Take the xfs writeback code and move it to fs/iomap. A new structure with three methods is added as the abstraction from the generic writeback code to the file system. These methods are used to map blocks, submit an ioend, and cancel a page that encountered an error before it was added to an ioend.
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| @@ -4,6 +4,7 @@ · 3 unmodified lines | ||
| 4 | 4 | |
| 5 | 5 | #include <linux/atomic.h> |
| 6 | 6 | #include <linux/bitmap.h> |
| 7 | +#include <linux/blk_types.h> | |
| 7 | 8 | #include <linux/mm.h> |
| 8 | 9 | #include <linux/types.h> |
| 9 | 10 | #include <linux/mm_types.h> |
| @@ -12,6 +13,7 @@ · 2 unmodified lines | ||
| 12 | 13 | struct address_space; |
| 13 | 14 | struct fiemap_extent_info; |
| 14 | 15 | struct inode; |
| 16 | +struct iomap_writepage_ctx; | |
| 15 | 17 | struct iov_iter; |
| 16 | 18 | struct kiocb; |
| 17 | 19 | struct page; |
| @@ -185,6 +187,63 @@ loff_t iomap_seek_data(struct inode *inode, loff_t offset, · 167 unmodified lines | ||
| 185 | 187 | sector_t iomap_bmap(struct address_space *mapping, sector_t bno, |
| 186 | 188 | const struct iomap_ops *ops); |
| 187 | 189 | |
| 190 | +/* | |
| 191 | + * Structure for writeback I/O completions. | |
| 192 | + */ | |
| 193 | +struct iomap_ioend { | |
| 194 | + struct list_head io_list; /* next ioend in chain */ | |
| 195 | + u16 io_type; | |
| 196 | + u16 io_flags; /* IOMAP_F_* */ | |
| 197 | + struct inode *io_inode; /* file being written to */ | |
| 198 | + size_t io_size; /* size of the extent */ | |
| 199 | + loff_t io_offset; /* offset in the file */ | |
| 200 | + void *io_private; /* file system private data */ | |
| 201 | + struct bio *io_bio; /* bio being built */ | |
| 202 | + struct bio io_inline_bio; /* MUST BE LAST! */ | |
| 203 | +}; | |
| 204 | + | |
| 205 | +struct iomap_writeback_ops { | |
| 206 | + /* | |
| 207 | + * Required, maps the blocks so that writeback can be performed on | |
| 208 | + * the range starting at offset. | |
| 209 | + */ | |
| 210 | + int (*map_blocks)(struct iomap_writepage_ctx *wpc, struct inode *inode, | |
| 211 | + loff_t offset); | |
| 212 | + | |
| 213 | + /* | |
| 214 | + * Optional, allows the file systems to perform actions just before | |
| 215 | + * submitting the bio and/or override the bio end_io handler for complex | |
| 216 | + * operations like copy on write extent manipulation or unwritten extent | |
| 217 | + * conversions. | |
| 218 | + */ | |
| 219 | + int (*prepare_ioend)(struct iomap_ioend *ioend, int status); | |
| 220 | + | |
| 221 | + /* | |
| 222 | + * Optional, allows the file system to discard state on a page where | |
| 223 | + * we failed to submit any I/O. | |
| 224 | + */ | |
| 225 | + void (*discard_page)(struct page *page); | |
| 226 | +}; | |
| 227 | + | |
| 228 | +struct iomap_writepage_ctx { | |
| 229 | + struct iomap iomap; | |
| 230 | + struct iomap_ioend *ioend; | |
| 231 | + const struct iomap_writeback_ops *ops; | |
| 232 | +}; | |
| 233 | + | |
| 234 | +void iomap_finish_ioends(struct iomap_ioend *ioend, int error); | |
| 235 | +void iomap_ioend_try_merge(struct iomap_ioend *ioend, | |
| 236 | + struct list_head *more_ioends, | |
| 237 | + void (*merge_private)(struct iomap_ioend *ioend, | |
| 238 | + struct iomap_ioend *next)); | |
| 239 | +void iomap_sort_ioends(struct list_head *ioend_list); | |
| 240 | +int iomap_writepage(struct page *page, struct writeback_control *wbc, | |
| 241 | + struct iomap_writepage_ctx *wpc, | |
| 242 | + const struct iomap_writeback_ops *ops); | |
| 243 | +int iomap_writepages(struct address_space *mapping, | |
| 244 | + struct writeback_control *wbc, struct iomap_writepage_ctx *wpc, | |
| 245 | + const struct iomap_writeback_ops *ops); | |
| 246 | + | |
| 188 | 247 | /* |
| 189 | 248 | * Flags for direct I/O ->end_io: |
| 190 | 249 | */ |