linux/fs/btrfs
Johannes Thumshirn d2e174d5d3 btrfs: document extent mapping assumptions in checksum
Document why map_private_extent_buffer() cannot return '1' (i.e. the map
spans two pages) for the csum_tree_block() case.

The current algorithm for detecting a page boundary crossing in
map_private_extent_buffer() will return a '1' *IFF* the extent buffer's
offset in the page + the offset passed in by csum_tree_block() and the
minimal length passed in by csum_tree_block() - 1 are bigger than
PAGE_SIZE.

We always pass BTRFS_CSUM_SIZE (32) as offset and a minimal length of 32
and the current extent buffer allocator always guarantees page aligned
extends, so the above condition can't be true.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:41 +01:00
..
tests btrfs: use EXPORT_FOR_TESTS for conditionally exported functions 2018-12-17 14:51:37 +01:00
acl.c btrfs: remove unnecessary curly braces in btrfs_get_acl 2018-08-06 13:12:41 +02:00
async-thread.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
async-thread.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
backref.c btrfs: Remove needless tree locking in iterate_inode_extrefs 2018-12-17 14:51:30 +01:00
backref.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
btrfs_inode.h btrfs: use tagged writepage to mitigate livelock of snapshot 2018-12-17 14:51:33 +01:00
check-integrity.c btrfs: Remove fsid/metadata_fsid fields from btrfs_info 2018-12-17 14:51:37 +01:00
check-integrity.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
compression.c btrfs: Remove unused extent_state argument from btrfs_writepage_endio_finish_ordered 2018-12-17 14:51:32 +01:00
compression.h btrfs: compression: Add linux/sizes.h for compression.h 2018-05-29 18:13:00 +02:00
ctree.c btrfs: Remove fsid/metadata_fsid fields from btrfs_info 2018-12-17 14:51:37 +01:00
ctree.h btrfs: Remove fsid/metadata_fsid fields from btrfs_info 2018-12-17 14:51:37 +01:00
dedupe.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
delayed-inode.c Btrfs: kill btrfs_clear_path_blocking 2018-10-15 17:23:38 +02:00
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: delayed-ref: extract find_first_ref_head from find_ref_head 2018-10-17 19:21:00 +02:00
delayed-ref.h btrfs: delayed-ref: pass delayed_refs directly to btrfs_delayed_ref_lock 2018-10-15 17:23:41 +02:00
dev-replace.c btrfs: don't report user-requested cancel as an error 2018-12-17 14:51:36 +01:00
dev-replace.h btrfs: mark btrfs_dev_replace_start as static 2018-12-17 14:51:34 +01:00
dir-item.c btrfs: Remove root parameter from btrfs_insert_dir_item 2018-10-15 17:23:25 +02:00
disk-io.c btrfs: document extent mapping assumptions in checksum 2018-12-17 14:51:41 +01:00
disk-io.h btrfs: unify end_io callbacks of async_submit_bio 2018-08-06 13:12:55 +02:00
export.c btrfs: Remove 'objectid' member from struct btrfs_root 2018-10-15 17:23:25 +02:00
export.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
extent_io.c btrfs: don't initialize 'offset' in map_private_extent_buffer() 2018-12-17 14:51:41 +01:00
extent_io.h btrfs: Remove extent_io_ops::readpage_io_failed_hook 2018-12-17 14:51:41 +01:00
extent_map.c Btrfs: extent_map: use rb_first_cached 2018-10-15 17:23:33 +02:00
extent_map.h Btrfs: extent_map: use rb_first_cached 2018-10-15 17:23:33 +02:00
extent-tree.c Btrfs: allow clear_extent_dirty() to receive a cached extent state record 2018-12-17 14:51:38 +01:00
file-item.c btrfs: replace btrfs_io_bio::end_io with a simple helper 2018-12-17 14:51:40 +01:00
file.c Btrfs: remove no longer used io_err from btrfs_log_ctx 2018-12-17 14:51:31 +01:00
free-space-cache.c Btrfs: fix deadlock on tree root leaf when finding free extent 2018-11-06 16:42:32 +01:00
free-space-cache.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
free-space-tree.c btrfs: use EXPORT_FOR_TESTS for conditionally exported functions 2018-12-17 14:51:37 +01:00
free-space-tree.h btrfs: Remove fs_info argument from add_to_free_space_tree 2018-05-28 18:07:36 +02:00
inode-item.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
inode-map.c btrfs: prune unused includes 2018-08-06 13:12:43 +02:00
inode-map.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
inode.c btrfs: Remove extent_io_ops::readpage_io_failed_hook 2018-12-17 14:51:41 +01:00
ioctl.c btrfs: Remove fsid/metadata_fsid fields from btrfs_info 2018-12-17 14:51:37 +01:00
Kconfig btrfs: add SPDX header to Kconfig 2018-04-12 16:29:55 +02:00
locking.c btrfs: replace waitqueue_actvie with cond_wake_up 2018-05-28 18:23:09 +02:00
locking.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
lzo.c btrfs: lzo: Harden inline lzo compressed extent decompression 2018-05-30 16:46:43 +02:00
Makefile btrfs: Remove custom crc32c init code 2018-03-26 15:09:39 +02:00
math.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
ordered-data.c Btrfs: remove no longer used stuff for tracking pending ordered extents 2018-12-17 14:51:25 +01:00
ordered-data.h Btrfs: remove no longer used stuff for tracking pending ordered extents 2018-12-17 14:51:25 +01:00
orphan.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
print-tree.c btrfs: annotate unlikely branches after V0 extent type removal 2018-08-06 13:12:41 +02:00
print-tree.h btrfs: print-tree: debugging output enhancement 2018-04-20 19:18:16 +02:00
props.c btrfs: property: Set incompat flag if lzo/zstd compression is set 2018-05-17 14:18:25 +02:00
props.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
qgroup.c Btrfs: fix deadlock when enabling quotas due to concurrent snapshot creation 2018-12-17 14:51:39 +01:00
qgroup.h btrfs: qgroup: Avoid calling qgroup functions if qgroup is not enabled 2018-10-15 17:23:40 +02:00
raid56.c btrfs: raid56: catch errors from full_stripe_write 2018-08-06 13:12:45 +02:00
raid56.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
rcu-string.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
reada.c btrfs: prune unused includes 2018-08-06 13:12:43 +02:00
ref-verify.c btrfs: Remove 'objectid' member from struct btrfs_root 2018-10-15 17:23:25 +02:00
ref-verify.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
relocation.c btrfs: add helper to describe block group flags 2018-12-17 14:51:39 +01:00
root-tree.c btrfs: Remove fs_info from btrfs_add_root_ref 2018-08-06 13:13:00 +02:00
scrub.c Btrfs: fix deadlock with memory reclaim during scrub 2018-12-17 14:51:41 +01:00
send.c Btrfs: send, fix infinite loop due to directory rename dependencies 2018-11-21 17:03:50 +01:00
send.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
struct-funcs.c btrfs: prune unused includes 2018-08-06 13:12:43 +02:00
super.c btrfs: Remove fsid/metadata_fsid fields from btrfs_info 2018-12-17 14:51:37 +01:00
sysfs.c btrfs: Add sysfs support for metadata_uuid feature 2018-12-17 14:51:37 +01:00
sysfs.h btrfs: sysfs: Use enum/define value for feature array definitions 2018-05-28 18:23:39 +02:00
transaction.c Btrfs: remove no longer used stuff for tracking pending ordered extents 2018-12-17 14:51:25 +01:00
transaction.h Btrfs: remove no longer used stuff for tracking pending ordered extents 2018-12-17 14:51:25 +01:00
tree-checker.c btrfs: tree-checker: Don't check max block group size as current max chunk size limit is unreliable 2018-12-04 15:05:30 +01:00
tree-checker.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
tree-defrag.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
tree-log.c Btrfs: simpler and more efficient cleanup of a log tree's extent io tree 2018-12-17 14:51:31 +01:00
tree-log.h Btrfs: remove no longer used io_err from btrfs_log_ctx 2018-12-17 14:51:31 +01:00
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 fs_info argument from btrfs_uuid_tree_rem 2018-05-30 16:46:53 +02:00
volumes.c btrfs: balance: print to system log when balance ends or is paused 2018-12-17 14:51:39 +01:00
volumes.h btrfs: remove btrfs_bio_end_io_t 2018-12-17 14:51:40 +01:00
xattr.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
xattr.h btrfs: replace GPL boilerplate by SPDX -- headers 2018-04-12 16:29:46 +02:00
zlib.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00
zstd.c btrfs: replace GPL boilerplate by SPDX -- sources 2018-04-12 16:29:51 +02:00