| Message ID | 152246895649.36038.5391043415273091960.stgit@dwillia2-desk3.amr.corp.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri 30-03-18 21:02:36, Dan Williams wrote: > In preparation for the dax implementation to start associating dax pages > to inodes via page->mapping, we need to provide a 'struct > address_space_operations' instance for dax. Otherwise, direct-I/O > triggers incorrect page cache assumptions and warnings. > > Cc: "Theodore Ts'o" <tytso@mit.edu> > Cc: Andreas Dilger <adilger.kernel@dilger.ca> > Cc: linux-ext4@vger.kernel.org > Cc: Jan Kara <jack@suse.cz> > Signed-off-by: Dan Williams <dan.j.williams@intel.com> Looks good. You can add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > fs/ext4/inode.c | 42 +++++++++++++++++++++++++++++++----------- > 1 file changed, 31 insertions(+), 11 deletions(-) > > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c > index c94780075b04..249a97b19181 100644 > --- a/fs/ext4/inode.c > +++ b/fs/ext4/inode.c > @@ -2725,12 +2725,6 @@ static int ext4_writepages(struct address_space *mapping, > percpu_down_read(&sbi->s_journal_flag_rwsem); > trace_ext4_writepages(inode, wbc); > > - if (dax_mapping(mapping)) { > - ret = dax_writeback_mapping_range(mapping, inode->i_sb->s_bdev, > - wbc); > - goto out_writepages; > - } > - > /* > * No pages to write? This is mainly a kludge to avoid starting > * a transaction for special inodes like journal inode on last iput() > @@ -2955,6 +2949,27 @@ static int ext4_writepages(struct address_space *mapping, > return ret; > } > > +static int ext4_dax_writepages(struct address_space *mapping, > + struct writeback_control *wbc) > +{ > + int ret; > + long nr_to_write = wbc->nr_to_write; > + struct inode *inode = mapping->host; > + struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb); > + > + if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) > + return -EIO; > + > + percpu_down_read(&sbi->s_journal_flag_rwsem); > + trace_ext4_writepages(inode, wbc); > + > + ret = dax_writeback_mapping_range(mapping, inode->i_sb->s_bdev, wbc); > + trace_ext4_writepages_result(inode, wbc, ret, > + nr_to_write - wbc->nr_to_write); > + percpu_up_read(&sbi->s_journal_flag_rwsem); > + return ret; > +} > + > static int ext4_nonda_switch(struct super_block *sb) > { > s64 free_clusters, dirty_clusters; > @@ -3857,10 +3872,6 @@ static ssize_t ext4_direct_IO(struct kiocb *iocb, struct iov_iter *iter) > if (ext4_has_inline_data(inode)) > return 0; > > - /* DAX uses iomap path now */ > - if (WARN_ON_ONCE(IS_DAX(inode))) > - return 0; > - > trace_ext4_direct_IO_enter(inode, offset, count, iov_iter_rw(iter)); > if (iov_iter_rw(iter) == READ) > ret = ext4_direct_IO_read(iocb, iter); > @@ -3946,6 +3957,13 @@ static const struct address_space_operations ext4_da_aops = { > .error_remove_page = generic_error_remove_page, > }; > > +static const struct address_space_operations ext4_dax_aops = { > + .writepages = ext4_dax_writepages, > + .direct_IO = noop_direct_IO, > + .set_page_dirty = noop_set_page_dirty, > + .invalidatepage = noop_invalidatepage, > +}; > + > void ext4_set_aops(struct inode *inode) > { > switch (ext4_inode_journal_mode(inode)) { > @@ -3958,7 +3976,9 @@ void ext4_set_aops(struct inode *inode) > default: > BUG(); > } > - if (test_opt(inode->i_sb, DELALLOC)) > + if (IS_DAX(inode)) > + inode->i_mapping->a_ops = &ext4_dax_aops; > + else if (test_opt(inode->i_sb, DELALLOC)) > inode->i_mapping->a_ops = &ext4_da_aops; > else > inode->i_mapping->a_ops = &ext4_aops; >
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index c94780075b04..249a97b19181 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -2725,12 +2725,6 @@ static int ext4_writepages(struct address_space *mapping, percpu_down_read(&sbi->s_journal_flag_rwsem); trace_ext4_writepages(inode, wbc); - if (dax_mapping(mapping)) { - ret = dax_writeback_mapping_range(mapping, inode->i_sb->s_bdev, - wbc); - goto out_writepages; - } - /* * No pages to write? This is mainly a kludge to avoid starting * a transaction for special inodes like journal inode on last iput() @@ -2955,6 +2949,27 @@ static int ext4_writepages(struct address_space *mapping, return ret; } +static int ext4_dax_writepages(struct address_space *mapping, + struct writeback_control *wbc) +{ + int ret; + long nr_to_write = wbc->nr_to_write; + struct inode *inode = mapping->host; + struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb); + + if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) + return -EIO; + + percpu_down_read(&sbi->s_journal_flag_rwsem); + trace_ext4_writepages(inode, wbc); + + ret = dax_writeback_mapping_range(mapping, inode->i_sb->s_bdev, wbc); + trace_ext4_writepages_result(inode, wbc, ret, + nr_to_write - wbc->nr_to_write); + percpu_up_read(&sbi->s_journal_flag_rwsem); + return ret; +} + static int ext4_nonda_switch(struct super_block *sb) { s64 free_clusters, dirty_clusters; @@ -3857,10 +3872,6 @@ static ssize_t ext4_direct_IO(struct kiocb *iocb, struct iov_iter *iter) if (ext4_has_inline_data(inode)) return 0; - /* DAX uses iomap path now */ - if (WARN_ON_ONCE(IS_DAX(inode))) - return 0; - trace_ext4_direct_IO_enter(inode, offset, count, iov_iter_rw(iter)); if (iov_iter_rw(iter) == READ) ret = ext4_direct_IO_read(iocb, iter); @@ -3946,6 +3957,13 @@ static const struct address_space_operations ext4_da_aops = { .error_remove_page = generic_error_remove_page, }; +static const struct address_space_operations ext4_dax_aops = { + .writepages = ext4_dax_writepages, + .direct_IO = noop_direct_IO, + .set_page_dirty = noop_set_page_dirty, + .invalidatepage = noop_invalidatepage, +}; + void ext4_set_aops(struct inode *inode) { switch (ext4_inode_journal_mode(inode)) { @@ -3958,7 +3976,9 @@ void ext4_set_aops(struct inode *inode) default: BUG(); } - if (test_opt(inode->i_sb, DELALLOC)) + if (IS_DAX(inode)) + inode->i_mapping->a_ops = &ext4_dax_aops; + else if (test_opt(inode->i_sb, DELALLOC)) inode->i_mapping->a_ops = &ext4_da_aops; else inode->i_mapping->a_ops = &ext4_aops;
In preparation for the dax implementation to start associating dax pages to inodes via page->mapping, we need to provide a 'struct address_space_operations' instance for dax. Otherwise, direct-I/O triggers incorrect page cache assumptions and warnings. Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: linux-ext4@vger.kernel.org Cc: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- fs/ext4/inode.c | 42 +++++++++++++++++++++++++++++++----------- 1 file changed, 31 insertions(+), 11 deletions(-)