1d475c634SMatthew Wilcox /* 2d475c634SMatthew Wilcox * fs/dax.c - Direct Access filesystem code 3d475c634SMatthew Wilcox * Copyright (c) 2013-2014 Intel Corporation 4d475c634SMatthew Wilcox * Author: Matthew Wilcox <matthew.r.wilcox@intel.com> 5d475c634SMatthew Wilcox * Author: Ross Zwisler <ross.zwisler@linux.intel.com> 6d475c634SMatthew Wilcox * 7d475c634SMatthew Wilcox * This program is free software; you can redistribute it and/or modify it 8d475c634SMatthew Wilcox * under the terms and conditions of the GNU General Public License, 9d475c634SMatthew Wilcox * version 2, as published by the Free Software Foundation. 10d475c634SMatthew Wilcox * 11d475c634SMatthew Wilcox * This program is distributed in the hope it will be useful, but WITHOUT 12d475c634SMatthew Wilcox * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13d475c634SMatthew Wilcox * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 14d475c634SMatthew Wilcox * more details. 15d475c634SMatthew Wilcox */ 16d475c634SMatthew Wilcox 17d475c634SMatthew Wilcox #include <linux/atomic.h> 18d475c634SMatthew Wilcox #include <linux/blkdev.h> 19d475c634SMatthew Wilcox #include <linux/buffer_head.h> 20d77e92e2SRoss Zwisler #include <linux/dax.h> 21d475c634SMatthew Wilcox #include <linux/fs.h> 22d475c634SMatthew Wilcox #include <linux/genhd.h> 23f7ca90b1SMatthew Wilcox #include <linux/highmem.h> 24f7ca90b1SMatthew Wilcox #include <linux/memcontrol.h> 25f7ca90b1SMatthew Wilcox #include <linux/mm.h> 26d475c634SMatthew Wilcox #include <linux/mutex.h> 279973c98eSRoss Zwisler #include <linux/pagevec.h> 28289c6aedSMatthew Wilcox #include <linux/sched.h> 29f361bf4aSIngo Molnar #include <linux/sched/signal.h> 30d475c634SMatthew Wilcox #include <linux/uio.h> 31f7ca90b1SMatthew Wilcox #include <linux/vmstat.h> 3234c0fd54SDan Williams #include <linux/pfn_t.h> 330e749e54SDan Williams #include <linux/sizes.h> 344b4bb46dSJan Kara #include <linux/mmu_notifier.h> 35a254e568SChristoph Hellwig #include <linux/iomap.h> 36a254e568SChristoph Hellwig #include "internal.h" 37d475c634SMatthew Wilcox 38282a8e03SRoss Zwisler #define CREATE_TRACE_POINTS 39282a8e03SRoss Zwisler #include <trace/events/fs_dax.h> 40282a8e03SRoss Zwisler 41ac401cc7SJan Kara /* We choose 4096 entries - same as per-zone page wait tables */ 42ac401cc7SJan Kara #define DAX_WAIT_TABLE_BITS 12 43ac401cc7SJan Kara #define DAX_WAIT_TABLE_ENTRIES (1 << DAX_WAIT_TABLE_BITS) 44ac401cc7SJan Kara 45ce95ab0fSRoss Zwisler static wait_queue_head_t wait_table[DAX_WAIT_TABLE_ENTRIES]; 46ac401cc7SJan Kara 47ac401cc7SJan Kara static int __init init_dax_wait_table(void) 48ac401cc7SJan Kara { 49ac401cc7SJan Kara int i; 50ac401cc7SJan Kara 51ac401cc7SJan Kara for (i = 0; i < DAX_WAIT_TABLE_ENTRIES; i++) 52ac401cc7SJan Kara init_waitqueue_head(wait_table + i); 53ac401cc7SJan Kara return 0; 54ac401cc7SJan Kara } 55ac401cc7SJan Kara fs_initcall(init_dax_wait_table); 56ac401cc7SJan Kara 57527b19d0SRoss Zwisler /* 58527b19d0SRoss Zwisler * We use lowest available bit in exceptional entry for locking, one bit for 59527b19d0SRoss Zwisler * the entry size (PMD) and two more to tell us if the entry is a zero page or 60527b19d0SRoss Zwisler * an empty entry that is just used for locking. In total four special bits. 61527b19d0SRoss Zwisler * 62527b19d0SRoss Zwisler * If the PMD bit isn't set the entry has size PAGE_SIZE, and if the ZERO_PAGE 63527b19d0SRoss Zwisler * and EMPTY bits aren't set the entry is a normal DAX entry with a filesystem 64527b19d0SRoss Zwisler * block allocation. 65527b19d0SRoss Zwisler */ 66527b19d0SRoss Zwisler #define RADIX_DAX_SHIFT (RADIX_TREE_EXCEPTIONAL_SHIFT + 4) 67527b19d0SRoss Zwisler #define RADIX_DAX_ENTRY_LOCK (1 << RADIX_TREE_EXCEPTIONAL_SHIFT) 68527b19d0SRoss Zwisler #define RADIX_DAX_PMD (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 1)) 69527b19d0SRoss Zwisler #define RADIX_DAX_ZERO_PAGE (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 2)) 70527b19d0SRoss Zwisler #define RADIX_DAX_EMPTY (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 3)) 71527b19d0SRoss Zwisler 72527b19d0SRoss Zwisler static unsigned long dax_radix_sector(void *entry) 73527b19d0SRoss Zwisler { 74527b19d0SRoss Zwisler return (unsigned long)entry >> RADIX_DAX_SHIFT; 75527b19d0SRoss Zwisler } 76527b19d0SRoss Zwisler 77527b19d0SRoss Zwisler static void *dax_radix_locked_entry(sector_t sector, unsigned long flags) 78527b19d0SRoss Zwisler { 79527b19d0SRoss Zwisler return (void *)(RADIX_TREE_EXCEPTIONAL_ENTRY | flags | 80527b19d0SRoss Zwisler ((unsigned long)sector << RADIX_DAX_SHIFT) | 81527b19d0SRoss Zwisler RADIX_DAX_ENTRY_LOCK); 82527b19d0SRoss Zwisler } 83527b19d0SRoss Zwisler 84527b19d0SRoss Zwisler static unsigned int dax_radix_order(void *entry) 85527b19d0SRoss Zwisler { 86527b19d0SRoss Zwisler if ((unsigned long)entry & RADIX_DAX_PMD) 87527b19d0SRoss Zwisler return PMD_SHIFT - PAGE_SHIFT; 88527b19d0SRoss Zwisler return 0; 89527b19d0SRoss Zwisler } 90527b19d0SRoss Zwisler 91642261acSRoss Zwisler static int dax_is_pmd_entry(void *entry) 92642261acSRoss Zwisler { 93642261acSRoss Zwisler return (unsigned long)entry & RADIX_DAX_PMD; 94642261acSRoss Zwisler } 95642261acSRoss Zwisler 96642261acSRoss Zwisler static int dax_is_pte_entry(void *entry) 97642261acSRoss Zwisler { 98642261acSRoss Zwisler return !((unsigned long)entry & RADIX_DAX_PMD); 99642261acSRoss Zwisler } 100642261acSRoss Zwisler 101642261acSRoss Zwisler static int dax_is_zero_entry(void *entry) 102642261acSRoss Zwisler { 10391d25ba8SRoss Zwisler return (unsigned long)entry & RADIX_DAX_ZERO_PAGE; 104642261acSRoss Zwisler } 105642261acSRoss Zwisler 106642261acSRoss Zwisler static int dax_is_empty_entry(void *entry) 107642261acSRoss Zwisler { 108642261acSRoss Zwisler return (unsigned long)entry & RADIX_DAX_EMPTY; 109642261acSRoss Zwisler } 110642261acSRoss Zwisler 111f7ca90b1SMatthew Wilcox /* 112ac401cc7SJan Kara * DAX radix tree locking 113ac401cc7SJan Kara */ 114ac401cc7SJan Kara struct exceptional_entry_key { 115ac401cc7SJan Kara struct address_space *mapping; 11663e95b5cSRoss Zwisler pgoff_t entry_start; 117ac401cc7SJan Kara }; 118ac401cc7SJan Kara 119ac401cc7SJan Kara struct wait_exceptional_entry_queue { 120ac6424b9SIngo Molnar wait_queue_entry_t wait; 121ac401cc7SJan Kara struct exceptional_entry_key key; 122ac401cc7SJan Kara }; 123ac401cc7SJan Kara 12463e95b5cSRoss Zwisler static wait_queue_head_t *dax_entry_waitqueue(struct address_space *mapping, 12563e95b5cSRoss Zwisler pgoff_t index, void *entry, struct exceptional_entry_key *key) 12663e95b5cSRoss Zwisler { 12763e95b5cSRoss Zwisler unsigned long hash; 12863e95b5cSRoss Zwisler 12963e95b5cSRoss Zwisler /* 13063e95b5cSRoss Zwisler * If 'entry' is a PMD, align the 'index' that we use for the wait 13163e95b5cSRoss Zwisler * queue to the start of that PMD. This ensures that all offsets in 13263e95b5cSRoss Zwisler * the range covered by the PMD map to the same bit lock. 13363e95b5cSRoss Zwisler */ 134642261acSRoss Zwisler if (dax_is_pmd_entry(entry)) 13563e95b5cSRoss Zwisler index &= ~((1UL << (PMD_SHIFT - PAGE_SHIFT)) - 1); 13663e95b5cSRoss Zwisler 13763e95b5cSRoss Zwisler key->mapping = mapping; 13863e95b5cSRoss Zwisler key->entry_start = index; 13963e95b5cSRoss Zwisler 14063e95b5cSRoss Zwisler hash = hash_long((unsigned long)mapping ^ index, DAX_WAIT_TABLE_BITS); 14163e95b5cSRoss Zwisler return wait_table + hash; 14263e95b5cSRoss Zwisler } 14363e95b5cSRoss Zwisler 144ac6424b9SIngo Molnar static int wake_exceptional_entry_func(wait_queue_entry_t *wait, unsigned int mode, 145ac401cc7SJan Kara int sync, void *keyp) 146ac401cc7SJan Kara { 147ac401cc7SJan Kara struct exceptional_entry_key *key = keyp; 148ac401cc7SJan Kara struct wait_exceptional_entry_queue *ewait = 149ac401cc7SJan Kara container_of(wait, struct wait_exceptional_entry_queue, wait); 150ac401cc7SJan Kara 151ac401cc7SJan Kara if (key->mapping != ewait->key.mapping || 15263e95b5cSRoss Zwisler key->entry_start != ewait->key.entry_start) 153ac401cc7SJan Kara return 0; 154ac401cc7SJan Kara return autoremove_wake_function(wait, mode, sync, NULL); 155ac401cc7SJan Kara } 156ac401cc7SJan Kara 157ac401cc7SJan Kara /* 158e30331ffSRoss Zwisler * We do not necessarily hold the mapping->tree_lock when we call this 159e30331ffSRoss Zwisler * function so it is possible that 'entry' is no longer a valid item in the 160e30331ffSRoss Zwisler * radix tree. This is okay because all we really need to do is to find the 161e30331ffSRoss Zwisler * correct waitqueue where tasks might be waiting for that old 'entry' and 162e30331ffSRoss Zwisler * wake them. 163e30331ffSRoss Zwisler */ 164d01ad197SRoss Zwisler static void dax_wake_mapping_entry_waiter(struct address_space *mapping, 165e30331ffSRoss Zwisler pgoff_t index, void *entry, bool wake_all) 166e30331ffSRoss Zwisler { 167e30331ffSRoss Zwisler struct exceptional_entry_key key; 168e30331ffSRoss Zwisler wait_queue_head_t *wq; 169e30331ffSRoss Zwisler 170e30331ffSRoss Zwisler wq = dax_entry_waitqueue(mapping, index, entry, &key); 171e30331ffSRoss Zwisler 172e30331ffSRoss Zwisler /* 173e30331ffSRoss Zwisler * Checking for locked entry and prepare_to_wait_exclusive() happens 174e30331ffSRoss Zwisler * under mapping->tree_lock, ditto for entry handling in our callers. 175e30331ffSRoss Zwisler * So at this point all tasks that could have seen our entry locked 176e30331ffSRoss Zwisler * must be in the waitqueue and the following check will see them. 177e30331ffSRoss Zwisler */ 178e30331ffSRoss Zwisler if (waitqueue_active(wq)) 179e30331ffSRoss Zwisler __wake_up(wq, TASK_NORMAL, wake_all ? 0 : 1, &key); 180e30331ffSRoss Zwisler } 181e30331ffSRoss Zwisler 182e30331ffSRoss Zwisler /* 183ac401cc7SJan Kara * Check whether the given slot is locked. The function must be called with 184ac401cc7SJan Kara * mapping->tree_lock held 185ac401cc7SJan Kara */ 186ac401cc7SJan Kara static inline int slot_locked(struct address_space *mapping, void **slot) 187ac401cc7SJan Kara { 188ac401cc7SJan Kara unsigned long entry = (unsigned long) 189ac401cc7SJan Kara radix_tree_deref_slot_protected(slot, &mapping->tree_lock); 190ac401cc7SJan Kara return entry & RADIX_DAX_ENTRY_LOCK; 191ac401cc7SJan Kara } 192ac401cc7SJan Kara 193ac401cc7SJan Kara /* 194ac401cc7SJan Kara * Mark the given slot is locked. The function must be called with 195ac401cc7SJan Kara * mapping->tree_lock held 196ac401cc7SJan Kara */ 197ac401cc7SJan Kara static inline void *lock_slot(struct address_space *mapping, void **slot) 198ac401cc7SJan Kara { 199ac401cc7SJan Kara unsigned long entry = (unsigned long) 200ac401cc7SJan Kara radix_tree_deref_slot_protected(slot, &mapping->tree_lock); 201ac401cc7SJan Kara 202ac401cc7SJan Kara entry |= RADIX_DAX_ENTRY_LOCK; 2036d75f366SJohannes Weiner radix_tree_replace_slot(&mapping->page_tree, slot, (void *)entry); 204ac401cc7SJan Kara return (void *)entry; 205ac401cc7SJan Kara } 206ac401cc7SJan Kara 207ac401cc7SJan Kara /* 208ac401cc7SJan Kara * Mark the given slot is unlocked. The function must be called with 209ac401cc7SJan Kara * mapping->tree_lock held 210ac401cc7SJan Kara */ 211ac401cc7SJan Kara static inline void *unlock_slot(struct address_space *mapping, void **slot) 212ac401cc7SJan Kara { 213ac401cc7SJan Kara unsigned long entry = (unsigned long) 214ac401cc7SJan Kara radix_tree_deref_slot_protected(slot, &mapping->tree_lock); 215ac401cc7SJan Kara 216ac401cc7SJan Kara entry &= ~(unsigned long)RADIX_DAX_ENTRY_LOCK; 2176d75f366SJohannes Weiner radix_tree_replace_slot(&mapping->page_tree, slot, (void *)entry); 218ac401cc7SJan Kara return (void *)entry; 219ac401cc7SJan Kara } 220ac401cc7SJan Kara 221ac401cc7SJan Kara /* 222ac401cc7SJan Kara * Lookup entry in radix tree, wait for it to become unlocked if it is 223ac401cc7SJan Kara * exceptional entry and return it. The caller must call 224ac401cc7SJan Kara * put_unlocked_mapping_entry() when he decided not to lock the entry or 225ac401cc7SJan Kara * put_locked_mapping_entry() when he locked the entry and now wants to 226ac401cc7SJan Kara * unlock it. 227ac401cc7SJan Kara * 228ac401cc7SJan Kara * The function must be called with mapping->tree_lock held. 229ac401cc7SJan Kara */ 230ac401cc7SJan Kara static void *get_unlocked_mapping_entry(struct address_space *mapping, 231ac401cc7SJan Kara pgoff_t index, void ***slotp) 232ac401cc7SJan Kara { 233e3ad61c6SRoss Zwisler void *entry, **slot; 234ac401cc7SJan Kara struct wait_exceptional_entry_queue ewait; 23563e95b5cSRoss Zwisler wait_queue_head_t *wq; 236ac401cc7SJan Kara 237ac401cc7SJan Kara init_wait(&ewait.wait); 238ac401cc7SJan Kara ewait.wait.func = wake_exceptional_entry_func; 239ac401cc7SJan Kara 240ac401cc7SJan Kara for (;;) { 241e3ad61c6SRoss Zwisler entry = __radix_tree_lookup(&mapping->page_tree, index, NULL, 242ac401cc7SJan Kara &slot); 24391d25ba8SRoss Zwisler if (!entry || 24491d25ba8SRoss Zwisler WARN_ON_ONCE(!radix_tree_exceptional_entry(entry)) || 245ac401cc7SJan Kara !slot_locked(mapping, slot)) { 246ac401cc7SJan Kara if (slotp) 247ac401cc7SJan Kara *slotp = slot; 248e3ad61c6SRoss Zwisler return entry; 249ac401cc7SJan Kara } 25063e95b5cSRoss Zwisler 25163e95b5cSRoss Zwisler wq = dax_entry_waitqueue(mapping, index, entry, &ewait.key); 252ac401cc7SJan Kara prepare_to_wait_exclusive(wq, &ewait.wait, 253ac401cc7SJan Kara TASK_UNINTERRUPTIBLE); 254ac401cc7SJan Kara spin_unlock_irq(&mapping->tree_lock); 255ac401cc7SJan Kara schedule(); 256ac401cc7SJan Kara finish_wait(wq, &ewait.wait); 257ac401cc7SJan Kara spin_lock_irq(&mapping->tree_lock); 258ac401cc7SJan Kara } 259ac401cc7SJan Kara } 260ac401cc7SJan Kara 261b1aa812bSJan Kara static void dax_unlock_mapping_entry(struct address_space *mapping, 262b1aa812bSJan Kara pgoff_t index) 263b1aa812bSJan Kara { 264b1aa812bSJan Kara void *entry, **slot; 265b1aa812bSJan Kara 266b1aa812bSJan Kara spin_lock_irq(&mapping->tree_lock); 267b1aa812bSJan Kara entry = __radix_tree_lookup(&mapping->page_tree, index, NULL, &slot); 268b1aa812bSJan Kara if (WARN_ON_ONCE(!entry || !radix_tree_exceptional_entry(entry) || 269b1aa812bSJan Kara !slot_locked(mapping, slot))) { 270b1aa812bSJan Kara spin_unlock_irq(&mapping->tree_lock); 271b1aa812bSJan Kara return; 272b1aa812bSJan Kara } 273b1aa812bSJan Kara unlock_slot(mapping, slot); 274b1aa812bSJan Kara spin_unlock_irq(&mapping->tree_lock); 275b1aa812bSJan Kara dax_wake_mapping_entry_waiter(mapping, index, entry, false); 276b1aa812bSJan Kara } 277b1aa812bSJan Kara 278ac401cc7SJan Kara static void put_locked_mapping_entry(struct address_space *mapping, 27991d25ba8SRoss Zwisler pgoff_t index) 280ac401cc7SJan Kara { 281bc2466e4SJan Kara dax_unlock_mapping_entry(mapping, index); 282ac401cc7SJan Kara } 283ac401cc7SJan Kara 284ac401cc7SJan Kara /* 285ac401cc7SJan Kara * Called when we are done with radix tree entry we looked up via 286ac401cc7SJan Kara * get_unlocked_mapping_entry() and which we didn't lock in the end. 287ac401cc7SJan Kara */ 288ac401cc7SJan Kara static void put_unlocked_mapping_entry(struct address_space *mapping, 289ac401cc7SJan Kara pgoff_t index, void *entry) 290ac401cc7SJan Kara { 29191d25ba8SRoss Zwisler if (!entry) 292ac401cc7SJan Kara return; 293ac401cc7SJan Kara 294ac401cc7SJan Kara /* We have to wake up next waiter for the radix tree entry lock */ 295422476c4SRoss Zwisler dax_wake_mapping_entry_waiter(mapping, index, entry, false); 296422476c4SRoss Zwisler } 297422476c4SRoss Zwisler 298ac401cc7SJan Kara /* 29991d25ba8SRoss Zwisler * Find radix tree entry at given index. If it points to an exceptional entry, 30091d25ba8SRoss Zwisler * return it with the radix tree entry locked. If the radix tree doesn't 30191d25ba8SRoss Zwisler * contain given index, create an empty exceptional entry for the index and 30291d25ba8SRoss Zwisler * return with it locked. 303ac401cc7SJan Kara * 304642261acSRoss Zwisler * When requesting an entry with size RADIX_DAX_PMD, grab_mapping_entry() will 305642261acSRoss Zwisler * either return that locked entry or will return an error. This error will 30691d25ba8SRoss Zwisler * happen if there are any 4k entries within the 2MiB range that we are 30791d25ba8SRoss Zwisler * requesting. 308642261acSRoss Zwisler * 309642261acSRoss Zwisler * We always favor 4k entries over 2MiB entries. There isn't a flow where we 310642261acSRoss Zwisler * evict 4k entries in order to 'upgrade' them to a 2MiB entry. A 2MiB 311642261acSRoss Zwisler * insertion will fail if it finds any 4k entries already in the tree, and a 312642261acSRoss Zwisler * 4k insertion will cause an existing 2MiB entry to be unmapped and 313642261acSRoss Zwisler * downgraded to 4k entries. This happens for both 2MiB huge zero pages as 314642261acSRoss Zwisler * well as 2MiB empty entries. 315642261acSRoss Zwisler * 316642261acSRoss Zwisler * The exception to this downgrade path is for 2MiB DAX PMD entries that have 317642261acSRoss Zwisler * real storage backing them. We will leave these real 2MiB DAX entries in 318642261acSRoss Zwisler * the tree, and PTE writes will simply dirty the entire 2MiB DAX entry. 319642261acSRoss Zwisler * 320ac401cc7SJan Kara * Note: Unlike filemap_fault() we don't honor FAULT_FLAG_RETRY flags. For 321ac401cc7SJan Kara * persistent memory the benefit is doubtful. We can add that later if we can 322ac401cc7SJan Kara * show it helps. 323ac401cc7SJan Kara */ 324642261acSRoss Zwisler static void *grab_mapping_entry(struct address_space *mapping, pgoff_t index, 325642261acSRoss Zwisler unsigned long size_flag) 326ac401cc7SJan Kara { 327642261acSRoss Zwisler bool pmd_downgrade = false; /* splitting 2MiB entry into 4k entries? */ 328e3ad61c6SRoss Zwisler void *entry, **slot; 329ac401cc7SJan Kara 330ac401cc7SJan Kara restart: 331ac401cc7SJan Kara spin_lock_irq(&mapping->tree_lock); 332e3ad61c6SRoss Zwisler entry = get_unlocked_mapping_entry(mapping, index, &slot); 333642261acSRoss Zwisler 33491d25ba8SRoss Zwisler if (WARN_ON_ONCE(entry && !radix_tree_exceptional_entry(entry))) { 33591d25ba8SRoss Zwisler entry = ERR_PTR(-EIO); 33691d25ba8SRoss Zwisler goto out_unlock; 33791d25ba8SRoss Zwisler } 33891d25ba8SRoss Zwisler 339642261acSRoss Zwisler if (entry) { 340642261acSRoss Zwisler if (size_flag & RADIX_DAX_PMD) { 34191d25ba8SRoss Zwisler if (dax_is_pte_entry(entry)) { 342642261acSRoss Zwisler put_unlocked_mapping_entry(mapping, index, 343642261acSRoss Zwisler entry); 344642261acSRoss Zwisler entry = ERR_PTR(-EEXIST); 345642261acSRoss Zwisler goto out_unlock; 346642261acSRoss Zwisler } 347642261acSRoss Zwisler } else { /* trying to grab a PTE entry */ 34891d25ba8SRoss Zwisler if (dax_is_pmd_entry(entry) && 349642261acSRoss Zwisler (dax_is_zero_entry(entry) || 350642261acSRoss Zwisler dax_is_empty_entry(entry))) { 351642261acSRoss Zwisler pmd_downgrade = true; 352642261acSRoss Zwisler } 353642261acSRoss Zwisler } 354642261acSRoss Zwisler } 355642261acSRoss Zwisler 356ac401cc7SJan Kara /* No entry for given index? Make sure radix tree is big enough. */ 357642261acSRoss Zwisler if (!entry || pmd_downgrade) { 358ac401cc7SJan Kara int err; 359ac401cc7SJan Kara 360642261acSRoss Zwisler if (pmd_downgrade) { 361642261acSRoss Zwisler /* 362642261acSRoss Zwisler * Make sure 'entry' remains valid while we drop 363642261acSRoss Zwisler * mapping->tree_lock. 364642261acSRoss Zwisler */ 365642261acSRoss Zwisler entry = lock_slot(mapping, slot); 366642261acSRoss Zwisler } 367642261acSRoss Zwisler 368ac401cc7SJan Kara spin_unlock_irq(&mapping->tree_lock); 369642261acSRoss Zwisler /* 370642261acSRoss Zwisler * Besides huge zero pages the only other thing that gets 371642261acSRoss Zwisler * downgraded are empty entries which don't need to be 372642261acSRoss Zwisler * unmapped. 373642261acSRoss Zwisler */ 374642261acSRoss Zwisler if (pmd_downgrade && dax_is_zero_entry(entry)) 375642261acSRoss Zwisler unmap_mapping_range(mapping, 376642261acSRoss Zwisler (index << PAGE_SHIFT) & PMD_MASK, PMD_SIZE, 0); 377642261acSRoss Zwisler 3780cb80b48SJan Kara err = radix_tree_preload( 3790cb80b48SJan Kara mapping_gfp_mask(mapping) & ~__GFP_HIGHMEM); 3800cb80b48SJan Kara if (err) { 3810cb80b48SJan Kara if (pmd_downgrade) 38291d25ba8SRoss Zwisler put_locked_mapping_entry(mapping, index); 3830cb80b48SJan Kara return ERR_PTR(err); 3840cb80b48SJan Kara } 385ac401cc7SJan Kara spin_lock_irq(&mapping->tree_lock); 386642261acSRoss Zwisler 387e11f8b7bSRoss Zwisler if (!entry) { 388e11f8b7bSRoss Zwisler /* 389e11f8b7bSRoss Zwisler * We needed to drop the page_tree lock while calling 390e11f8b7bSRoss Zwisler * radix_tree_preload() and we didn't have an entry to 391e11f8b7bSRoss Zwisler * lock. See if another thread inserted an entry at 392e11f8b7bSRoss Zwisler * our index during this time. 393e11f8b7bSRoss Zwisler */ 394e11f8b7bSRoss Zwisler entry = __radix_tree_lookup(&mapping->page_tree, index, 395e11f8b7bSRoss Zwisler NULL, &slot); 396e11f8b7bSRoss Zwisler if (entry) { 397e11f8b7bSRoss Zwisler radix_tree_preload_end(); 398e11f8b7bSRoss Zwisler spin_unlock_irq(&mapping->tree_lock); 399e11f8b7bSRoss Zwisler goto restart; 400e11f8b7bSRoss Zwisler } 401e11f8b7bSRoss Zwisler } 402e11f8b7bSRoss Zwisler 403642261acSRoss Zwisler if (pmd_downgrade) { 404642261acSRoss Zwisler radix_tree_delete(&mapping->page_tree, index); 405642261acSRoss Zwisler mapping->nrexceptional--; 406642261acSRoss Zwisler dax_wake_mapping_entry_waiter(mapping, index, entry, 407642261acSRoss Zwisler true); 408642261acSRoss Zwisler } 409642261acSRoss Zwisler 410642261acSRoss Zwisler entry = dax_radix_locked_entry(0, size_flag | RADIX_DAX_EMPTY); 411642261acSRoss Zwisler 412642261acSRoss Zwisler err = __radix_tree_insert(&mapping->page_tree, index, 413642261acSRoss Zwisler dax_radix_order(entry), entry); 414ac401cc7SJan Kara radix_tree_preload_end(); 415ac401cc7SJan Kara if (err) { 416ac401cc7SJan Kara spin_unlock_irq(&mapping->tree_lock); 417642261acSRoss Zwisler /* 418e11f8b7bSRoss Zwisler * Our insertion of a DAX entry failed, most likely 419e11f8b7bSRoss Zwisler * because we were inserting a PMD entry and it 420e11f8b7bSRoss Zwisler * collided with a PTE sized entry at a different 421e11f8b7bSRoss Zwisler * index in the PMD range. We haven't inserted 422e11f8b7bSRoss Zwisler * anything into the radix tree and have no waiters to 423e11f8b7bSRoss Zwisler * wake. 424642261acSRoss Zwisler */ 425ac401cc7SJan Kara return ERR_PTR(err); 426ac401cc7SJan Kara } 427ac401cc7SJan Kara /* Good, we have inserted empty locked entry into the tree. */ 428ac401cc7SJan Kara mapping->nrexceptional++; 429ac401cc7SJan Kara spin_unlock_irq(&mapping->tree_lock); 430e3ad61c6SRoss Zwisler return entry; 431ac401cc7SJan Kara } 432e3ad61c6SRoss Zwisler entry = lock_slot(mapping, slot); 433642261acSRoss Zwisler out_unlock: 434ac401cc7SJan Kara spin_unlock_irq(&mapping->tree_lock); 435e3ad61c6SRoss Zwisler return entry; 436ac401cc7SJan Kara } 437ac401cc7SJan Kara 438c6dcf52cSJan Kara static int __dax_invalidate_mapping_entry(struct address_space *mapping, 439c6dcf52cSJan Kara pgoff_t index, bool trunc) 440c6dcf52cSJan Kara { 441c6dcf52cSJan Kara int ret = 0; 442c6dcf52cSJan Kara void *entry; 443c6dcf52cSJan Kara struct radix_tree_root *page_tree = &mapping->page_tree; 444c6dcf52cSJan Kara 445c6dcf52cSJan Kara spin_lock_irq(&mapping->tree_lock); 446c6dcf52cSJan Kara entry = get_unlocked_mapping_entry(mapping, index, NULL); 44791d25ba8SRoss Zwisler if (!entry || WARN_ON_ONCE(!radix_tree_exceptional_entry(entry))) 448c6dcf52cSJan Kara goto out; 449c6dcf52cSJan Kara if (!trunc && 450c6dcf52cSJan Kara (radix_tree_tag_get(page_tree, index, PAGECACHE_TAG_DIRTY) || 451c6dcf52cSJan Kara radix_tree_tag_get(page_tree, index, PAGECACHE_TAG_TOWRITE))) 452c6dcf52cSJan Kara goto out; 453c6dcf52cSJan Kara radix_tree_delete(page_tree, index); 454c6dcf52cSJan Kara mapping->nrexceptional--; 455c6dcf52cSJan Kara ret = 1; 456c6dcf52cSJan Kara out: 457c6dcf52cSJan Kara put_unlocked_mapping_entry(mapping, index, entry); 458c6dcf52cSJan Kara spin_unlock_irq(&mapping->tree_lock); 459c6dcf52cSJan Kara return ret; 460c6dcf52cSJan Kara } 461ac401cc7SJan Kara /* 462ac401cc7SJan Kara * Delete exceptional DAX entry at @index from @mapping. Wait for radix tree 463ac401cc7SJan Kara * entry to get unlocked before deleting it. 464ac401cc7SJan Kara */ 465ac401cc7SJan Kara int dax_delete_mapping_entry(struct address_space *mapping, pgoff_t index) 466ac401cc7SJan Kara { 467c6dcf52cSJan Kara int ret = __dax_invalidate_mapping_entry(mapping, index, true); 468ac401cc7SJan Kara 469ac401cc7SJan Kara /* 470ac401cc7SJan Kara * This gets called from truncate / punch_hole path. As such, the caller 471ac401cc7SJan Kara * must hold locks protecting against concurrent modifications of the 472ac401cc7SJan Kara * radix tree (usually fs-private i_mmap_sem for writing). Since the 473ac401cc7SJan Kara * caller has seen exceptional entry for this index, we better find it 474ac401cc7SJan Kara * at that index as well... 475ac401cc7SJan Kara */ 476c6dcf52cSJan Kara WARN_ON_ONCE(!ret); 477c6dcf52cSJan Kara return ret; 478ac401cc7SJan Kara } 479ac401cc7SJan Kara 480c6dcf52cSJan Kara /* 481c6dcf52cSJan Kara * Invalidate exceptional DAX entry if it is clean. 482c6dcf52cSJan Kara */ 483c6dcf52cSJan Kara int dax_invalidate_mapping_entry_sync(struct address_space *mapping, 484c6dcf52cSJan Kara pgoff_t index) 485c6dcf52cSJan Kara { 486c6dcf52cSJan Kara return __dax_invalidate_mapping_entry(mapping, index, false); 487ac401cc7SJan Kara } 488ac401cc7SJan Kara 489cccbce67SDan Williams static int copy_user_dax(struct block_device *bdev, struct dax_device *dax_dev, 490cccbce67SDan Williams sector_t sector, size_t size, struct page *to, 491cccbce67SDan Williams unsigned long vaddr) 492f7ca90b1SMatthew Wilcox { 493cccbce67SDan Williams void *vto, *kaddr; 494cccbce67SDan Williams pgoff_t pgoff; 495cccbce67SDan Williams pfn_t pfn; 496cccbce67SDan Williams long rc; 497cccbce67SDan Williams int id; 498e2e05394SRoss Zwisler 499cccbce67SDan Williams rc = bdev_dax_pgoff(bdev, sector, size, &pgoff); 500cccbce67SDan Williams if (rc) 501cccbce67SDan Williams return rc; 502cccbce67SDan Williams 503cccbce67SDan Williams id = dax_read_lock(); 504cccbce67SDan Williams rc = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size), &kaddr, &pfn); 505cccbce67SDan Williams if (rc < 0) { 506cccbce67SDan Williams dax_read_unlock(id); 507cccbce67SDan Williams return rc; 508cccbce67SDan Williams } 509f7ca90b1SMatthew Wilcox vto = kmap_atomic(to); 510cccbce67SDan Williams copy_user_page(vto, (void __force *)kaddr, vaddr, to); 511f7ca90b1SMatthew Wilcox kunmap_atomic(vto); 512cccbce67SDan Williams dax_read_unlock(id); 513f7ca90b1SMatthew Wilcox return 0; 514f7ca90b1SMatthew Wilcox } 515f7ca90b1SMatthew Wilcox 516642261acSRoss Zwisler /* 517642261acSRoss Zwisler * By this point grab_mapping_entry() has ensured that we have a locked entry 518642261acSRoss Zwisler * of the appropriate size so we don't have to worry about downgrading PMDs to 519642261acSRoss Zwisler * PTEs. If we happen to be trying to insert a PTE and there is a PMD 520642261acSRoss Zwisler * already in the tree, we will skip the insertion and just dirty the PMD as 521642261acSRoss Zwisler * appropriate. 522642261acSRoss Zwisler */ 523ac401cc7SJan Kara static void *dax_insert_mapping_entry(struct address_space *mapping, 524ac401cc7SJan Kara struct vm_fault *vmf, 525642261acSRoss Zwisler void *entry, sector_t sector, 526642261acSRoss Zwisler unsigned long flags) 5279973c98eSRoss Zwisler { 5289973c98eSRoss Zwisler struct radix_tree_root *page_tree = &mapping->page_tree; 529ac401cc7SJan Kara void *new_entry; 530ac401cc7SJan Kara pgoff_t index = vmf->pgoff; 5319973c98eSRoss Zwisler 532ac401cc7SJan Kara if (vmf->flags & FAULT_FLAG_WRITE) 5339973c98eSRoss Zwisler __mark_inode_dirty(mapping->host, I_DIRTY_PAGES); 5349973c98eSRoss Zwisler 53591d25ba8SRoss Zwisler if (dax_is_zero_entry(entry) && !(flags & RADIX_DAX_ZERO_PAGE)) { 53691d25ba8SRoss Zwisler /* we are replacing a zero page with block mapping */ 53791d25ba8SRoss Zwisler if (dax_is_pmd_entry(entry)) 53891d25ba8SRoss Zwisler unmap_mapping_range(mapping, 53991d25ba8SRoss Zwisler (vmf->pgoff << PAGE_SHIFT) & PMD_MASK, 54091d25ba8SRoss Zwisler PMD_SIZE, 0); 54191d25ba8SRoss Zwisler else /* pte entry */ 542ac401cc7SJan Kara unmap_mapping_range(mapping, vmf->pgoff << PAGE_SHIFT, 543ac401cc7SJan Kara PAGE_SIZE, 0); 544ac401cc7SJan Kara } 5459973c98eSRoss Zwisler 546ac401cc7SJan Kara spin_lock_irq(&mapping->tree_lock); 547642261acSRoss Zwisler new_entry = dax_radix_locked_entry(sector, flags); 548642261acSRoss Zwisler 54991d25ba8SRoss Zwisler if (dax_is_zero_entry(entry) || dax_is_empty_entry(entry)) { 550642261acSRoss Zwisler /* 551642261acSRoss Zwisler * Only swap our new entry into the radix tree if the current 552642261acSRoss Zwisler * entry is a zero page or an empty entry. If a normal PTE or 553642261acSRoss Zwisler * PMD entry is already in the tree, we leave it alone. This 554642261acSRoss Zwisler * means that if we are trying to insert a PTE and the 555642261acSRoss Zwisler * existing entry is a PMD, we will just leave the PMD in the 556642261acSRoss Zwisler * tree and dirty it if necessary. 557642261acSRoss Zwisler */ 558f7942430SJohannes Weiner struct radix_tree_node *node; 559ac401cc7SJan Kara void **slot; 560ac401cc7SJan Kara void *ret; 561ac401cc7SJan Kara 562f7942430SJohannes Weiner ret = __radix_tree_lookup(page_tree, index, &node, &slot); 563ac401cc7SJan Kara WARN_ON_ONCE(ret != entry); 5644d693d08SJohannes Weiner __radix_tree_replace(page_tree, node, slot, 5654d693d08SJohannes Weiner new_entry, NULL, NULL); 56691d25ba8SRoss Zwisler entry = new_entry; 567ac401cc7SJan Kara } 56891d25ba8SRoss Zwisler 569ac401cc7SJan Kara if (vmf->flags & FAULT_FLAG_WRITE) 5709973c98eSRoss Zwisler radix_tree_tag_set(page_tree, index, PAGECACHE_TAG_DIRTY); 57191d25ba8SRoss Zwisler 5729973c98eSRoss Zwisler spin_unlock_irq(&mapping->tree_lock); 57391d25ba8SRoss Zwisler return entry; 5749973c98eSRoss Zwisler } 5759973c98eSRoss Zwisler 5764b4bb46dSJan Kara static inline unsigned long 5774b4bb46dSJan Kara pgoff_address(pgoff_t pgoff, struct vm_area_struct *vma) 5784b4bb46dSJan Kara { 5794b4bb46dSJan Kara unsigned long address; 5804b4bb46dSJan Kara 5814b4bb46dSJan Kara address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT); 5824b4bb46dSJan Kara VM_BUG_ON_VMA(address < vma->vm_start || address >= vma->vm_end, vma); 5834b4bb46dSJan Kara return address; 5844b4bb46dSJan Kara } 5854b4bb46dSJan Kara 5864b4bb46dSJan Kara /* Walk all mappings of a given index of a file and writeprotect them */ 5874b4bb46dSJan Kara static void dax_mapping_entry_mkclean(struct address_space *mapping, 5884b4bb46dSJan Kara pgoff_t index, unsigned long pfn) 5894b4bb46dSJan Kara { 5904b4bb46dSJan Kara struct vm_area_struct *vma; 591f729c8c9SRoss Zwisler pte_t pte, *ptep = NULL; 592f729c8c9SRoss Zwisler pmd_t *pmdp = NULL; 5934b4bb46dSJan Kara spinlock_t *ptl; 5944b4bb46dSJan Kara 5954b4bb46dSJan Kara i_mmap_lock_read(mapping); 5964b4bb46dSJan Kara vma_interval_tree_foreach(vma, &mapping->i_mmap, index, index) { 597a4d1a885SJérôme Glisse unsigned long address, start, end; 5984b4bb46dSJan Kara 5994b4bb46dSJan Kara cond_resched(); 6004b4bb46dSJan Kara 6014b4bb46dSJan Kara if (!(vma->vm_flags & VM_SHARED)) 6024b4bb46dSJan Kara continue; 6034b4bb46dSJan Kara 6044b4bb46dSJan Kara address = pgoff_address(index, vma); 605a4d1a885SJérôme Glisse 606a4d1a885SJérôme Glisse /* 607a4d1a885SJérôme Glisse * Note because we provide start/end to follow_pte_pmd it will 608a4d1a885SJérôme Glisse * call mmu_notifier_invalidate_range_start() on our behalf 609a4d1a885SJérôme Glisse * before taking any lock. 610a4d1a885SJérôme Glisse */ 611a4d1a885SJérôme Glisse if (follow_pte_pmd(vma->vm_mm, address, &start, &end, &ptep, &pmdp, &ptl)) 6124b4bb46dSJan Kara continue; 613f729c8c9SRoss Zwisler 614f729c8c9SRoss Zwisler if (pmdp) { 615f729c8c9SRoss Zwisler #ifdef CONFIG_FS_DAX_PMD 616f729c8c9SRoss Zwisler pmd_t pmd; 617f729c8c9SRoss Zwisler 618f729c8c9SRoss Zwisler if (pfn != pmd_pfn(*pmdp)) 619f729c8c9SRoss Zwisler goto unlock_pmd; 620f729c8c9SRoss Zwisler if (!pmd_dirty(*pmdp) && !pmd_write(*pmdp)) 621f729c8c9SRoss Zwisler goto unlock_pmd; 622f729c8c9SRoss Zwisler 623f729c8c9SRoss Zwisler flush_cache_page(vma, address, pfn); 624f729c8c9SRoss Zwisler pmd = pmdp_huge_clear_flush(vma, address, pmdp); 625f729c8c9SRoss Zwisler pmd = pmd_wrprotect(pmd); 626f729c8c9SRoss Zwisler pmd = pmd_mkclean(pmd); 627f729c8c9SRoss Zwisler set_pmd_at(vma->vm_mm, address, pmdp, pmd); 628a4d1a885SJérôme Glisse mmu_notifier_invalidate_range(vma->vm_mm, start, end); 629f729c8c9SRoss Zwisler unlock_pmd: 630f729c8c9SRoss Zwisler spin_unlock(ptl); 631f729c8c9SRoss Zwisler #endif 632f729c8c9SRoss Zwisler } else { 6334b4bb46dSJan Kara if (pfn != pte_pfn(*ptep)) 634f729c8c9SRoss Zwisler goto unlock_pte; 6354b4bb46dSJan Kara if (!pte_dirty(*ptep) && !pte_write(*ptep)) 636f729c8c9SRoss Zwisler goto unlock_pte; 6374b4bb46dSJan Kara 6384b4bb46dSJan Kara flush_cache_page(vma, address, pfn); 6394b4bb46dSJan Kara pte = ptep_clear_flush(vma, address, ptep); 6404b4bb46dSJan Kara pte = pte_wrprotect(pte); 6414b4bb46dSJan Kara pte = pte_mkclean(pte); 6424b4bb46dSJan Kara set_pte_at(vma->vm_mm, address, ptep, pte); 643a4d1a885SJérôme Glisse mmu_notifier_invalidate_range(vma->vm_mm, start, end); 644f729c8c9SRoss Zwisler unlock_pte: 6454b4bb46dSJan Kara pte_unmap_unlock(ptep, ptl); 646f729c8c9SRoss Zwisler } 6474b4bb46dSJan Kara 648a4d1a885SJérôme Glisse mmu_notifier_invalidate_range_end(vma->vm_mm, start, end); 6494b4bb46dSJan Kara } 6504b4bb46dSJan Kara i_mmap_unlock_read(mapping); 6514b4bb46dSJan Kara } 6524b4bb46dSJan Kara 6539973c98eSRoss Zwisler static int dax_writeback_one(struct block_device *bdev, 654cccbce67SDan Williams struct dax_device *dax_dev, struct address_space *mapping, 655cccbce67SDan Williams pgoff_t index, void *entry) 6569973c98eSRoss Zwisler { 6579973c98eSRoss Zwisler struct radix_tree_root *page_tree = &mapping->page_tree; 658cccbce67SDan Williams void *entry2, **slot, *kaddr; 659cccbce67SDan Williams long ret = 0, id; 660cccbce67SDan Williams sector_t sector; 661cccbce67SDan Williams pgoff_t pgoff; 662cccbce67SDan Williams size_t size; 663cccbce67SDan Williams pfn_t pfn; 6649973c98eSRoss Zwisler 6659973c98eSRoss Zwisler /* 666a6abc2c0SJan Kara * A page got tagged dirty in DAX mapping? Something is seriously 667a6abc2c0SJan Kara * wrong. 6689973c98eSRoss Zwisler */ 669a6abc2c0SJan Kara if (WARN_ON(!radix_tree_exceptional_entry(entry))) 670a6abc2c0SJan Kara return -EIO; 6719973c98eSRoss Zwisler 672a6abc2c0SJan Kara spin_lock_irq(&mapping->tree_lock); 673a6abc2c0SJan Kara entry2 = get_unlocked_mapping_entry(mapping, index, &slot); 674a6abc2c0SJan Kara /* Entry got punched out / reallocated? */ 67591d25ba8SRoss Zwisler if (!entry2 || WARN_ON_ONCE(!radix_tree_exceptional_entry(entry2))) 676a6abc2c0SJan Kara goto put_unlocked; 677a6abc2c0SJan Kara /* 678a6abc2c0SJan Kara * Entry got reallocated elsewhere? No need to writeback. We have to 679a6abc2c0SJan Kara * compare sectors as we must not bail out due to difference in lockbit 680a6abc2c0SJan Kara * or entry type. 681a6abc2c0SJan Kara */ 682a6abc2c0SJan Kara if (dax_radix_sector(entry2) != dax_radix_sector(entry)) 683a6abc2c0SJan Kara goto put_unlocked; 684642261acSRoss Zwisler if (WARN_ON_ONCE(dax_is_empty_entry(entry) || 685642261acSRoss Zwisler dax_is_zero_entry(entry))) { 6869973c98eSRoss Zwisler ret = -EIO; 687a6abc2c0SJan Kara goto put_unlocked; 6889973c98eSRoss Zwisler } 6899973c98eSRoss Zwisler 690a6abc2c0SJan Kara /* Another fsync thread may have already written back this entry */ 691a6abc2c0SJan Kara if (!radix_tree_tag_get(page_tree, index, PAGECACHE_TAG_TOWRITE)) 692a6abc2c0SJan Kara goto put_unlocked; 693a6abc2c0SJan Kara /* Lock the entry to serialize with page faults */ 694a6abc2c0SJan Kara entry = lock_slot(mapping, slot); 695a6abc2c0SJan Kara /* 696a6abc2c0SJan Kara * We can clear the tag now but we have to be careful so that concurrent 697a6abc2c0SJan Kara * dax_writeback_one() calls for the same index cannot finish before we 698a6abc2c0SJan Kara * actually flush the caches. This is achieved as the calls will look 699a6abc2c0SJan Kara * at the entry only under tree_lock and once they do that they will 700a6abc2c0SJan Kara * see the entry locked and wait for it to unlock. 701a6abc2c0SJan Kara */ 702a6abc2c0SJan Kara radix_tree_tag_clear(page_tree, index, PAGECACHE_TAG_TOWRITE); 703a6abc2c0SJan Kara spin_unlock_irq(&mapping->tree_lock); 704a6abc2c0SJan Kara 705642261acSRoss Zwisler /* 706642261acSRoss Zwisler * Even if dax_writeback_mapping_range() was given a wbc->range_start 707642261acSRoss Zwisler * in the middle of a PMD, the 'index' we are given will be aligned to 708642261acSRoss Zwisler * the start index of the PMD, as will the sector we pull from 709642261acSRoss Zwisler * 'entry'. This allows us to flush for PMD_SIZE and not have to 710642261acSRoss Zwisler * worry about partial PMD writebacks. 711642261acSRoss Zwisler */ 712cccbce67SDan Williams sector = dax_radix_sector(entry); 713cccbce67SDan Williams size = PAGE_SIZE << dax_radix_order(entry); 714cccbce67SDan Williams 715cccbce67SDan Williams id = dax_read_lock(); 716cccbce67SDan Williams ret = bdev_dax_pgoff(bdev, sector, size, &pgoff); 717cccbce67SDan Williams if (ret) 718cccbce67SDan Williams goto dax_unlock; 7199973c98eSRoss Zwisler 7209973c98eSRoss Zwisler /* 721cccbce67SDan Williams * dax_direct_access() may sleep, so cannot hold tree_lock over 722cccbce67SDan Williams * its invocation. 7239973c98eSRoss Zwisler */ 724cccbce67SDan Williams ret = dax_direct_access(dax_dev, pgoff, size / PAGE_SIZE, &kaddr, &pfn); 725cccbce67SDan Williams if (ret < 0) 726cccbce67SDan Williams goto dax_unlock; 7279973c98eSRoss Zwisler 728cccbce67SDan Williams if (WARN_ON_ONCE(ret < size / PAGE_SIZE)) { 7299973c98eSRoss Zwisler ret = -EIO; 730cccbce67SDan Williams goto dax_unlock; 7319973c98eSRoss Zwisler } 7329973c98eSRoss Zwisler 733cccbce67SDan Williams dax_mapping_entry_mkclean(mapping, index, pfn_t_to_pfn(pfn)); 7346318770aSDan Williams dax_flush(dax_dev, pgoff, kaddr, size); 7354b4bb46dSJan Kara /* 7364b4bb46dSJan Kara * After we have flushed the cache, we can clear the dirty tag. There 7374b4bb46dSJan Kara * cannot be new dirty data in the pfn after the flush has completed as 7384b4bb46dSJan Kara * the pfn mappings are writeprotected and fault waits for mapping 7394b4bb46dSJan Kara * entry lock. 7404b4bb46dSJan Kara */ 7414b4bb46dSJan Kara spin_lock_irq(&mapping->tree_lock); 7424b4bb46dSJan Kara radix_tree_tag_clear(page_tree, index, PAGECACHE_TAG_DIRTY); 7434b4bb46dSJan Kara spin_unlock_irq(&mapping->tree_lock); 744f9bc3a07SRoss Zwisler trace_dax_writeback_one(mapping->host, index, size >> PAGE_SHIFT); 745cccbce67SDan Williams dax_unlock: 746cccbce67SDan Williams dax_read_unlock(id); 74791d25ba8SRoss Zwisler put_locked_mapping_entry(mapping, index); 7489973c98eSRoss Zwisler return ret; 7499973c98eSRoss Zwisler 750a6abc2c0SJan Kara put_unlocked: 751a6abc2c0SJan Kara put_unlocked_mapping_entry(mapping, index, entry2); 7529973c98eSRoss Zwisler spin_unlock_irq(&mapping->tree_lock); 7539973c98eSRoss Zwisler return ret; 7549973c98eSRoss Zwisler } 7559973c98eSRoss Zwisler 7569973c98eSRoss Zwisler /* 7579973c98eSRoss Zwisler * Flush the mapping to the persistent domain within the byte range of [start, 7589973c98eSRoss Zwisler * end]. This is required by data integrity operations to ensure file data is 7599973c98eSRoss Zwisler * on persistent storage prior to completion of the operation. 7609973c98eSRoss Zwisler */ 7617f6d5b52SRoss Zwisler int dax_writeback_mapping_range(struct address_space *mapping, 7627f6d5b52SRoss Zwisler struct block_device *bdev, struct writeback_control *wbc) 7639973c98eSRoss Zwisler { 7649973c98eSRoss Zwisler struct inode *inode = mapping->host; 765642261acSRoss Zwisler pgoff_t start_index, end_index; 7669973c98eSRoss Zwisler pgoff_t indices[PAGEVEC_SIZE]; 767cccbce67SDan Williams struct dax_device *dax_dev; 7689973c98eSRoss Zwisler struct pagevec pvec; 7699973c98eSRoss Zwisler bool done = false; 7709973c98eSRoss Zwisler int i, ret = 0; 7719973c98eSRoss Zwisler 7729973c98eSRoss Zwisler if (WARN_ON_ONCE(inode->i_blkbits != PAGE_SHIFT)) 7739973c98eSRoss Zwisler return -EIO; 7749973c98eSRoss Zwisler 7757f6d5b52SRoss Zwisler if (!mapping->nrexceptional || wbc->sync_mode != WB_SYNC_ALL) 7767f6d5b52SRoss Zwisler return 0; 7777f6d5b52SRoss Zwisler 778cccbce67SDan Williams dax_dev = dax_get_by_host(bdev->bd_disk->disk_name); 779cccbce67SDan Williams if (!dax_dev) 780cccbce67SDan Williams return -EIO; 781cccbce67SDan Williams 78209cbfeafSKirill A. Shutemov start_index = wbc->range_start >> PAGE_SHIFT; 78309cbfeafSKirill A. Shutemov end_index = wbc->range_end >> PAGE_SHIFT; 7849973c98eSRoss Zwisler 785d14a3f48SRoss Zwisler trace_dax_writeback_range(inode, start_index, end_index); 786d14a3f48SRoss Zwisler 7879973c98eSRoss Zwisler tag_pages_for_writeback(mapping, start_index, end_index); 7889973c98eSRoss Zwisler 7899973c98eSRoss Zwisler pagevec_init(&pvec, 0); 7909973c98eSRoss Zwisler while (!done) { 7919973c98eSRoss Zwisler pvec.nr = find_get_entries_tag(mapping, start_index, 7929973c98eSRoss Zwisler PAGECACHE_TAG_TOWRITE, PAGEVEC_SIZE, 7939973c98eSRoss Zwisler pvec.pages, indices); 7949973c98eSRoss Zwisler 7959973c98eSRoss Zwisler if (pvec.nr == 0) 7969973c98eSRoss Zwisler break; 7979973c98eSRoss Zwisler 7989973c98eSRoss Zwisler for (i = 0; i < pvec.nr; i++) { 7999973c98eSRoss Zwisler if (indices[i] > end_index) { 8009973c98eSRoss Zwisler done = true; 8019973c98eSRoss Zwisler break; 8029973c98eSRoss Zwisler } 8039973c98eSRoss Zwisler 804cccbce67SDan Williams ret = dax_writeback_one(bdev, dax_dev, mapping, 805cccbce67SDan Williams indices[i], pvec.pages[i]); 806819ec6b9SJeff Layton if (ret < 0) { 807819ec6b9SJeff Layton mapping_set_error(mapping, ret); 808d14a3f48SRoss Zwisler goto out; 809d14a3f48SRoss Zwisler } 810d14a3f48SRoss Zwisler } 8111eb643d0SJan Kara start_index = indices[pvec.nr - 1] + 1; 812d14a3f48SRoss Zwisler } 813d14a3f48SRoss Zwisler out: 814cccbce67SDan Williams put_dax(dax_dev); 815d14a3f48SRoss Zwisler trace_dax_writeback_range_done(inode, start_index, end_index); 816d14a3f48SRoss Zwisler return (ret < 0 ? ret : 0); 8179973c98eSRoss Zwisler } 8189973c98eSRoss Zwisler EXPORT_SYMBOL_GPL(dax_writeback_mapping_range); 8199973c98eSRoss Zwisler 820ac401cc7SJan Kara static int dax_insert_mapping(struct address_space *mapping, 821cccbce67SDan Williams struct block_device *bdev, struct dax_device *dax_dev, 82291d25ba8SRoss Zwisler sector_t sector, size_t size, void *entry, 823cccbce67SDan Williams struct vm_area_struct *vma, struct vm_fault *vmf) 824f7ca90b1SMatthew Wilcox { 8251a29d85eSJan Kara unsigned long vaddr = vmf->address; 826cccbce67SDan Williams void *ret, *kaddr; 827cccbce67SDan Williams pgoff_t pgoff; 828cccbce67SDan Williams int id, rc; 829cccbce67SDan Williams pfn_t pfn; 830f7ca90b1SMatthew Wilcox 831cccbce67SDan Williams rc = bdev_dax_pgoff(bdev, sector, size, &pgoff); 832cccbce67SDan Williams if (rc) 833cccbce67SDan Williams return rc; 834f7ca90b1SMatthew Wilcox 835cccbce67SDan Williams id = dax_read_lock(); 836cccbce67SDan Williams rc = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size), &kaddr, &pfn); 837cccbce67SDan Williams if (rc < 0) { 838cccbce67SDan Williams dax_read_unlock(id); 839cccbce67SDan Williams return rc; 840cccbce67SDan Williams } 841cccbce67SDan Williams dax_read_unlock(id); 842cccbce67SDan Williams 843cccbce67SDan Williams ret = dax_insert_mapping_entry(mapping, vmf, entry, sector, 0); 8444d9a2c87SJan Kara if (IS_ERR(ret)) 8454d9a2c87SJan Kara return PTR_ERR(ret); 8469973c98eSRoss Zwisler 847b4440734SRoss Zwisler trace_dax_insert_mapping(mapping->host, vmf, ret); 84891d25ba8SRoss Zwisler if (vmf->flags & FAULT_FLAG_WRITE) 84991d25ba8SRoss Zwisler return vm_insert_mixed_mkwrite(vma, vaddr, pfn); 85091d25ba8SRoss Zwisler else 851cccbce67SDan Williams return vm_insert_mixed(vma, vaddr, pfn); 852f7ca90b1SMatthew Wilcox } 853f7ca90b1SMatthew Wilcox 8542f89dc12SJan Kara /* 85591d25ba8SRoss Zwisler * The user has performed a load from a hole in the file. Allocating a new 85691d25ba8SRoss Zwisler * page in the file would cause excessive storage usage for workloads with 85791d25ba8SRoss Zwisler * sparse files. Instead we insert a read-only mapping of the 4k zero page. 85891d25ba8SRoss Zwisler * If this page is ever written to we will re-fault and change the mapping to 85991d25ba8SRoss Zwisler * point to real DAX storage instead. 8602f89dc12SJan Kara */ 86191d25ba8SRoss Zwisler static int dax_load_hole(struct address_space *mapping, void *entry, 862e30331ffSRoss Zwisler struct vm_fault *vmf) 863e30331ffSRoss Zwisler { 864e30331ffSRoss Zwisler struct inode *inode = mapping->host; 86591d25ba8SRoss Zwisler unsigned long vaddr = vmf->address; 86691d25ba8SRoss Zwisler int ret = VM_FAULT_NOPAGE; 86791d25ba8SRoss Zwisler struct page *zero_page; 86891d25ba8SRoss Zwisler void *entry2; 869e30331ffSRoss Zwisler 87091d25ba8SRoss Zwisler zero_page = ZERO_PAGE(0); 87191d25ba8SRoss Zwisler if (unlikely(!zero_page)) { 872e30331ffSRoss Zwisler ret = VM_FAULT_OOM; 873e30331ffSRoss Zwisler goto out; 874e30331ffSRoss Zwisler } 875e30331ffSRoss Zwisler 87691d25ba8SRoss Zwisler entry2 = dax_insert_mapping_entry(mapping, vmf, entry, 0, 87791d25ba8SRoss Zwisler RADIX_DAX_ZERO_PAGE); 87891d25ba8SRoss Zwisler if (IS_ERR(entry2)) { 87991d25ba8SRoss Zwisler ret = VM_FAULT_SIGBUS; 88091d25ba8SRoss Zwisler goto out; 881e30331ffSRoss Zwisler } 88291d25ba8SRoss Zwisler 88391d25ba8SRoss Zwisler vm_insert_mixed(vmf->vma, vaddr, page_to_pfn_t(zero_page)); 884e30331ffSRoss Zwisler out: 885e30331ffSRoss Zwisler trace_dax_load_hole(inode, vmf, ret); 886e30331ffSRoss Zwisler return ret; 887e30331ffSRoss Zwisler } 888e30331ffSRoss Zwisler 8894b0228faSVishal Verma static bool dax_range_is_aligned(struct block_device *bdev, 8904b0228faSVishal Verma unsigned int offset, unsigned int length) 8914b0228faSVishal Verma { 8924b0228faSVishal Verma unsigned short sector_size = bdev_logical_block_size(bdev); 8934b0228faSVishal Verma 8944b0228faSVishal Verma if (!IS_ALIGNED(offset, sector_size)) 8954b0228faSVishal Verma return false; 8964b0228faSVishal Verma if (!IS_ALIGNED(length, sector_size)) 8974b0228faSVishal Verma return false; 8984b0228faSVishal Verma 8994b0228faSVishal Verma return true; 9004b0228faSVishal Verma } 9014b0228faSVishal Verma 902cccbce67SDan Williams int __dax_zero_page_range(struct block_device *bdev, 903cccbce67SDan Williams struct dax_device *dax_dev, sector_t sector, 904cccbce67SDan Williams unsigned int offset, unsigned int size) 905679c8bd3SChristoph Hellwig { 906cccbce67SDan Williams if (dax_range_is_aligned(bdev, offset, size)) { 907cccbce67SDan Williams sector_t start_sector = sector + (offset >> 9); 9084b0228faSVishal Verma 9094b0228faSVishal Verma return blkdev_issue_zeroout(bdev, start_sector, 91053ef7d0eSLinus Torvalds size >> 9, GFP_NOFS, 0); 9114b0228faSVishal Verma } else { 912cccbce67SDan Williams pgoff_t pgoff; 913cccbce67SDan Williams long rc, id; 914cccbce67SDan Williams void *kaddr; 915cccbce67SDan Williams pfn_t pfn; 916cccbce67SDan Williams 917e84b83b9SDan Williams rc = bdev_dax_pgoff(bdev, sector, PAGE_SIZE, &pgoff); 918cccbce67SDan Williams if (rc) 919cccbce67SDan Williams return rc; 920cccbce67SDan Williams 921cccbce67SDan Williams id = dax_read_lock(); 922e84b83b9SDan Williams rc = dax_direct_access(dax_dev, pgoff, 1, &kaddr, 923cccbce67SDan Williams &pfn); 924cccbce67SDan Williams if (rc < 0) { 925cccbce67SDan Williams dax_read_unlock(id); 926cccbce67SDan Williams return rc; 927cccbce67SDan Williams } 92881f55870SDan Williams memset(kaddr + offset, 0, size); 92981f55870SDan Williams dax_flush(dax_dev, pgoff, kaddr + offset, size); 930cccbce67SDan Williams dax_read_unlock(id); 9314b0228faSVishal Verma } 932679c8bd3SChristoph Hellwig return 0; 933679c8bd3SChristoph Hellwig } 934679c8bd3SChristoph Hellwig EXPORT_SYMBOL_GPL(__dax_zero_page_range); 935679c8bd3SChristoph Hellwig 936333ccc97SRoss Zwisler static sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos) 937333ccc97SRoss Zwisler { 938333ccc97SRoss Zwisler return iomap->blkno + (((pos & PAGE_MASK) - iomap->offset) >> 9); 939333ccc97SRoss Zwisler } 940333ccc97SRoss Zwisler 941a254e568SChristoph Hellwig static loff_t 94211c59c92SRoss Zwisler dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data, 943a254e568SChristoph Hellwig struct iomap *iomap) 944a254e568SChristoph Hellwig { 945cccbce67SDan Williams struct block_device *bdev = iomap->bdev; 946cccbce67SDan Williams struct dax_device *dax_dev = iomap->dax_dev; 947a254e568SChristoph Hellwig struct iov_iter *iter = data; 948a254e568SChristoph Hellwig loff_t end = pos + length, done = 0; 949a254e568SChristoph Hellwig ssize_t ret = 0; 950cccbce67SDan Williams int id; 951a254e568SChristoph Hellwig 952a254e568SChristoph Hellwig if (iov_iter_rw(iter) == READ) { 953a254e568SChristoph Hellwig end = min(end, i_size_read(inode)); 954a254e568SChristoph Hellwig if (pos >= end) 955a254e568SChristoph Hellwig return 0; 956a254e568SChristoph Hellwig 957a254e568SChristoph Hellwig if (iomap->type == IOMAP_HOLE || iomap->type == IOMAP_UNWRITTEN) 958a254e568SChristoph Hellwig return iov_iter_zero(min(length, end - pos), iter); 959a254e568SChristoph Hellwig } 960a254e568SChristoph Hellwig 961a254e568SChristoph Hellwig if (WARN_ON_ONCE(iomap->type != IOMAP_MAPPED)) 962a254e568SChristoph Hellwig return -EIO; 963a254e568SChristoph Hellwig 964e3fce68cSJan Kara /* 965e3fce68cSJan Kara * Write can allocate block for an area which has a hole page mapped 966e3fce68cSJan Kara * into page tables. We have to tear down these mappings so that data 967e3fce68cSJan Kara * written by write(2) is visible in mmap. 968e3fce68cSJan Kara */ 969cd656375SJan Kara if (iomap->flags & IOMAP_F_NEW) { 970e3fce68cSJan Kara invalidate_inode_pages2_range(inode->i_mapping, 971e3fce68cSJan Kara pos >> PAGE_SHIFT, 972e3fce68cSJan Kara (end - 1) >> PAGE_SHIFT); 973e3fce68cSJan Kara } 974e3fce68cSJan Kara 975cccbce67SDan Williams id = dax_read_lock(); 976a254e568SChristoph Hellwig while (pos < end) { 977a254e568SChristoph Hellwig unsigned offset = pos & (PAGE_SIZE - 1); 978cccbce67SDan Williams const size_t size = ALIGN(length + offset, PAGE_SIZE); 979cccbce67SDan Williams const sector_t sector = dax_iomap_sector(iomap, pos); 980a254e568SChristoph Hellwig ssize_t map_len; 981cccbce67SDan Williams pgoff_t pgoff; 982cccbce67SDan Williams void *kaddr; 983cccbce67SDan Williams pfn_t pfn; 984a254e568SChristoph Hellwig 985d1908f52SMichal Hocko if (fatal_signal_pending(current)) { 986d1908f52SMichal Hocko ret = -EINTR; 987d1908f52SMichal Hocko break; 988d1908f52SMichal Hocko } 989d1908f52SMichal Hocko 990cccbce67SDan Williams ret = bdev_dax_pgoff(bdev, sector, size, &pgoff); 991cccbce67SDan Williams if (ret) 992cccbce67SDan Williams break; 993cccbce67SDan Williams 994cccbce67SDan Williams map_len = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size), 995cccbce67SDan Williams &kaddr, &pfn); 996a254e568SChristoph Hellwig if (map_len < 0) { 997a254e568SChristoph Hellwig ret = map_len; 998a254e568SChristoph Hellwig break; 999a254e568SChristoph Hellwig } 1000a254e568SChristoph Hellwig 1001cccbce67SDan Williams map_len = PFN_PHYS(map_len); 1002cccbce67SDan Williams kaddr += offset; 1003a254e568SChristoph Hellwig map_len -= offset; 1004a254e568SChristoph Hellwig if (map_len > end - pos) 1005a254e568SChristoph Hellwig map_len = end - pos; 1006a254e568SChristoph Hellwig 1007a254e568SChristoph Hellwig if (iov_iter_rw(iter) == WRITE) 1008fec53774SDan Williams map_len = dax_copy_from_iter(dax_dev, pgoff, kaddr, 1009fec53774SDan Williams map_len, iter); 1010a254e568SChristoph Hellwig else 1011cccbce67SDan Williams map_len = copy_to_iter(kaddr, map_len, iter); 1012a254e568SChristoph Hellwig if (map_len <= 0) { 1013a254e568SChristoph Hellwig ret = map_len ? map_len : -EFAULT; 1014a254e568SChristoph Hellwig break; 1015a254e568SChristoph Hellwig } 1016a254e568SChristoph Hellwig 1017a254e568SChristoph Hellwig pos += map_len; 1018a254e568SChristoph Hellwig length -= map_len; 1019a254e568SChristoph Hellwig done += map_len; 1020a254e568SChristoph Hellwig } 1021cccbce67SDan Williams dax_read_unlock(id); 1022a254e568SChristoph Hellwig 1023a254e568SChristoph Hellwig return done ? done : ret; 1024a254e568SChristoph Hellwig } 1025a254e568SChristoph Hellwig 1026a254e568SChristoph Hellwig /** 102711c59c92SRoss Zwisler * dax_iomap_rw - Perform I/O to a DAX file 1028a254e568SChristoph Hellwig * @iocb: The control block for this I/O 1029a254e568SChristoph Hellwig * @iter: The addresses to do I/O from or to 1030a254e568SChristoph Hellwig * @ops: iomap ops passed from the file system 1031a254e568SChristoph Hellwig * 1032a254e568SChristoph Hellwig * This function performs read and write operations to directly mapped 1033a254e568SChristoph Hellwig * persistent memory. The callers needs to take care of read/write exclusion 1034a254e568SChristoph Hellwig * and evicting any page cache pages in the region under I/O. 1035a254e568SChristoph Hellwig */ 1036a254e568SChristoph Hellwig ssize_t 103711c59c92SRoss Zwisler dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter, 10388ff6daa1SChristoph Hellwig const struct iomap_ops *ops) 1039a254e568SChristoph Hellwig { 1040a254e568SChristoph Hellwig struct address_space *mapping = iocb->ki_filp->f_mapping; 1041a254e568SChristoph Hellwig struct inode *inode = mapping->host; 1042a254e568SChristoph Hellwig loff_t pos = iocb->ki_pos, ret = 0, done = 0; 1043a254e568SChristoph Hellwig unsigned flags = 0; 1044a254e568SChristoph Hellwig 1045168316dbSChristoph Hellwig if (iov_iter_rw(iter) == WRITE) { 1046168316dbSChristoph Hellwig lockdep_assert_held_exclusive(&inode->i_rwsem); 1047a254e568SChristoph Hellwig flags |= IOMAP_WRITE; 1048168316dbSChristoph Hellwig } else { 1049168316dbSChristoph Hellwig lockdep_assert_held(&inode->i_rwsem); 1050168316dbSChristoph Hellwig } 1051a254e568SChristoph Hellwig 1052a254e568SChristoph Hellwig while (iov_iter_count(iter)) { 1053a254e568SChristoph Hellwig ret = iomap_apply(inode, pos, iov_iter_count(iter), flags, ops, 105411c59c92SRoss Zwisler iter, dax_iomap_actor); 1055a254e568SChristoph Hellwig if (ret <= 0) 1056a254e568SChristoph Hellwig break; 1057a254e568SChristoph Hellwig pos += ret; 1058a254e568SChristoph Hellwig done += ret; 1059a254e568SChristoph Hellwig } 1060a254e568SChristoph Hellwig 1061a254e568SChristoph Hellwig iocb->ki_pos += done; 1062a254e568SChristoph Hellwig return done ? done : ret; 1063a254e568SChristoph Hellwig } 106411c59c92SRoss Zwisler EXPORT_SYMBOL_GPL(dax_iomap_rw); 1065a7d73fe6SChristoph Hellwig 10669f141d6eSJan Kara static int dax_fault_return(int error) 10679f141d6eSJan Kara { 10689f141d6eSJan Kara if (error == 0) 10699f141d6eSJan Kara return VM_FAULT_NOPAGE; 10709f141d6eSJan Kara if (error == -ENOMEM) 10719f141d6eSJan Kara return VM_FAULT_OOM; 10729f141d6eSJan Kara return VM_FAULT_SIGBUS; 10739f141d6eSJan Kara } 10749f141d6eSJan Kara 1075a2d58167SDave Jiang static int dax_iomap_pte_fault(struct vm_fault *vmf, 1076a2d58167SDave Jiang const struct iomap_ops *ops) 1077a7d73fe6SChristoph Hellwig { 107811bac800SDave Jiang struct address_space *mapping = vmf->vma->vm_file->f_mapping; 1079a7d73fe6SChristoph Hellwig struct inode *inode = mapping->host; 10801a29d85eSJan Kara unsigned long vaddr = vmf->address; 1081a7d73fe6SChristoph Hellwig loff_t pos = (loff_t)vmf->pgoff << PAGE_SHIFT; 1082a7d73fe6SChristoph Hellwig sector_t sector; 1083a7d73fe6SChristoph Hellwig struct iomap iomap = { 0 }; 10849484ab1bSJan Kara unsigned flags = IOMAP_FAULT; 1085a7d73fe6SChristoph Hellwig int error, major = 0; 1086b1aa812bSJan Kara int vmf_ret = 0; 1087a7d73fe6SChristoph Hellwig void *entry; 1088a7d73fe6SChristoph Hellwig 1089a9c42b33SRoss Zwisler trace_dax_pte_fault(inode, vmf, vmf_ret); 1090a7d73fe6SChristoph Hellwig /* 1091a7d73fe6SChristoph Hellwig * Check whether offset isn't beyond end of file now. Caller is supposed 1092a7d73fe6SChristoph Hellwig * to hold locks serializing us with truncate / punch hole so this is 1093a7d73fe6SChristoph Hellwig * a reliable test. 1094a7d73fe6SChristoph Hellwig */ 1095a9c42b33SRoss Zwisler if (pos >= i_size_read(inode)) { 1096a9c42b33SRoss Zwisler vmf_ret = VM_FAULT_SIGBUS; 1097a9c42b33SRoss Zwisler goto out; 1098a9c42b33SRoss Zwisler } 1099a7d73fe6SChristoph Hellwig 1100a7d73fe6SChristoph Hellwig if ((vmf->flags & FAULT_FLAG_WRITE) && !vmf->cow_page) 1101a7d73fe6SChristoph Hellwig flags |= IOMAP_WRITE; 1102a7d73fe6SChristoph Hellwig 110313e451fdSJan Kara entry = grab_mapping_entry(mapping, vmf->pgoff, 0); 110413e451fdSJan Kara if (IS_ERR(entry)) { 110513e451fdSJan Kara vmf_ret = dax_fault_return(PTR_ERR(entry)); 110613e451fdSJan Kara goto out; 110713e451fdSJan Kara } 110813e451fdSJan Kara 1109a7d73fe6SChristoph Hellwig /* 1110e2093926SRoss Zwisler * It is possible, particularly with mixed reads & writes to private 1111e2093926SRoss Zwisler * mappings, that we have raced with a PMD fault that overlaps with 1112e2093926SRoss Zwisler * the PTE we need to set up. If so just return and the fault will be 1113e2093926SRoss Zwisler * retried. 1114e2093926SRoss Zwisler */ 1115e2093926SRoss Zwisler if (pmd_trans_huge(*vmf->pmd) || pmd_devmap(*vmf->pmd)) { 1116e2093926SRoss Zwisler vmf_ret = VM_FAULT_NOPAGE; 1117e2093926SRoss Zwisler goto unlock_entry; 1118e2093926SRoss Zwisler } 1119e2093926SRoss Zwisler 1120e2093926SRoss Zwisler /* 1121a7d73fe6SChristoph Hellwig * Note that we don't bother to use iomap_apply here: DAX required 1122a7d73fe6SChristoph Hellwig * the file system block size to be equal the page size, which means 1123a7d73fe6SChristoph Hellwig * that we never have to deal with more than a single extent here. 1124a7d73fe6SChristoph Hellwig */ 1125a7d73fe6SChristoph Hellwig error = ops->iomap_begin(inode, pos, PAGE_SIZE, flags, &iomap); 1126a9c42b33SRoss Zwisler if (error) { 1127a9c42b33SRoss Zwisler vmf_ret = dax_fault_return(error); 112813e451fdSJan Kara goto unlock_entry; 1129a9c42b33SRoss Zwisler } 1130a7d73fe6SChristoph Hellwig if (WARN_ON_ONCE(iomap.offset + iomap.length < pos + PAGE_SIZE)) { 113113e451fdSJan Kara error = -EIO; /* fs corruption? */ 113213e451fdSJan Kara goto error_finish_iomap; 1133a7d73fe6SChristoph Hellwig } 1134a7d73fe6SChristoph Hellwig 1135333ccc97SRoss Zwisler sector = dax_iomap_sector(&iomap, pos); 1136a7d73fe6SChristoph Hellwig 1137a7d73fe6SChristoph Hellwig if (vmf->cow_page) { 1138a7d73fe6SChristoph Hellwig switch (iomap.type) { 1139a7d73fe6SChristoph Hellwig case IOMAP_HOLE: 1140a7d73fe6SChristoph Hellwig case IOMAP_UNWRITTEN: 1141a7d73fe6SChristoph Hellwig clear_user_highpage(vmf->cow_page, vaddr); 1142a7d73fe6SChristoph Hellwig break; 1143a7d73fe6SChristoph Hellwig case IOMAP_MAPPED: 1144cccbce67SDan Williams error = copy_user_dax(iomap.bdev, iomap.dax_dev, 1145cccbce67SDan Williams sector, PAGE_SIZE, vmf->cow_page, vaddr); 1146a7d73fe6SChristoph Hellwig break; 1147a7d73fe6SChristoph Hellwig default: 1148a7d73fe6SChristoph Hellwig WARN_ON_ONCE(1); 1149a7d73fe6SChristoph Hellwig error = -EIO; 1150a7d73fe6SChristoph Hellwig break; 1151a7d73fe6SChristoph Hellwig } 1152a7d73fe6SChristoph Hellwig 1153a7d73fe6SChristoph Hellwig if (error) 115413e451fdSJan Kara goto error_finish_iomap; 1155b1aa812bSJan Kara 1156b1aa812bSJan Kara __SetPageUptodate(vmf->cow_page); 1157b1aa812bSJan Kara vmf_ret = finish_fault(vmf); 1158b1aa812bSJan Kara if (!vmf_ret) 1159b1aa812bSJan Kara vmf_ret = VM_FAULT_DONE_COW; 116013e451fdSJan Kara goto finish_iomap; 1161a7d73fe6SChristoph Hellwig } 1162a7d73fe6SChristoph Hellwig 1163a7d73fe6SChristoph Hellwig switch (iomap.type) { 1164a7d73fe6SChristoph Hellwig case IOMAP_MAPPED: 1165a7d73fe6SChristoph Hellwig if (iomap.flags & IOMAP_F_NEW) { 1166a7d73fe6SChristoph Hellwig count_vm_event(PGMAJFAULT); 11672262185cSRoman Gushchin count_memcg_event_mm(vmf->vma->vm_mm, PGMAJFAULT); 1168a7d73fe6SChristoph Hellwig major = VM_FAULT_MAJOR; 1169a7d73fe6SChristoph Hellwig } 1170cccbce67SDan Williams error = dax_insert_mapping(mapping, iomap.bdev, iomap.dax_dev, 117191d25ba8SRoss Zwisler sector, PAGE_SIZE, entry, vmf->vma, vmf); 11729f141d6eSJan Kara /* -EBUSY is fine, somebody else faulted on the same PTE */ 11739f141d6eSJan Kara if (error == -EBUSY) 11749f141d6eSJan Kara error = 0; 1175a7d73fe6SChristoph Hellwig break; 1176a7d73fe6SChristoph Hellwig case IOMAP_UNWRITTEN: 1177a7d73fe6SChristoph Hellwig case IOMAP_HOLE: 11781550290bSRoss Zwisler if (!(vmf->flags & FAULT_FLAG_WRITE)) { 117991d25ba8SRoss Zwisler vmf_ret = dax_load_hole(mapping, entry, vmf); 118013e451fdSJan Kara goto finish_iomap; 11811550290bSRoss Zwisler } 1182a7d73fe6SChristoph Hellwig /*FALLTHRU*/ 1183a7d73fe6SChristoph Hellwig default: 1184a7d73fe6SChristoph Hellwig WARN_ON_ONCE(1); 1185a7d73fe6SChristoph Hellwig error = -EIO; 1186a7d73fe6SChristoph Hellwig break; 1187a7d73fe6SChristoph Hellwig } 1188a7d73fe6SChristoph Hellwig 118913e451fdSJan Kara error_finish_iomap: 11909f141d6eSJan Kara vmf_ret = dax_fault_return(error) | major; 11919f141d6eSJan Kara finish_iomap: 11929f141d6eSJan Kara if (ops->iomap_end) { 11939f141d6eSJan Kara int copied = PAGE_SIZE; 11949f141d6eSJan Kara 11959f141d6eSJan Kara if (vmf_ret & VM_FAULT_ERROR) 11969f141d6eSJan Kara copied = 0; 11979f141d6eSJan Kara /* 11989f141d6eSJan Kara * The fault is done by now and there's no way back (other 11999f141d6eSJan Kara * thread may be already happily using PTE we have installed). 12009f141d6eSJan Kara * Just ignore error from ->iomap_end since we cannot do much 12019f141d6eSJan Kara * with it. 12029f141d6eSJan Kara */ 12039f141d6eSJan Kara ops->iomap_end(inode, pos, PAGE_SIZE, copied, flags, &iomap); 12041550290bSRoss Zwisler } 120513e451fdSJan Kara unlock_entry: 120691d25ba8SRoss Zwisler put_locked_mapping_entry(mapping, vmf->pgoff); 1207a9c42b33SRoss Zwisler out: 1208a9c42b33SRoss Zwisler trace_dax_pte_fault_done(inode, vmf, vmf_ret); 12099f141d6eSJan Kara return vmf_ret; 1210a7d73fe6SChristoph Hellwig } 1211642261acSRoss Zwisler 1212642261acSRoss Zwisler #ifdef CONFIG_FS_DAX_PMD 1213642261acSRoss Zwisler /* 1214642261acSRoss Zwisler * The 'colour' (ie low bits) within a PMD of a page offset. This comes up 1215642261acSRoss Zwisler * more often than one might expect in the below functions. 1216642261acSRoss Zwisler */ 1217642261acSRoss Zwisler #define PG_PMD_COLOUR ((PMD_SIZE >> PAGE_SHIFT) - 1) 1218642261acSRoss Zwisler 1219f4200391SDave Jiang static int dax_pmd_insert_mapping(struct vm_fault *vmf, struct iomap *iomap, 122091d25ba8SRoss Zwisler loff_t pos, void *entry) 1221642261acSRoss Zwisler { 1222f4200391SDave Jiang struct address_space *mapping = vmf->vma->vm_file->f_mapping; 1223cccbce67SDan Williams const sector_t sector = dax_iomap_sector(iomap, pos); 1224cccbce67SDan Williams struct dax_device *dax_dev = iomap->dax_dev; 1225642261acSRoss Zwisler struct block_device *bdev = iomap->bdev; 122627a7ffacSRoss Zwisler struct inode *inode = mapping->host; 1227cccbce67SDan Williams const size_t size = PMD_SIZE; 1228cccbce67SDan Williams void *ret = NULL, *kaddr; 1229cccbce67SDan Williams long length = 0; 1230cccbce67SDan Williams pgoff_t pgoff; 1231cccbce67SDan Williams pfn_t pfn; 1232cccbce67SDan Williams int id; 1233642261acSRoss Zwisler 1234cccbce67SDan Williams if (bdev_dax_pgoff(bdev, sector, size, &pgoff) != 0) 123527a7ffacSRoss Zwisler goto fallback; 1236642261acSRoss Zwisler 1237cccbce67SDan Williams id = dax_read_lock(); 1238cccbce67SDan Williams length = dax_direct_access(dax_dev, pgoff, PHYS_PFN(size), &kaddr, &pfn); 1239cccbce67SDan Williams if (length < 0) 1240cccbce67SDan Williams goto unlock_fallback; 1241cccbce67SDan Williams length = PFN_PHYS(length); 1242642261acSRoss Zwisler 1243cccbce67SDan Williams if (length < size) 1244cccbce67SDan Williams goto unlock_fallback; 1245cccbce67SDan Williams if (pfn_t_to_pfn(pfn) & PG_PMD_COLOUR) 1246cccbce67SDan Williams goto unlock_fallback; 1247cccbce67SDan Williams if (!pfn_t_devmap(pfn)) 1248cccbce67SDan Williams goto unlock_fallback; 1249cccbce67SDan Williams dax_read_unlock(id); 1250cccbce67SDan Williams 125191d25ba8SRoss Zwisler ret = dax_insert_mapping_entry(mapping, vmf, entry, sector, 1252642261acSRoss Zwisler RADIX_DAX_PMD); 1253642261acSRoss Zwisler if (IS_ERR(ret)) 125427a7ffacSRoss Zwisler goto fallback; 1255642261acSRoss Zwisler 1256cccbce67SDan Williams trace_dax_pmd_insert_mapping(inode, vmf, length, pfn, ret); 1257f4200391SDave Jiang return vmf_insert_pfn_pmd(vmf->vma, vmf->address, vmf->pmd, 1258cccbce67SDan Williams pfn, vmf->flags & FAULT_FLAG_WRITE); 1259642261acSRoss Zwisler 1260cccbce67SDan Williams unlock_fallback: 1261cccbce67SDan Williams dax_read_unlock(id); 126227a7ffacSRoss Zwisler fallback: 1263cccbce67SDan Williams trace_dax_pmd_insert_mapping_fallback(inode, vmf, length, pfn, ret); 1264642261acSRoss Zwisler return VM_FAULT_FALLBACK; 1265642261acSRoss Zwisler } 1266642261acSRoss Zwisler 1267f4200391SDave Jiang static int dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap, 126891d25ba8SRoss Zwisler void *entry) 1269642261acSRoss Zwisler { 1270f4200391SDave Jiang struct address_space *mapping = vmf->vma->vm_file->f_mapping; 1271f4200391SDave Jiang unsigned long pmd_addr = vmf->address & PMD_MASK; 1272653b2ea3SRoss Zwisler struct inode *inode = mapping->host; 1273642261acSRoss Zwisler struct page *zero_page; 1274653b2ea3SRoss Zwisler void *ret = NULL; 1275642261acSRoss Zwisler spinlock_t *ptl; 1276642261acSRoss Zwisler pmd_t pmd_entry; 1277642261acSRoss Zwisler 1278f4200391SDave Jiang zero_page = mm_get_huge_zero_page(vmf->vma->vm_mm); 1279642261acSRoss Zwisler 1280642261acSRoss Zwisler if (unlikely(!zero_page)) 1281653b2ea3SRoss Zwisler goto fallback; 1282642261acSRoss Zwisler 128391d25ba8SRoss Zwisler ret = dax_insert_mapping_entry(mapping, vmf, entry, 0, 128491d25ba8SRoss Zwisler RADIX_DAX_PMD | RADIX_DAX_ZERO_PAGE); 1285642261acSRoss Zwisler if (IS_ERR(ret)) 1286653b2ea3SRoss Zwisler goto fallback; 1287642261acSRoss Zwisler 1288f4200391SDave Jiang ptl = pmd_lock(vmf->vma->vm_mm, vmf->pmd); 1289f4200391SDave Jiang if (!pmd_none(*(vmf->pmd))) { 1290642261acSRoss Zwisler spin_unlock(ptl); 1291653b2ea3SRoss Zwisler goto fallback; 1292642261acSRoss Zwisler } 1293642261acSRoss Zwisler 1294f4200391SDave Jiang pmd_entry = mk_pmd(zero_page, vmf->vma->vm_page_prot); 1295642261acSRoss Zwisler pmd_entry = pmd_mkhuge(pmd_entry); 1296f4200391SDave Jiang set_pmd_at(vmf->vma->vm_mm, pmd_addr, vmf->pmd, pmd_entry); 1297642261acSRoss Zwisler spin_unlock(ptl); 1298f4200391SDave Jiang trace_dax_pmd_load_hole(inode, vmf, zero_page, ret); 1299642261acSRoss Zwisler return VM_FAULT_NOPAGE; 1300653b2ea3SRoss Zwisler 1301653b2ea3SRoss Zwisler fallback: 1302f4200391SDave Jiang trace_dax_pmd_load_hole_fallback(inode, vmf, zero_page, ret); 1303642261acSRoss Zwisler return VM_FAULT_FALLBACK; 1304642261acSRoss Zwisler } 1305642261acSRoss Zwisler 1306a2d58167SDave Jiang static int dax_iomap_pmd_fault(struct vm_fault *vmf, 1307a2d58167SDave Jiang const struct iomap_ops *ops) 1308642261acSRoss Zwisler { 1309f4200391SDave Jiang struct vm_area_struct *vma = vmf->vma; 1310642261acSRoss Zwisler struct address_space *mapping = vma->vm_file->f_mapping; 1311d8a849e1SDave Jiang unsigned long pmd_addr = vmf->address & PMD_MASK; 1312d8a849e1SDave Jiang bool write = vmf->flags & FAULT_FLAG_WRITE; 13139484ab1bSJan Kara unsigned int iomap_flags = (write ? IOMAP_WRITE : 0) | IOMAP_FAULT; 1314642261acSRoss Zwisler struct inode *inode = mapping->host; 1315642261acSRoss Zwisler int result = VM_FAULT_FALLBACK; 1316642261acSRoss Zwisler struct iomap iomap = { 0 }; 1317642261acSRoss Zwisler pgoff_t max_pgoff, pgoff; 1318642261acSRoss Zwisler void *entry; 1319642261acSRoss Zwisler loff_t pos; 1320642261acSRoss Zwisler int error; 1321642261acSRoss Zwisler 1322282a8e03SRoss Zwisler /* 1323282a8e03SRoss Zwisler * Check whether offset isn't beyond end of file now. Caller is 1324282a8e03SRoss Zwisler * supposed to hold locks serializing us with truncate / punch hole so 1325282a8e03SRoss Zwisler * this is a reliable test. 1326282a8e03SRoss Zwisler */ 1327282a8e03SRoss Zwisler pgoff = linear_page_index(vma, pmd_addr); 1328282a8e03SRoss Zwisler max_pgoff = (i_size_read(inode) - 1) >> PAGE_SHIFT; 1329282a8e03SRoss Zwisler 1330f4200391SDave Jiang trace_dax_pmd_fault(inode, vmf, max_pgoff, 0); 1331282a8e03SRoss Zwisler 1332fffa281bSRoss Zwisler /* 1333fffa281bSRoss Zwisler * Make sure that the faulting address's PMD offset (color) matches 1334fffa281bSRoss Zwisler * the PMD offset from the start of the file. This is necessary so 1335fffa281bSRoss Zwisler * that a PMD range in the page table overlaps exactly with a PMD 1336fffa281bSRoss Zwisler * range in the radix tree. 1337fffa281bSRoss Zwisler */ 1338fffa281bSRoss Zwisler if ((vmf->pgoff & PG_PMD_COLOUR) != 1339fffa281bSRoss Zwisler ((vmf->address >> PAGE_SHIFT) & PG_PMD_COLOUR)) 1340fffa281bSRoss Zwisler goto fallback; 1341fffa281bSRoss Zwisler 1342642261acSRoss Zwisler /* Fall back to PTEs if we're going to COW */ 1343642261acSRoss Zwisler if (write && !(vma->vm_flags & VM_SHARED)) 1344642261acSRoss Zwisler goto fallback; 1345642261acSRoss Zwisler 1346642261acSRoss Zwisler /* If the PMD would extend outside the VMA */ 1347642261acSRoss Zwisler if (pmd_addr < vma->vm_start) 1348642261acSRoss Zwisler goto fallback; 1349642261acSRoss Zwisler if ((pmd_addr + PMD_SIZE) > vma->vm_end) 1350642261acSRoss Zwisler goto fallback; 1351642261acSRoss Zwisler 1352282a8e03SRoss Zwisler if (pgoff > max_pgoff) { 1353282a8e03SRoss Zwisler result = VM_FAULT_SIGBUS; 1354282a8e03SRoss Zwisler goto out; 1355282a8e03SRoss Zwisler } 1356642261acSRoss Zwisler 1357642261acSRoss Zwisler /* If the PMD would extend beyond the file size */ 1358642261acSRoss Zwisler if ((pgoff | PG_PMD_COLOUR) > max_pgoff) 1359642261acSRoss Zwisler goto fallback; 1360642261acSRoss Zwisler 1361642261acSRoss Zwisler /* 136291d25ba8SRoss Zwisler * grab_mapping_entry() will make sure we get a 2MiB empty entry, a 136391d25ba8SRoss Zwisler * 2MiB zero page entry or a DAX PMD. If it can't (because a 4k page 136491d25ba8SRoss Zwisler * is already in the tree, for instance), it will return -EEXIST and 136591d25ba8SRoss Zwisler * we just fall back to 4k entries. 13669f141d6eSJan Kara */ 13679f141d6eSJan Kara entry = grab_mapping_entry(mapping, pgoff, RADIX_DAX_PMD); 13689f141d6eSJan Kara if (IS_ERR(entry)) 1369876f2946SRoss Zwisler goto fallback; 1370876f2946SRoss Zwisler 1371876f2946SRoss Zwisler /* 1372e2093926SRoss Zwisler * It is possible, particularly with mixed reads & writes to private 1373e2093926SRoss Zwisler * mappings, that we have raced with a PTE fault that overlaps with 1374e2093926SRoss Zwisler * the PMD we need to set up. If so just return and the fault will be 1375e2093926SRoss Zwisler * retried. 1376e2093926SRoss Zwisler */ 1377e2093926SRoss Zwisler if (!pmd_none(*vmf->pmd) && !pmd_trans_huge(*vmf->pmd) && 1378e2093926SRoss Zwisler !pmd_devmap(*vmf->pmd)) { 1379e2093926SRoss Zwisler result = 0; 1380e2093926SRoss Zwisler goto unlock_entry; 1381e2093926SRoss Zwisler } 1382e2093926SRoss Zwisler 1383e2093926SRoss Zwisler /* 1384876f2946SRoss Zwisler * Note that we don't use iomap_apply here. We aren't doing I/O, only 1385876f2946SRoss Zwisler * setting up a mapping, so really we're using iomap_begin() as a way 1386876f2946SRoss Zwisler * to look up our filesystem block. 1387876f2946SRoss Zwisler */ 1388876f2946SRoss Zwisler pos = (loff_t)pgoff << PAGE_SHIFT; 1389876f2946SRoss Zwisler error = ops->iomap_begin(inode, pos, PMD_SIZE, iomap_flags, &iomap); 1390876f2946SRoss Zwisler if (error) 1391876f2946SRoss Zwisler goto unlock_entry; 1392876f2946SRoss Zwisler 1393876f2946SRoss Zwisler if (iomap.offset + iomap.length < pos + PMD_SIZE) 13949f141d6eSJan Kara goto finish_iomap; 13959f141d6eSJan Kara 1396642261acSRoss Zwisler switch (iomap.type) { 1397642261acSRoss Zwisler case IOMAP_MAPPED: 139891d25ba8SRoss Zwisler result = dax_pmd_insert_mapping(vmf, &iomap, pos, entry); 1399642261acSRoss Zwisler break; 1400642261acSRoss Zwisler case IOMAP_UNWRITTEN: 1401642261acSRoss Zwisler case IOMAP_HOLE: 1402642261acSRoss Zwisler if (WARN_ON_ONCE(write)) 1403876f2946SRoss Zwisler break; 140491d25ba8SRoss Zwisler result = dax_pmd_load_hole(vmf, &iomap, entry); 1405642261acSRoss Zwisler break; 1406642261acSRoss Zwisler default: 1407642261acSRoss Zwisler WARN_ON_ONCE(1); 1408642261acSRoss Zwisler break; 1409642261acSRoss Zwisler } 1410642261acSRoss Zwisler 14119f141d6eSJan Kara finish_iomap: 14129f141d6eSJan Kara if (ops->iomap_end) { 14139f141d6eSJan Kara int copied = PMD_SIZE; 14149f141d6eSJan Kara 14159f141d6eSJan Kara if (result == VM_FAULT_FALLBACK) 14169f141d6eSJan Kara copied = 0; 14179f141d6eSJan Kara /* 14189f141d6eSJan Kara * The fault is done by now and there's no way back (other 14199f141d6eSJan Kara * thread may be already happily using PMD we have installed). 14209f141d6eSJan Kara * Just ignore error from ->iomap_end since we cannot do much 14219f141d6eSJan Kara * with it. 14229f141d6eSJan Kara */ 14239f141d6eSJan Kara ops->iomap_end(inode, pos, PMD_SIZE, copied, iomap_flags, 14249f141d6eSJan Kara &iomap); 14259f141d6eSJan Kara } 1426876f2946SRoss Zwisler unlock_entry: 142791d25ba8SRoss Zwisler put_locked_mapping_entry(mapping, pgoff); 1428642261acSRoss Zwisler fallback: 1429642261acSRoss Zwisler if (result == VM_FAULT_FALLBACK) { 1430d8a849e1SDave Jiang split_huge_pmd(vma, vmf->pmd, vmf->address); 1431642261acSRoss Zwisler count_vm_event(THP_FAULT_FALLBACK); 1432642261acSRoss Zwisler } 1433282a8e03SRoss Zwisler out: 1434f4200391SDave Jiang trace_dax_pmd_fault_done(inode, vmf, max_pgoff, result); 1435642261acSRoss Zwisler return result; 1436642261acSRoss Zwisler } 1437a2d58167SDave Jiang #else 143801cddfe9SArnd Bergmann static int dax_iomap_pmd_fault(struct vm_fault *vmf, 143901cddfe9SArnd Bergmann const struct iomap_ops *ops) 1440a2d58167SDave Jiang { 1441a2d58167SDave Jiang return VM_FAULT_FALLBACK; 1442a2d58167SDave Jiang } 1443642261acSRoss Zwisler #endif /* CONFIG_FS_DAX_PMD */ 1444a2d58167SDave Jiang 1445a2d58167SDave Jiang /** 1446a2d58167SDave Jiang * dax_iomap_fault - handle a page fault on a DAX file 1447a2d58167SDave Jiang * @vmf: The description of the fault 1448a2d58167SDave Jiang * @ops: iomap ops passed from the file system 1449a2d58167SDave Jiang * 1450a2d58167SDave Jiang * When a page fault occurs, filesystems may call this helper in 1451a2d58167SDave Jiang * their fault handler for DAX files. dax_iomap_fault() assumes the caller 1452a2d58167SDave Jiang * has done all the necessary locking for page fault to proceed 1453a2d58167SDave Jiang * successfully. 1454a2d58167SDave Jiang */ 1455c791ace1SDave Jiang int dax_iomap_fault(struct vm_fault *vmf, enum page_entry_size pe_size, 1456c791ace1SDave Jiang const struct iomap_ops *ops) 1457a2d58167SDave Jiang { 1458c791ace1SDave Jiang switch (pe_size) { 1459c791ace1SDave Jiang case PE_SIZE_PTE: 1460a2d58167SDave Jiang return dax_iomap_pte_fault(vmf, ops); 1461c791ace1SDave Jiang case PE_SIZE_PMD: 1462a2d58167SDave Jiang return dax_iomap_pmd_fault(vmf, ops); 1463a2d58167SDave Jiang default: 1464a2d58167SDave Jiang return VM_FAULT_FALLBACK; 1465a2d58167SDave Jiang } 1466a2d58167SDave Jiang } 1467a2d58167SDave Jiang EXPORT_SYMBOL_GPL(dax_iomap_fault); 1468