From: Johannes Thumshirn johannes.thumshirn@wdc.com
commit 35156d852762b58855f513b4f8bb7f32d69dc9c5 upstream
Don't allow more than one process to add pages to a relocation inode on a zoned filesystem, otherwise we cannot guarantee the sequential write rule once we're filling preallocated extents on a zoned filesystem.
Signed-off-by: Johannes Thumshirn johannes.thumshirn@wdc.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Johannes Thumshirn johannes.thumshirn@wdc.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/extent_io.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
--- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -5120,6 +5120,9 @@ int extent_write_locked_range(struct ino int extent_writepages(struct address_space *mapping, struct writeback_control *wbc) { + struct inode *inode = mapping->host; + const bool data_reloc = btrfs_is_data_reloc_root(BTRFS_I(inode)->root); + const bool zoned = btrfs_is_zoned(BTRFS_I(inode)->root->fs_info); int ret = 0; struct extent_page_data epd = { .bio_ctrl = { 0 }, @@ -5127,7 +5130,15 @@ int extent_writepages(struct address_spa .sync_io = wbc->sync_mode == WB_SYNC_ALL, };
+ /* + * Allow only a single thread to do the reloc work in zoned mode to + * protect the write pointer updates. + */ + if (data_reloc && zoned) + btrfs_inode_lock(inode, 0); ret = extent_write_cache_pages(mapping, wbc, &epd); + if (data_reloc && zoned) + btrfs_inode_unlock(inode, 0); ASSERT(ret <= 0); if (ret < 0) { end_write_bio(&epd, ret);