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1365 lines
35 KiB
1365 lines
35 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* dax: direct host memory access |
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* Copyright (C) 2020 Red Hat, Inc. |
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*/ |
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|
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#include "fuse_i.h" |
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|
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#include <linux/delay.h> |
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#include <linux/dax.h> |
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#include <linux/uio.h> |
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#include <linux/pfn_t.h> |
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#include <linux/iomap.h> |
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#include <linux/interval_tree.h> |
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|
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/* |
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* Default memory range size. A power of 2 so it agrees with common FUSE_INIT |
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* map_alignment values 4KB and 64KB. |
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*/ |
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#define FUSE_DAX_SHIFT 21 |
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#define FUSE_DAX_SZ (1 << FUSE_DAX_SHIFT) |
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#define FUSE_DAX_PAGES (FUSE_DAX_SZ / PAGE_SIZE) |
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|
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/* Number of ranges reclaimer will try to free in one invocation */ |
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#define FUSE_DAX_RECLAIM_CHUNK (10) |
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|
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/* |
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* Dax memory reclaim threshold in percetage of total ranges. When free |
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* number of free ranges drops below this threshold, reclaim can trigger |
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* Default is 20% |
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*/ |
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#define FUSE_DAX_RECLAIM_THRESHOLD (20) |
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|
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/** Translation information for file offsets to DAX window offsets */ |
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struct fuse_dax_mapping { |
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/* Pointer to inode where this memory range is mapped */ |
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struct inode *inode; |
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|
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/* Will connect in fcd->free_ranges to keep track of free memory */ |
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struct list_head list; |
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|
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/* For interval tree in file/inode */ |
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struct interval_tree_node itn; |
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|
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/* Will connect in fc->busy_ranges to keep track busy memory */ |
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struct list_head busy_list; |
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|
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/** Position in DAX window */ |
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u64 window_offset; |
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|
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/** Length of mapping, in bytes */ |
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loff_t length; |
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|
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/* Is this mapping read-only or read-write */ |
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bool writable; |
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|
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/* reference count when the mapping is used by dax iomap. */ |
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refcount_t refcnt; |
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}; |
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|
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/* Per-inode dax map */ |
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struct fuse_inode_dax { |
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/* Semaphore to protect modifications to the dmap tree */ |
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struct rw_semaphore sem; |
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|
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/* Sorted rb tree of struct fuse_dax_mapping elements */ |
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struct rb_root_cached tree; |
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unsigned long nr; |
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}; |
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|
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struct fuse_conn_dax { |
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/* DAX device */ |
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struct dax_device *dev; |
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|
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/* Lock protecting accessess to members of this structure */ |
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spinlock_t lock; |
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|
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/* List of memory ranges which are busy */ |
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unsigned long nr_busy_ranges; |
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struct list_head busy_ranges; |
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|
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/* Worker to free up memory ranges */ |
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struct delayed_work free_work; |
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|
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/* Wait queue for a dax range to become free */ |
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wait_queue_head_t range_waitq; |
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|
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/* DAX Window Free Ranges */ |
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long nr_free_ranges; |
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struct list_head free_ranges; |
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|
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unsigned long nr_ranges; |
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}; |
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|
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static inline struct fuse_dax_mapping * |
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node_to_dmap(struct interval_tree_node *node) |
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{ |
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if (!node) |
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return NULL; |
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|
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return container_of(node, struct fuse_dax_mapping, itn); |
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} |
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|
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static struct fuse_dax_mapping * |
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alloc_dax_mapping_reclaim(struct fuse_conn_dax *fcd, struct inode *inode); |
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|
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static void |
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__kick_dmap_free_worker(struct fuse_conn_dax *fcd, unsigned long delay_ms) |
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{ |
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unsigned long free_threshold; |
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|
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/* If number of free ranges are below threshold, start reclaim */ |
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free_threshold = max_t(unsigned long, fcd->nr_ranges * FUSE_DAX_RECLAIM_THRESHOLD / 100, |
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1); |
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if (fcd->nr_free_ranges < free_threshold) |
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queue_delayed_work(system_long_wq, &fcd->free_work, |
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msecs_to_jiffies(delay_ms)); |
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} |
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|
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static void kick_dmap_free_worker(struct fuse_conn_dax *fcd, |
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unsigned long delay_ms) |
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{ |
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spin_lock(&fcd->lock); |
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__kick_dmap_free_worker(fcd, delay_ms); |
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spin_unlock(&fcd->lock); |
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} |
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|
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static struct fuse_dax_mapping *alloc_dax_mapping(struct fuse_conn_dax *fcd) |
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{ |
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struct fuse_dax_mapping *dmap; |
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|
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spin_lock(&fcd->lock); |
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dmap = list_first_entry_or_null(&fcd->free_ranges, |
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struct fuse_dax_mapping, list); |
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if (dmap) { |
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list_del_init(&dmap->list); |
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WARN_ON(fcd->nr_free_ranges <= 0); |
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fcd->nr_free_ranges--; |
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} |
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spin_unlock(&fcd->lock); |
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|
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kick_dmap_free_worker(fcd, 0); |
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return dmap; |
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} |
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|
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/* This assumes fcd->lock is held */ |
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static void __dmap_remove_busy_list(struct fuse_conn_dax *fcd, |
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struct fuse_dax_mapping *dmap) |
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{ |
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list_del_init(&dmap->busy_list); |
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WARN_ON(fcd->nr_busy_ranges == 0); |
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fcd->nr_busy_ranges--; |
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} |
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|
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static void dmap_remove_busy_list(struct fuse_conn_dax *fcd, |
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struct fuse_dax_mapping *dmap) |
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{ |
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spin_lock(&fcd->lock); |
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__dmap_remove_busy_list(fcd, dmap); |
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spin_unlock(&fcd->lock); |
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} |
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|
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/* This assumes fcd->lock is held */ |
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static void __dmap_add_to_free_pool(struct fuse_conn_dax *fcd, |
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struct fuse_dax_mapping *dmap) |
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{ |
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list_add_tail(&dmap->list, &fcd->free_ranges); |
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fcd->nr_free_ranges++; |
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wake_up(&fcd->range_waitq); |
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} |
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|
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static void dmap_add_to_free_pool(struct fuse_conn_dax *fcd, |
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struct fuse_dax_mapping *dmap) |
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{ |
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/* Return fuse_dax_mapping to free list */ |
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spin_lock(&fcd->lock); |
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__dmap_add_to_free_pool(fcd, dmap); |
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spin_unlock(&fcd->lock); |
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} |
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|
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static int fuse_setup_one_mapping(struct inode *inode, unsigned long start_idx, |
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struct fuse_dax_mapping *dmap, bool writable, |
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bool upgrade) |
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{ |
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struct fuse_mount *fm = get_fuse_mount(inode); |
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struct fuse_conn_dax *fcd = fm->fc->dax; |
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struct fuse_inode *fi = get_fuse_inode(inode); |
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struct fuse_setupmapping_in inarg; |
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loff_t offset = start_idx << FUSE_DAX_SHIFT; |
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FUSE_ARGS(args); |
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ssize_t err; |
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|
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WARN_ON(fcd->nr_free_ranges < 0); |
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|
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/* Ask fuse daemon to setup mapping */ |
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memset(&inarg, 0, sizeof(inarg)); |
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inarg.foffset = offset; |
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inarg.fh = -1; |
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inarg.moffset = dmap->window_offset; |
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inarg.len = FUSE_DAX_SZ; |
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inarg.flags |= FUSE_SETUPMAPPING_FLAG_READ; |
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if (writable) |
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inarg.flags |= FUSE_SETUPMAPPING_FLAG_WRITE; |
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args.opcode = FUSE_SETUPMAPPING; |
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args.nodeid = fi->nodeid; |
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args.in_numargs = 1; |
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args.in_args[0].size = sizeof(inarg); |
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args.in_args[0].value = &inarg; |
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err = fuse_simple_request(fm, &args); |
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if (err < 0) |
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return err; |
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dmap->writable = writable; |
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if (!upgrade) { |
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/* |
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* We don't take a refernce on inode. inode is valid right now |
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* and when inode is going away, cleanup logic should first |
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* cleanup dmap entries. |
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*/ |
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dmap->inode = inode; |
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dmap->itn.start = dmap->itn.last = start_idx; |
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/* Protected by fi->dax->sem */ |
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interval_tree_insert(&dmap->itn, &fi->dax->tree); |
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fi->dax->nr++; |
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spin_lock(&fcd->lock); |
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list_add_tail(&dmap->busy_list, &fcd->busy_ranges); |
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fcd->nr_busy_ranges++; |
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spin_unlock(&fcd->lock); |
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} |
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return 0; |
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} |
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|
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static int fuse_send_removemapping(struct inode *inode, |
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struct fuse_removemapping_in *inargp, |
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struct fuse_removemapping_one *remove_one) |
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{ |
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struct fuse_inode *fi = get_fuse_inode(inode); |
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struct fuse_mount *fm = get_fuse_mount(inode); |
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FUSE_ARGS(args); |
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|
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args.opcode = FUSE_REMOVEMAPPING; |
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args.nodeid = fi->nodeid; |
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args.in_numargs = 2; |
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args.in_args[0].size = sizeof(*inargp); |
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args.in_args[0].value = inargp; |
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args.in_args[1].size = inargp->count * sizeof(*remove_one); |
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args.in_args[1].value = remove_one; |
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return fuse_simple_request(fm, &args); |
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} |
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static int dmap_removemapping_list(struct inode *inode, unsigned int num, |
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struct list_head *to_remove) |
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{ |
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struct fuse_removemapping_one *remove_one, *ptr; |
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struct fuse_removemapping_in inarg; |
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struct fuse_dax_mapping *dmap; |
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int ret, i = 0, nr_alloc; |
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|
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nr_alloc = min_t(unsigned int, num, FUSE_REMOVEMAPPING_MAX_ENTRY); |
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remove_one = kmalloc_array(nr_alloc, sizeof(*remove_one), GFP_NOFS); |
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if (!remove_one) |
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return -ENOMEM; |
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ptr = remove_one; |
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list_for_each_entry(dmap, to_remove, list) { |
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ptr->moffset = dmap->window_offset; |
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ptr->len = dmap->length; |
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ptr++; |
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i++; |
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num--; |
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if (i >= nr_alloc || num == 0) { |
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memset(&inarg, 0, sizeof(inarg)); |
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inarg.count = i; |
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ret = fuse_send_removemapping(inode, &inarg, |
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remove_one); |
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if (ret) |
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goto out; |
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ptr = remove_one; |
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i = 0; |
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} |
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} |
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out: |
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kfree(remove_one); |
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return ret; |
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} |
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|
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/* |
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* Cleanup dmap entry and add back to free list. This should be called with |
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* fcd->lock held. |
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*/ |
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static void dmap_reinit_add_to_free_pool(struct fuse_conn_dax *fcd, |
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struct fuse_dax_mapping *dmap) |
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{ |
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pr_debug("fuse: freeing memory range start_idx=0x%lx end_idx=0x%lx window_offset=0x%llx length=0x%llx\n", |
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dmap->itn.start, dmap->itn.last, dmap->window_offset, |
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dmap->length); |
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__dmap_remove_busy_list(fcd, dmap); |
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dmap->inode = NULL; |
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dmap->itn.start = dmap->itn.last = 0; |
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__dmap_add_to_free_pool(fcd, dmap); |
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} |
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|
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/* |
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* Free inode dmap entries whose range falls inside [start, end]. |
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* Does not take any locks. At this point of time it should only be |
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* called from evict_inode() path where we know all dmap entries can be |
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* reclaimed. |
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*/ |
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static void inode_reclaim_dmap_range(struct fuse_conn_dax *fcd, |
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struct inode *inode, |
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loff_t start, loff_t end) |
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{ |
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struct fuse_inode *fi = get_fuse_inode(inode); |
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struct fuse_dax_mapping *dmap, *n; |
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int err, num = 0; |
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LIST_HEAD(to_remove); |
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unsigned long start_idx = start >> FUSE_DAX_SHIFT; |
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unsigned long end_idx = end >> FUSE_DAX_SHIFT; |
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struct interval_tree_node *node; |
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|
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while (1) { |
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node = interval_tree_iter_first(&fi->dax->tree, start_idx, |
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end_idx); |
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if (!node) |
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break; |
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dmap = node_to_dmap(node); |
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/* inode is going away. There should not be any users of dmap */ |
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WARN_ON(refcount_read(&dmap->refcnt) > 1); |
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interval_tree_remove(&dmap->itn, &fi->dax->tree); |
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num++; |
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list_add(&dmap->list, &to_remove); |
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} |
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|
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/* Nothing to remove */ |
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if (list_empty(&to_remove)) |
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return; |
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|
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WARN_ON(fi->dax->nr < num); |
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fi->dax->nr -= num; |
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err = dmap_removemapping_list(inode, num, &to_remove); |
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if (err && err != -ENOTCONN) { |
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pr_warn("Failed to removemappings. start=0x%llx end=0x%llx\n", |
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start, end); |
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} |
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spin_lock(&fcd->lock); |
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list_for_each_entry_safe(dmap, n, &to_remove, list) { |
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list_del_init(&dmap->list); |
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dmap_reinit_add_to_free_pool(fcd, dmap); |
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} |
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spin_unlock(&fcd->lock); |
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} |
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|
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static int dmap_removemapping_one(struct inode *inode, |
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struct fuse_dax_mapping *dmap) |
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{ |
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struct fuse_removemapping_one forget_one; |
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struct fuse_removemapping_in inarg; |
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|
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memset(&inarg, 0, sizeof(inarg)); |
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inarg.count = 1; |
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memset(&forget_one, 0, sizeof(forget_one)); |
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forget_one.moffset = dmap->window_offset; |
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forget_one.len = dmap->length; |
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|
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return fuse_send_removemapping(inode, &inarg, &forget_one); |
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} |
|
|
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/* |
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* It is called from evict_inode() and by that time inode is going away. So |
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* this function does not take any locks like fi->dax->sem for traversing |
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* that fuse inode interval tree. If that lock is taken then lock validator |
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* complains of deadlock situation w.r.t fs_reclaim lock. |
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*/ |
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void fuse_dax_inode_cleanup(struct inode *inode) |
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{ |
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struct fuse_conn *fc = get_fuse_conn(inode); |
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struct fuse_inode *fi = get_fuse_inode(inode); |
|
|
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/* |
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* fuse_evict_inode() has already called truncate_inode_pages_final() |
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* before we arrive here. So we should not have to worry about any |
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* pages/exception entries still associated with inode. |
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*/ |
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inode_reclaim_dmap_range(fc->dax, inode, 0, -1); |
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WARN_ON(fi->dax->nr); |
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} |
|
|
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static void fuse_fill_iomap_hole(struct iomap *iomap, loff_t length) |
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{ |
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iomap->addr = IOMAP_NULL_ADDR; |
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iomap->length = length; |
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iomap->type = IOMAP_HOLE; |
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} |
|
|
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static void fuse_fill_iomap(struct inode *inode, loff_t pos, loff_t length, |
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struct iomap *iomap, struct fuse_dax_mapping *dmap, |
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unsigned int flags) |
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{ |
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loff_t offset, len; |
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loff_t i_size = i_size_read(inode); |
|
|
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offset = pos - (dmap->itn.start << FUSE_DAX_SHIFT); |
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len = min(length, dmap->length - offset); |
|
|
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/* If length is beyond end of file, truncate further */ |
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if (pos + len > i_size) |
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len = i_size - pos; |
|
|
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if (len > 0) { |
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iomap->addr = dmap->window_offset + offset; |
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iomap->length = len; |
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if (flags & IOMAP_FAULT) |
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iomap->length = ALIGN(len, PAGE_SIZE); |
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iomap->type = IOMAP_MAPPED; |
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/* |
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* increace refcnt so that reclaim code knows this dmap is in |
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* use. This assumes fi->dax->sem mutex is held either |
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* shared/exclusive. |
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*/ |
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refcount_inc(&dmap->refcnt); |
|
|
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/* iomap->private should be NULL */ |
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WARN_ON_ONCE(iomap->private); |
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iomap->private = dmap; |
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} else { |
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/* Mapping beyond end of file is hole */ |
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fuse_fill_iomap_hole(iomap, length); |
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} |
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} |
|
|
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static int fuse_setup_new_dax_mapping(struct inode *inode, loff_t pos, |
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loff_t length, unsigned int flags, |
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struct iomap *iomap) |
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{ |
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struct fuse_inode *fi = get_fuse_inode(inode); |
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struct fuse_conn *fc = get_fuse_conn(inode); |
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struct fuse_conn_dax *fcd = fc->dax; |
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struct fuse_dax_mapping *dmap, *alloc_dmap = NULL; |
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int ret; |
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bool writable = flags & IOMAP_WRITE; |
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unsigned long start_idx = pos >> FUSE_DAX_SHIFT; |
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struct interval_tree_node *node; |
|
|
|
/* |
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* Can't do inline reclaim in fault path. We call |
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* dax_layout_busy_page() before we free a range. And |
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* fuse_wait_dax_page() drops fi->i_mmap_sem lock and requires it. |
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* In fault path we enter with fi->i_mmap_sem held and can't drop |
|
* it. Also in fault path we hold fi->i_mmap_sem shared and not |
|
* exclusive, so that creates further issues with fuse_wait_dax_page(). |
|
* Hence return -EAGAIN and fuse_dax_fault() will wait for a memory |
|
* range to become free and retry. |
|
*/ |
|
if (flags & IOMAP_FAULT) { |
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alloc_dmap = alloc_dax_mapping(fcd); |
|
if (!alloc_dmap) |
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return -EAGAIN; |
|
} else { |
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alloc_dmap = alloc_dax_mapping_reclaim(fcd, inode); |
|
if (IS_ERR(alloc_dmap)) |
|
return PTR_ERR(alloc_dmap); |
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} |
|
|
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/* If we are here, we should have memory allocated */ |
|
if (WARN_ON(!alloc_dmap)) |
|
return -EIO; |
|
|
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/* |
|
* Take write lock so that only one caller can try to setup mapping |
|
* and other waits. |
|
*/ |
|
down_write(&fi->dax->sem); |
|
/* |
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* We dropped lock. Check again if somebody else setup |
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* mapping already. |
|
*/ |
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node = interval_tree_iter_first(&fi->dax->tree, start_idx, start_idx); |
|
if (node) { |
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dmap = node_to_dmap(node); |
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fuse_fill_iomap(inode, pos, length, iomap, dmap, flags); |
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dmap_add_to_free_pool(fcd, alloc_dmap); |
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up_write(&fi->dax->sem); |
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return 0; |
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} |
|
|
|
/* Setup one mapping */ |
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ret = fuse_setup_one_mapping(inode, pos >> FUSE_DAX_SHIFT, alloc_dmap, |
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writable, false); |
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if (ret < 0) { |
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dmap_add_to_free_pool(fcd, alloc_dmap); |
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up_write(&fi->dax->sem); |
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return ret; |
|
} |
|
fuse_fill_iomap(inode, pos, length, iomap, alloc_dmap, flags); |
|
up_write(&fi->dax->sem); |
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return 0; |
|
} |
|
|
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static int fuse_upgrade_dax_mapping(struct inode *inode, loff_t pos, |
|
loff_t length, unsigned int flags, |
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struct iomap *iomap) |
|
{ |
|
struct fuse_inode *fi = get_fuse_inode(inode); |
|
struct fuse_dax_mapping *dmap; |
|
int ret; |
|
unsigned long idx = pos >> FUSE_DAX_SHIFT; |
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struct interval_tree_node *node; |
|
|
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/* |
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* Take exclusive lock so that only one caller can try to setup |
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* mapping and others wait. |
|
*/ |
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down_write(&fi->dax->sem); |
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node = interval_tree_iter_first(&fi->dax->tree, idx, idx); |
|
|
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/* We are holding either inode lock or i_mmap_sem, and that should |
|
* ensure that dmap can't be truncated. We are holding a reference |
|
* on dmap and that should make sure it can't be reclaimed. So dmap |
|
* should still be there in tree despite the fact we dropped and |
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* re-acquired the fi->dax->sem lock. |
|
*/ |
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ret = -EIO; |
|
if (WARN_ON(!node)) |
|
goto out_err; |
|
|
|
dmap = node_to_dmap(node); |
|
|
|
/* We took an extra reference on dmap to make sure its not reclaimd. |
|
* Now we hold fi->dax->sem lock and that reference is not needed |
|
* anymore. Drop it. |
|
*/ |
|
if (refcount_dec_and_test(&dmap->refcnt)) { |
|
/* refcount should not hit 0. This object only goes |
|
* away when fuse connection goes away |
|
*/ |
|
WARN_ON_ONCE(1); |
|
} |
|
|
|
/* Maybe another thread already upgraded mapping while we were not |
|
* holding lock. |
|
*/ |
|
if (dmap->writable) { |
|
ret = 0; |
|
goto out_fill_iomap; |
|
} |
|
|
|
ret = fuse_setup_one_mapping(inode, pos >> FUSE_DAX_SHIFT, dmap, true, |
|
true); |
|
if (ret < 0) |
|
goto out_err; |
|
out_fill_iomap: |
|
fuse_fill_iomap(inode, pos, length, iomap, dmap, flags); |
|
out_err: |
|
up_write(&fi->dax->sem); |
|
return ret; |
|
} |
|
|
|
/* This is just for DAX and the mapping is ephemeral, do not use it for other |
|
* purposes since there is no block device with a permanent mapping. |
|
*/ |
|
static int fuse_iomap_begin(struct inode *inode, loff_t pos, loff_t length, |
|
unsigned int flags, struct iomap *iomap, |
|
struct iomap *srcmap) |
|
{ |
|
struct fuse_inode *fi = get_fuse_inode(inode); |
|
struct fuse_conn *fc = get_fuse_conn(inode); |
|
struct fuse_dax_mapping *dmap; |
|
bool writable = flags & IOMAP_WRITE; |
|
unsigned long start_idx = pos >> FUSE_DAX_SHIFT; |
|
struct interval_tree_node *node; |
|
|
|
/* We don't support FIEMAP */ |
|
if (WARN_ON(flags & IOMAP_REPORT)) |
|
return -EIO; |
|
|
|
iomap->offset = pos; |
|
iomap->flags = 0; |
|
iomap->bdev = NULL; |
|
iomap->dax_dev = fc->dax->dev; |
|
|
|
/* |
|
* Both read/write and mmap path can race here. So we need something |
|
* to make sure if we are setting up mapping, then other path waits |
|
* |
|
* For now, use a semaphore for this. It probably needs to be |
|
* optimized later. |
|
*/ |
|
down_read(&fi->dax->sem); |
|
node = interval_tree_iter_first(&fi->dax->tree, start_idx, start_idx); |
|
if (node) { |
|
dmap = node_to_dmap(node); |
|
if (writable && !dmap->writable) { |
|
/* Upgrade read-only mapping to read-write. This will |
|
* require exclusive fi->dax->sem lock as we don't want |
|
* two threads to be trying to this simultaneously |
|
* for same dmap. So drop shared lock and acquire |
|
* exclusive lock. |
|
* |
|
* Before dropping fi->dax->sem lock, take reference |
|
* on dmap so that its not freed by range reclaim. |
|
*/ |
|
refcount_inc(&dmap->refcnt); |
|
up_read(&fi->dax->sem); |
|
pr_debug("%s: Upgrading mapping at offset 0x%llx length 0x%llx\n", |
|
__func__, pos, length); |
|
return fuse_upgrade_dax_mapping(inode, pos, length, |
|
flags, iomap); |
|
} else { |
|
fuse_fill_iomap(inode, pos, length, iomap, dmap, flags); |
|
up_read(&fi->dax->sem); |
|
return 0; |
|
} |
|
} else { |
|
up_read(&fi->dax->sem); |
|
pr_debug("%s: no mapping at offset 0x%llx length 0x%llx\n", |
|
__func__, pos, length); |
|
if (pos >= i_size_read(inode)) |
|
goto iomap_hole; |
|
|
|
return fuse_setup_new_dax_mapping(inode, pos, length, flags, |
|
iomap); |
|
} |
|
|
|
/* |
|
* If read beyond end of file happnes, fs code seems to return |
|
* it as hole |
|
*/ |
|
iomap_hole: |
|
fuse_fill_iomap_hole(iomap, length); |
|
pr_debug("%s returning hole mapping. pos=0x%llx length_asked=0x%llx length_returned=0x%llx\n", |
|
__func__, pos, length, iomap->length); |
|
return 0; |
|
} |
|
|
|
static int fuse_iomap_end(struct inode *inode, loff_t pos, loff_t length, |
|
ssize_t written, unsigned int flags, |
|
struct iomap *iomap) |
|
{ |
|
struct fuse_dax_mapping *dmap = iomap->private; |
|
|
|
if (dmap) { |
|
if (refcount_dec_and_test(&dmap->refcnt)) { |
|
/* refcount should not hit 0. This object only goes |
|
* away when fuse connection goes away |
|
*/ |
|
WARN_ON_ONCE(1); |
|
} |
|
} |
|
|
|
/* DAX writes beyond end-of-file aren't handled using iomap, so the |
|
* file size is unchanged and there is nothing to do here. |
|
*/ |
|
return 0; |
|
} |
|
|
|
static const struct iomap_ops fuse_iomap_ops = { |
|
.iomap_begin = fuse_iomap_begin, |
|
.iomap_end = fuse_iomap_end, |
|
}; |
|
|
|
static void fuse_wait_dax_page(struct inode *inode) |
|
{ |
|
struct fuse_inode *fi = get_fuse_inode(inode); |
|
|
|
up_write(&fi->i_mmap_sem); |
|
schedule(); |
|
down_write(&fi->i_mmap_sem); |
|
} |
|
|
|
/* Should be called with fi->i_mmap_sem lock held exclusively */ |
|
static int __fuse_dax_break_layouts(struct inode *inode, bool *retry, |
|
loff_t start, loff_t end) |
|
{ |
|
struct page *page; |
|
|
|
page = dax_layout_busy_page_range(inode->i_mapping, start, end); |
|
if (!page) |
|
return 0; |
|
|
|
*retry = true; |
|
return ___wait_var_event(&page->_refcount, |
|
atomic_read(&page->_refcount) == 1, TASK_INTERRUPTIBLE, |
|
0, 0, fuse_wait_dax_page(inode)); |
|
} |
|
|
|
/* dmap_end == 0 leads to unmapping of whole file */ |
|
int fuse_dax_break_layouts(struct inode *inode, u64 dmap_start, |
|
u64 dmap_end) |
|
{ |
|
bool retry; |
|
int ret; |
|
|
|
do { |
|
retry = false; |
|
ret = __fuse_dax_break_layouts(inode, &retry, dmap_start, |
|
dmap_end); |
|
} while (ret == 0 && retry); |
|
|
|
return ret; |
|
} |
|
|
|
ssize_t fuse_dax_read_iter(struct kiocb *iocb, struct iov_iter *to) |
|
{ |
|
struct inode *inode = file_inode(iocb->ki_filp); |
|
ssize_t ret; |
|
|
|
if (iocb->ki_flags & IOCB_NOWAIT) { |
|
if (!inode_trylock_shared(inode)) |
|
return -EAGAIN; |
|
} else { |
|
inode_lock_shared(inode); |
|
} |
|
|
|
ret = dax_iomap_rw(iocb, to, &fuse_iomap_ops); |
|
inode_unlock_shared(inode); |
|
|
|
/* TODO file_accessed(iocb->f_filp) */ |
|
return ret; |
|
} |
|
|
|
static bool file_extending_write(struct kiocb *iocb, struct iov_iter *from) |
|
{ |
|
struct inode *inode = file_inode(iocb->ki_filp); |
|
|
|
return (iov_iter_rw(from) == WRITE && |
|
((iocb->ki_pos) >= i_size_read(inode) || |
|
(iocb->ki_pos + iov_iter_count(from) > i_size_read(inode)))); |
|
} |
|
|
|
static ssize_t fuse_dax_direct_write(struct kiocb *iocb, struct iov_iter *from) |
|
{ |
|
struct inode *inode = file_inode(iocb->ki_filp); |
|
struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb); |
|
ssize_t ret; |
|
|
|
ret = fuse_direct_io(&io, from, &iocb->ki_pos, FUSE_DIO_WRITE); |
|
if (ret < 0) |
|
return ret; |
|
|
|
fuse_invalidate_attr(inode); |
|
fuse_write_update_size(inode, iocb->ki_pos); |
|
return ret; |
|
} |
|
|
|
ssize_t fuse_dax_write_iter(struct kiocb *iocb, struct iov_iter *from) |
|
{ |
|
struct inode *inode = file_inode(iocb->ki_filp); |
|
ssize_t ret; |
|
|
|
if (iocb->ki_flags & IOCB_NOWAIT) { |
|
if (!inode_trylock(inode)) |
|
return -EAGAIN; |
|
} else { |
|
inode_lock(inode); |
|
} |
|
|
|
ret = generic_write_checks(iocb, from); |
|
if (ret <= 0) |
|
goto out; |
|
|
|
ret = file_remove_privs(iocb->ki_filp); |
|
if (ret) |
|
goto out; |
|
/* TODO file_update_time() but we don't want metadata I/O */ |
|
|
|
/* Do not use dax for file extending writes as write and on |
|
* disk i_size increase are not atomic otherwise. |
|
*/ |
|
if (file_extending_write(iocb, from)) |
|
ret = fuse_dax_direct_write(iocb, from); |
|
else |
|
ret = dax_iomap_rw(iocb, from, &fuse_iomap_ops); |
|
|
|
out: |
|
inode_unlock(inode); |
|
|
|
if (ret > 0) |
|
ret = generic_write_sync(iocb, ret); |
|
return ret; |
|
} |
|
|
|
static int fuse_dax_writepages(struct address_space *mapping, |
|
struct writeback_control *wbc) |
|
{ |
|
|
|
struct inode *inode = mapping->host; |
|
struct fuse_conn *fc = get_fuse_conn(inode); |
|
|
|
return dax_writeback_mapping_range(mapping, fc->dax->dev, wbc); |
|
} |
|
|
|
static vm_fault_t __fuse_dax_fault(struct vm_fault *vmf, |
|
enum page_entry_size pe_size, bool write) |
|
{ |
|
vm_fault_t ret; |
|
struct inode *inode = file_inode(vmf->vma->vm_file); |
|
struct super_block *sb = inode->i_sb; |
|
pfn_t pfn; |
|
int error = 0; |
|
struct fuse_conn *fc = get_fuse_conn(inode); |
|
struct fuse_conn_dax *fcd = fc->dax; |
|
bool retry = false; |
|
|
|
if (write) |
|
sb_start_pagefault(sb); |
|
retry: |
|
if (retry && !(fcd->nr_free_ranges > 0)) |
|
wait_event(fcd->range_waitq, (fcd->nr_free_ranges > 0)); |
|
|
|
/* |
|
* We need to serialize against not only truncate but also against |
|
* fuse dax memory range reclaim. While a range is being reclaimed, |
|
* we do not want any read/write/mmap to make progress and try |
|
* to populate page cache or access memory we are trying to free. |
|
*/ |
|
down_read(&get_fuse_inode(inode)->i_mmap_sem); |
|
ret = dax_iomap_fault(vmf, pe_size, &pfn, &error, &fuse_iomap_ops); |
|
if ((ret & VM_FAULT_ERROR) && error == -EAGAIN) { |
|
error = 0; |
|
retry = true; |
|
up_read(&get_fuse_inode(inode)->i_mmap_sem); |
|
goto retry; |
|
} |
|
|
|
if (ret & VM_FAULT_NEEDDSYNC) |
|
ret = dax_finish_sync_fault(vmf, pe_size, pfn); |
|
up_read(&get_fuse_inode(inode)->i_mmap_sem); |
|
|
|
if (write) |
|
sb_end_pagefault(sb); |
|
|
|
return ret; |
|
} |
|
|
|
static vm_fault_t fuse_dax_fault(struct vm_fault *vmf) |
|
{ |
|
return __fuse_dax_fault(vmf, PE_SIZE_PTE, |
|
vmf->flags & FAULT_FLAG_WRITE); |
|
} |
|
|
|
static vm_fault_t fuse_dax_huge_fault(struct vm_fault *vmf, |
|
enum page_entry_size pe_size) |
|
{ |
|
return __fuse_dax_fault(vmf, pe_size, vmf->flags & FAULT_FLAG_WRITE); |
|
} |
|
|
|
static vm_fault_t fuse_dax_page_mkwrite(struct vm_fault *vmf) |
|
{ |
|
return __fuse_dax_fault(vmf, PE_SIZE_PTE, true); |
|
} |
|
|
|
static vm_fault_t fuse_dax_pfn_mkwrite(struct vm_fault *vmf) |
|
{ |
|
return __fuse_dax_fault(vmf, PE_SIZE_PTE, true); |
|
} |
|
|
|
static const struct vm_operations_struct fuse_dax_vm_ops = { |
|
.fault = fuse_dax_fault, |
|
.huge_fault = fuse_dax_huge_fault, |
|
.page_mkwrite = fuse_dax_page_mkwrite, |
|
.pfn_mkwrite = fuse_dax_pfn_mkwrite, |
|
}; |
|
|
|
int fuse_dax_mmap(struct file *file, struct vm_area_struct *vma) |
|
{ |
|
file_accessed(file); |
|
vma->vm_ops = &fuse_dax_vm_ops; |
|
vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE; |
|
return 0; |
|
} |
|
|
|
static int dmap_writeback_invalidate(struct inode *inode, |
|
struct fuse_dax_mapping *dmap) |
|
{ |
|
int ret; |
|
loff_t start_pos = dmap->itn.start << FUSE_DAX_SHIFT; |
|
loff_t end_pos = (start_pos + FUSE_DAX_SZ - 1); |
|
|
|
ret = filemap_fdatawrite_range(inode->i_mapping, start_pos, end_pos); |
|
if (ret) { |
|
pr_debug("fuse: filemap_fdatawrite_range() failed. err=%d start_pos=0x%llx, end_pos=0x%llx\n", |
|
ret, start_pos, end_pos); |
|
return ret; |
|
} |
|
|
|
ret = invalidate_inode_pages2_range(inode->i_mapping, |
|
start_pos >> PAGE_SHIFT, |
|
end_pos >> PAGE_SHIFT); |
|
if (ret) |
|
pr_debug("fuse: invalidate_inode_pages2_range() failed err=%d\n", |
|
ret); |
|
|
|
return ret; |
|
} |
|
|
|
static int reclaim_one_dmap_locked(struct inode *inode, |
|
struct fuse_dax_mapping *dmap) |
|
{ |
|
int ret; |
|
struct fuse_inode *fi = get_fuse_inode(inode); |
|
|
|
/* |
|
* igrab() was done to make sure inode won't go under us, and this |
|
* further avoids the race with evict(). |
|
*/ |
|
ret = dmap_writeback_invalidate(inode, dmap); |
|
if (ret) |
|
return ret; |
|
|
|
/* Remove dax mapping from inode interval tree now */ |
|
interval_tree_remove(&dmap->itn, &fi->dax->tree); |
|
fi->dax->nr--; |
|
|
|
/* It is possible that umount/shutdown has killed the fuse connection |
|
* and worker thread is trying to reclaim memory in parallel. Don't |
|
* warn in that case. |
|
*/ |
|
ret = dmap_removemapping_one(inode, dmap); |
|
if (ret && ret != -ENOTCONN) { |
|
pr_warn("Failed to remove mapping. offset=0x%llx len=0x%llx ret=%d\n", |
|
dmap->window_offset, dmap->length, ret); |
|
} |
|
return 0; |
|
} |
|
|
|
/* Find first mapped dmap for an inode and return file offset. Caller needs |
|
* to hold fi->dax->sem lock either shared or exclusive. |
|
*/ |
|
static struct fuse_dax_mapping *inode_lookup_first_dmap(struct inode *inode) |
|
{ |
|
struct fuse_inode *fi = get_fuse_inode(inode); |
|
struct fuse_dax_mapping *dmap; |
|
struct interval_tree_node *node; |
|
|
|
for (node = interval_tree_iter_first(&fi->dax->tree, 0, -1); node; |
|
node = interval_tree_iter_next(node, 0, -1)) { |
|
dmap = node_to_dmap(node); |
|
/* still in use. */ |
|
if (refcount_read(&dmap->refcnt) > 1) |
|
continue; |
|
|
|
return dmap; |
|
} |
|
|
|
return NULL; |
|
} |
|
|
|
/* |
|
* Find first mapping in the tree and free it and return it. Do not add |
|
* it back to free pool. |
|
*/ |
|
static struct fuse_dax_mapping * |
|
inode_inline_reclaim_one_dmap(struct fuse_conn_dax *fcd, struct inode *inode, |
|
bool *retry) |
|
{ |
|
struct fuse_inode *fi = get_fuse_inode(inode); |
|
struct fuse_dax_mapping *dmap; |
|
u64 dmap_start, dmap_end; |
|
unsigned long start_idx; |
|
int ret; |
|
struct interval_tree_node *node; |
|
|
|
down_write(&fi->i_mmap_sem); |
|
|
|
/* Lookup a dmap and corresponding file offset to reclaim. */ |
|
down_read(&fi->dax->sem); |
|
dmap = inode_lookup_first_dmap(inode); |
|
if (dmap) { |
|
start_idx = dmap->itn.start; |
|
dmap_start = start_idx << FUSE_DAX_SHIFT; |
|
dmap_end = dmap_start + FUSE_DAX_SZ - 1; |
|
} |
|
up_read(&fi->dax->sem); |
|
|
|
if (!dmap) |
|
goto out_mmap_sem; |
|
/* |
|
* Make sure there are no references to inode pages using |
|
* get_user_pages() |
|
*/ |
|
ret = fuse_dax_break_layouts(inode, dmap_start, dmap_end); |
|
if (ret) { |
|
pr_debug("fuse: fuse_dax_break_layouts() failed. err=%d\n", |
|
ret); |
|
dmap = ERR_PTR(ret); |
|
goto out_mmap_sem; |
|
} |
|
|
|
down_write(&fi->dax->sem); |
|
node = interval_tree_iter_first(&fi->dax->tree, start_idx, start_idx); |
|
/* Range already got reclaimed by somebody else */ |
|
if (!node) { |
|
if (retry) |
|
*retry = true; |
|
goto out_write_dmap_sem; |
|
} |
|
|
|
dmap = node_to_dmap(node); |
|
/* still in use. */ |
|
if (refcount_read(&dmap->refcnt) > 1) { |
|
dmap = NULL; |
|
if (retry) |
|
*retry = true; |
|
goto out_write_dmap_sem; |
|
} |
|
|
|
ret = reclaim_one_dmap_locked(inode, dmap); |
|
if (ret < 0) { |
|
dmap = ERR_PTR(ret); |
|
goto out_write_dmap_sem; |
|
} |
|
|
|
/* Clean up dmap. Do not add back to free list */ |
|
dmap_remove_busy_list(fcd, dmap); |
|
dmap->inode = NULL; |
|
dmap->itn.start = dmap->itn.last = 0; |
|
|
|
pr_debug("fuse: %s: inline reclaimed memory range. inode=%p, window_offset=0x%llx, length=0x%llx\n", |
|
__func__, inode, dmap->window_offset, dmap->length); |
|
|
|
out_write_dmap_sem: |
|
up_write(&fi->dax->sem); |
|
out_mmap_sem: |
|
up_write(&fi->i_mmap_sem); |
|
return dmap; |
|
} |
|
|
|
static struct fuse_dax_mapping * |
|
alloc_dax_mapping_reclaim(struct fuse_conn_dax *fcd, struct inode *inode) |
|
{ |
|
struct fuse_dax_mapping *dmap; |
|
struct fuse_inode *fi = get_fuse_inode(inode); |
|
|
|
while (1) { |
|
bool retry = false; |
|
|
|
dmap = alloc_dax_mapping(fcd); |
|
if (dmap) |
|
return dmap; |
|
|
|
dmap = inode_inline_reclaim_one_dmap(fcd, inode, &retry); |
|
/* |
|
* Either we got a mapping or it is an error, return in both |
|
* the cases. |
|
*/ |
|
if (dmap) |
|
return dmap; |
|
|
|
/* If we could not reclaim a mapping because it |
|
* had a reference or some other temporary failure, |
|
* Try again. We want to give up inline reclaim only |
|
* if there is no range assigned to this node. Otherwise |
|
* if a deadlock is possible if we sleep with fi->i_mmap_sem |
|
* held and worker to free memory can't make progress due |
|
* to unavailability of fi->i_mmap_sem lock. So sleep |
|
* only if fi->dax->nr=0 |
|
*/ |
|
if (retry) |
|
continue; |
|
/* |
|
* There are no mappings which can be reclaimed. Wait for one. |
|
* We are not holding fi->dax->sem. So it is possible |
|
* that range gets added now. But as we are not holding |
|
* fi->i_mmap_sem, worker should still be able to free up |
|
* a range and wake us up. |
|
*/ |
|
if (!fi->dax->nr && !(fcd->nr_free_ranges > 0)) { |
|
if (wait_event_killable_exclusive(fcd->range_waitq, |
|
(fcd->nr_free_ranges > 0))) { |
|
return ERR_PTR(-EINTR); |
|
} |
|
} |
|
} |
|
} |
|
|
|
static int lookup_and_reclaim_dmap_locked(struct fuse_conn_dax *fcd, |
|
struct inode *inode, |
|
unsigned long start_idx) |
|
{ |
|
int ret; |
|
struct fuse_inode *fi = get_fuse_inode(inode); |
|
struct fuse_dax_mapping *dmap; |
|
struct interval_tree_node *node; |
|
|
|
/* Find fuse dax mapping at file offset inode. */ |
|
node = interval_tree_iter_first(&fi->dax->tree, start_idx, start_idx); |
|
|
|
/* Range already got cleaned up by somebody else */ |
|
if (!node) |
|
return 0; |
|
dmap = node_to_dmap(node); |
|
|
|
/* still in use. */ |
|
if (refcount_read(&dmap->refcnt) > 1) |
|
return 0; |
|
|
|
ret = reclaim_one_dmap_locked(inode, dmap); |
|
if (ret < 0) |
|
return ret; |
|
|
|
/* Cleanup dmap entry and add back to free list */ |
|
spin_lock(&fcd->lock); |
|
dmap_reinit_add_to_free_pool(fcd, dmap); |
|
spin_unlock(&fcd->lock); |
|
return ret; |
|
} |
|
|
|
/* |
|
* Free a range of memory. |
|
* Locking: |
|
* 1. Take fi->i_mmap_sem to block dax faults. |
|
* 2. Take fi->dax->sem to protect interval tree and also to make sure |
|
* read/write can not reuse a dmap which we might be freeing. |
|
*/ |
|
static int lookup_and_reclaim_dmap(struct fuse_conn_dax *fcd, |
|
struct inode *inode, |
|
unsigned long start_idx, |
|
unsigned long end_idx) |
|
{ |
|
int ret; |
|
struct fuse_inode *fi = get_fuse_inode(inode); |
|
loff_t dmap_start = start_idx << FUSE_DAX_SHIFT; |
|
loff_t dmap_end = (dmap_start + FUSE_DAX_SZ) - 1; |
|
|
|
down_write(&fi->i_mmap_sem); |
|
ret = fuse_dax_break_layouts(inode, dmap_start, dmap_end); |
|
if (ret) { |
|
pr_debug("virtio_fs: fuse_dax_break_layouts() failed. err=%d\n", |
|
ret); |
|
goto out_mmap_sem; |
|
} |
|
|
|
down_write(&fi->dax->sem); |
|
ret = lookup_and_reclaim_dmap_locked(fcd, inode, start_idx); |
|
up_write(&fi->dax->sem); |
|
out_mmap_sem: |
|
up_write(&fi->i_mmap_sem); |
|
return ret; |
|
} |
|
|
|
static int try_to_free_dmap_chunks(struct fuse_conn_dax *fcd, |
|
unsigned long nr_to_free) |
|
{ |
|
struct fuse_dax_mapping *dmap, *pos, *temp; |
|
int ret, nr_freed = 0; |
|
unsigned long start_idx = 0, end_idx = 0; |
|
struct inode *inode = NULL; |
|
|
|
/* Pick first busy range and free it for now*/ |
|
while (1) { |
|
if (nr_freed >= nr_to_free) |
|
break; |
|
|
|
dmap = NULL; |
|
spin_lock(&fcd->lock); |
|
|
|
if (!fcd->nr_busy_ranges) { |
|
spin_unlock(&fcd->lock); |
|
return 0; |
|
} |
|
|
|
list_for_each_entry_safe(pos, temp, &fcd->busy_ranges, |
|
busy_list) { |
|
/* skip this range if it's in use. */ |
|
if (refcount_read(&pos->refcnt) > 1) |
|
continue; |
|
|
|
inode = igrab(pos->inode); |
|
/* |
|
* This inode is going away. That will free |
|
* up all the ranges anyway, continue to |
|
* next range. |
|
*/ |
|
if (!inode) |
|
continue; |
|
/* |
|
* Take this element off list and add it tail. If |
|
* this element can't be freed, it will help with |
|
* selecting new element in next iteration of loop. |
|
*/ |
|
dmap = pos; |
|
list_move_tail(&dmap->busy_list, &fcd->busy_ranges); |
|
start_idx = end_idx = dmap->itn.start; |
|
break; |
|
} |
|
spin_unlock(&fcd->lock); |
|
if (!dmap) |
|
return 0; |
|
|
|
ret = lookup_and_reclaim_dmap(fcd, inode, start_idx, end_idx); |
|
iput(inode); |
|
if (ret) |
|
return ret; |
|
nr_freed++; |
|
} |
|
return 0; |
|
} |
|
|
|
static void fuse_dax_free_mem_worker(struct work_struct *work) |
|
{ |
|
int ret; |
|
struct fuse_conn_dax *fcd = container_of(work, struct fuse_conn_dax, |
|
free_work.work); |
|
ret = try_to_free_dmap_chunks(fcd, FUSE_DAX_RECLAIM_CHUNK); |
|
if (ret) { |
|
pr_debug("fuse: try_to_free_dmap_chunks() failed with err=%d\n", |
|
ret); |
|
} |
|
|
|
/* If number of free ranges are still below threhold, requeue */ |
|
kick_dmap_free_worker(fcd, 1); |
|
} |
|
|
|
static void fuse_free_dax_mem_ranges(struct list_head *mem_list) |
|
{ |
|
struct fuse_dax_mapping *range, *temp; |
|
|
|
/* Free All allocated elements */ |
|
list_for_each_entry_safe(range, temp, mem_list, list) { |
|
list_del(&range->list); |
|
if (!list_empty(&range->busy_list)) |
|
list_del(&range->busy_list); |
|
kfree(range); |
|
} |
|
} |
|
|
|
void fuse_dax_conn_free(struct fuse_conn *fc) |
|
{ |
|
if (fc->dax) { |
|
fuse_free_dax_mem_ranges(&fc->dax->free_ranges); |
|
kfree(fc->dax); |
|
} |
|
} |
|
|
|
static int fuse_dax_mem_range_init(struct fuse_conn_dax *fcd) |
|
{ |
|
long nr_pages, nr_ranges; |
|
void *kaddr; |
|
pfn_t pfn; |
|
struct fuse_dax_mapping *range; |
|
int ret, id; |
|
size_t dax_size = -1; |
|
unsigned long i; |
|
|
|
init_waitqueue_head(&fcd->range_waitq); |
|
INIT_LIST_HEAD(&fcd->free_ranges); |
|
INIT_LIST_HEAD(&fcd->busy_ranges); |
|
INIT_DELAYED_WORK(&fcd->free_work, fuse_dax_free_mem_worker); |
|
|
|
id = dax_read_lock(); |
|
nr_pages = dax_direct_access(fcd->dev, 0, PHYS_PFN(dax_size), &kaddr, |
|
&pfn); |
|
dax_read_unlock(id); |
|
if (nr_pages < 0) { |
|
pr_debug("dax_direct_access() returned %ld\n", nr_pages); |
|
return nr_pages; |
|
} |
|
|
|
nr_ranges = nr_pages/FUSE_DAX_PAGES; |
|
pr_debug("%s: dax mapped %ld pages. nr_ranges=%ld\n", |
|
__func__, nr_pages, nr_ranges); |
|
|
|
for (i = 0; i < nr_ranges; i++) { |
|
range = kzalloc(sizeof(struct fuse_dax_mapping), GFP_KERNEL); |
|
ret = -ENOMEM; |
|
if (!range) |
|
goto out_err; |
|
|
|
/* TODO: This offset only works if virtio-fs driver is not |
|
* having some memory hidden at the beginning. This needs |
|
* better handling |
|
*/ |
|
range->window_offset = i * FUSE_DAX_SZ; |
|
range->length = FUSE_DAX_SZ; |
|
INIT_LIST_HEAD(&range->busy_list); |
|
refcount_set(&range->refcnt, 1); |
|
list_add_tail(&range->list, &fcd->free_ranges); |
|
} |
|
|
|
fcd->nr_free_ranges = nr_ranges; |
|
fcd->nr_ranges = nr_ranges; |
|
return 0; |
|
out_err: |
|
/* Free All allocated elements */ |
|
fuse_free_dax_mem_ranges(&fcd->free_ranges); |
|
return ret; |
|
} |
|
|
|
int fuse_dax_conn_alloc(struct fuse_conn *fc, struct dax_device *dax_dev) |
|
{ |
|
struct fuse_conn_dax *fcd; |
|
int err; |
|
|
|
if (!dax_dev) |
|
return 0; |
|
|
|
fcd = kzalloc(sizeof(*fcd), GFP_KERNEL); |
|
if (!fcd) |
|
return -ENOMEM; |
|
|
|
spin_lock_init(&fcd->lock); |
|
fcd->dev = dax_dev; |
|
err = fuse_dax_mem_range_init(fcd); |
|
if (err) { |
|
kfree(fcd); |
|
return err; |
|
} |
|
|
|
fc->dax = fcd; |
|
return 0; |
|
} |
|
|
|
bool fuse_dax_inode_alloc(struct super_block *sb, struct fuse_inode *fi) |
|
{ |
|
struct fuse_conn *fc = get_fuse_conn_super(sb); |
|
|
|
fi->dax = NULL; |
|
if (fc->dax) { |
|
fi->dax = kzalloc(sizeof(*fi->dax), GFP_KERNEL_ACCOUNT); |
|
if (!fi->dax) |
|
return false; |
|
|
|
init_rwsem(&fi->dax->sem); |
|
fi->dax->tree = RB_ROOT_CACHED; |
|
} |
|
|
|
return true; |
|
} |
|
|
|
static const struct address_space_operations fuse_dax_file_aops = { |
|
.writepages = fuse_dax_writepages, |
|
.direct_IO = noop_direct_IO, |
|
.set_page_dirty = noop_set_page_dirty, |
|
.invalidatepage = noop_invalidatepage, |
|
}; |
|
|
|
void fuse_dax_inode_init(struct inode *inode) |
|
{ |
|
struct fuse_conn *fc = get_fuse_conn(inode); |
|
|
|
if (!fc->dax) |
|
return; |
|
|
|
inode->i_flags |= S_DAX; |
|
inode->i_data.a_ops = &fuse_dax_file_aops; |
|
} |
|
|
|
bool fuse_dax_check_alignment(struct fuse_conn *fc, unsigned int map_alignment) |
|
{ |
|
if (fc->dax && (map_alignment > FUSE_DAX_SHIFT)) { |
|
pr_warn("FUSE: map_alignment %u incompatible with dax mem range size %u\n", |
|
map_alignment, FUSE_DAX_SZ); |
|
return false; |
|
} |
|
return true; |
|
} |
|
|
|
void fuse_dax_cancel_work(struct fuse_conn *fc) |
|
{ |
|
struct fuse_conn_dax *fcd = fc->dax; |
|
|
|
if (fcd) |
|
cancel_delayed_work_sync(&fcd->free_work); |
|
|
|
} |
|
EXPORT_SYMBOL_GPL(fuse_dax_cancel_work);
|
|
|