diff options
Diffstat (limited to 'fs/dax.c')
-rw-r--r-- | fs/dax.c | 175 |
1 files changed, 107 insertions, 68 deletions
@@ -35,6 +35,9 @@ #include <linux/iomap.h> #include "internal.h" +#define CREATE_TRACE_POINTS +#include <trace/events/fs_dax.h> + /* We choose 4096 entries - same as per-zone page wait tables */ #define DAX_WAIT_TABLE_BITS 12 #define DAX_WAIT_TABLE_ENTRIES (1 << DAX_WAIT_TABLE_BITS) @@ -922,12 +925,11 @@ static int dax_insert_mapping(struct address_space *mapping, /** * dax_pfn_mkwrite - handle first write to DAX page - * @vma: The virtual memory area where the fault occurred * @vmf: The description of the fault */ -int dax_pfn_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) +int dax_pfn_mkwrite(struct vm_fault *vmf) { - struct file *file = vma->vm_file; + struct file *file = vmf->vma->vm_file; struct address_space *mapping = file->f_mapping; void *entry, **slot; pgoff_t index = vmf->pgoff; @@ -1031,6 +1033,11 @@ dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data, struct blk_dax_ctl dax = { 0 }; ssize_t map_len; + if (fatal_signal_pending(current)) { + ret = -EINTR; + break; + } + dax.sector = dax_iomap_sector(iomap, pos); dax.size = (length + offset + PAGE_SIZE - 1) & PAGE_MASK; map_len = dax_map_atomic(iomap->bdev, &dax); @@ -1074,15 +1081,19 @@ dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data, */ ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter, - struct iomap_ops *ops) + const struct iomap_ops *ops) { struct address_space *mapping = iocb->ki_filp->f_mapping; struct inode *inode = mapping->host; loff_t pos = iocb->ki_pos, ret = 0, done = 0; unsigned flags = 0; - if (iov_iter_rw(iter) == WRITE) + if (iov_iter_rw(iter) == WRITE) { + lockdep_assert_held_exclusive(&inode->i_rwsem); flags |= IOMAP_WRITE; + } else { + lockdep_assert_held(&inode->i_rwsem); + } while (iov_iter_count(iter)) { ret = iomap_apply(inode, pos, iov_iter_count(iter), flags, ops, @@ -1107,20 +1118,10 @@ static int dax_fault_return(int error) return VM_FAULT_SIGBUS; } -/** - * dax_iomap_fault - handle a page fault on a DAX file - * @vma: The virtual memory area where the fault occurred - * @vmf: The description of the fault - * @ops: iomap ops passed from the file system - * - * When a page fault occurs, filesystems may call this helper in their fault - * or mkwrite handler for DAX files. Assumes the caller has done all the - * necessary locking for the page fault to proceed successfully. - */ -int dax_iomap_fault(struct vm_area_struct *vma, struct vm_fault *vmf, - struct iomap_ops *ops) +static int dax_iomap_pte_fault(struct vm_fault *vmf, + const struct iomap_ops *ops) { - struct address_space *mapping = vma->vm_file->f_mapping; + struct address_space *mapping = vmf->vma->vm_file->f_mapping; struct inode *inode = mapping->host; unsigned long vaddr = vmf->address; loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT; @@ -1193,11 +1194,11 @@ int dax_iomap_fault(struct vm_area_struct *vma, struct vm_fault *vmf, case IOMAP_MAPPED: if (iomap.flags & IOMAP_F_NEW) { count_vm_event(PGMAJFAULT); - mem_cgroup_count_vm_event(vma->vm_mm, PGMAJFAULT); + mem_cgroup_count_vm_event(vmf->vma->vm_mm, PGMAJFAULT); major = VM_FAULT_MAJOR; } error = dax_insert_mapping(mapping, iomap.bdev, sector, - PAGE_SIZE, &entry, vma, vmf); + PAGE_SIZE, &entry, vmf->vma, vmf); /* -EBUSY is fine, somebody else faulted on the same PTE */ if (error == -EBUSY) error = 0; @@ -1235,7 +1236,6 @@ int dax_iomap_fault(struct vm_area_struct *vma, struct vm_fault *vmf, } return vmf_ret; } -EXPORT_SYMBOL_GPL(dax_iomap_fault); #ifdef CONFIG_FS_DAX_PMD /* @@ -1244,21 +1244,21 @@ EXPORT_SYMBOL_GPL(dax_iomap_fault); */ #define PG_PMD_COLOUR ((PMD_SIZE >> PAGE_SHIFT) - 1) -static int dax_pmd_insert_mapping(struct vm_area_struct *vma, pmd_t *pmd, - struct vm_fault *vmf, unsigned long address, - struct iomap *iomap, loff_t pos, bool write, void **entryp) +static int dax_pmd_insert_mapping(struct vm_fault *vmf, struct iomap *iomap, + loff_t pos, void **entryp) { - struct address_space *mapping = vma->vm_file->f_mapping; + struct address_space *mapping = vmf->vma->vm_file->f_mapping; struct block_device *bdev = iomap->bdev; + struct inode *inode = mapping->host; struct blk_dax_ctl dax = { .sector = dax_iomap_sector(iomap, pos), .size = PMD_SIZE, }; long length = dax_map_atomic(bdev, &dax); - void *ret; + void *ret = NULL; if (length < 0) /* dax_map_atomic() failed */ - return VM_FAULT_FALLBACK; + goto fallback; if (length < PMD_SIZE) goto unmap_fallback; if (pfn_t_to_pfn(dax.pfn) & PG_PMD_COLOUR) @@ -1271,67 +1271,87 @@ static int dax_pmd_insert_mapping(struct vm_area_struct *vma, pmd_t *pmd, ret = dax_insert_mapping_entry(mapping, vmf, *entryp, dax.sector, RADIX_DAX_PMD); if (IS_ERR(ret)) - return VM_FAULT_FALLBACK; + goto fallback; *entryp = ret; - return vmf_insert_pfn_pmd(vma, address, pmd, dax.pfn, write); + trace_dax_pmd_insert_mapping(inode, vmf, length, dax.pfn, ret); + return vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd, + dax.pfn, vmf->flags & FAULT_FLAG_WRITE); unmap_fallback: dax_unmap_atomic(bdev, &dax); +fallback: + trace_dax_pmd_insert_mapping_fallback(inode, vmf, length, + dax.pfn, ret); return VM_FAULT_FALLBACK; } -static int dax_pmd_load_hole(struct vm_area_struct *vma, pmd_t *pmd, - struct vm_fault *vmf, unsigned long address, - struct iomap *iomap, void **entryp) +static int dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap, + void **entryp) { - struct address_space *mapping = vma->vm_file->f_mapping; - unsigned long pmd_addr = address & PMD_MASK; + struct address_space *mapping = vmf->vma->vm_file->f_mapping; + unsigned long pmd_addr = vmf->address & PMD_MASK; + struct inode *inode = mapping->host; struct page *zero_page; + void *ret = NULL; spinlock_t *ptl; pmd_t pmd_entry; - void *ret; - zero_page = mm_get_huge_zero_page(vma->vm_mm); + zero_page = mm_get_huge_zero_page(vmf->vma->vm_mm); if (unlikely(!zero_page)) - return VM_FAULT_FALLBACK; + goto fallback; ret = dax_insert_mapping_entry(mapping, vmf, *entryp, 0, RADIX_DAX_PMD | RADIX_DAX_HZP); if (IS_ERR(ret)) - return VM_FAULT_FALLBACK; + goto fallback; *entryp = ret; - ptl = pmd_lock(vma->vm_mm, pmd); - if (!pmd_none(*pmd)) { + ptl = pmd_lock(vmf->vma->vm_mm, vmf->pmd); + if (!pmd_none(*(vmf->pmd))) { spin_unlock(ptl); - return VM_FAULT_FALLBACK; + goto fallback; } - pmd_entry = mk_pmd(zero_page, vma->vm_page_prot); + pmd_entry = mk_pmd(zero_page, vmf->vma->vm_page_prot); pmd_entry = pmd_mkhuge(pmd_entry); - set_pmd_at(vma->vm_mm, pmd_addr, pmd, pmd_entry); + set_pmd_at(vmf->vma->vm_mm, pmd_addr, vmf->pmd, pmd_entry); spin_unlock(ptl); + trace_dax_pmd_load_hole(inode, vmf, zero_page, ret); return VM_FAULT_NOPAGE; + +fallback: + trace_dax_pmd_load_hole_fallback(inode, vmf, zero_page, ret); + return VM_FAULT_FALLBACK; } -int dax_iomap_pmd_fault(struct vm_area_struct *vma, unsigned long address, - pmd_t *pmd, unsigned int flags, struct iomap_ops *ops) +static int dax_iomap_pmd_fault(struct vm_fault *vmf, + const struct iomap_ops *ops) { + struct vm_area_struct *vma = vmf->vma; struct address_space *mapping = vma->vm_file->f_mapping; - unsigned long pmd_addr = address & PMD_MASK; - bool write = flags & FAULT_FLAG_WRITE; + unsigned long pmd_addr = vmf->address & PMD_MASK; + bool write = vmf->flags & FAULT_FLAG_WRITE; unsigned int iomap_flags = (write ? IOMAP_WRITE : 0) | IOMAP_FAULT; struct inode *inode = mapping->host; int result = VM_FAULT_FALLBACK; struct iomap iomap = { 0 }; pgoff_t max_pgoff, pgoff; - struct vm_fault vmf; void *entry; loff_t pos; int error; + /* + * Check whether offset isn't beyond end of file now. Caller is + * supposed to hold locks serializing us with truncate / punch hole so + * this is a reliable test. + */ + pgoff = linear_page_index(vma, pmd_addr); + max_pgoff = (i_size_read(inode) - 1) >> PAGE_SHIFT; + + trace_dax_pmd_fault(inode, vmf, max_pgoff, 0); + /* Fall back to PTEs if we're going to COW */ if (write && !(vma->vm_flags & VM_SHARED)) goto fallback; @@ -1342,16 +1362,10 @@ int dax_iomap_pmd_fault(struct vm_area_struct *vma, unsigned long address, if ((pmd_addr + PMD_SIZE) > vma->vm_end) goto fallback; - /* - * Check whether offset isn't beyond end of file now. Caller is - * supposed to hold locks serializing us with truncate / punch hole so - * this is a reliable test. - */ - pgoff = linear_page_index(vma, pmd_addr); - max_pgoff = (i_size_read(inode) - 1) >> PAGE_SHIFT; - - if (pgoff > max_pgoff) - return VM_FAULT_SIGBUS; + if (pgoff > max_pgoff) { + result = VM_FAULT_SIGBUS; + goto out; + } /* If the PMD would extend beyond the file size */ if ((pgoff | PG_PMD_COLOUR) > max_pgoff) @@ -1380,21 +1394,15 @@ int dax_iomap_pmd_fault(struct vm_area_struct *vma, unsigned long address, if (IS_ERR(entry)) goto finish_iomap; - vmf.pgoff = pgoff; - vmf.flags = flags; - vmf.gfp_mask = mapping_gfp_mask(mapping) | __GFP_IO; - switch (iomap.type) { case IOMAP_MAPPED: - result = dax_pmd_insert_mapping(vma, pmd, &vmf, address, - &iomap, pos, write, &entry); + result = dax_pmd_insert_mapping(vmf, &iomap, pos, &entry); break; case IOMAP_UNWRITTEN: case IOMAP_HOLE: if (WARN_ON_ONCE(write)) goto unlock_entry; - result = dax_pmd_load_hole(vma, pmd, &vmf, address, &iomap, - &entry); + result = dax_pmd_load_hole(vmf, &iomap, &entry); break; default: WARN_ON_ONCE(1); @@ -1420,10 +1428,41 @@ int dax_iomap_pmd_fault(struct vm_area_struct *vma, unsigned long address, } fallback: if (result == VM_FAULT_FALLBACK) { - split_huge_pmd(vma, pmd, address); + split_huge_pmd(vma, vmf->pmd, vmf->address); count_vm_event(THP_FAULT_FALLBACK); } +out: + trace_dax_pmd_fault_done(inode, vmf, max_pgoff, result); return result; } -EXPORT_SYMBOL_GPL(dax_iomap_pmd_fault); +#else +static int dax_iomap_pmd_fault(struct vm_fault *vmf, + const struct iomap_ops *ops) +{ + return VM_FAULT_FALLBACK; +} #endif /* CONFIG_FS_DAX_PMD */ + +/** + * dax_iomap_fault - handle a page fault on a DAX file + * @vmf: The description of the fault + * @ops: iomap ops passed from the file system + * + * When a page fault occurs, filesystems may call this helper in + * their fault handler for DAX files. dax_iomap_fault() assumes the caller + * has done all the necessary locking for page fault to proceed + * successfully. + */ +int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size, + const struct iomap_ops *ops) +{ + switch (pe_size) { + case PE_SIZE_PTE: + return dax_iomap_pte_fault(vmf, ops); + case PE_SIZE_PMD: + return dax_iomap_pmd_fault(vmf, ops); + default: + return VM_FAULT_FALLBACK; + } +} +EXPORT_SYMBOL_GPL(dax_iomap_fault); |