[PATCH v3 00/14] Make btrfs W=1 clean

[PATCH v3 00/14] Make btrfs W=1 clean

[Nikolay Borisov]

Reworked patches to make touched kdocs adhere to the style described at
https://btrfs.wiki.kernel.org/index.php/Development_notes#Coding_style_preferences

Namely:

 * Removed function names from first line and left only short description
 * Aligned all arguments


Nikolay Borisov (14):
  btrfs: Document modified parameter of add_extent_mapping
  btrfs: Fix parameter description of btrfs_add_extent_mapping
  btrfs: Fix function description format
  btrfs: Fix parameter description in delayed-ref.c functions
  btrfs: Improve parameter description for __btrfs_write_out_cache
  btrfs: Document now parameter of peek_discard_list
  btrfs: Document fs_info in btrfs_rmap_block
  btrfs: Fix description format of fs_info parameter of
    btrfs_wait_on_delayed_iputs
  btrfs: Document btrfs_check_shared parameters
  btrfs: Fix parameter description of
    btrfs_inode_rsv_release/btrfs_delalloc_release_space
  btrfs: Fix parameter description in space-info.c
  btrfs: Fix parameter description for functions in extent_io.c
  lib/zstd: Convert constants to defines
  btrfs: Enable W=1 checks for btrfs

 fs/btrfs/Makefile           | 17 +++++++++++++
 fs/btrfs/backref.c          |  8 +++++-
 fs/btrfs/block-group.c      |  4 ++-
 fs/btrfs/delalloc-space.c   | 29 ++++++++++++---------
 fs/btrfs/delayed-ref.c      | 23 +++++++++--------
 fs/btrfs/discard.c          |  6 +++--
 fs/btrfs/extent_io.c        | 50 +++++++++++++++++++------------------
 fs/btrfs/extent_map.c       | 18 +++++++------
 fs/btrfs/file-item.c        | 22 ++++++++++------
 fs/btrfs/free-space-cache.c | 13 ++++++----
 fs/btrfs/inode.c            |  5 ++--
 fs/btrfs/space-info.c       | 46 ++++++++++++++++++----------------
 include/linux/zstd.h        |  8 +++---
 13 files changed, 151 insertions(+), 98 deletions(-)

--
2.25.1

[PATCH v3 01/14] btrfs: Document modified parameter of add_extent_mapping

[Nikolay Borisov]

Fixes fs/btrfs/extent_map.c:399: warning: Function parameter or member
'modified' not described in 'add_extent_mapping'

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---
 fs/btrfs/extent_map.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index bd6229fb2b6f..c540a37cbdb2 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -385,9 +385,12 @@ static void extent_map_device_clear_bits(struct extent_map *em, unsigned bits)
 }
 
 /**
- * add_extent_mapping - add new extent map to the extent tree
+ * Add new extent map to the extent tree
+ *
  * @tree:	tree to insert new map in
  * @em:		map to insert
+ * @modified:	bool indicating whether the given @em should be added to the
+ *	        modified list, which indicates the extent needs to be logged
  *
  * Insert @em into @tree or perform a simple forward/backward merge with
  * existing mappings.  The extent_map struct passed in will be inserted
-- 
2.25.1

[PATCH v3 02/14] btrfs: Fix parameter description of btrfs_add_extent_mapping

[Nikolay Borisov]

This fixes the following compiler warnings:

fs/btrfs/extent_map.c:601: warning: Function parameter or member 'fs_info' not described in 'btrfs_add_extent_mapping'
fs/btrfs/extent_map.c:601: warning: Function parameter or member 'em_tree' not described in 'btrfs_add_extent_mapping'
fs/btrfs/extent_map.c:601: warning: Function parameter or member 'em_in' not described in 'btrfs_add_extent_mapping'
fs/btrfs/extent_map.c:601: warning: Function parameter or member 'start' not described in 'btrfs_add_extent_mapping'
fs/btrfs/extent_map.c:601: warning: Function parameter or member 'len' not described in 'btrfs_add_extent_mapping'

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---
 fs/btrfs/extent_map.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index c540a37cbdb2..fc6503218caa 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -577,12 +577,13 @@ static noinline int merge_extent_mapping(struct extent_map_tree *em_tree,
 }
 
 /**
- * btrfs_add_extent_mapping - add extent mapping into em_tree
- * @fs_info - used for tracepoint
- * @em_tree - the extent tree into which we want to insert the extent mapping
- * @em_in   - extent we are inserting
- * @start   - start of the logical range btrfs_get_extent() is requesting
- * @len     - length of the logical range btrfs_get_extent() is requesting
+ * Add extent mapping into em_tree
+ *
+ * @fs_info:  the filesystem
+ * @em_tree:  the extent tree into which we want to insert the extent mapping
+ * @em_in:    extent we are inserting
+ * @start:    start of the logical range btrfs_get_extent() is requesting
+ * @len:      length of the logical range btrfs_get_extent() is requesting
  *
  * Note that @em_in's range may be different from [start, start+len),
  * but they must be overlapped.
-- 
2.25.1

[PATCH v3 03/14] btrfs: Fix function description format

[Nikolay Borisov]

This fixes following W=1 warnings:

fs/btrfs/file-item.c:27: warning: Cannot understand  * @inode:  the inode we want to update the disk_i_size for
 on line 27 - I thought it was a doc line
fs/btrfs/file-item.c:65: warning: Cannot understand  * @inode - the inode we're modifying
 on line 65 - I thought it was a doc line
fs/btrfs/file-item.c:91: warning: Cannot understand  * @inode - the inode we're modifying
 on line 91 - I thought it was a doc line

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---
 fs/btrfs/file-item.c | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 6ccfc019ad90..784adae2d0f9 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -24,8 +24,10 @@
 				       PAGE_SIZE))
 
 /**
- * @inode - the inode we want to update the disk_i_size for
- * @new_i_size - the i_size we want to set to, 0 if we use i_size
+ * Set inode's size according to filesystem options
+ *
+ * @inode:      the inode we want to update the disk_i_size for
+ * @new_i_size: the i_size we want to set to, 0 if we use i_size
  *
  * With NO_HOLES set this simply sets the disk_is_size to whatever i_size_read()
  * returns as it is perfectly fine with a file that has holes without hole file
@@ -62,9 +64,11 @@ void btrfs_inode_safe_disk_i_size_write(struct btrfs_inode *inode, u64 new_i_siz
 }
 
 /**
- * @inode - the inode we're modifying
- * @start - the start file offset of the file extent we've inserted
- * @len - the logical length of the file extent item
+ * Marks a range within a file as having a new extent inserted
+ *
+ * @inode: the inode being modifying
+ * @start: the start file offset of the file extent we've inserted
+ * @len:   logical length of the file extent item
  *
  * Call when we are inserting a new file extent where there was none before.
  * Does not need to call this in the case where we're replacing an existing file
@@ -88,9 +92,11 @@ int btrfs_inode_set_file_extent_range(struct btrfs_inode *inode, u64 start,
 }
 
 /**
- * @inode - the inode we're modifying
- * @start - the start file offset of the file extent we've inserted
- * @len - the logical length of the file extent item
+ * Marks an inode range as not having a backing extent
+ *
+ * @inode: the inode being modifying
+ * @start: the start file offset of the file extent we've inserted
+ * @len:   the logical length of the file extent item
  *
  * Called when we drop a file extent, for example when we truncate.  Doesn't
  * need to be called for cases where we're replacing a file extent, like when
-- 
2.25.1

[PATCH v3 04/14] btrfs: Fix parameter description in delayed-ref.c functions

[Nikolay Borisov]

This fixes the following warnings:

fs/btrfs/delayed-ref.c:80: warning: Function parameter or member 'fs_info' not described in 'btrfs_delayed_refs_rsv_release'
fs/btrfs/delayed-ref.c:80: warning: Function parameter or member 'nr' not described in 'btrfs_delayed_refs_rsv_release'
fs/btrfs/delayed-ref.c:128: warning: Function parameter or member 'fs_info' not described in 'btrfs_migrate_to_delayed_refs_rsv'
fs/btrfs/delayed-ref.c:128: warning: Function parameter or member 'src' not described in 'btrfs_migrate_to_delayed_refs_rsv'
fs/btrfs/delayed-ref.c:128: warning: Function parameter or member 'num_bytes' not described in 'btrfs_migrate_to_delayed_refs_rsv'
fs/btrfs/delayed-ref.c:174: warning: Function parameter or member 'fs_info' not described in 'btrfs_delayed_refs_rsv_refill'
fs/btrfs/delayed-ref.c:174: warning: Function parameter or member 'flush' not described in 'btrfs_delayed_refs_rsv_refill'

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---
 fs/btrfs/delayed-ref.c | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c
index 353cc2994d10..7425d76fcfa8 100644
--- a/fs/btrfs/delayed-ref.c
+++ b/fs/btrfs/delayed-ref.c
@@ -69,9 +69,10 @@ int btrfs_should_throttle_delayed_refs(struct btrfs_trans_handle *trans)
 }
 
 /**
- * btrfs_delayed_refs_rsv_release - release a ref head's reservation.
- * @fs_info - the fs_info for our fs.
- * @nr - the number of items to drop.
+ * Release a ref head's reservation.
+ *
+ * @fs_info:  the filesystem
+ * @nr:       the number of items to drop.
  *
  * This drops the delayed ref head's count from the delayed refs rsv and frees
  * any excess reservation we had.
@@ -114,10 +115,11 @@ void btrfs_update_delayed_refs_rsv(struct btrfs_trans_handle *trans)
 }
 
 /**
- * btrfs_migrate_to_delayed_refs_rsv - transfer bytes to our delayed refs rsv.
- * @fs_info - the fs info for our fs.
- * @src - the source block rsv to transfer from.
- * @num_bytes - the number of bytes to transfer.
+ * Transfer bytes to our delayed refs rsv.
+ *
+ * @fs_info:   the filesystem
+ * @src:       the source block rsv to transfer from.
+ * @num_bytes: the number of bytes to transfer.
  *
  * This transfers up to the num_bytes amount from the src rsv to the
  * delayed_refs_rsv.  Any extra bytes are returned to the space info.
@@ -162,9 +164,10 @@ void btrfs_migrate_to_delayed_refs_rsv(struct btrfs_fs_info *fs_info,
 }
 
 /**
- * btrfs_delayed_refs_rsv_refill - refill based on our delayed refs usage.
- * @fs_info - the fs_info for our fs.
- * @flush - control how we can flush for this reservation.
+ * Refill based on our delayed refs usage.
+ *
+ * @fs_info: the filesystem
+ * @flush:   control how we can flush for this reservation.
  *
  * This will refill the delayed block_rsv up to 1 items size worth of space and
  * will return -ENOSPC if we can't make the reservation.
-- 
2.25.1

[PATCH v3 05/14] btrfs: Improve parameter description for __btrfs_write_out_cache

[Nikolay Borisov]

Fixes following W=1 warnings:
fs/btrfs/free-space-cache.c:1317: warning: Function parameter or member 'root' not described in '__btrfs_write_out_cache'
fs/btrfs/free-space-cache.c:1317: warning: Function parameter or member 'inode' not described in '__btrfs_write_out_cache'
fs/btrfs/free-space-cache.c:1317: warning: Function parameter or member 'ctl' not described in '__btrfs_write_out_cache'
fs/btrfs/free-space-cache.c:1317: warning: Function parameter or member 'block_group' not described in '__btrfs_write_out_cache'
fs/btrfs/free-space-cache.c:1317: warning: Function parameter or member 'io_ctl' not described in '__btrfs_write_out_cache'
fs/btrfs/free-space-cache.c:1317: warning: Function parameter or member 'trans' not described in '__btrfs_write_out_cache'

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---
 fs/btrfs/free-space-cache.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index fd6ddd6b8165..324540993fc5 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -1299,11 +1299,14 @@ int btrfs_wait_cache_io(struct btrfs_trans_handle *trans,
 }
 
 /**
- * __btrfs_write_out_cache - write out cached info to an inode
- * @root - the root the inode belongs to
- * @ctl - the free space cache we are going to write out
- * @block_group - the block_group for this cache if it belongs to a block_group
- * @trans - the trans handle
+ * Write out cached info to an inode
+ *
+ * @root:        root the inode belongs to
+ * @inode:       freespace inode we are writing out
+ * @ctl:         the free space cache we are going to write out
+ * @block_group: the block_group for this cache if it belongs to a block_group
+ * @io_ctl:      holds context for the io
+ * @trans:       the trans handle
  *
  * This function writes out a free space cache struct to disk for quick recovery
  * on mount.  This will return 0 if it was successful in writing the cache out,
-- 
2.25.1

[PATCH v3 06/14] btrfs: Document now parameter of peek_discard_list

[Nikolay Borisov]

Fixes fs/btrfs/discard.c:203: warning: Function parameter or member 'now' not described in 'peek_discard_list'

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---
 fs/btrfs/discard.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/discard.c b/fs/btrfs/discard.c
index 2b8383d41144..306ff20af70f 100644
--- a/fs/btrfs/discard.c
+++ b/fs/btrfs/discard.c
@@ -185,10 +185,12 @@ static struct btrfs_block_group *find_next_block_group(
 }
 
 /**
- * peek_discard_list - wrap find_next_block_group()
- * @discard_ctl: discard control
+ * Wrap find_next_block_group()
+ *
+ * @discard_ctl:   discard control
  * @discard_state: the discard_state of the block_group after state management
  * @discard_index: the discard_index of the block_group after state management
+ * @now:           time when discard was invoked, in ns
  *
  * This wraps find_next_block_group() and sets the block_group to be in use.
  * discard_state's control flow is managed here.  Variables related to
-- 
2.25.1

[PATCH v3 07/14] btrfs: Document fs_info in btrfs_rmap_block

[Nikolay Borisov]

Fixes fs/btrfs/block-group.c:1570: warning: Function parameter or member 'fs_info' not described in 'btrfs_rmap_block'

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---
 fs/btrfs/block-group.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index 0886e81e5540..cd277c483777 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -1553,7 +1553,9 @@ static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
 }
 
 /**
- * btrfs_rmap_block - Map a physical disk address to a list of logical addresses
+ * Map a physical disk address to a list of logical addresses
+ *
+ * @fs_info:       the filesystem
  * @chunk_start:   logical address of block group
  * @physical:	   physical address to map to logical addresses
  * @logical:	   return array of logical addresses which map to @physical
-- 
2.25.1

[PATCH v3 08/14] btrfs: Fix description format of fs_info parameter of btrfs_wait_on_delayed_iputs

[Nikolay Borisov]

Fixes fs/btrfs/inode.c:3101: warning: Function parameter or member 'fs_info' not described in 'btrfs_wait_on_delayed_iputs'

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---
 fs/btrfs/inode.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 5906b4267204..72b892251764 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3088,8 +3088,9 @@ void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info)
 }
 
 /**
- * btrfs_wait_on_delayed_iputs - wait on the delayed iputs to be done running
- * @fs_info - the fs_info for this fs
+ * Wait for flushing all delayed iputs
+ *
+ * @fs_info:  the fs_info for this fs
  * @return - EINTR if we were killed, 0 if nothing's pending
  *
  * This will wait on any delayed iputs that are currently running with KILLABLE
-- 
2.25.1

[PATCH v3 09/14] btrfs: Document btrfs_check_shared parameters

[Nikolay Borisov]

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---
 fs/btrfs/backref.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index ef71aba5bc15..bbe50affb554 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -1501,7 +1501,13 @@ int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
 }
 
 /**
- * btrfs_check_shared - tell us whether an extent is shared
+ * Checks if an extent is shared or not
+ *
+ * @root:   root inode belongs to
+ * @inum:   inode number of the inode whose extent we are checking
+ * @bytenr: logical bytenr of the extent we are checking
+ * @roots:  list of roots this extent is shared among
+ * @tmp:    temporary list used for iteration
  *
  * btrfs_check_shared uses the backref walking code but will short
  * circuit as soon as it finds a root or inode that doesn't match the
-- 
2.25.1

[PATCH v3 10/14] btrfs: Fix parameter description of btrfs_inode_rsv_release/btrfs_delalloc_release_space

[Nikolay Borisov]

Fixes following warnings:

fs/btrfs/delalloc-space.c:205: warning: Function parameter or member 'inode' not described in 'btrfs_inode_rsv_release'
fs/btrfs/delalloc-space.c:205: warning: Function parameter or member 'qgroup_free' not described in 'btrfs_inode_rsv_release'
fs/btrfs/delalloc-space.c:472: warning: Function parameter or member 'reserved' not described in 'btrfs_delalloc_release_space'
fs/btrfs/delalloc-space.c:472: warning: Function parameter or member 'qgroup_free' not described in 'btrfs_delalloc_release_space'
fs/btrfs/delalloc-space.c:472: warning: Excess function parameter 'release_bytes' description in 'btrfs_delalloc_release_space'

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---
 fs/btrfs/delalloc-space.c | 29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/fs/btrfs/delalloc-space.c b/fs/btrfs/delalloc-space.c
index bacee09b7bfd..35f25a3d897b 100644
--- a/fs/btrfs/delalloc-space.c
+++ b/fs/btrfs/delalloc-space.c
@@ -191,12 +191,14 @@ void btrfs_free_reserved_data_space(struct btrfs_inode *inode,
 }
 
 /**
- * btrfs_inode_rsv_release - release any excessive reservation.
- * @inode - the inode we need to release from.
- * @qgroup_free - free or convert qgroup meta.
- *   Unlike normal operation, qgroup meta reservation needs to know if we are
- *   freeing qgroup reservation or just converting it into per-trans.  Normally
- *   @qgroup_free is true for error handling, and false for normal release.
+ * Release any excessive reservation.
+ *
+ * @inode:       the inode we need to release from.
+ * @qgroup_free: free or convert qgroup meta. Unlike normal operation, qgroup
+ *               meta reservation needs to know if we are freeing qgroup
+ *               reservation or just converting it into per-trans.  Normally
+ *               @qgroup_free is true for error handling, and false for normal
+ *               release.
  *
  * This is the same as btrfs_block_rsv_release, except that it handles the
  * tracepoint for the reservation.
@@ -361,7 +363,8 @@ int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes)
 }
 
 /**
- * btrfs_delalloc_release_metadata - release a metadata reservation for an inode
+ * Release a metadata reservation for an inode
+ *
  * @inode: the inode to release the reservation for.
  * @num_bytes: the number of bytes we are releasing.
  * @qgroup_free: free qgroup reservation or convert it to per-trans reservation
@@ -455,11 +458,13 @@ int btrfs_delalloc_reserve_space(struct btrfs_inode *inode,
 }
 
 /**
- * btrfs_delalloc_release_space - release data and metadata space for delalloc
- * @inode: inode we're releasing space for
- * @start: start position of the space already reserved
- * @len: the len of the space already reserved
- * @release_bytes: the len of the space we consumed or didn't use
+ * Release data and metadata space for delalloc
+ *
+ * @inode:       inode we're releasing space for
+ * @reserved:    list of changed/reserved ranges
+ * @start:       start position of the space already reserved
+ * @len:         the len of the space already reserved
+ * @qgroup_free: should qgroup reserved-space also be freed
  *
  * This function will release the metadata space that was not used and will
  * decrement ->delalloc_bytes and remove it from the fs_info delalloc_inodes
-- 
2.25.1

[PATCH v3 11/14] btrfs: Fix parameter description in space-info.c

[Nikolay Borisov]

With these fixes space-info.c is clearn for W=1 warnings, namely the
following ones are fixed:

fs/btrfs/space-info.c:575: warning: Function parameter or member 'fs_info' not described in 'may_commit_transaction'
fs/btrfs/space-info.c:575: warning: Function parameter or member 'space_info' not described in 'may_commit_transaction'
fs/btrfs/space-info.c:1231: warning: Function parameter or member 'fs_info' not described in 'handle_reserve_ticket'
fs/btrfs/space-info.c:1231: warning: Function parameter or member 'space_info' not described in 'handle_reserve_ticket'
fs/btrfs/space-info.c:1231: warning: Function parameter or member 'ticket' not described in 'handle_reserve_ticket'
fs/btrfs/space-info.c:1231: warning: Function parameter or member 'flush' not described in 'handle_reserve_ticket'
fs/btrfs/space-info.c:1315: warning: Function parameter or member 'fs_info' not described in '__reserve_bytes'
fs/btrfs/space-info.c:1315: warning: Function parameter or member 'space_info' not described in '__reserve_bytes'
fs/btrfs/space-info.c:1315: warning: Function parameter or member 'orig_bytes' not described in '__reserve_bytes'
fs/btrfs/space-info.c:1315: warning: Function parameter or member 'flush' not described in '__reserve_bytes'
fs/btrfs/space-info.c:1427: warning: Function parameter or member 'root' not described in 'btrfs_reserve_metadata_bytes'
fs/btrfs/space-info.c:1427: warning: Function parameter or member 'block_rsv' not described in 'btrfs_reserve_metadata_bytes'
fs/btrfs/space-info.c:1427: warning: Function parameter or member 'orig_bytes' not described in 'btrfs_reserve_metadata_bytes'
fs/btrfs/space-info.c:1427: warning: Function parameter or member 'flush' not described in 'btrfs_reserve_metadata_bytes'
fs/btrfs/space-info.c:1462: warning: Function parameter or member 'fs_info' not described in 'btrfs_reserve_data_bytes'
fs/btrfs/space-info.c:1462: warning: Function parameter or member 'bytes' not described in 'btrfs_reserve_data_bytes'
fs/btrfs/space-info.c:1462: warning: Function parameter or member 'flush' not described in 'btrfs_reserve_data_bytes'

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---
 fs/btrfs/space-info.c | 46 ++++++++++++++++++++++---------------------
 1 file changed, 24 insertions(+), 22 deletions(-)

diff --git a/fs/btrfs/space-info.c b/fs/btrfs/space-info.c
index 84fb94e78a8f..5f4b9ac99ae6 100644
--- a/fs/btrfs/space-info.c
+++ b/fs/btrfs/space-info.c
@@ -561,10 +561,10 @@ static void shrink_delalloc(struct btrfs_fs_info *fs_info,
 }
 
 /**
- * maybe_commit_transaction - possibly commit the transaction if its ok to
- * @root - the root we're allocating for
- * @bytes - the number of bytes we want to reserve
- * @force - force the commit
+ * Possibly commit the transaction if its ok to
+ *
+ * @fs_info:    the filesystem
+ * @space_info: space_info we are checking for commit, either data or metadata
  *
  * This will check to make sure that committing the transaction will actually
  * get us somewhere and then commit the transaction if it does.  Otherwise it
@@ -1216,10 +1216,10 @@ static void wait_reserve_ticket(struct btrfs_fs_info *fs_info,
 
 /**
  * handle_reserve_ticket - do the appropriate flushing and waiting for a ticket
- * @fs_info - the fs
- * @space_info - the space_info for the reservation
- * @ticket - the ticket for the reservation
- * @flush - how much we can flush
+ * @fs_info:    the filesystem
+ * @space_info: the space_info for the reservation
+ * @ticket:     the ticket for the reservation
+ * @flush:      how much we can flush
  *
  * This does the work of figuring out how to flush for the ticket, waiting for
  * the reservation, and returning the appropriate error if there is one.
@@ -1296,11 +1296,12 @@ static inline bool is_normal_flushing(enum btrfs_reserve_flush_enum flush)
 }
 
 /**
- * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space
- * @root - the root we're allocating for
- * @space_info - the space info we want to allocate from
- * @orig_bytes - the number of bytes we want
- * @flush - whether or not we can flush to make our reservation
+ * Tries to reserve bytes from the block_rsv's space
+ *
+ * @fs_info:    the filesystem
+ * @space_info: the space info we want to allocate from
+ * @orig_bytes: the number of bytes we want
+ * @flush:      whether or not we can flush to make our reservation
  *
  * This will reserve orig_bytes number of bytes from the space info associated
  * with the block_rsv.  If there is not enough space it will make an attempt to
@@ -1407,11 +1408,12 @@ static int __reserve_bytes(struct btrfs_fs_info *fs_info,
 }
 
 /**
- * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space
- * @root - the root we're allocating for
- * @block_rsv - the block_rsv we're allocating for
- * @orig_bytes - the number of bytes we want
- * @flush - whether or not we can flush to make our reservation
+ * Tries to reserve metadata bytes from the block_rsv's space
+ *
+ * @root:       the root we're allocating for
+ * @block_rsv:  the block_rsv we're allocating for
+ * @orig_bytes: the number of bytes we want
+ * @flush:      whether or not we can flush to make our reservation
  *
  * This will reserve orig_bytes number of bytes from the space info associated
  * with the block_rsv.  If there is not enough space it will make an attempt to
@@ -1449,10 +1451,10 @@ int btrfs_reserve_metadata_bytes(struct btrfs_root *root,
 }
 
 /**
- * btrfs_reserve_data_bytes - try to reserve data bytes for an allocation
- * @fs_info - the filesystem
- * @bytes - the number of bytes we need
- * @flush - how we are allowed to flush
+ * Tries to reserve data bytes for an allocation
+ * @fs_info: the filesystem
+ * @bytes:   the number of bytes we need
+ * @flush:   how we are allowed to flush
  *
  * This will reserve bytes from the data space info.  If there is not enough
  * space then we will attempt to flush space as specified by flush.
-- 
2.25.1

[PATCH v3 12/14] btrfs: Fix parameter description for functions in extent_io.c

[Nikolay Borisov]

This makes the file W=1 clean and fixes the following warnings:

fs/btrfs/extent_io.c:414: warning: Function parameter or member 'tree' not described in '__etree_search'
fs/btrfs/extent_io.c:414: warning: Function parameter or member 'offset' not described in '__etree_search'
fs/btrfs/extent_io.c:414: warning: Function parameter or member 'next_ret' not described in '__etree_search'
fs/btrfs/extent_io.c:414: warning: Function parameter or member 'prev_ret' not described in '__etree_search'
fs/btrfs/extent_io.c:414: warning: Function parameter or member 'p_ret' not described in '__etree_search'
fs/btrfs/extent_io.c:414: warning: Function parameter or member 'parent_ret' not described in '__etree_search'
fs/btrfs/extent_io.c:1607: warning: Function parameter or member 'tree' not described in 'find_contiguous_extent_bit'
fs/btrfs/extent_io.c:1607: warning: Function parameter or member 'start' not described in 'find_contiguous_extent_bit'
fs/btrfs/extent_io.c:1607: warning: Function parameter or member 'start_ret' not described in 'find_contiguous_extent_bit'
fs/btrfs/extent_io.c:1607: warning: Function parameter or member 'end_ret' not described in 'find_contiguous_extent_bit'
fs/btrfs/extent_io.c:1607: warning: Function parameter or member 'bits' not described in 'find_contiguous_extent_bit'
fs/btrfs/extent_io.c:1644: warning: Function parameter or member 'tree' not described in 'find_first_clear_extent_bit'
fs/btrfs/extent_io.c:1644: warning: Function parameter or member 'start' not described in 'find_first_clear_extent_bit'
fs/btrfs/extent_io.c:1644: warning: Function parameter or member 'start_ret' not described in 'find_first_clear_extent_bit'
fs/btrfs/extent_io.c:1644: warning: Function parameter or member 'end_ret' not described in 'find_first_clear_extent_bit'
fs/btrfs/extent_io.c:1644: warning: Function parameter or member 'bits' not described in 'find_first_clear_extent_bit'
fs/btrfs/extent_io.c:4187: warning: Function parameter or member 'epd' not described in 'extent_write_cache_pages'
fs/btrfs/extent_io.c:4187: warning: Excess function parameter 'data' description in 'extent_write_cache_pages'

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---
 fs/btrfs/extent_io.c | 50 +++++++++++++++++++++++---------------------
 1 file changed, 26 insertions(+), 24 deletions(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 7f689ad7709c..98937f8ea138 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -389,16 +389,16 @@ static struct rb_node *tree_insert(struct rb_root *root,
 }
 
 /**
- * __etree_search - searche @tree for an entry that contains @offset. Such
+ * Searches @tree for an entry that contains @offset. Such
  * entry would have entry->start <= offset && entry->end >= offset.
  *
- * @tree - the tree to search
- * @offset - offset that should fall within an entry in @tree
- * @next_ret - pointer to the first entry whose range ends after @offset
- * @prev - pointer to the first entry whose range begins before @offset
- * @p_ret - pointer where new node should be anchored (used when inserting an
- *	    entry in the tree)
- * @parent_ret - points to entry which would have been the parent of the entry,
+ * @tree:       the tree to search
+ * @offset:     offset that should fall within an entry in @tree
+ * @next_ret:   pointer to the first entry whose range ends after @offset
+ * @prev_ret:   pointer to the first entry whose range begins before @offset
+ * @p_ret:      pointer where new node should be anchored (used when inserting an
+ *	        entry in the tree)
+ * @parent_ret: points to entry which would have been the parent of the entry,
  *               containing @offset
  *
  * This function returns a pointer to the entry that contains @offset byte
@@ -1588,12 +1588,13 @@ int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
 }
 
 /**
- * find_contiguous_extent_bit: find a contiguous area of bits
- * @tree - io tree to check
- * @start - offset to start the search from
- * @start_ret - the first offset we found with the bits set
- * @end_ret - the final contiguous range of the bits that were set
- * @bits - bits to look for
+ * Find a contiguous area of bits
+ *
+ * @tree:      io tree to check
+ * @start:     offset to start the search from
+ * @start_ret: the first offset we found with the bits set
+ * @end_ret:   the final contiguous range of the bits that were set
+ * @bits:      bits to look for
  *
  * set_extent_bit and clear_extent_bit can temporarily split contiguous ranges
  * to set bits appropriately, and then merge them again.  During this time it
@@ -1625,14 +1626,14 @@ int find_contiguous_extent_bit(struct extent_io_tree *tree, u64 start,
 }
 
 /**
- * find_first_clear_extent_bit - find the first range that has @bits not set.
- * This range could start before @start.
+ * Find the first range that has @bits not set. This range could start before
+ * @start.
  *
- * @tree - the tree to search
- * @start - the offset at/after which the found extent should start
- * @start_ret - records the beginning of the range
- * @end_ret - records the end of the range (inclusive)
- * @bits - the set of bits which must be unset
+ * @tree:      the tree to search
+ * @start:     the offset at/after which the found extent should start
+ * @start_ret: records the beginning of the range
+ * @end_ret:   records the end of the range (inclusive)
+ * @bits:      the set of bits which must be unset
  *
  * Since unallocated range is also considered one which doesn't have the bits
  * set it's possible that @end_ret contains -1, this happens in case the range
@@ -4168,10 +4169,11 @@ int btree_write_cache_pages(struct address_space *mapping,
 }
 
 /**
- * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
+ * Walk the list of dirty pages of the given address space and write all of them.
+ *
  * @mapping: address space structure to write
- * @wbc: subtract the number of written pages from *@wbc->nr_to_write
- * @data: data passed to __extent_writepage function
+ * @wbc:     subtract the number of written pages from *@wbc->nr_to_write
+ * @epd:     holds context for the write, namely the bio
  *
  * If a page is already under I/O, write_cache_pages() skips it, even
  * if it's dirty.  This is desirable behaviour for memory-cleaning writeback,
-- 
2.25.1

[PATCH v3 13/14] lib/zstd: Convert constants to defines

[Nikolay Borisov]

Those constants are really used internally by zstd and including
linux/zstd.h into users results in the following warnings:

In file included from fs/btrfs/zstd.c:19:
./include/linux/zstd.h:798:21: warning: ‘ZSTD_skippableHeaderSize’ defined but not used [-Wunused-const-variable=]
  798 | static const size_t ZSTD_skippableHeaderSize = 8;
      |                     ^~~~~~~~~~~~~~~~~~~~~~~~
./include/linux/zstd.h:796:21: warning: ‘ZSTD_frameHeaderSize_max’ defined but not used [-Wunused-const-variable=]
  796 | static const size_t ZSTD_frameHeaderSize_max = ZSTD_FRAMEHEADERSIZE_MAX;
      |                     ^~~~~~~~~~~~~~~~~~~~~~~~
./include/linux/zstd.h:795:21: warning: ‘ZSTD_frameHeaderSize_min’ defined but not used [-Wunused-const-variable=]
  795 | static const size_t ZSTD_frameHeaderSize_min = ZSTD_FRAMEHEADERSIZE_MIN;
      |                     ^~~~~~~~~~~~~~~~~~~~~~~~
./include/linux/zstd.h:794:21: warning: ‘ZSTD_frameHeaderSize_prefix’ defined but not used [-Wunused-const-variable=]
  794 | static const size_t ZSTD_frameHeaderSize_prefix = 5;

So fix those warnings by turning the constants into defines.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---
 include/linux/zstd.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/linux/zstd.h b/include/linux/zstd.h
index 249575e2485f..e87f78c9b19c 100644
--- a/include/linux/zstd.h
+++ b/include/linux/zstd.h
@@ -791,11 +791,11 @@ size_t ZSTD_DStreamOutSize(void);
 /* for static allocation */
 #define ZSTD_FRAMEHEADERSIZE_MAX 18
 #define ZSTD_FRAMEHEADERSIZE_MIN  6
-static const size_t ZSTD_frameHeaderSize_prefix = 5;
-static const size_t ZSTD_frameHeaderSize_min = ZSTD_FRAMEHEADERSIZE_MIN;
-static const size_t ZSTD_frameHeaderSize_max = ZSTD_FRAMEHEADERSIZE_MAX;
+#define ZSTD_frameHeaderSize_prefix 5
+#define ZSTD_frameHeaderSize_min ZSTD_FRAMEHEADERSIZE_MIN
+#define ZSTD_frameHeaderSize_max ZSTD_FRAMEHEADERSIZE_MAX
 /* magic number + skippable frame length */
-static const size_t ZSTD_skippableHeaderSize = 8;
+#define ZSTD_skippableHeaderSize 8
 
 
 /*-*************************************
-- 
2.25.1

[PATCH v3 14/14] btrfs: Enable W=1 checks for btrfs

[Nikolay Borisov]

Now that the btrfs' codebase is clean of W=1 warning let's enable those
checks unconditionally for the entire fs/btrfs/ and its subdirectories.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---
 fs/btrfs/Makefile | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
index 9f1b1a88e317..44faee776027 100644
--- a/fs/btrfs/Makefile
+++ b/fs/btrfs/Makefile
@@ -1,5 +1,22 @@
 # SPDX-License-Identifier: GPL-2.0
 
+subdir-ccflags-y += -Wextra -Wunused -Wno-unused-parameter
+subdir-ccflags-y += -Wmissing-declarations
+subdir-ccflags-y += -Wmissing-format-attribute
+subdir-ccflags-y += -Wmissing-prototypes
+subdir-ccflags-y += -Wold-style-definition
+subdir-ccflags-y += -Wmissing-include-dirs
+subdir-ccflags-y += $(call cc-option, -Wunused-but-set-variable)
+subdir-ccflags-y += $(call cc-option, -Wunused-const-variable)
+subdir-ccflags-y += $(call cc-option, -Wpacked-not-aligned)
+subdir-ccflags-y += $(call cc-option, -Wstringop-truncation)
+# The following turn off the warnings enabled by -Wextra
+subdir-ccflags-y += -Wno-missing-field-initializers
+subdir-ccflags-y += -Wno-sign-compare
+subdir-ccflags-y += -Wno-type-limits
+
+cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $<
+
 obj-$(CONFIG_BTRFS_FS) := btrfs.o
 
 btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
-- 
2.25.1

Re: [PATCH v3 13/14] lib/zstd: Convert constants to defines

[Nikolay Borisov]

Nick,

Can we get your ACK for the below changes. THey don't seem to be used
outside of core zstd code, yet they result in warnings in code which
includes zstd.h. By switching them to defines we don't lose anything.

On 22.01.21 г. 11:58 ч., Nikolay Borisov wrote:
> Those constants are really used internally by zstd and including
> linux/zstd.h into users results in the following warnings:
> 
> In file included from fs/btrfs/zstd.c:19:
> ./include/linux/zstd.h:798:21: warning: ‘ZSTD_skippableHeaderSize’ defined but not used [-Wunused-const-variable=]
>   798 | static const size_t ZSTD_skippableHeaderSize = 8;
>       |                     ^~~~~~~~~~~~~~~~~~~~~~~~
> ./include/linux/zstd.h:796:21: warning: ‘ZSTD_frameHeaderSize_max’ defined but not used [-Wunused-const-variable=]
>   796 | static const size_t ZSTD_frameHeaderSize_max = ZSTD_FRAMEHEADERSIZE_MAX;
>       |                     ^~~~~~~~~~~~~~~~~~~~~~~~
> ./include/linux/zstd.h:795:21: warning: ‘ZSTD_frameHeaderSize_min’ defined but not used [-Wunused-const-variable=]
>   795 | static const size_t ZSTD_frameHeaderSize_min = ZSTD_FRAMEHEADERSIZE_MIN;
>       |                     ^~~~~~~~~~~~~~~~~~~~~~~~
> ./include/linux/zstd.h:794:21: warning: ‘ZSTD_frameHeaderSize_prefix’ defined but not used [-Wunused-const-variable=]
>   794 | static const size_t ZSTD_frameHeaderSize_prefix = 5;
> 
> So fix those warnings by turning the constants into defines.
> 
> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
> ---
>  include/linux/zstd.h | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/include/linux/zstd.h b/include/linux/zstd.h
> index 249575e2485f..e87f78c9b19c 100644
> --- a/include/linux/zstd.h
> +++ b/include/linux/zstd.h
> @@ -791,11 +791,11 @@ size_t ZSTD_DStreamOutSize(void);
>  /* for static allocation */
>  #define ZSTD_FRAMEHEADERSIZE_MAX 18
>  #define ZSTD_FRAMEHEADERSIZE_MIN  6
> -static const size_t ZSTD_frameHeaderSize_prefix = 5;
> -static const size_t ZSTD_frameHeaderSize_min = ZSTD_FRAMEHEADERSIZE_MIN;
> -static const size_t ZSTD_frameHeaderSize_max = ZSTD_FRAMEHEADERSIZE_MAX;
> +#define ZSTD_frameHeaderSize_prefix 5
> +#define ZSTD_frameHeaderSize_min ZSTD_FRAMEHEADERSIZE_MIN
> +#define ZSTD_frameHeaderSize_max ZSTD_FRAMEHEADERSIZE_MAX
>  /* magic number + skippable frame length */
> -static const size_t ZSTD_skippableHeaderSize = 8;
> +#define ZSTD_skippableHeaderSize 8
>  
>  
>  /*-*************************************
> 

Re: [PATCH v3 01/14] btrfs: Document modified parameter of add_extent_mapping

[Johannes Thumshirn]

On 22/01/2021 11:17, Nikolay Borisov wrote:
> Fixes fs/btrfs/extent_map.c:399: warning: Function parameter or member
> 'modified' not described in 'add_extent_mapping'
> 
> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
> ---
>  fs/btrfs/extent_map.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
> index bd6229fb2b6f..c540a37cbdb2 100644
> --- a/fs/btrfs/extent_map.c
> +++ b/fs/btrfs/extent_map.c
> @@ -385,9 +385,12 @@ static void extent_map_device_clear_bits(struct extent_map *em, unsigned bits)
>  }
>  
>  /**
> - * add_extent_mapping - add new extent map to the extent tree
> + * Add new extent map to the extent tree
> + *
>   * @tree:	tree to insert new map in
>   * @em:		map to insert
> + * @modified:	bool indicating whether the given @em should be added to the
> + *	        modified list, which indicates the extent needs to be logged
>   *
>   * Insert @em into @tree or perform a simple forward/backward merge with
>   * existing mappings.  The extent_map struct passed in will be inserted
> 

Looks good,
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>

Although this warrants a follow up patch changing modified from int to bool
(and for setup_extent_mapping as well).

Re: [PATCH v3 02/14] btrfs: Fix parameter description of btrfs_add_extent_mapping

[Johannes Thumshirn]

Looks good,
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>

Re: [PATCH v3 03/14] btrfs: Fix function description format

[Johannes Thumshirn]

On 22/01/2021 11:17, Nikolay Borisov wrote:
> This fixes following W=1 warnings:
> 
> fs/btrfs/file-item.c:27: warning: Cannot understand  * @inode:  the inode we want to update the disk_i_size for
>  on line 27 - I thought it was a doc line
> fs/btrfs/file-item.c:65: warning: Cannot understand  * @inode - the inode we're modifying
>  on line 65 - I thought it was a doc line
> fs/btrfs/file-item.c:91: warning: Cannot understand  * @inode - the inode we're modifying
>  on line 91 - I thought it was a doc line
> 
> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
> ---
>  fs/btrfs/file-item.c | 22 ++++++++++++++--------
>  1 file changed, 14 insertions(+), 8 deletions(-)
> 
> diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
> index 6ccfc019ad90..784adae2d0f9 100644
> --- a/fs/btrfs/file-item.c
> +++ b/fs/btrfs/file-item.c
> @@ -24,8 +24,10 @@
>  				       PAGE_SIZE))
>  
>  /**
> - * @inode - the inode we want to update the disk_i_size for
> - * @new_i_size - the i_size we want to set to, 0 if we use i_size
> + * Set inode's size according to filesystem options
> + *
> + * @inode:      the inode we want to update the disk_i_size for
> + * @new_i_size: the i_size we want to set to, 0 if we use i_size
>   *
>   * With NO_HOLES set this simply sets the disk_is_size to whatever i_size_read()
>   * returns as it is perfectly fine with a file that has holes without hole file
> @@ -62,9 +64,11 @@ void btrfs_inode_safe_disk_i_size_write(struct btrfs_inode *inode, u64 new_i_siz
>  }
>  
>  /**
> - * @inode - the inode we're modifying
> - * @start - the start file offset of the file extent we've inserted
> - * @len - the logical length of the file extent item
> + * Marks a range within a file as having a new extent inserted
> + *
> + * @inode: the inode being modifying

being modified or we're modifying

> + * @start: the start file offset of the file extent we've inserted
> + * @len:   logical length of the file extent item
>   *
>   * Call when we are inserting a new file extent where there was none before.
>   * Does not need to call this in the case where we're replacing an existing file
> @@ -88,9 +92,11 @@ int btrfs_inode_set_file_extent_range(struct btrfs_inode *inode, u64 start,
>  }
>  
>  /**
> - * @inode - the inode we're modifying
> - * @start - the start file offset of the file extent we've inserted
> - * @len - the logical length of the file extent item
> + * Marks an inode range as not having a backing extent
> + *
> + * @inode: the inode being modifying

Same here

> + * @start: the start file offset of the file extent we've inserted
> + * @len:   the logical length of the file extent item
>   *
>   * Called when we drop a file extent, for example when we truncate.  Doesn't
>   * need to be called for cases where we're replacing a file extent, like when
> 

Re: [PATCH v3 04/14] btrfs: Fix parameter description in delayed-ref.c functions

[Johannes Thumshirn]

Looks good,
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>

Re: [PATCH v3 14/14] btrfs: Enable W=1 checks for btrfs

[David Sterba]

On Fri, Jan 22, 2021 at 11:58:05AM +0200, Nikolay Borisov wrote:
> Now that the btrfs' codebase is clean of W=1 warning let's enable those
> checks unconditionally for the entire fs/btrfs/ and its subdirectories.
> 
> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
> ---
>  fs/btrfs/Makefile | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
> 
> diff --git a/fs/btrfs/Makefile b/fs/btrfs/Makefile
> index 9f1b1a88e317..44faee776027 100644
> --- a/fs/btrfs/Makefile
> +++ b/fs/btrfs/Makefile
> @@ -1,5 +1,22 @@
>  # SPDX-License-Identifier: GPL-2.0
>  
> +subdir-ccflags-y += -Wextra -Wunused -Wno-unused-parameter
> +subdir-ccflags-y += -Wmissing-declarations
> +subdir-ccflags-y += -Wmissing-format-attribute
> +subdir-ccflags-y += -Wmissing-prototypes
> +subdir-ccflags-y += -Wold-style-definition
> +subdir-ccflags-y += -Wmissing-include-dirs
> +subdir-ccflags-y += $(call cc-option, -Wunused-but-set-variable)
> +subdir-ccflags-y += $(call cc-option, -Wunused-const-variable)

-Wunused-const-variable triggers the zstd warning, I would leave it out
for now until the zstd patch is merged as I want to add the rest of the
series to misc-next and this would not be a clean build.



> +subdir-ccflags-y += $(call cc-option, -Wpacked-not-aligned)
> +subdir-ccflags-y += $(call cc-option, -Wstringop-truncation)
> +# The following turn off the warnings enabled by -Wextra
> +subdir-ccflags-y += -Wno-missing-field-initializers
> +subdir-ccflags-y += -Wno-sign-compare
> +subdir-ccflags-y += -Wno-type-limits
> +
> +cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $<

I'll add a comment what this means

>  obj-$(CONFIG_BTRFS_FS) := btrfs.o
>  
>  btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
> -- 
> 2.25.1

Re: [PATCH v3 13/14] lib/zstd: Convert constants to defines

[Nick Terrell]

> On Jan 22, 2021, at 1:58 AM, Nikolay Borisov <nborisov@suse.com> wrote:
> 
> Those constants are really used internally by zstd and including
> linux/zstd.h into users results in the following warnings:
> 
> In file included from fs/btrfs/zstd.c:19:
> ./include/linux/zstd.h:798:21: warning: ‘ZSTD_skippableHeaderSize’ defined but not used [-Wunused-const-variable=]
>  798 | static const size_t ZSTD_skippableHeaderSize = 8;
>      |                     ^~~~~~~~~~~~~~~~~~~~~~~~
> ./include/linux/zstd.h:796:21: warning: ‘ZSTD_frameHeaderSize_max’ defined but not used [-Wunused-const-variable=]
>  796 | static const size_t ZSTD_frameHeaderSize_max = ZSTD_FRAMEHEADERSIZE_MAX;
>      |                     ^~~~~~~~~~~~~~~~~~~~~~~~
> ./include/linux/zstd.h:795:21: warning: ‘ZSTD_frameHeaderSize_min’ defined but not used [-Wunused-const-variable=]
>  795 | static const size_t ZSTD_frameHeaderSize_min = ZSTD_FRAMEHEADERSIZE_MIN;
>      |                     ^~~~~~~~~~~~~~~~~~~~~~~~
> ./include/linux/zstd.h:794:21: warning: ‘ZSTD_frameHeaderSize_prefix’ defined but not used [-Wunused-const-variable=]
>  794 | static const size_t ZSTD_frameHeaderSize_prefix = 5;
> 
> So fix those warnings by turning the constants into defines.
> 
> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
> ---
> include/linux/zstd.h | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/include/linux/zstd.h b/include/linux/zstd.h
> index 249575e2485f..e87f78c9b19c 100644
> --- a/include/linux/zstd.h
> +++ b/include/linux/zstd.h
> @@ -791,11 +791,11 @@ size_t ZSTD_DStreamOutSize(void);
> /* for static allocation */
> #define ZSTD_FRAMEHEADERSIZE_MAX 18
> #define ZSTD_FRAMEHEADERSIZE_MIN  6
> -static const size_t ZSTD_frameHeaderSize_prefix = 5;
> -static const size_t ZSTD_frameHeaderSize_min = ZSTD_FRAMEHEADERSIZE_MIN;
> -static const size_t ZSTD_frameHeaderSize_max = ZSTD_FRAMEHEADERSIZE_MAX;
> +#define ZSTD_frameHeaderSize_prefix 5
> +#define ZSTD_frameHeaderSize_min ZSTD_FRAMEHEADERSIZE_MIN
> +#define ZSTD_frameHeaderSize_max ZSTD_FRAMEHEADERSIZE_MAX
> /* magic number + skippable frame length */
> -static const size_t ZSTD_skippableHeaderSize = 8;
> +#define ZSTD_skippableHeaderSize 8
> 
> 
> /*-*************************************
This looks good to me! We removed these constants from the upstream header a
while ago, for similar reasons.

You can add:

Reviewed-by: Nick Terrell <terrelln@fb.com>

-Nick

Re: [PATCH v3 13/14] lib/zstd: Convert constants to defines

[David Sterba]

On Sat, Jan 23, 2021 at 05:50:52PM +0000, Nick Terrell wrote:
> 
> 
> > On Jan 22, 2021, at 1:58 AM, Nikolay Borisov <nborisov@suse.com> wrote:
> > 
> > Those constants are really used internally by zstd and including
> > linux/zstd.h into users results in the following warnings:
> > 
> > In file included from fs/btrfs/zstd.c:19:
> > ./include/linux/zstd.h:798:21: warning: ‘ZSTD_skippableHeaderSize’ defined but not used [-Wunused-const-variable=]
> >  798 | static const size_t ZSTD_skippableHeaderSize = 8;
> >      |                     ^~~~~~~~~~~~~~~~~~~~~~~~
> > ./include/linux/zstd.h:796:21: warning: ‘ZSTD_frameHeaderSize_max’ defined but not used [-Wunused-const-variable=]
> >  796 | static const size_t ZSTD_frameHeaderSize_max = ZSTD_FRAMEHEADERSIZE_MAX;
> >      |                     ^~~~~~~~~~~~~~~~~~~~~~~~
> > ./include/linux/zstd.h:795:21: warning: ‘ZSTD_frameHeaderSize_min’ defined but not used [-Wunused-const-variable=]
> >  795 | static const size_t ZSTD_frameHeaderSize_min = ZSTD_FRAMEHEADERSIZE_MIN;
> >      |                     ^~~~~~~~~~~~~~~~~~~~~~~~
> > ./include/linux/zstd.h:794:21: warning: ‘ZSTD_frameHeaderSize_prefix’ defined but not used [-Wunused-const-variable=]
> >  794 | static const size_t ZSTD_frameHeaderSize_prefix = 5;
> > 
> > So fix those warnings by turning the constants into defines.
> > 
> > Signed-off-by: Nikolay Borisov <nborisov@suse.com>
> > ---
> > include/linux/zstd.h | 8 ++++----
> > 1 file changed, 4 insertions(+), 4 deletions(-)
> > 
> > diff --git a/include/linux/zstd.h b/include/linux/zstd.h
> > index 249575e2485f..e87f78c9b19c 100644
> > --- a/include/linux/zstd.h
> > +++ b/include/linux/zstd.h
> > @@ -791,11 +791,11 @@ size_t ZSTD_DStreamOutSize(void);
> > /* for static allocation */
> > #define ZSTD_FRAMEHEADERSIZE_MAX 18
> > #define ZSTD_FRAMEHEADERSIZE_MIN  6
> > -static const size_t ZSTD_frameHeaderSize_prefix = 5;
> > -static const size_t ZSTD_frameHeaderSize_min = ZSTD_FRAMEHEADERSIZE_MIN;
> > -static const size_t ZSTD_frameHeaderSize_max = ZSTD_FRAMEHEADERSIZE_MAX;
> > +#define ZSTD_frameHeaderSize_prefix 5
> > +#define ZSTD_frameHeaderSize_min ZSTD_FRAMEHEADERSIZE_MIN
> > +#define ZSTD_frameHeaderSize_max ZSTD_FRAMEHEADERSIZE_MAX
> > /* magic number + skippable frame length */
> > -static const size_t ZSTD_skippableHeaderSize = 8;
> > +#define ZSTD_skippableHeaderSize 8
> > 
> > 
> > /*-*************************************
> This looks good to me! We removed these constants from the upstream header a
> while ago, for similar reasons.
> 
> You can add:
> 
> Reviewed-by: Nick Terrell <terrelln@fb.com>

Thank you, patch added to misc-next, the warning -Wunused-const-variable
added back to Makefile.