| Message ID | b0bd320dba85d72a34a4f7e5ba6b6c42caedbe41.1742443383.git.wqu@suse.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | btrfs: refactor btrfs_buffered_write() for the incoming large data folios | expand |
Looks good,
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
On Thu, Mar 20, 2025 at 5:36 AM Qu Wenruo <wqu@suse.com> wrote: > > Inside the main loop of btrfs_buffered_write(), if something wrong > happened, there is a out-of-loop cleanup path to release the reserved > space. > > This behavior saves some code lines, but makes it much harder to read, > as we need to check release_bytes to make sure when we need to do the > cleanup. > > Extract the cleanup part into a helper, release_reserved_space(), to do > the cleanup inside the main loop, so that we can move @release_bytes > inside the loop. > > This will make later refactor of the main loop much easier. > > Signed-off-by: Qu Wenruo <wqu@suse.com> > --- > fs/btrfs/file.c | 47 +++++++++++++++++++++++++++++++---------------- > 1 file changed, 31 insertions(+), 16 deletions(-) > > diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c > index b7eb1f0164bb..f68846c14ed5 100644 > --- a/fs/btrfs/file.c > +++ b/fs/btrfs/file.c > @@ -1074,6 +1074,27 @@ int btrfs_write_check(struct kiocb *iocb, size_t count) > return 0; > } > > +static void release_space(struct btrfs_inode *inode, > + struct extent_changeset *data_reserved, > + u64 start, u64 len, > + bool only_release_metadata) > +{ > + const struct btrfs_fs_info *fs_info = inode->root->fs_info; > + > + if (!len) > + return; > + > + if (only_release_metadata) { > + btrfs_check_nocow_unlock(inode); > + btrfs_delalloc_release_metadata(inode, len, true); > + } else { > + btrfs_delalloc_release_space(inode, > + data_reserved, > + round_down(start, fs_info->sectorsize), > + len, true); > + } > +} > + > ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) > { > struct file *file = iocb->ki_filp; > @@ -1081,7 +1102,6 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) > struct inode *inode = file_inode(file); > struct btrfs_fs_info *fs_info = inode_to_fs_info(inode); > struct extent_changeset *data_reserved = NULL; > - u64 release_bytes = 0; > u64 lockstart; > u64 lockend; > size_t num_written = 0; > @@ -1090,7 +1110,6 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) > unsigned int ilock_flags = 0; > const bool nowait = (iocb->ki_flags & IOCB_NOWAIT); > unsigned int bdp_flags = (nowait ? BDP_ASYNC : 0); > - bool only_release_metadata = false; > > if (nowait) > ilock_flags |= BTRFS_ILOCK_TRY; > @@ -1125,7 +1144,9 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) > size_t dirty_sectors; > size_t num_sectors; > struct folio *folio = NULL; > + u64 release_bytes = 0; We don't actually need to initialize this anymore. > int extents_locked; > + bool only_release_metadata = false; > > /* > * Fault pages before locking them in prepare_one_folio() > @@ -1136,7 +1157,6 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) > break; > } > > - only_release_metadata = false; > sector_offset = pos & (fs_info->sectorsize - 1); > > extent_changeset_release(data_reserved); > @@ -1191,6 +1211,8 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) > ret = balance_dirty_pages_ratelimited_flags(inode->i_mapping, bdp_flags); > if (ret) { > btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes); > + release_space(BTRFS_I(inode), data_reserved, > + pos, release_bytes, only_release_metadata); > break; > } > > @@ -1198,6 +1220,8 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) > if (ret) { > btrfs_delalloc_release_extents(BTRFS_I(inode), > reserve_bytes); > + release_space(BTRFS_I(inode), data_reserved, > + pos, release_bytes, only_release_metadata); > break; > } > > @@ -1210,6 +1234,8 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) > > btrfs_delalloc_release_extents(BTRFS_I(inode), > reserve_bytes); > + release_space(BTRFS_I(inode), data_reserved, > + pos, release_bytes, only_release_metadata); > ret = extents_locked; > break; > } > @@ -1277,6 +1303,8 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) > btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes); > if (ret) { > btrfs_drop_folio(fs_info, folio, pos, copied); > + release_space(BTRFS_I(inode), data_reserved, > + pos, release_bytes, only_release_metadata); > break; > } After this, we also don't need to set 'release_bytes' to 0 anymore either. Anyway, these are small things, so: Reviewed-by: Filipe Manana <fdmanana@suse.com> Thanks. > > @@ -1292,19 +1320,6 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) > num_written += copied; > } > > - if (release_bytes) { > - if (only_release_metadata) { > - btrfs_check_nocow_unlock(BTRFS_I(inode)); > - btrfs_delalloc_release_metadata(BTRFS_I(inode), > - release_bytes, true); > - } else { > - btrfs_delalloc_release_space(BTRFS_I(inode), > - data_reserved, > - round_down(pos, fs_info->sectorsize), > - release_bytes, true); > - } > - } > - > extent_changeset_free(data_reserved); > if (num_written > 0) { > pagecache_isize_extended(inode, old_isize, iocb->ki_pos); > -- > 2.49.0 > >
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index b7eb1f0164bb..f68846c14ed5 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1074,6 +1074,27 @@ int btrfs_write_check(struct kiocb *iocb, size_t count) return 0; } +static void release_space(struct btrfs_inode *inode, + struct extent_changeset *data_reserved, + u64 start, u64 len, + bool only_release_metadata) +{ + const struct btrfs_fs_info *fs_info = inode->root->fs_info; + + if (!len) + return; + + if (only_release_metadata) { + btrfs_check_nocow_unlock(inode); + btrfs_delalloc_release_metadata(inode, len, true); + } else { + btrfs_delalloc_release_space(inode, + data_reserved, + round_down(start, fs_info->sectorsize), + len, true); + } +} + ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) { struct file *file = iocb->ki_filp; @@ -1081,7 +1102,6 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) struct inode *inode = file_inode(file); struct btrfs_fs_info *fs_info = inode_to_fs_info(inode); struct extent_changeset *data_reserved = NULL; - u64 release_bytes = 0; u64 lockstart; u64 lockend; size_t num_written = 0; @@ -1090,7 +1110,6 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) unsigned int ilock_flags = 0; const bool nowait = (iocb->ki_flags & IOCB_NOWAIT); unsigned int bdp_flags = (nowait ? BDP_ASYNC : 0); - bool only_release_metadata = false; if (nowait) ilock_flags |= BTRFS_ILOCK_TRY; @@ -1125,7 +1144,9 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) size_t dirty_sectors; size_t num_sectors; struct folio *folio = NULL; + u64 release_bytes = 0; int extents_locked; + bool only_release_metadata = false; /* * Fault pages before locking them in prepare_one_folio() @@ -1136,7 +1157,6 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) break; } - only_release_metadata = false; sector_offset = pos & (fs_info->sectorsize - 1); extent_changeset_release(data_reserved); @@ -1191,6 +1211,8 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) ret = balance_dirty_pages_ratelimited_flags(inode->i_mapping, bdp_flags); if (ret) { btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes); + release_space(BTRFS_I(inode), data_reserved, + pos, release_bytes, only_release_metadata); break; } @@ -1198,6 +1220,8 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) if (ret) { btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes); + release_space(BTRFS_I(inode), data_reserved, + pos, release_bytes, only_release_metadata); break; } @@ -1210,6 +1234,8 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes); + release_space(BTRFS_I(inode), data_reserved, + pos, release_bytes, only_release_metadata); ret = extents_locked; break; } @@ -1277,6 +1303,8 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes); if (ret) { btrfs_drop_folio(fs_info, folio, pos, copied); + release_space(BTRFS_I(inode), data_reserved, + pos, release_bytes, only_release_metadata); break; } @@ -1292,19 +1320,6 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) num_written += copied; } - if (release_bytes) { - if (only_release_metadata) { - btrfs_check_nocow_unlock(BTRFS_I(inode)); - btrfs_delalloc_release_metadata(BTRFS_I(inode), - release_bytes, true); - } else { - btrfs_delalloc_release_space(BTRFS_I(inode), - data_reserved, - round_down(pos, fs_info->sectorsize), - release_bytes, true); - } - } - extent_changeset_free(data_reserved); if (num_written > 0) { pagecache_isize_extended(inode, old_isize, iocb->ki_pos);
Inside the main loop of btrfs_buffered_write(), if something wrong happened, there is a out-of-loop cleanup path to release the reserved space. This behavior saves some code lines, but makes it much harder to read, as we need to check release_bytes to make sure when we need to do the cleanup. Extract the cleanup part into a helper, release_reserved_space(), to do the cleanup inside the main loop, so that we can move @release_bytes inside the loop. This will make later refactor of the main loop much easier. Signed-off-by: Qu Wenruo <wqu@suse.com> --- fs/btrfs/file.c | 47 +++++++++++++++++++++++++++++++---------------- 1 file changed, 31 insertions(+), 16 deletions(-)