OpenCloudOS-Kernel/fs/btrfs
Nikolay Borisov d79b7c26b1 btrfs: Speed up btrfs_file_llseek
Modifying the file position is done on a per-file basis. This renders
holding the inode lock for writing useless and makes the performance of
concurrent llseek's abysmal.

Fix this by holding the inode for read. This provides protection against
concurrent truncates and find_desired_extent already includes proper
extent locking for the range which ensures proper locking against
concurrent writes. SEEK_CUR and SEEK_END can be done lockessly.

The former is synchronized by file::f_lock spinlock. SEEK_END is not
synchronized but atomic, but that's OK since there is not guarantee that
SEEK_END will always be at the end of the file in the face of tail
modifications.

This change brings ~82% performance improvement when doing a lot of
parallel fseeks. The workload essentially does:

    for (d=0; d<num_seek_read; d++)
      {
	/* offset %= 16777216; */
	fseek (f, 256 * d % 16777216, SEEK_SET);
	fread (buffer, 64, 1, f);
      }

Without patch:

num workprocesses = 16
num fseek/fread = 8000000
step = 256
fork 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

real	0m41.412s
user	0m28.777s
sys	2m16.510s

With patch:

num workprocesses = 16
num fseek/fread = 8000000
step = 256
fork 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

real	0m11.479s
user	0m27.629s
sys	0m21.040s

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18 12:46:59 +01:00
..
tests Btrfs: fix selftests failure due to uninitialized i_mode in test inodes 2019-09-24 14:45:02 +02:00
Kconfig btrfs: Fix build error while LIBCRC32C is module 2019-07-17 17:03:30 +02:00
Makefile btrfs: migrate the block group lookup code 2019-09-09 14:59:04 +02:00
acl.c btrfs: cleanup btrfs_setxattr_trans and drop transaction parameter 2019-04-29 19:02:44 +02:00
async-thread.c btrfs: add __pure attribute to functions 2019-11-18 12:46:52 +01:00
async-thread.h btrfs: add __pure attribute to functions 2019-11-18 12:46:52 +01:00
backref.c Btrfs: fix deadlock between fiemap and transaction commits 2019-07-30 18:25:12 +02:00
backref.h btrfs: fiemap: preallocate ulists for btrfs_check_shared 2019-07-01 13:34:53 +02:00
block-group.c btrfs: use btrfs_block_group_cache_done in update_block_group 2019-11-18 12:46:56 +01:00
block-group.h btrfs: move struct io_ctl to free-space-cache.h 2019-09-09 14:59:15 +02:00
block-rsv.c btrfs: use btrfs_try_granting_tickets in update_global_rsv 2019-09-09 14:59:19 +02:00
block-rsv.h btrfs: migrate the global_block_rsv helpers to block-rsv.c 2019-07-02 12:30:55 +02:00
btrfs_inode.h btrfs: remove assumption about csum type form btrfs_print_data_csum_error() 2019-07-01 13:35:02 +02:00
check-integrity.c btrfs: reduce stack usage for btrfsic_process_written_block 2019-09-09 14:58:58 +02:00
check-integrity.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
compression.c btrfs: compression: remove ops pointer from workspace_manager 2019-11-18 12:46:59 +01:00
compression.h btrfs: compression: remove ops pointer from workspace_manager 2019-11-18 12:46:59 +01:00
ctree.c btrfs: opencode extent_buffer_get 2019-11-18 12:46:54 +01:00
ctree.h Btrfs: delete the entire async bio submission framework 2019-11-18 12:46:53 +01:00
delalloc-space.c Btrfs: fix qgroup double free after failure to reserve metadata for delalloc 2019-10-17 20:13:44 +02:00
delalloc-space.h btrfs: migrate the delalloc space stuff to it's own home 2019-07-04 17:26:17 +02:00
delayed-inode.c btrfs: use refcount_inc_not_zero in kill_all_nodes 2019-11-18 12:46:51 +01:00
delayed-inode.h Btrfs: delayed-inode: use rb_first_cached for ins_root and del_root 2018-10-15 17:23:33 +02:00
delayed-ref.c btrfs: rename btrfs_space_info_add_old_bytes 2019-09-09 14:59:18 +02:00
delayed-ref.h btrfs: migrate the delayed refs rsv code 2019-07-04 17:26:17 +02:00
dev-replace.c btrfs: add __pure attribute to functions 2019-11-18 12:46:52 +01:00
dev-replace.h btrfs: add __pure attribute to functions 2019-11-18 12:46:52 +01:00
dir-item.c btrfs: remove unused parameter fs_info from btrfs_extend_item 2019-04-29 19:02:50 +02:00
disk-io.c btrfs: use bool argument in free_root_pointers() 2019-11-18 12:46:55 +01:00
disk-io.h btrfs: add __cold attribute to more functions 2019-11-18 12:46:52 +01:00
export.c btrfs: drop unused parameter is_new from btrfs_iget 2019-11-18 12:46:52 +01:00
export.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
extent-io-tree.h btrfs: move the failrec tree stuff into extent-io-tree.h 2019-11-18 12:46:47 +01:00
extent-tree.c btrfs: User assert to document transaction requirement 2019-11-18 12:46:54 +01:00
extent_io.c btrfs: Avoid getting stuck during cyclic writebacks 2019-11-18 12:46:54 +01:00
extent_io.h btrfs: opencode extent_buffer_get 2019-11-18 12:46:54 +01:00
extent_map.c btrfs: assert extent map tree lock in add_extent_mapping 2019-09-09 14:59:00 +02:00
extent_map.h btrfs: Remove impossible condition from mergable_maps 2019-02-25 14:13:21 +01:00
file-item.c btrfs: directly call into crypto framework for checksumming 2019-07-01 13:35:02 +02:00
file.c btrfs: Speed up btrfs_file_llseek 2019-11-18 12:46:59 +01:00
free-space-cache.c btrfs: check page->mapping when loading free space cache 2019-11-18 12:46:56 +01:00
free-space-cache.h btrfs: move struct io_ctl to free-space-cache.h 2019-09-09 14:59:15 +02:00
free-space-tree.c btrfs: move basic block_group definitions to their own header 2019-09-09 14:59:03 +02:00
free-space-tree.h btrfs: move basic block_group definitions to their own header 2019-09-09 14:59:03 +02:00
inode-item.c btrfs: Make btrfs_find_name_in_ext_backref return struct btrfs_inode_extref 2019-09-09 14:59:16 +02:00
inode-map.c btrfs: qgroup: Always free PREALLOC META reserve in btrfs_delalloc_release_extents() 2019-10-15 18:50:07 +02:00
inode-map.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
inode.c Btrfs: fix metadata space leak on fixup worker failure to set range as delalloc 2019-11-18 12:46:56 +01:00
ioctl.c btrfs: ioctl: Try to use btrfs_fs_info instead of *file 2019-11-18 12:46:55 +01:00
locking.c btrfs: move btrfs_unlock_up_safe to other locking functions 2019-11-18 12:46:49 +01:00
locking.h btrfs: move btrfs_unlock_up_safe to other locking functions 2019-11-18 12:46:49 +01:00
lzo.c btrfs: compression: inline free_workspace 2019-11-18 12:46:59 +01:00
misc.h btrfs: add 64bit safe helper for power of two checks 2019-11-18 12:46:50 +01:00
ordered-data.c btrfs: get rid of unique workqueue helper functions 2019-11-18 12:46:48 +01:00
ordered-data.h btrfs: don't assume ordered sums to be 4 bytes 2019-07-01 13:35:00 +02:00
orphan.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
print-tree.c btrfs: switch extent_buffer write_locks from atomic to int 2019-07-02 12:30:47 +02:00
print-tree.h btrfs: print-tree: debugging output enhancement 2018-04-20 19:18:16 +02:00
props.c btrfs: props: remove unnecessary hash_init() 2019-11-18 12:46:55 +01:00
props.h btrfs: delete unused function btrfs_set_prop_trans 2019-04-29 19:02:54 +02:00
qgroup.c btrfs: opencode extent_buffer_get 2019-11-18 12:46:54 +01:00
qgroup.h btrfs: qgroup: Move reserved data accounting from btrfs_delayed_ref_head to btrfs_qgroup_extent_record 2019-02-25 14:13:39 +01:00
raid56.c btrfs: get rid of unique workqueue helper functions 2019-11-18 12:46:48 +01:00
raid56.h btrfs: constify map parameter for nr_parity_stripes and nr_data_stripes 2019-07-01 13:34:58 +02:00
rcu-string.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
reada.c btrfs: get rid of unique workqueue helper functions 2019-11-18 12:46:48 +01:00
ref-verify.c btrfs: fix uninitialized ret in ref-verify 2019-10-03 15:00:56 +02:00
ref-verify.h btrfs: ref-verify: Use btrfs_ref to refactor btrfs_ref_tree_mod() 2019-04-29 19:02:49 +02:00
relocation.c btrfs: opencode extent_buffer_get 2019-11-18 12:46:54 +01:00
root-tree.c btrfs: rename the btrfs_calc_*_metadata_size helpers 2019-09-09 14:59:13 +02:00
scrub.c btrfs: get rid of unique workqueue helper functions 2019-11-18 12:46:48 +01:00
send.c btrfs: drop unused parameter is_new from btrfs_iget 2019-11-18 12:46:52 +01:00
send.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
space-info.c btrfs: add __pure attribute to functions 2019-11-18 12:46:52 +01:00
space-info.h btrfs: add __pure attribute to functions 2019-11-18 12:46:52 +01:00
struct-funcs.c btrfs: tie extent buffer and it's token together 2019-09-09 14:59:16 +02:00
super.c Btrfs: delete the entire async bio submission framework 2019-11-18 12:46:53 +01:00
sysfs.c btrfs: sysfs: move helper macros to sysfs.c 2019-09-09 14:59:08 +02:00
sysfs.h btrfs: sysfs: move helper macros to sysfs.c 2019-09-09 14:59:08 +02:00
transaction.c btrfs: Rename btrfs_join_transaction_nolock 2019-11-18 12:46:54 +01:00
transaction.h btrfs: Rename btrfs_join_transaction_nolock 2019-11-18 12:46:54 +01:00
tree-checker.c btrfs: use better definition of number of compression type 2019-11-18 12:46:55 +01:00
tree-checker.h btrfs: get fs_info from eb in btrfs_check_chunk_valid 2019-04-29 19:02:39 +02:00
tree-defrag.c btrfs: open code now trivial btrfs_set_lock_blocking 2019-02-25 14:13:27 +01:00
tree-log.c btrfs: opencode extent_buffer_get 2019-11-18 12:46:54 +01:00
tree-log.h btrfs: get fs_info from trans in btrfs_set_log_full_commit 2019-04-29 19:02:41 +02:00
ulist.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
ulist.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
uuid-tree.c btrfs: remove unused parameter fs_info from btrfs_extend_item 2019-04-29 19:02:50 +02:00
volumes.c Btrfs: delete the entire async bio submission framework 2019-11-18 12:46:53 +01:00
volumes.h Btrfs: delete the entire async bio submission framework 2019-11-18 12:46:53 +01:00
xattr.c Btrfs: fix failure to persist compression property xattr deletion on fsync 2019-06-17 16:37:17 +02:00
xattr.h btrfs: cleanup btrfs_setxattr_trans and drop transaction parameter 2019-04-29 19:02:44 +02:00
zlib.c btrfs: compression: inline free_workspace 2019-11-18 12:46:59 +01:00
zstd.c btrfs: compression: inline free_workspace 2019-11-18 12:46:59 +01:00