| Message ID | 20190802220048.16142-6-rgoldwyn@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Btrfs iomap | expand |
On Fri, Aug 02, 2019 at 05:00:40PM -0500, Goldwyn Rodrigues wrote: > From: Goldwyn Rodrigues <rgoldwyn@suse.com> > > Set iomap->type to IOMAP_COW and fill up the source map in case > the I/O is not page aligned. ..... > static void btrfs_buffered_page_done(struct inode *inode, loff_t pos, > unsigned copied, struct page *page, > struct iomap *iomap) > @@ -188,6 +217,7 @@ static int btrfs_buffered_iomap_begin(struct inode *inode, loff_t pos, > int ret; > size_t write_bytes = length; > struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); > + size_t end; > size_t sector_offset = pos & (fs_info->sectorsize - 1); > struct btrfs_iomap *bi; > > @@ -255,6 +285,17 @@ static int btrfs_buffered_iomap_begin(struct inode *inode, loff_t pos, > iomap->private = bi; > iomap->length = round_up(write_bytes, fs_info->sectorsize); > iomap->offset = round_down(pos, fs_info->sectorsize); > + end = pos + write_bytes; > + /* Set IOMAP_COW if start/end is not page aligned */ > + if (((pos & (PAGE_SIZE - 1)) || (end & (PAGE_SIZE - 1)))) { > + iomap->type = IOMAP_COW; > + ret = get_iomap(inode, pos, length, srcmap); > + if (ret < 0) > + goto release; I suspect you didn't test this case, because.... > + } else { > + iomap->type = IOMAP_DELALLOC; > + } > + > iomap->addr = IOMAP_NULL_ADDR; > iomap->type = IOMAP_DELALLOC; The iomap->type is overwritten here and so IOMAP_COW will never be seen by the iomap infrastructure... Cheers, Dave.
On 10:13 05/08, Dave Chinner wrote: > On Fri, Aug 02, 2019 at 05:00:40PM -0500, Goldwyn Rodrigues wrote: > > From: Goldwyn Rodrigues <rgoldwyn@suse.com> > > > > Set iomap->type to IOMAP_COW and fill up the source map in case > > the I/O is not page aligned. > ..... > > static void btrfs_buffered_page_done(struct inode *inode, loff_t pos, > > unsigned copied, struct page *page, > > struct iomap *iomap) > > @@ -188,6 +217,7 @@ static int btrfs_buffered_iomap_begin(struct inode *inode, loff_t pos, > > int ret; > > size_t write_bytes = length; > > struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); > > + size_t end; > > size_t sector_offset = pos & (fs_info->sectorsize - 1); > > struct btrfs_iomap *bi; > > > > @@ -255,6 +285,17 @@ static int btrfs_buffered_iomap_begin(struct inode *inode, loff_t pos, > > iomap->private = bi; > > iomap->length = round_up(write_bytes, fs_info->sectorsize); > > iomap->offset = round_down(pos, fs_info->sectorsize); > > + end = pos + write_bytes; > > + /* Set IOMAP_COW if start/end is not page aligned */ > > + if (((pos & (PAGE_SIZE - 1)) || (end & (PAGE_SIZE - 1)))) { > > + iomap->type = IOMAP_COW; > > + ret = get_iomap(inode, pos, length, srcmap); > > + if (ret < 0) > > + goto release; > > I suspect you didn't test this case, because.... > > > + } else { > > + iomap->type = IOMAP_DELALLOC; > > + } > > + > > iomap->addr = IOMAP_NULL_ADDR; > > iomap->type = IOMAP_DELALLOC; > > The iomap->type is overwritten here and so IOMAP_COW will never be > seen by the iomap infrastructure... Yes, thats correct. I will fix this.
diff --git a/fs/btrfs/iomap.c b/fs/btrfs/iomap.c index 9eb5e7b7603a..879038e2f1a0 100644 --- a/fs/btrfs/iomap.c +++ b/fs/btrfs/iomap.c @@ -165,6 +165,35 @@ static int btrfs_find_new_delalloc_bytes(struct btrfs_inode *inode, return 0; } +/* + * get_iomap: Get the block map and fill the iomap structure + * @pos: file position + * @length: I/O length + * @iomap: The iomap structure to fill + */ + +static int get_iomap(struct inode *inode, loff_t pos, loff_t length, + struct iomap *iomap) +{ + struct extent_map *em; + iomap->addr = IOMAP_NULL_ADDR; + em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, pos, length, 0); + if (IS_ERR(em)) + return PTR_ERR(em); + /* XXX Do we need to check for em->flags here? */ + if (em->block_start == EXTENT_MAP_HOLE) { + iomap->type = IOMAP_HOLE; + } else { + iomap->addr = em->block_start; + iomap->type = IOMAP_MAPPED; + } + iomap->offset = em->start; + iomap->bdev = em->bdev; + iomap->length = em->len; + free_extent_map(em); + return 0; +} + static void btrfs_buffered_page_done(struct inode *inode, loff_t pos, unsigned copied, struct page *page, struct iomap *iomap) @@ -188,6 +217,7 @@ static int btrfs_buffered_iomap_begin(struct inode *inode, loff_t pos, int ret; size_t write_bytes = length; struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + size_t end; size_t sector_offset = pos & (fs_info->sectorsize - 1); struct btrfs_iomap *bi; @@ -255,6 +285,17 @@ static int btrfs_buffered_iomap_begin(struct inode *inode, loff_t pos, iomap->private = bi; iomap->length = round_up(write_bytes, fs_info->sectorsize); iomap->offset = round_down(pos, fs_info->sectorsize); + end = pos + write_bytes; + /* Set IOMAP_COW if start/end is not page aligned */ + if (((pos & (PAGE_SIZE - 1)) || (end & (PAGE_SIZE - 1)))) { + iomap->type = IOMAP_COW; + ret = get_iomap(inode, pos, length, srcmap); + if (ret < 0) + goto release; + } else { + iomap->type = IOMAP_DELALLOC; + } + iomap->addr = IOMAP_NULL_ADDR; iomap->type = IOMAP_DELALLOC; iomap->bdev = fs_info->fs_devices->latest_bdev;