diff options
| -rw-r--r-- | fs/dax.c | 39 | ||||
| -rw-r--r-- | include/linux/iomap.h | 5 | ||||
| -rw-r--r-- | include/linux/mm.h | 6 |
3 files changed, 47 insertions, 3 deletions
@@ -1091,6 +1091,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, unsigned flags = IOMAP_FAULT; int error, major = 0; bool write = vmf->flags & FAULT_FLAG_WRITE; + bool sync; int vmf_ret = 0; void *entry; pfn_t pfn; @@ -1169,6 +1170,8 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, goto finish_iomap; } + sync = (vma->vm_flags & VM_SYNC) && (iomap.flags & IOMAP_F_DIRTY); + switch (iomap.type) { case IOMAP_MAPPED: if (iomap.flags & IOMAP_F_NEW) { @@ -1182,12 +1185,27 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, entry = dax_insert_mapping_entry(mapping, vmf, entry, dax_iomap_sector(&iomap, pos), - 0, write); + 0, write && !sync); if (IS_ERR(entry)) { error = PTR_ERR(entry); goto error_finish_iomap; } + /* + * If we are doing synchronous page fault and inode needs fsync, + * we can insert PTE into page tables only after that happens. + * Skip insertion for now and return the pfn so that caller can + * insert it after fsync is done. + */ + if (sync) { + if (WARN_ON_ONCE(!pfnp)) { + error = -EIO; + goto error_finish_iomap; + } + *pfnp = pfn; + vmf_ret = VM_FAULT_NEEDDSYNC | major; + goto finish_iomap; + } trace_dax_insert_mapping(inode, vmf, entry); if (write) error = vm_insert_mixed_mkwrite(vma, vaddr, pfn); @@ -1287,6 +1305,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, struct address_space *mapping = vma->vm_file->f_mapping; unsigned long pmd_addr = vmf->address & PMD_MASK; bool write = vmf->flags & FAULT_FLAG_WRITE; + bool sync; unsigned int iomap_flags = (write ? IOMAP_WRITE : 0) | IOMAP_FAULT; struct inode *inode = mapping->host; int result = VM_FAULT_FALLBACK; @@ -1371,6 +1390,8 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, if (iomap.offset + iomap.length < pos + PMD_SIZE) goto finish_iomap; + sync = (vma->vm_flags & VM_SYNC) && (iomap.flags & IOMAP_F_DIRTY); + switch (iomap.type) { case IOMAP_MAPPED: error = dax_iomap_pfn(&iomap, pos, PMD_SIZE, &pfn); @@ -1379,10 +1400,24 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, entry = dax_insert_mapping_entry(mapping, vmf, entry, dax_iomap_sector(&iomap, pos), - RADIX_DAX_PMD, write); + RADIX_DAX_PMD, write && !sync); if (IS_ERR(entry)) goto finish_iomap; + /* + * If we are doing synchronous page fault and inode needs fsync, + * we can insert PMD into page tables only after that happens. + * Skip insertion for now and return the pfn so that caller can + * insert it after fsync is done. + */ + if (sync) { + if (WARN_ON_ONCE(!pfnp)) + goto finish_iomap; + *pfnp = pfn; + result = VM_FAULT_NEEDDSYNC; + goto finish_iomap; + } + trace_dax_pmd_insert_mapping(inode, vmf, PMD_SIZE, pfn, entry); result = vmf_insert_pfn_pmd(vma, vmf->address, vmf->pmd, pfn, write); diff --git a/include/linux/iomap.h b/include/linux/iomap.h index f64dc6ce5161..73e3b7085dbe 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -22,6 +22,11 @@ struct vm_fault; * Flags for all iomap mappings: */ #define IOMAP_F_NEW 0x01 /* blocks have been newly allocated */ +/* + * IOMAP_F_DIRTY indicates the inode has uncommitted metadata needed to access + * written data and requires fdatasync to commit them to persistent storage. + */ +#define IOMAP_F_DIRTY 0x02 /* * Flags that only need to be reported for IOMAP_REPORT requests: diff --git a/include/linux/mm.h b/include/linux/mm.h index 5411cb7442de..f57e55782d7d 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1182,6 +1182,9 @@ static inline void clear_page_pfmemalloc(struct page *page) #define VM_FAULT_RETRY 0x0400 /* ->fault blocked, must retry */ #define VM_FAULT_FALLBACK 0x0800 /* huge page fault failed, fall back to small */ #define VM_FAULT_DONE_COW 0x1000 /* ->fault has fully handled COW */ +#define VM_FAULT_NEEDDSYNC 0x2000 /* ->fault did not modify page tables + * and needs fsync() to complete (for + * synchronous page faults in DAX) */ #define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV | \ VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE | \ @@ -1199,7 +1202,8 @@ static inline void clear_page_pfmemalloc(struct page *page) { VM_FAULT_LOCKED, "LOCKED" }, \ { VM_FAULT_RETRY, "RETRY" }, \ { VM_FAULT_FALLBACK, "FALLBACK" }, \ - { VM_FAULT_DONE_COW, "DONE_COW" } + { VM_FAULT_DONE_COW, "DONE_COW" }, \ + { VM_FAULT_NEEDDSYNC, "NEEDDSYNC" } /* Encode hstate index for a hwpoisoned large page */ #define VM_FAULT_SET_HINDEX(x) ((x) << 12) |