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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /fs/cachefiles/cache.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'fs/cachefiles/cache.c')
| -rw-r--r-- | fs/cachefiles/cache.c | 428 |
1 files changed, 428 insertions, 0 deletions
diff --git a/fs/cachefiles/cache.c b/fs/cachefiles/cache.c new file mode 100644 index 000000000..9fb06dc16 --- /dev/null +++ b/fs/cachefiles/cache.c @@ -0,0 +1,428 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Manage high-level VFS aspects of a cache. + * + * Copyright (C) 2007, 2021 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include <linux/slab.h> +#include <linux/statfs.h> +#include <linux/namei.h> +#include <trace/events/fscache.h> +#include "internal.h" + +/* + * Bring a cache online. + */ +int cachefiles_add_cache(struct cachefiles_cache *cache) +{ + struct fscache_cache *cache_cookie; + struct path path; + struct kstatfs stats; + struct dentry *graveyard, *cachedir, *root; + const struct cred *saved_cred; + int ret; + + _enter(""); + + cache_cookie = fscache_acquire_cache(cache->tag); + if (IS_ERR(cache_cookie)) + return PTR_ERR(cache_cookie); + + /* we want to work under the module's security ID */ + ret = cachefiles_get_security_ID(cache); + if (ret < 0) + goto error_getsec; + + cachefiles_begin_secure(cache, &saved_cred); + + /* look up the directory at the root of the cache */ + ret = kern_path(cache->rootdirname, LOOKUP_DIRECTORY, &path); + if (ret < 0) + goto error_open_root; + + cache->mnt = path.mnt; + root = path.dentry; + + ret = -EINVAL; + if (is_idmapped_mnt(path.mnt)) { + pr_warn("File cache on idmapped mounts not supported"); + goto error_unsupported; + } + + /* Check features of the backing filesystem: + * - Directories must support looking up and directory creation + * - We create tmpfiles to handle invalidation + * - We use xattrs to store metadata + * - We need to be able to query the amount of space available + * - We want to be able to sync the filesystem when stopping the cache + * - We use DIO to/from pages, so the blocksize mustn't be too big. + */ + ret = -EOPNOTSUPP; + if (d_is_negative(root) || + !d_backing_inode(root)->i_op->lookup || + !d_backing_inode(root)->i_op->mkdir || + !d_backing_inode(root)->i_op->tmpfile || + !(d_backing_inode(root)->i_opflags & IOP_XATTR) || + !root->d_sb->s_op->statfs || + !root->d_sb->s_op->sync_fs || + root->d_sb->s_blocksize > PAGE_SIZE) + goto error_unsupported; + + ret = -EROFS; + if (sb_rdonly(root->d_sb)) + goto error_unsupported; + + /* determine the security of the on-disk cache as this governs + * security ID of files we create */ + ret = cachefiles_determine_cache_security(cache, root, &saved_cred); + if (ret < 0) + goto error_unsupported; + + /* get the cache size and blocksize */ + ret = vfs_statfs(&path, &stats); + if (ret < 0) + goto error_unsupported; + + ret = -ERANGE; + if (stats.f_bsize <= 0) + goto error_unsupported; + + ret = -EOPNOTSUPP; + if (stats.f_bsize > PAGE_SIZE) + goto error_unsupported; + + cache->bsize = stats.f_bsize; + cache->bshift = ilog2(stats.f_bsize); + + _debug("blksize %u (shift %u)", + cache->bsize, cache->bshift); + + _debug("size %llu, avail %llu", + (unsigned long long) stats.f_blocks, + (unsigned long long) stats.f_bavail); + + /* set up caching limits */ + do_div(stats.f_files, 100); + cache->fstop = stats.f_files * cache->fstop_percent; + cache->fcull = stats.f_files * cache->fcull_percent; + cache->frun = stats.f_files * cache->frun_percent; + + _debug("limits {%llu,%llu,%llu} files", + (unsigned long long) cache->frun, + (unsigned long long) cache->fcull, + (unsigned long long) cache->fstop); + + do_div(stats.f_blocks, 100); + cache->bstop = stats.f_blocks * cache->bstop_percent; + cache->bcull = stats.f_blocks * cache->bcull_percent; + cache->brun = stats.f_blocks * cache->brun_percent; + + _debug("limits {%llu,%llu,%llu} blocks", + (unsigned long long) cache->brun, + (unsigned long long) cache->bcull, + (unsigned long long) cache->bstop); + + /* get the cache directory and check its type */ + cachedir = cachefiles_get_directory(cache, root, "cache", NULL); + if (IS_ERR(cachedir)) { + ret = PTR_ERR(cachedir); + goto error_unsupported; + } + + cache->store = cachedir; + + /* get the graveyard directory */ + graveyard = cachefiles_get_directory(cache, root, "graveyard", NULL); + if (IS_ERR(graveyard)) { + ret = PTR_ERR(graveyard); + goto error_unsupported; + } + + cache->graveyard = graveyard; + cache->cache = cache_cookie; + + ret = fscache_add_cache(cache_cookie, &cachefiles_cache_ops, cache); + if (ret < 0) + goto error_add_cache; + + /* done */ + set_bit(CACHEFILES_READY, &cache->flags); + dput(root); + + pr_info("File cache on %s registered\n", cache_cookie->name); + + /* check how much space the cache has */ + cachefiles_has_space(cache, 0, 0, cachefiles_has_space_check); + cachefiles_end_secure(cache, saved_cred); + _leave(" = 0 [%px]", cache->cache); + return 0; + +error_add_cache: + cachefiles_put_directory(cache->graveyard); + cache->graveyard = NULL; +error_unsupported: + cachefiles_put_directory(cache->store); + cache->store = NULL; + mntput(cache->mnt); + cache->mnt = NULL; + dput(root); +error_open_root: + cachefiles_end_secure(cache, saved_cred); + put_cred(cache->cache_cred); + cache->cache_cred = NULL; +error_getsec: + fscache_relinquish_cache(cache_cookie); + cache->cache = NULL; + pr_err("Failed to register: %d\n", ret); + return ret; +} + +/* + * See if we have space for a number of pages and/or a number of files in the + * cache + */ +int cachefiles_has_space(struct cachefiles_cache *cache, + unsigned fnr, unsigned bnr, + enum cachefiles_has_space_for reason) +{ + struct kstatfs stats; + u64 b_avail, b_writing; + int ret; + + struct path path = { + .mnt = cache->mnt, + .dentry = cache->mnt->mnt_root, + }; + + //_enter("{%llu,%llu,%llu,%llu,%llu,%llu},%u,%u", + // (unsigned long long) cache->frun, + // (unsigned long long) cache->fcull, + // (unsigned long long) cache->fstop, + // (unsigned long long) cache->brun, + // (unsigned long long) cache->bcull, + // (unsigned long long) cache->bstop, + // fnr, bnr); + + /* find out how many pages of blockdev are available */ + memset(&stats, 0, sizeof(stats)); + + ret = vfs_statfs(&path, &stats); + if (ret < 0) { + trace_cachefiles_vfs_error(NULL, d_inode(path.dentry), ret, + cachefiles_trace_statfs_error); + if (ret == -EIO) + cachefiles_io_error(cache, "statfs failed"); + _leave(" = %d", ret); + return ret; + } + + b_avail = stats.f_bavail; + b_writing = atomic_long_read(&cache->b_writing); + if (b_avail > b_writing) + b_avail -= b_writing; + else + b_avail = 0; + + //_debug("avail %llu,%llu", + // (unsigned long long)stats.f_ffree, + // (unsigned long long)b_avail); + + /* see if there is sufficient space */ + if (stats.f_ffree > fnr) + stats.f_ffree -= fnr; + else + stats.f_ffree = 0; + + if (b_avail > bnr) + b_avail -= bnr; + else + b_avail = 0; + + ret = -ENOBUFS; + if (stats.f_ffree < cache->fstop || + b_avail < cache->bstop) + goto stop_and_begin_cull; + + ret = 0; + if (stats.f_ffree < cache->fcull || + b_avail < cache->bcull) + goto begin_cull; + + if (test_bit(CACHEFILES_CULLING, &cache->flags) && + stats.f_ffree >= cache->frun && + b_avail >= cache->brun && + test_and_clear_bit(CACHEFILES_CULLING, &cache->flags) + ) { + _debug("cease culling"); + cachefiles_state_changed(cache); + } + + //_leave(" = 0"); + return 0; + +stop_and_begin_cull: + switch (reason) { + case cachefiles_has_space_for_write: + fscache_count_no_write_space(); + break; + case cachefiles_has_space_for_create: + fscache_count_no_create_space(); + break; + default: + break; + } +begin_cull: + if (!test_and_set_bit(CACHEFILES_CULLING, &cache->flags)) { + _debug("### CULL CACHE ###"); + cachefiles_state_changed(cache); + } + + _leave(" = %d", ret); + return ret; +} + +/* + * Mark all the objects as being out of service and queue them all for cleanup. + */ +static void cachefiles_withdraw_objects(struct cachefiles_cache *cache) +{ + struct cachefiles_object *object; + unsigned int count = 0; + + _enter(""); + + spin_lock(&cache->object_list_lock); + + while (!list_empty(&cache->object_list)) { + object = list_first_entry(&cache->object_list, + struct cachefiles_object, cache_link); + cachefiles_see_object(object, cachefiles_obj_see_withdrawal); + list_del_init(&object->cache_link); + fscache_withdraw_cookie(object->cookie); + count++; + if ((count & 63) == 0) { + spin_unlock(&cache->object_list_lock); + cond_resched(); + spin_lock(&cache->object_list_lock); + } + } + + spin_unlock(&cache->object_list_lock); + _leave(" [%u objs]", count); +} + +/* + * Withdraw fscache volumes. + */ +static void cachefiles_withdraw_fscache_volumes(struct cachefiles_cache *cache) +{ + struct list_head *cur; + struct cachefiles_volume *volume; + struct fscache_volume *vcookie; + + _enter(""); +retry: + spin_lock(&cache->object_list_lock); + list_for_each(cur, &cache->volumes) { + volume = list_entry(cur, struct cachefiles_volume, cache_link); + + if (atomic_read(&volume->vcookie->n_accesses) == 0) + continue; + + vcookie = fscache_try_get_volume(volume->vcookie, + fscache_volume_get_withdraw); + if (vcookie) { + spin_unlock(&cache->object_list_lock); + fscache_withdraw_volume(vcookie); + fscache_put_volume(vcookie, fscache_volume_put_withdraw); + goto retry; + } + } + spin_unlock(&cache->object_list_lock); + + _leave(""); +} + +/* + * Withdraw cachefiles volumes. + */ +static void cachefiles_withdraw_volumes(struct cachefiles_cache *cache) +{ + _enter(""); + + for (;;) { + struct fscache_volume *vcookie = NULL; + struct cachefiles_volume *volume = NULL; + + spin_lock(&cache->object_list_lock); + if (!list_empty(&cache->volumes)) { + volume = list_first_entry(&cache->volumes, + struct cachefiles_volume, cache_link); + vcookie = fscache_try_get_volume(volume->vcookie, + fscache_volume_get_withdraw); + if (!vcookie) { + spin_unlock(&cache->object_list_lock); + cpu_relax(); + continue; + } + list_del_init(&volume->cache_link); + } + spin_unlock(&cache->object_list_lock); + if (!volume) + break; + + cachefiles_withdraw_volume(volume); + fscache_put_volume(vcookie, fscache_volume_put_withdraw); + } + + _leave(""); +} + +/* + * Sync a cache to backing disk. + */ +static void cachefiles_sync_cache(struct cachefiles_cache *cache) +{ + const struct cred *saved_cred; + int ret; + + _enter("%s", cache->cache->name); + + /* make sure all pages pinned by operations on behalf of the netfs are + * written to disc */ + cachefiles_begin_secure(cache, &saved_cred); + down_read(&cache->mnt->mnt_sb->s_umount); + ret = sync_filesystem(cache->mnt->mnt_sb); + up_read(&cache->mnt->mnt_sb->s_umount); + cachefiles_end_secure(cache, saved_cred); + + if (ret == -EIO) + cachefiles_io_error(cache, + "Attempt to sync backing fs superblock returned error %d", + ret); +} + +/* + * Withdraw cache objects. + */ +void cachefiles_withdraw_cache(struct cachefiles_cache *cache) +{ + struct fscache_cache *fscache = cache->cache; + + pr_info("File cache on %s unregistering\n", fscache->name); + + fscache_withdraw_cache(fscache); + cachefiles_withdraw_fscache_volumes(cache); + + /* we now have to destroy all the active objects pertaining to this + * cache - which we do by passing them off to thread pool to be + * disposed of */ + cachefiles_withdraw_objects(cache); + fscache_wait_for_objects(fscache); + + cachefiles_withdraw_volumes(cache); + cachefiles_sync_cache(cache); + cache->cache = NULL; + fscache_relinquish_cache(fscache); +} |
