Move the page_done callback into a separate iomap_page_ops structure and add a page_prepare calback to be called before the next page is written to. In gfs2, we'll want to start a transaction in page_prepare and end it in page_done. Other filesystems that implement data journaling will require the same kind of mechanism.
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| @@ -53,6 +53,8 @@ struct vm_fault; · 52 unmodified lines | |||
| 53 | */ | 53 | */ |
| 54 | #define IOMAP_NULL_ADDR -1ULL /* addr is not valid */ | 54 | #define IOMAP_NULL_ADDR -1ULL /* addr is not valid */ |
| 55 | 55 | ||
| 56 | struct iomap_page_ops; | ||
| 57 | |||
| 56 | struct iomap { | 58 | struct iomap { |
| 57 | u64 addr; /* disk offset of mapping, bytes */ | 59 | u64 addr; /* disk offset of mapping, bytes */ |
| 58 | loff_t offset; /* file offset of mapping, bytes */ | 60 | loff_t offset; /* file offset of mapping, bytes */ |
| @@ -63,12 +65,22 @@ struct iomap { · 4 unmodified lines | |||
| 63 | struct dax_device *dax_dev; /* dax_dev for dax operations */ | 65 | struct dax_device *dax_dev; /* dax_dev for dax operations */ |
| 64 | void *inline_data; | 66 | void *inline_data; |
| 65 | void *private; /* filesystem private */ | 67 | void *private; /* filesystem private */ |
| 68 | const struct iomap_page_ops *page_ops; | ||
| 69 | }; | ||
| 66 | 70 | ||
| 67 | /* | 71 | /* |
| 68 | * Called when finished processing a page in the mapping returned in | 72 | * When a filesystem sets page_ops in an iomap mapping it returns, page_prepare |
| 69 | * this iomap. At least for now this is only supported in the buffered | 73 | * and page_done will be called for each page written to. This only applies to |
| 70 | * write path. | 74 | * buffered writes as unbuffered writes will not typically have pages |
| 71 | */ | 75 | * associated with them. |
| 76 | * | ||
| 77 | * When page_prepare succeeds, page_done will always be called to do any | ||
| 78 | * cleanup work necessary. In that page_done call, @page will be NULL if the | ||
| 79 | * associated page could not be obtained. | ||
| 80 | */ | ||
| 81 | struct iomap_page_ops { | ||
| 82 | int (*page_prepare)(struct inode *inode, loff_t pos, unsigned len, | ||
| 83 | struct iomap *iomap); | ||
| 72 | void (*page_done)(struct inode *inode, loff_t pos, unsigned copied, | 84 | void (*page_done)(struct inode *inode, loff_t pos, unsigned copied, |
| 73 | struct page *page, struct iomap *iomap); | 85 | struct page *page, struct iomap *iomap); |
| 74 | }; | 86 | }; |