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From: Filipe Manana <fdmanana@kernel.org>
To: Qu Wenruo <wqu@suse.com>
Cc: linux-btrfs@vger.kernel.org, David Sterba <dsterba@suse.com>
Subject: Re: [PATCH v2 03/11] btrfs: introduce new members for extent_map
Date: Thu, 9 May 2024 18:05:01 +0100	[thread overview]
Message-ID: <CAL3q7H7uWw=LnWYXZnZV+kYKho+F4iBcBgZ5GziWeTofVPLDYw@mail.gmail.com> (raw)
In-Reply-To: <f0be8547f0df8d8a4578c5e4d9b560c053dab8db.1714707707.git.wqu@suse.com>

On Fri, May 3, 2024 at 7:02 AM Qu Wenruo <wqu@suse.com> wrote:
>
> Introduce two new members for extent_map:
>
> - disk_bytenr
> - offset
>
> Both are matching the members with the same name inside
> btrfs_file_extent_items.
>
> For now this patch only touches those members when:
>
> - Reading btrfs_file_extent_items from disk
> - Inserting new holes
> - Merging two extent maps
>   With the new disk_bytenr and disk_num_bytes, doing merging would be a
>   little complex, as we have 3 different cases:
>
>   * Both extent maps are referring to the same data extent
>   * Both extent maps are referring to different data extents, but
>     those data extents are adjacent, and extent maps are at head/tail
>     of each data extents

I have no idea what this last part of the sentence means:

"and extent maps are at head/tail of each data extents"

>   * One of the extent map is referring to an merged and larger data

map -> maps
an -> a

>     extent that covers both extent maps

Not sure if I can understand this. How can one of the extent maps
already cover the range of the other extent map?
This suggests some overlapping, or most likely I misunderstood what
this is trying to say.

>
>   The 3rd case seems only valid in selftest (test_case_3()), but
>   a new helper merge_ondisk_extents() should be able to handle all of
>   them.
>
> To properly assign values for those new members, a new btrfs_file_extent
> parameter is introduced to all the involved call sites.
>
> - For NOCOW writes the btrfs_file_extent would be exposed from
>   can_nocow_file_extent().
>
> - For other writes, the members can be easily calculated
>   As most of them have 0 offset and utilizing the whole on-disk data
>   extent.
>   The exception is encoded write, but thankfully that interface provided
>   offset directly and all other needed info.
>
> For now, both the old members (block_start/block_len/orig_start) are
> co-existing with the new members (disk_bytenr/offset), meanwhile all the
> critical code is still using the old members only.
>
> The cleanup would happen later after all the older and newer members are
> properly validated.
>
> Signed-off-by: Qu Wenruo <wqu@suse.com>
> Signed-off-by: David Sterba <dsterba@suse.com>
> ---
>  fs/btrfs/defrag.c     |  4 +++
>  fs/btrfs/extent_map.c | 75 +++++++++++++++++++++++++++++++++++++++++--
>  fs/btrfs/extent_map.h | 17 ++++++++++
>  fs/btrfs/file-item.c  |  9 +++++-
>  fs/btrfs/file.c       |  1 +
>  fs/btrfs/inode.c      | 60 ++++++++++++++++++++++++++++++----
>  6 files changed, 155 insertions(+), 11 deletions(-)
>
> diff --git a/fs/btrfs/defrag.c b/fs/btrfs/defrag.c
> index 407ccec3e57e..242c5469f4ba 100644
> --- a/fs/btrfs/defrag.c
> +++ b/fs/btrfs/defrag.c
> @@ -709,6 +709,10 @@ static struct extent_map *defrag_get_extent(struct btrfs_inode *inode,
>                         em->start = start;
>                         em->orig_start = start;
>                         em->block_start = EXTENT_MAP_HOLE;
> +                       em->disk_bytenr = EXTENT_MAP_HOLE;
> +                       em->disk_num_bytes = 0;
> +                       em->ram_bytes = 0;
> +                       em->offset = 0;
>                         em->len = key.offset - start;
>                         break;
>                 }
> diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
> index 4230dd0f34cc..4d4ac9fc43e2 100644
> --- a/fs/btrfs/extent_map.c
> +++ b/fs/btrfs/extent_map.c
> @@ -232,6 +232,58 @@ static bool mergeable_maps(const struct extent_map *prev, const struct extent_ma
>         return next->block_start == prev->block_start;
>  }
>
> +/*
> + * Handle the ondisk data extents merge for @prev and @next.
> + *
> + * Only touches disk_bytenr/disk_num_bytes/offset/ram_bytes.
> + * For now only uncompressed regular extent can be merged.
> + *
> + * @prev and @next will be both updated to point to the new merged range.
> + * Thus one of them should be removed by the caller.
> + */
> +static void merge_ondisk_extents(struct extent_map *prev, struct extent_map *next)
> +{
> +       u64 new_disk_bytenr;
> +       u64 new_disk_num_bytes;
> +       u64 new_offset;
> +
> +       /* @prev and @next should not be compressed. */
> +       ASSERT(!extent_map_is_compressed(prev));
> +       ASSERT(!extent_map_is_compressed(next));
> +
> +       /*
> +        * There are several different cases that @prev and @next can be merged.

that -> where

> +        *
> +        * 1) They are referring to the same data extent
> +        * 2) Their ondisk data extents are adjacent and @prev is the tail
> +        *    and @next is the head of their data extents

This thing of head and tail is confusing.
Just say that they are adjacent on disk, it's clear enough and
head/tail suggest some part of an extent only, which isn't the case.

> +        * 3) One of @prev/@next is referrring to a larger merged data extent.

referrring -> referring

> +        *    (test_case_3 of extent maps tests).

If something is only exercised by the self tests but can't happen in
practice, I'd rather change the tests and assert such a case can't
happen.

> +        *
> +        * The calculation here always merge the data extents first, then update
> +        * @offset using the new data extents.
> +        *
> +        * For case 1), the merged data extent would be the same.
> +        * For case 2), we just merge the two data extents into one.
> +        * For case 3), we just got the larger data extent.
> +        */
> +       new_disk_bytenr = min(prev->disk_bytenr, next->disk_bytenr);
> +       new_disk_num_bytes = max(prev->disk_bytenr + prev->disk_num_bytes,
> +                                next->disk_bytenr + next->disk_num_bytes) -
> +                            new_disk_bytenr;

So this is confusing, disk_num_bytes being a max between the two
extent maps and not their sum.
I gather this is modelled after what we already do at
btrfs_drop_extent_map_range() when splitting.

But the truth is we never used the disk_num_bytes of an extent map
that was merged - we also didn't do it before this patch, for that
reason.
It's only used for logging new extents - which can't be merged - they
can be merged only after being logged.

We can set this to the sum, or leave with some value to signal it's invalid.
Just leave a comment saying disk_num_bytes it's not used anywhere for
merged extent maps.

In the splitting case at btrfs_drop_extent_map_range() it's what we
need since in the case the extent is new and not logged (in the
modified list), disk_num_bytes always represents the size of the
original, before split, extent.

> +       new_offset = prev->disk_bytenr + prev->offset - new_disk_bytenr;
> +
> +       prev->disk_bytenr = new_disk_bytenr;
> +       prev->disk_num_bytes = new_disk_num_bytes;
> +       prev->ram_bytes = new_disk_num_bytes;
> +       prev->offset = new_offset;
> +
> +       next->disk_bytenr = new_disk_bytenr;
> +       next->disk_num_bytes = new_disk_num_bytes;
> +       next->ram_bytes = new_disk_num_bytes;
> +       next->offset = new_offset;
> +}
> +
>  static void try_merge_map(struct btrfs_inode *inode, struct extent_map *em)
>  {
>         struct extent_map_tree *tree = &inode->extent_tree;
> @@ -263,6 +315,9 @@ static void try_merge_map(struct btrfs_inode *inode, struct extent_map *em)
>                         em->block_len += merge->block_len;
>                         em->block_start = merge->block_start;
>                         em->generation = max(em->generation, merge->generation);
> +
> +                       if (em->disk_bytenr < EXTENT_MAP_LAST_BYTE)
> +                               merge_ondisk_extents(merge, em);
>                         em->flags |= EXTENT_FLAG_MERGED;
>
>                         rb_erase_cached(&merge->rb_node, &tree->map);
> @@ -278,6 +333,8 @@ static void try_merge_map(struct btrfs_inode *inode, struct extent_map *em)
>         if (rb && can_merge_extent_map(merge) && mergeable_maps(em, merge)) {
>                 em->len += merge->len;
>                 em->block_len += merge->block_len;
> +               if (em->disk_bytenr < EXTENT_MAP_LAST_BYTE)
> +                       merge_ondisk_extents(em, merge);
>                 rb_erase_cached(&merge->rb_node, &tree->map);
>                 RB_CLEAR_NODE(&merge->rb_node);
>                 em->generation = max(em->generation, merge->generation);
> @@ -565,6 +622,7 @@ static noinline int merge_extent_mapping(struct btrfs_inode *inode,
>             !extent_map_is_compressed(em)) {
>                 em->block_start += start_diff;
>                 em->block_len = em->len;
> +               em->offset += start_diff;
>         }
>         return add_extent_mapping(inode, em, 0);
>  }
> @@ -783,14 +841,18 @@ void btrfs_drop_extent_map_range(struct btrfs_inode *inode, u64 start, u64 end,
>                                         split->block_len = em->block_len;
>                                 else
>                                         split->block_len = split->len;
> +                               split->disk_bytenr = em->disk_bytenr;
>                                 split->disk_num_bytes = max(split->block_len,
>                                                             em->disk_num_bytes);
> +                               split->offset = em->offset;
>                                 split->ram_bytes = em->ram_bytes;
>                         } else {
>                                 split->orig_start = split->start;
>                                 split->block_len = 0;
>                                 split->block_start = em->block_start;
> +                               split->disk_bytenr = em->disk_bytenr;
>                                 split->disk_num_bytes = 0;
> +                               split->offset = 0;
>                                 split->ram_bytes = split->len;
>                         }
>
> @@ -811,13 +873,14 @@ void btrfs_drop_extent_map_range(struct btrfs_inode *inode, u64 start, u64 end,
>                         split->start = end;
>                         split->len = em_end - end;
>                         split->block_start = em->block_start;
> +                       split->disk_bytenr = em->disk_bytenr;
>                         split->flags = flags;
>                         split->generation = gen;
>
>                         if (em->block_start < EXTENT_MAP_LAST_BYTE) {
>                                 split->disk_num_bytes = max(em->block_len,
>                                                             em->disk_num_bytes);
> -
> +                               split->offset = em->offset + end - em->start;
>                                 split->ram_bytes = em->ram_bytes;
>                                 if (compressed) {
>                                         split->block_len = em->block_len;
> @@ -830,10 +893,11 @@ void btrfs_drop_extent_map_range(struct btrfs_inode *inode, u64 start, u64 end,
>                                         split->orig_start = em->orig_start;
>                                 }
>                         } else {
> +                               split->disk_num_bytes = 0;
> +                               split->offset = 0;
>                                 split->ram_bytes = split->len;
>                                 split->orig_start = split->start;
>                                 split->block_len = 0;
> -                               split->disk_num_bytes = 0;
>                         }
>
>                         if (extent_map_in_tree(em)) {
> @@ -987,6 +1051,9 @@ int split_extent_map(struct btrfs_inode *inode, u64 start, u64 len, u64 pre,
>         /* First, replace the em with a new extent_map starting from * em->start */
>         split_pre->start = em->start;
>         split_pre->len = pre;
> +       split_pre->disk_bytenr = new_logical;
> +       split_pre->disk_num_bytes = split_pre->len;
> +       split_pre->offset = 0;
>         split_pre->orig_start = split_pre->start;
>         split_pre->block_start = new_logical;
>         split_pre->block_len = split_pre->len;
> @@ -1005,10 +1072,12 @@ int split_extent_map(struct btrfs_inode *inode, u64 start, u64 len, u64 pre,
>         /* Insert the middle extent_map. */
>         split_mid->start = em->start + pre;
>         split_mid->len = em->len - pre;
> +       split_mid->disk_bytenr = em->block_start + pre;
> +       split_mid->disk_num_bytes = split_mid->len;
> +       split_mid->offset = 0;
>         split_mid->orig_start = split_mid->start;
>         split_mid->block_start = em->block_start + pre;
>         split_mid->block_len = split_mid->len;
> -       split_mid->disk_num_bytes = split_mid->block_len;
>         split_mid->ram_bytes = split_mid->len;
>         split_mid->flags = flags;
>         split_mid->generation = em->generation;
> diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h
> index 6ea0287b0d61..cc9c8092b704 100644
> --- a/fs/btrfs/extent_map.h
> +++ b/fs/btrfs/extent_map.h
> @@ -70,12 +70,29 @@ struct extent_map {
>          */
>         u64 orig_start;
>
> +       /*
> +        * The bytenr for of the full on-disk extent.

for of -> of

> +        *
> +        * For regular extents it's btrfs_file_extent_item::disk_bytenr.
> +        * For holes it's EXTENT_MAP_HOLE and for inline extents it's
> +        * EXTENT_MAP_INLINE.
> +        */
> +       u64 disk_bytenr;
> +
>         /*
>          * The full on-disk extent length, matching
>          * btrfs_file_extent_item::disk_num_bytes.
>          */
>         u64 disk_num_bytes;
>
> +       /*
> +        * Offset inside the decompressed extent.
> +        *
> +        * For regular extents it's btrfs_file_extent_item::offset.
> +        * For holes and inline extents it's 0.
> +        */
> +       u64 offset;
> +
>         /*
>          * The decompressed size of the whole on-disk extent, matching
>          * btrfs_file_extent_item::ram_bytes.
> diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
> index 2197cfe5443b..47bd4fe0a44b 100644
> --- a/fs/btrfs/file-item.c
> +++ b/fs/btrfs/file-item.c
> @@ -1294,12 +1294,17 @@ void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
>                 em->len = btrfs_file_extent_end(path) - extent_start;
>                 em->orig_start = extent_start -
>                         btrfs_file_extent_offset(leaf, fi);
> -               em->disk_num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
>                 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
>                 if (bytenr == 0) {
>                         em->block_start = EXTENT_MAP_HOLE;
> +                       em->disk_bytenr = EXTENT_MAP_HOLE;
> +                       em->disk_num_bytes = 0;
> +                       em->offset = 0;
>                         return;
>                 }
> +               em->disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
> +               em->disk_num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
> +               em->offset = btrfs_file_extent_offset(leaf, fi);
>                 if (compress_type != BTRFS_COMPRESS_NONE) {
>                         extent_map_set_compression(em, compress_type);
>                         em->block_start = bytenr;
> @@ -1316,8 +1321,10 @@ void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
>                 ASSERT(extent_start == 0);
>
>                 em->block_start = EXTENT_MAP_INLINE;
> +               em->disk_bytenr = EXTENT_MAP_INLINE;
>                 em->start = 0;
>                 em->len = fs_info->sectorsize;
> +               em->offset = 0;
>                 /*
>                  * Initialize orig_start and block_len with the same values
>                  * as in inode.c:btrfs_get_extent().
> diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
> index 63a13a4cace0..8931eeee199d 100644
> --- a/fs/btrfs/file.c
> +++ b/fs/btrfs/file.c
> @@ -2337,6 +2337,7 @@ static int fill_holes(struct btrfs_trans_handle *trans,
>                 hole_em->orig_start = offset;
>
>                 hole_em->block_start = EXTENT_MAP_HOLE;
> +               hole_em->disk_bytenr = EXTENT_MAP_HOLE;
>                 hole_em->block_len = 0;
>                 hole_em->disk_num_bytes = 0;
>                 hole_em->generation = trans->transid;
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index 2815b72f2d85..42fea12d509f 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -139,8 +139,9 @@ static noinline int run_delalloc_cow(struct btrfs_inode *inode,
>                                      bool pages_dirty);
>  static struct extent_map *create_io_em(struct btrfs_inode *inode, u64 start,
>                                        u64 len, u64 orig_start, u64 block_start,
> -                                      u64 block_len, u64 orig_block_len,
> +                                      u64 block_len, u64 disk_num_bytes,
>                                        u64 ram_bytes, int compress_type,
> +                                      struct btrfs_file_extent *file_extent,
>                                        int type);
>
>  static int data_reloc_print_warning_inode(u64 inum, u64 offset, u64 num_bytes,
> @@ -1152,6 +1153,7 @@ static void submit_one_async_extent(struct async_chunk *async_chunk,
>         struct btrfs_root *root = inode->root;
>         struct btrfs_fs_info *fs_info = root->fs_info;
>         struct btrfs_ordered_extent *ordered;
> +       struct btrfs_file_extent file_extent = { 0 };
>         struct btrfs_key ins;
>         struct page *locked_page = NULL;
>         struct extent_state *cached = NULL;
> @@ -1198,6 +1200,13 @@ static void submit_one_async_extent(struct async_chunk *async_chunk,
>         lock_extent(io_tree, start, end, &cached);
>
>         /* Here we're doing allocation and writeback of the compressed pages */
> +       file_extent.disk_bytenr = ins.objectid;
> +       file_extent.disk_num_bytes = ins.offset;
> +       file_extent.ram_bytes = async_extent->ram_size;
> +       file_extent.num_bytes = async_extent->ram_size;
> +       file_extent.offset = 0;
> +       file_extent.compression = async_extent->compress_type;
> +
>         em = create_io_em(inode, start,
>                           async_extent->ram_size,       /* len */
>                           start,                        /* orig_start */
> @@ -1206,6 +1215,7 @@ static void submit_one_async_extent(struct async_chunk *async_chunk,
>                           ins.offset,                   /* orig_block_len */
>                           async_extent->ram_size,       /* ram_bytes */
>                           async_extent->compress_type,
> +                         &file_extent,
>                           BTRFS_ORDERED_COMPRESSED);
>         if (IS_ERR(em)) {
>                 ret = PTR_ERR(em);
> @@ -1395,6 +1405,7 @@ static noinline int cow_file_range(struct btrfs_inode *inode,
>
>         while (num_bytes > 0) {
>                 struct btrfs_ordered_extent *ordered;
> +               struct btrfs_file_extent file_extent = { 0 };

Unnecessary initialization, see below.

>
>                 cur_alloc_size = num_bytes;
>                 ret = btrfs_reserve_extent(root, cur_alloc_size, cur_alloc_size,
> @@ -1431,6 +1442,12 @@ static noinline int cow_file_range(struct btrfs_inode *inode,
>                 extent_reserved = true;
>
>                 ram_size = ins.offset;
> +               file_extent.disk_bytenr = ins.objectid;
> +               file_extent.disk_num_bytes = ins.offset;
> +               file_extent.num_bytes = ins.offset;
> +               file_extent.ram_bytes = ins.offset;
> +               file_extent.offset = 0;
> +               file_extent.compression = BTRFS_COMPRESS_NONE;

If we always have to initialize all the members of the structure, it's
pointless to have it initialized to zeros when we declared it.

>
>                 lock_extent(&inode->io_tree, start, start + ram_size - 1,
>                             &cached);
> @@ -1442,6 +1459,7 @@ static noinline int cow_file_range(struct btrfs_inode *inode,
>                                   ins.offset, /* orig_block_len */
>                                   ram_size, /* ram_bytes */
>                                   BTRFS_COMPRESS_NONE, /* compress_type */
> +                                 &file_extent,
>                                   BTRFS_ORDERED_REGULAR /* type */);
>                 if (IS_ERR(em)) {
>                         unlock_extent(&inode->io_tree, start,
> @@ -1855,6 +1873,7 @@ struct can_nocow_file_extent_args {
>         u64 disk_bytenr;
>         u64 disk_num_bytes;
>         u64 extent_offset;
> +

Unrelated white space change.

>         /* Number of bytes that can be written to in NOCOW mode. */
>         u64 num_bytes;
>
> @@ -2182,6 +2201,7 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode,
>                                           nocow_args.num_bytes, /* block_len */
>                                           nocow_args.disk_num_bytes, /* orig_block_len */
>                                           ram_bytes, BTRFS_COMPRESS_NONE,
> +                                         &nocow_args.file_extent,
>                                           BTRFS_ORDERED_PREALLOC);
>                         if (IS_ERR(em)) {
>                                 unlock_extent(&inode->io_tree, cur_offset,
> @@ -4982,6 +5002,7 @@ int btrfs_cont_expand(struct btrfs_inode *inode, loff_t oldsize, loff_t size)
>                         hole_em->orig_start = cur_offset;
>
>                         hole_em->block_start = EXTENT_MAP_HOLE;
> +                       hole_em->disk_bytenr = EXTENT_MAP_HOLE;
>                         hole_em->block_len = 0;
>                         hole_em->disk_num_bytes = 0;
>                         hole_em->ram_bytes = hole_size;
> @@ -6842,6 +6863,7 @@ struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
>         }
>         em->start = EXTENT_MAP_HOLE;
>         em->orig_start = EXTENT_MAP_HOLE;
> +       em->disk_bytenr = EXTENT_MAP_HOLE;
>         em->len = (u64)-1;
>         em->block_len = (u64)-1;
>
> @@ -7007,7 +7029,8 @@ static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode,
>                                                   const u64 block_len,
>                                                   const u64 orig_block_len,
>                                                   const u64 ram_bytes,
> -                                                 const int type)
> +                                                 const int type,
> +                                                 struct btrfs_file_extent *file_extent)
>  {
>         struct extent_map *em = NULL;
>         struct btrfs_ordered_extent *ordered;
> @@ -7016,7 +7039,7 @@ static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode,
>                 em = create_io_em(inode, start, len, orig_start, block_start,
>                                   block_len, orig_block_len, ram_bytes,
>                                   BTRFS_COMPRESS_NONE, /* compress_type */
> -                                 type);
> +                                 file_extent, type);
>                 if (IS_ERR(em))
>                         goto out;
>         }
> @@ -7047,6 +7070,7 @@ static struct extent_map *btrfs_new_extent_direct(struct btrfs_inode *inode,
>  {
>         struct btrfs_root *root = inode->root;
>         struct btrfs_fs_info *fs_info = root->fs_info;
> +       struct btrfs_file_extent file_extent = { 0 };
>         struct extent_map *em;
>         struct btrfs_key ins;
>         u64 alloc_hint;
> @@ -7065,9 +7089,16 @@ static struct extent_map *btrfs_new_extent_direct(struct btrfs_inode *inode,
>         if (ret)
>                 return ERR_PTR(ret);
>
> +       file_extent.disk_bytenr = ins.objectid;
> +       file_extent.disk_num_bytes = ins.offset;
> +       file_extent.num_bytes = ins.offset;
> +       file_extent.ram_bytes = ins.offset;
> +       file_extent.offset = 0;
> +       file_extent.compression = BTRFS_COMPRESS_NONE;

Same as before:

"If we always have to initialize all the members of the structure,
it's pointless to have it initialized to zeros when we declared it."


>         em = btrfs_create_dio_extent(inode, dio_data, start, ins.offset, start,
>                                      ins.objectid, ins.offset, ins.offset,
> -                                    ins.offset, BTRFS_ORDERED_REGULAR);
> +                                    ins.offset, BTRFS_ORDERED_REGULAR,
> +                                    &file_extent);
>         btrfs_dec_block_group_reservations(fs_info, ins.objectid);
>         if (IS_ERR(em))
>                 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset,
> @@ -7310,6 +7341,7 @@ static struct extent_map *create_io_em(struct btrfs_inode *inode, u64 start,
>                                        u64 len, u64 orig_start, u64 block_start,
>                                        u64 block_len, u64 disk_num_bytes,
>                                        u64 ram_bytes, int compress_type,
> +                                      struct btrfs_file_extent *file_extent,
>                                        int type)
>  {
>         struct extent_map *em;
> @@ -7367,9 +7399,11 @@ static struct extent_map *create_io_em(struct btrfs_inode *inode, u64 start,
>         em->len = len;
>         em->block_len = block_len;
>         em->block_start = block_start;
> +       em->disk_bytenr = file_extent->disk_bytenr;
>         em->disk_num_bytes = disk_num_bytes;
>         em->ram_bytes = ram_bytes;
>         em->generation = -1;
> +       em->offset = file_extent->offset;
>         em->flags |= EXTENT_FLAG_PINNED;
>         if (type == BTRFS_ORDERED_COMPRESSED)
>                 extent_map_set_compression(em, compress_type);
> @@ -7393,6 +7427,7 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map,
>  {
>         const bool nowait = (iomap_flags & IOMAP_NOWAIT);
>         struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
> +       struct btrfs_file_extent file_extent = { 0 };
>         struct extent_map *em = *map;
>         int type;
>         u64 block_start, orig_start, orig_block_len, ram_bytes;
> @@ -7423,7 +7458,8 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map,
>                 block_start = em->block_start + (start - em->start);
>
>                 if (can_nocow_extent(inode, start, &len, &orig_start,
> -                                    &orig_block_len, &ram_bytes, NULL, false, false) == 1) {
> +                                    &orig_block_len, &ram_bytes,
> +                                    &file_extent, false, false) == 1) {
>                         bg = btrfs_inc_nocow_writers(fs_info, block_start);
>                         if (bg)
>                                 can_nocow = true;
> @@ -7451,7 +7487,8 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map,
>                 em2 = btrfs_create_dio_extent(BTRFS_I(inode), dio_data, start, len,
>                                               orig_start, block_start,
>                                               len, orig_block_len,
> -                                             ram_bytes, type);
> +                                             ram_bytes, type,
> +                                             &file_extent);
>                 btrfs_dec_nocow_writers(bg);
>                 if (type == BTRFS_ORDERED_PREALLOC) {
>                         free_extent_map(em);
> @@ -9602,6 +9639,8 @@ static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
>                 em->orig_start = cur_offset;
>                 em->len = ins.offset;
>                 em->block_start = ins.objectid;
> +               em->disk_bytenr = ins.objectid;
> +               em->offset = 0;
>                 em->block_len = ins.offset;
>                 em->disk_num_bytes = ins.offset;
>                 em->ram_bytes = ins.offset;
> @@ -10168,6 +10207,7 @@ ssize_t btrfs_do_encoded_write(struct kiocb *iocb, struct iov_iter *from,
>         struct extent_changeset *data_reserved = NULL;
>         struct extent_state *cached_state = NULL;
>         struct btrfs_ordered_extent *ordered;
> +       struct btrfs_file_extent file_extent = { 0 };
>         int compression;
>         size_t orig_count;
>         u64 start, end;
> @@ -10343,10 +10383,16 @@ ssize_t btrfs_do_encoded_write(struct kiocb *iocb, struct iov_iter *from,
>                 goto out_delalloc_release;
>         extent_reserved = true;
>
> +       file_extent.disk_bytenr = ins.objectid;
> +       file_extent.disk_num_bytes = ins.offset;
> +       file_extent.num_bytes = num_bytes;
> +       file_extent.ram_bytes = ram_bytes;
> +       file_extent.offset = encoded->unencoded_offset;
> +       file_extent.compression = compression;

Same as before:

"If we always have to initialize all the members of the structure,
it's pointless to have it initialized to zeros when we declared it."

The rest I suppose seems fine, but I have to look at the rest of the patchset.

Thanks.

>         em = create_io_em(inode, start, num_bytes,
>                           start - encoded->unencoded_offset, ins.objectid,
>                           ins.offset, ins.offset, ram_bytes, compression,
> -                         BTRFS_ORDERED_COMPRESSED);
> +                         &file_extent, BTRFS_ORDERED_COMPRESSED);
>         if (IS_ERR(em)) {
>                 ret = PTR_ERR(em);
>                 goto out_free_reserved;
> --
> 2.45.0
>
>

  reply	other threads:[~2024-05-09 17:05 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-05-03  6:01 [PATCH v2 00/11] btrfs: extent-map: unify the members with btrfs_ordered_extent Qu Wenruo
2024-05-03  6:01 ` [PATCH v2 01/11] btrfs: rename extent_map::orig_block_len to disk_num_bytes Qu Wenruo
2024-05-09 16:15   ` Filipe Manana
2024-05-03  6:01 ` [PATCH v2 02/11] btrfs: export the expected file extent through can_nocow_extent() Qu Wenruo
2024-05-09 16:22   ` Filipe Manana
2024-05-09 21:55     ` Qu Wenruo
2024-05-03  6:01 ` [PATCH v2 03/11] btrfs: introduce new members for extent_map Qu Wenruo
2024-05-09 17:05   ` Filipe Manana [this message]
2024-05-09 22:11     ` Qu Wenruo
2024-05-10 11:26       ` Filipe Manana
2024-05-10 22:26         ` Qu Wenruo
2024-05-13 12:48   ` Filipe Manana
2024-05-13 12:54     ` Filipe Manana
2024-05-13 17:31   ` Filipe Manana
2024-05-03  6:01 ` [PATCH v2 04/11] btrfs: introduce extra sanity checks for extent maps Qu Wenruo
2024-05-13 12:21   ` Filipe Manana
2024-05-13 22:34     ` Qu Wenruo
2024-05-03  6:01 ` [PATCH v2 05/11] btrfs: remove extent_map::orig_start member Qu Wenruo
2024-05-13 13:09   ` Filipe Manana
2024-05-13 22:14     ` Qu Wenruo
2024-05-03  6:01 ` [PATCH v2 06/11] btrfs: remove extent_map::block_len member Qu Wenruo
2024-05-13 17:44   ` Filipe Manana
2024-05-14  7:09     ` Qu Wenruo
2024-05-03  6:01 ` [PATCH v2 07/11] btrfs: remove extent_map::block_start member Qu Wenruo
2024-05-16 17:28   ` Filipe Manana
2024-05-16 22:45     ` Qu Wenruo
2024-05-03  6:01 ` [PATCH v2 08/11] btrfs: cleanup duplicated parameters related to can_nocow_file_extent_args Qu Wenruo
2024-05-20 15:55   ` Filipe Manana
2024-05-20 22:13     ` Qu Wenruo
2024-05-03  6:01 ` [PATCH v2 09/11] btrfs: cleanup duplicated parameters related to btrfs_alloc_ordered_extent Qu Wenruo
2024-05-20 16:31   ` Filipe Manana
2024-05-03  6:01 ` [PATCH v2 10/11] btrfs: cleanup duplicated parameters related to create_io_em() Qu Wenruo
2024-05-20 16:46   ` Filipe Manana
2024-05-03  6:01 ` [PATCH v2 11/11] btrfs: cleanup duplicated parameters related to btrfs_create_dio_extent() Qu Wenruo
2024-05-20 16:48   ` Filipe Manana
2024-05-23  4:03     ` Qu Wenruo
2024-05-03 11:53 ` [PATCH v2 00/11] btrfs: extent-map: unify the members with btrfs_ordered_extent David Sterba
2024-05-20 16:55 ` Filipe Manana

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