diff options
Diffstat (limited to 'drivers/dax/fsdev.c')
| -rw-r--r-- | drivers/dax/fsdev.c | 148 |
1 files changed, 104 insertions, 44 deletions
diff --git a/drivers/dax/fsdev.c b/drivers/dax/fsdev.c index 188b2526bee4..598604bf5ac5 100644 --- a/drivers/dax/fsdev.c +++ b/drivers/dax/fsdev.c @@ -45,15 +45,13 @@ static void fsdev_write_dax(void *addr, struct page *page, } static long __fsdev_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, - long nr_pages, enum dax_access_mode mode, void **kaddr, - unsigned long *pfn) + long nr_pages, enum dax_access_mode mode, void **kaddr, + unsigned long *pfn) { struct dev_dax *dev_dax = dax_get_private(dax_dev); size_t size = nr_pages << PAGE_SHIFT; size_t offset = pgoff << PAGE_SHIFT; - void *virt_addr = dev_dax->virt_addr + offset; phys_addr_t phys; - unsigned long local_pfn; phys = dax_pgoff_to_phys(dev_dax, pgoff, size); if (phys == -1) { @@ -63,11 +61,10 @@ static long __fsdev_dax_direct_access(struct dax_device *dax_dev, pgoff_t pgoff, } if (kaddr) - *kaddr = virt_addr; + *kaddr = __va(phys); - local_pfn = PHYS_PFN(phys); if (pfn) - *pfn = local_pfn; + *pfn = PHYS_PFN(phys); /* * Use cached_size which was computed at probe time. The size cannot @@ -83,7 +80,8 @@ static int fsdev_dax_zero_page_range(struct dax_device *dax_dev, long rc; WARN_ONCE(nr_pages > 1, "%s: nr_pages > 1\n", __func__); - rc = __fsdev_dax_direct_access(dax_dev, pgoff, 1, DAX_ACCESS, &kaddr, NULL); + rc = __fsdev_dax_direct_access(dax_dev, pgoff, 1, DAX_ACCESS, + &kaddr, NULL); if (rc < 0) return rc; fsdev_write_dax(kaddr, ZERO_PAGE(0), 0, PAGE_SIZE); @@ -91,15 +89,15 @@ static int fsdev_dax_zero_page_range(struct dax_device *dax_dev, } static long fsdev_dax_direct_access(struct dax_device *dax_dev, - pgoff_t pgoff, long nr_pages, enum dax_access_mode mode, - void **kaddr, unsigned long *pfn) + pgoff_t pgoff, long nr_pages, enum dax_access_mode mode, + void **kaddr, unsigned long *pfn) { return __fsdev_dax_direct_access(dax_dev, pgoff, nr_pages, mode, kaddr, pfn); } -static size_t fsdev_dax_recovery_write(struct dax_device *dax_dev, pgoff_t pgoff, - void *addr, size_t bytes, struct iov_iter *i) +static size_t fsdev_dax_recovery_write(struct dax_device *dax_dev, + pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i) { return _copy_from_iter_flushcache(addr, bytes, i); } @@ -127,6 +125,23 @@ static void fsdev_clear_ops(void *data) dax_set_ops(dev_dax->dax_dev, NULL); } +static void fsdev_clear_pgmap_ops(void *data) +{ + struct dev_pagemap *pgmap = data; + + /* + * fsdev installs pgmap->ops and ->owner at probe. For a static device + * the pgmap is shared and long-lived (owned by the dax bus), so + * leaving fsdev's ops behind on unbind would let a later + * memory_failure -- after rebind to another driver, or after this + * module is unloaded -- dispatch through a stale or freed + * ->memory_failure handler. Clear them so the pgmap carries no fsdev + * state once we are unbound. + */ + pgmap->ops = NULL; + pgmap->owner = NULL; +} + /* * Page map operations for FS-DAX mode * Similar to fsdax_pagemap_ops in drivers/nvdimm/pmem.c @@ -135,11 +150,26 @@ static void fsdev_clear_ops(void *data) * The core mm code in free_zone_device_folio() handles the wake_up_var() * directly for this memory type. */ +static u64 fsdev_pfn_to_offset(struct dev_dax *dev_dax, unsigned long pfn) +{ + phys_addr_t phys = PFN_PHYS(pfn); + u64 offset = 0; + + for (int i = 0; i < dev_dax->nr_range; i++) { + struct range *range = &dev_dax->ranges[i].range; + + if (phys >= range->start && phys <= range->end) + return offset + (phys - range->start); + offset += range_len(range); + } + return -1ULL; +} + static int fsdev_pagemap_memory_failure(struct dev_pagemap *pgmap, unsigned long pfn, unsigned long nr_pages, int mf_flags) { struct dev_dax *dev_dax = pgmap->owner; - u64 offset = PFN_PHYS(pfn) - dev_dax->ranges[0].range.start; + u64 offset = fsdev_pfn_to_offset(dev_dax, pfn); u64 len = nr_pages << PAGE_SHIFT; return dax_holder_notify_failure(dev_dax->dax_dev, offset, @@ -204,46 +234,62 @@ static const struct file_operations fsdev_fops = { .release = fsdev_release, }; -static int fsdev_dax_probe(struct dev_dax *dev_dax) +/* + * Acquire the dev_pagemap for probe: the static (pre-populated) one if + * present, or a devm-allocated one for the dynamic case. Note that + * dev_dax->pgmap is not set here; fsdev_dax_probe() sets it only once + * probe succeeds, so a failed probe never leaves a dangling pointer + * to a devres-freed pgmap. + */ +static struct dev_pagemap *fsdev_acquire_pgmap(struct dev_dax *dev_dax) { - struct dax_device *dax_dev = dev_dax->dax_dev; struct device *dev = &dev_dax->dev; struct dev_pagemap *pgmap; - struct inode *inode; - u64 data_offset = 0; - struct cdev *cdev; - void *addr; - int rc, i; + size_t pgmap_size; if (static_dev_dax(dev_dax)) { if (dev_dax->nr_range > 1) { - dev_warn(dev, "static pgmap / multi-range device conflict\n"); - return -EINVAL; + dev_warn(dev, + "static pgmap / multi-range device conflict\n"); + return ERR_PTR(-EINVAL); } pgmap = dev_dax->pgmap; - } else { - size_t pgmap_size; + pgmap->vmemmap_shift = 0; + return pgmap; + } - if (dev_dax->pgmap) { - dev_warn(dev, "dynamic-dax with pre-populated page map\n"); - return -EINVAL; - } + if (dev_dax->pgmap) { + dev_warn(dev, "dynamic-dax with pre-populated page map\n"); + return ERR_PTR(-EINVAL); + } - pgmap_size = struct_size(pgmap, ranges, dev_dax->nr_range - 1); - pgmap = devm_kzalloc(dev, pgmap_size, GFP_KERNEL); - if (!pgmap) - return -ENOMEM; + pgmap_size = struct_size(pgmap, ranges, dev_dax->nr_range - 1); + pgmap = devm_kzalloc(dev, pgmap_size, GFP_KERNEL); + if (!pgmap) + return ERR_PTR(-ENOMEM); - pgmap->nr_range = dev_dax->nr_range; - dev_dax->pgmap = pgmap; + pgmap->nr_range = dev_dax->nr_range; + for (int i = 0; i < dev_dax->nr_range; i++) + pgmap->ranges[i] = dev_dax->ranges[i].range; - for (i = 0; i < dev_dax->nr_range; i++) { - struct range *range = &dev_dax->ranges[i].range; + return pgmap; +} - pgmap->ranges[i] = *range; - } - } +static int fsdev_dax_probe(struct dev_dax *dev_dax) +{ + struct dax_device *dax_dev = dev_dax->dax_dev; + struct device *dev = &dev_dax->dev; + struct dev_pagemap *pgmap; + struct inode *inode; + u64 data_offset = 0; + struct cdev *cdev; + void *addr; + int rc, i; + + pgmap = fsdev_acquire_pgmap(dev_dax); + if (IS_ERR(pgmap)) + return PTR_ERR(pgmap); for (i = 0; i < dev_dax->nr_range; i++) { struct range *range = &dev_dax->ranges[i].range; @@ -275,6 +321,11 @@ static int fsdev_dax_probe(struct dev_dax *dev_dax) if (IS_ERR(addr)) return PTR_ERR(addr); + /* Drop fsdev's pgmap->ops/owner on unbind so no stale ops survive. */ + rc = devm_add_action_or_reset(dev, fsdev_clear_pgmap_ops, pgmap); + if (rc) + return rc; + /* * Clear any stale compound folio state left over from a previous * driver (e.g., device_dax with vmemmap_shift). Also register this @@ -290,15 +341,18 @@ static int fsdev_dax_probe(struct dev_dax *dev_dax) /* Detect whether the data is at a non-zero offset into the memory */ if (pgmap->range.start != dev_dax->ranges[0].range.start) { u64 phys = dev_dax->ranges[0].range.start; - u64 pgmap_phys = dev_dax->pgmap[0].range.start; + u64 pgmap_phys = pgmap[0].range.start; - if (!WARN_ON(pgmap_phys > phys)) - data_offset = phys - pgmap_phys; + if (pgmap_phys > phys) { + dev_err(dev, "pgmap start %#llx exceeds data start %#llx\n", + pgmap_phys, phys); + return -EINVAL; + } + data_offset = phys - pgmap_phys; pr_debug("%s: offset detected phys=%llx pgmap_phys=%llx offset=%llx\n", __func__, phys, pgmap_phys, data_offset); } - dev_dax->virt_addr = addr + data_offset; inode = dax_inode(dax_dev); cdev = inode->i_cdev; @@ -323,7 +377,13 @@ static int fsdev_dax_probe(struct dev_dax *dev_dax) return rc; run_dax(dax_dev); - return devm_add_action_or_reset(dev, fsdev_kill, dev_dax); + rc = devm_add_action_or_reset(dev, fsdev_kill, dev_dax); + if (rc) + return rc; + + /* Probe can no longer fail; expose the pgmap via dev_dax */ + dev_dax->pgmap = pgmap; + return 0; } static struct dax_device_driver fsdev_dax_driver = { |