX_FREE_NIDS for the free nids target
f2fs: introduce free nid bitmap
f2fs: new helper cur_cp_crc() getting crc in f2fs_checkpoint
f2fs: update the comment of default nr_pages to skipping
f2fs: drop the duplicate pval in f2fs_getxattr
f2fs: Don't update the xattr data that same as the exist
f2fs: kill __is_extent_same
f2fs: avoid bggc->fggc when enough free segments are avaliable after cp
f2fs: select target segment with closer temperature in SSR mode
f2fs: show simple call stack in fault injection message
f2fs: no need lock_op in f2fs_write_inline_data
...
In scenario of intensively node allocation, free nids will be ran out
soon, then it needs to stop to load free nids by traversing NAT blocks,
in worse case, if NAT blocks does not be cached in memory, it generates
IOs which slows down our foreground operations.
In order to speed up node allocation, in this patch we introduce a new
free_nid_bitmap array, so there is an bitmap table for each NAT block,
Once the NAT block is loaded, related bitmap cache will be switched on,
and bitmap will be set during traversing nat entries in NAT block, later
we can query and update nid usage status in memory completely.
With such implementation, I expect performance of node allocation can be
improved in the long-term after filesystem image is mounted.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
There are four places that getting the crc value in f2fs_checkpoint,
just add a new helper cur_cp_crc for them.
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Since commit ee6d182f2a ("f2fs: remove syncing inode page in all the
cases") delayed inode element updating from inode cache to node page
cache, so once largest cached extent is updated, we can make inode dirty
immediately instead of checking and updating it in the end of extent
cache update.
The above commit didn't clean up unneeded codes in extent_cache.c, let's
finish the job in this patch.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Previously kernel message can show that in which function we do the
injection, but unfortunately, most of the caller are the same, for
tracking more information of injection path, it needs to show upper
caller's name. This patch supports that ability.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This patches adds bitmaps to represent empty or full NAT blocks containing
free nid entries.
If we can find valid crc|cp_ver in the last block of checkpoint pack, we'll
use these bitmaps when building free nids. In order to avoid checkpointing
burden, up-to-date bitmaps will be flushed only during umount time. So,
normally we can get this gain, but when power-cut happens, we rely on fsck.f2fs
which recovers this bitmap again.
After this patch, we build free nids from nid #0 at mount time to make more
full NAT blocks, but in runtime, we check empty NAT blocks to load free nids
without loading any NAT pages from disk.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
David Miller
Linus Torvalds
Michal Hocko
Jaegeuk Kim
Chao Yu
Hou Pengyang
Arnd Bergmann
Tomohiro Kusumi
Yunlei He
Kinglong Mee
David Howells