From 4352b8aee98005853aa63f57d6377282de17a33f Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 23 Aug 2026 13:28:57 -0700 Subject: Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux 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 ... --- fs/cachefiles/io.c | 738 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 738 insertions(+) create mode 100644 fs/cachefiles/io.c (limited to 'fs/cachefiles/io.c') diff --git a/fs/cachefiles/io.c b/fs/cachefiles/io.c new file mode 100644 index 000000000..9540ec25b --- /dev/null +++ b/fs/cachefiles/io.c @@ -0,0 +1,738 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* kiocb-using read/write + * + * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "internal.h" + +struct cachefiles_kiocb { + struct kiocb iocb; + refcount_t ki_refcnt; + loff_t start; + union { + size_t skipped; + size_t len; + }; + struct cachefiles_object *object; + netfs_io_terminated_t term_func; + void *term_func_priv; + bool was_async; + unsigned int inval_counter; /* Copy of cookie->inval_counter */ + u64 b_writing; +}; + +static inline void cachefiles_put_kiocb(struct cachefiles_kiocb *ki) +{ + if (refcount_dec_and_test(&ki->ki_refcnt)) { + cachefiles_put_object(ki->object, cachefiles_obj_put_ioreq); + fput(ki->iocb.ki_filp); + kfree(ki); + } +} + +/* + * Handle completion of a read from the cache. + */ +static void cachefiles_read_complete(struct kiocb *iocb, long ret) +{ + struct cachefiles_kiocb *ki = container_of(iocb, struct cachefiles_kiocb, iocb); + struct inode *inode = file_inode(ki->iocb.ki_filp); + + _enter("%ld", ret); + + if (ret < 0) + trace_cachefiles_io_error(ki->object, inode, ret, + cachefiles_trace_read_error); + + if (ki->term_func) { + if (ret >= 0) { + if (ki->object->cookie->inval_counter == ki->inval_counter) + ki->skipped += ret; + else + ret = -ESTALE; + } + + ki->term_func(ki->term_func_priv, ret); + } + + cachefiles_put_kiocb(ki); +} + +/* + * Initiate a read from the cache. + */ +static int cachefiles_read(struct netfs_cache_resources *cres, + loff_t start_pos, + struct iov_iter *iter, + enum netfs_read_from_hole read_hole, + netfs_io_terminated_t term_func, + void *term_func_priv) +{ + struct cachefiles_object *object; + struct cachefiles_kiocb *ki; + struct file *file; + unsigned int old_nofs; + ssize_t ret = -ENOBUFS; + size_t len = iov_iter_count(iter), skipped = 0; + + if (!fscache_wait_for_operation(cres, FSCACHE_WANT_READ)) + goto presubmission_error; + + fscache_count_read(); + object = cachefiles_cres_object(cres); + file = cachefiles_cres_file(cres); + + _enter("%pD,%llu,%llx,%zx/%llx", + file, file_inode(file)->i_ino, start_pos, len, + i_size_read(file_inode(file))); + + /* If the caller asked us to seek for data before doing the read, then + * we should do that now. If we find a gap, we fill it with zeros. + */ + if (read_hole != NETFS_READ_HOLE_IGNORE) { + loff_t off = start_pos, off2; + + off2 = cachefiles_inject_read_error(); + if (off2 == 0) + off2 = vfs_llseek(file, off, SEEK_DATA); + if (off2 < 0 && off2 >= (loff_t)-MAX_ERRNO && off2 != -ENXIO) { + skipped = 0; + ret = off2; + goto presubmission_error; + } + + if (off2 == -ENXIO || off2 >= start_pos + len) { + /* The region is beyond the EOF or there's no more data + * in the region, so clear the rest of the buffer and + * return success. + */ + ret = -ENODATA; + if (read_hole == NETFS_READ_HOLE_FAIL) + goto presubmission_error; + + iov_iter_zero(len, iter); + skipped = len; + ret = 0; + goto presubmission_error; + } + + skipped = off2 - off; + iov_iter_zero(skipped, iter); + } + + ret = -ENOMEM; + ki = kzalloc_obj(struct cachefiles_kiocb); + if (!ki) + goto presubmission_error; + + refcount_set(&ki->ki_refcnt, 2); + ki->iocb.ki_filp = file; + ki->iocb.ki_pos = start_pos + skipped; + ki->iocb.ki_flags = IOCB_DIRECT; + ki->iocb.ki_ioprio = get_current_ioprio(); + ki->skipped = skipped; + ki->object = object; + ki->inval_counter = cres->inval_counter; + ki->term_func = term_func; + ki->term_func_priv = term_func_priv; + ki->was_async = true; + + if (ki->term_func) + ki->iocb.ki_complete = cachefiles_read_complete; + + get_file(ki->iocb.ki_filp); + cachefiles_grab_object(object, cachefiles_obj_get_ioreq); + + trace_cachefiles_read(object, file_inode(file), ki->iocb.ki_pos, len - skipped); + old_nofs = memalloc_nofs_save(); + ret = cachefiles_inject_read_error(); + if (ret == 0) + ret = vfs_iocb_iter_read(file, &ki->iocb, iter); + memalloc_nofs_restore(old_nofs); + switch (ret) { + case -EIOCBQUEUED: + goto in_progress; + + case -ERESTARTSYS: + case -ERESTARTNOINTR: + case -ERESTARTNOHAND: + case -ERESTART_RESTARTBLOCK: + /* There's no easy way to restart the syscall since other AIO's + * may be already running. Just fail this IO with EINTR. + */ + ret = -EINTR; + fallthrough; + default: + ki->was_async = false; + cachefiles_read_complete(&ki->iocb, ret); + if (ret > 0) + ret = 0; + break; + } + +in_progress: + cachefiles_put_kiocb(ki); + _leave(" = %zd", ret); + return ret; + +presubmission_error: + if (term_func) + term_func(term_func_priv, ret < 0 ? ret : skipped); + return ret; +} + +/* + * Query the occupancy of the cache in a region, returning where the next chunk + * of data starts and how long it is. + */ +static int cachefiles_query_occupancy(struct netfs_cache_resources *cres, + loff_t start, size_t len, size_t granularity, + loff_t *_data_start, size_t *_data_len) +{ + struct cachefiles_object *object; + struct file *file; + loff_t off, off2; + + *_data_start = -1; + *_data_len = 0; + + if (!fscache_wait_for_operation(cres, FSCACHE_WANT_READ)) + return -ENOBUFS; + + object = cachefiles_cres_object(cres); + file = cachefiles_cres_file(cres); + granularity = max_t(size_t, object->volume->cache->bsize, granularity); + + _enter("%pD,%llu,%llx,%zx/%llx", + file, file_inode(file)->i_ino, start, len, + i_size_read(file_inode(file))); + + off = cachefiles_inject_read_error(); + if (off == 0) + off = vfs_llseek(file, start, SEEK_DATA); + if (off == -ENXIO) + return -ENODATA; /* Beyond EOF */ + if (off < 0 && off >= (loff_t)-MAX_ERRNO) + return -ENOBUFS; /* Error. */ + if (round_up(off, granularity) >= start + len) + return -ENODATA; /* No data in range */ + + off2 = cachefiles_inject_read_error(); + if (off2 == 0) + off2 = vfs_llseek(file, off, SEEK_HOLE); + if (off2 == -ENXIO) + return -ENODATA; /* Beyond EOF */ + if (off2 < 0 && off2 >= (loff_t)-MAX_ERRNO) + return -ENOBUFS; /* Error. */ + + /* Round away partial blocks */ + off = round_up(off, granularity); + off2 = round_down(off2, granularity); + if (off2 <= off) + return -ENODATA; + + *_data_start = off; + if (off2 > start + len) + *_data_len = len; + else + *_data_len = off2 - off; + return 0; +} + +/* + * Handle completion of a write to the cache. + */ +static void cachefiles_write_complete(struct kiocb *iocb, long ret) +{ + struct cachefiles_kiocb *ki = container_of(iocb, struct cachefiles_kiocb, iocb); + struct cachefiles_object *object = ki->object; + struct inode *inode = file_inode(ki->iocb.ki_filp); + + _enter("%ld", ret); + + if (ki->was_async) + kiocb_end_write(iocb); + + if (ret < 0) + trace_cachefiles_io_error(object, inode, ret, + cachefiles_trace_write_error); + + atomic_long_sub(ki->b_writing, &object->volume->cache->b_writing); + set_bit(FSCACHE_COOKIE_HAVE_DATA, &object->cookie->flags); + if (ki->term_func) + ki->term_func(ki->term_func_priv, ret); + cachefiles_put_kiocb(ki); +} + +/* + * Initiate a write to the cache. + */ +int __cachefiles_write(struct cachefiles_object *object, + struct file *file, + loff_t start_pos, + struct iov_iter *iter, + netfs_io_terminated_t term_func, + void *term_func_priv) +{ + struct cachefiles_cache *cache; + struct cachefiles_kiocb *ki; + unsigned int old_nofs; + ssize_t ret; + size_t len = iov_iter_count(iter); + + fscache_count_write(); + cache = object->volume->cache; + + _enter("%pD,%llu,%llx,%zx/%llx", + file, file_inode(file)->i_ino, start_pos, len, + i_size_read(file_inode(file))); + + ki = kzalloc_obj(struct cachefiles_kiocb); + if (!ki) { + if (term_func) + term_func(term_func_priv, -ENOMEM); + return -ENOMEM; + } + + refcount_set(&ki->ki_refcnt, 2); + ki->iocb.ki_filp = file; + ki->iocb.ki_pos = start_pos; + ki->iocb.ki_flags = IOCB_DIRECT | IOCB_WRITE; + ki->iocb.ki_ioprio = get_current_ioprio(); + ki->object = object; + ki->start = start_pos; + ki->len = len; + ki->term_func = term_func; + ki->term_func_priv = term_func_priv; + ki->was_async = true; + ki->b_writing = (len + (1 << cache->bshift) - 1) >> cache->bshift; + + if (ki->term_func) + ki->iocb.ki_complete = cachefiles_write_complete; + atomic_long_add(ki->b_writing, &cache->b_writing); + + get_file(ki->iocb.ki_filp); + cachefiles_grab_object(object, cachefiles_obj_get_ioreq); + + trace_cachefiles_write(object, file_inode(file), ki->iocb.ki_pos, len); + old_nofs = memalloc_nofs_save(); + ret = cachefiles_inject_write_error(); + if (ret == 0) + ret = vfs_iocb_iter_write(file, &ki->iocb, iter); + memalloc_nofs_restore(old_nofs); + switch (ret) { + case -EIOCBQUEUED: + goto in_progress; + + case -ERESTARTSYS: + case -ERESTARTNOINTR: + case -ERESTARTNOHAND: + case -ERESTART_RESTARTBLOCK: + /* There's no easy way to restart the syscall since other AIO's + * may be already running. Just fail this IO with EINTR. + */ + ret = -EINTR; + fallthrough; + default: + ki->was_async = false; + cachefiles_write_complete(&ki->iocb, ret); + break; + } + +in_progress: + cachefiles_put_kiocb(ki); + _leave(" = %zd", ret); + return ret; +} + +static int cachefiles_write(struct netfs_cache_resources *cres, + loff_t start_pos, + struct iov_iter *iter, + netfs_io_terminated_t term_func, + void *term_func_priv) +{ + if (!fscache_wait_for_operation(cres, FSCACHE_WANT_WRITE)) { + if (term_func) + term_func(term_func_priv, -ENOBUFS); + trace_netfs_sreq(term_func_priv, netfs_sreq_trace_cache_nowrite); + return -ENOBUFS; + } + + return __cachefiles_write(cachefiles_cres_object(cres), + cachefiles_cres_file(cres), + start_pos, iter, + term_func, term_func_priv); +} + +static inline enum netfs_io_source +cachefiles_do_prepare_read(struct netfs_cache_resources *cres, + loff_t start, size_t *_len, loff_t i_size, + unsigned long *_flags, ino_t netfs_ino) +{ + enum cachefiles_prepare_read_trace why; + struct cachefiles_object *object = NULL; + struct cachefiles_cache *cache; + struct fscache_cookie *cookie = fscache_cres_cookie(cres); + const struct cred *saved_cred; + struct file *file = cachefiles_cres_file(cres); + enum netfs_io_source ret = NETFS_DOWNLOAD_FROM_SERVER; + size_t len = *_len; + loff_t off, to; + ino_t ino = file ? file_inode(file)->i_ino : 0; + + _enter("%zx @%llx/%llx", len, start, i_size); + + if (start >= i_size) { + ret = NETFS_FILL_WITH_ZEROES; + why = cachefiles_trace_read_after_eof; + goto out_no_object; + } + + if (test_bit(FSCACHE_COOKIE_NO_DATA_TO_READ, &cookie->flags)) { + __set_bit(NETFS_SREQ_COPY_TO_CACHE, _flags); + why = cachefiles_trace_read_no_data; + goto out_no_object; + } + + /* The object and the file may be being created in the background. */ + if (!file) { + why = cachefiles_trace_read_no_file; + if (!fscache_wait_for_operation(cres, FSCACHE_WANT_READ)) + goto out_no_object; + file = cachefiles_cres_file(cres); + if (!file) + goto out_no_object; + ino = file_inode(file)->i_ino; + } + + object = cachefiles_cres_object(cres); + cache = object->volume->cache; + cachefiles_begin_secure(cache, &saved_cred); + off = cachefiles_inject_read_error(); + if (off == 0) + off = vfs_llseek(file, start, SEEK_DATA); + if (off < 0 && off >= (loff_t)-MAX_ERRNO) { + if (off == (loff_t)-ENXIO) { + why = cachefiles_trace_read_seek_nxio; + goto download_and_store; + } + trace_cachefiles_io_error(object, file_inode(file), off, + cachefiles_trace_seek_error); + why = cachefiles_trace_read_seek_error; + goto out; + } + + if (off >= start + len) { + why = cachefiles_trace_read_found_hole; + goto download_and_store; + } + + if (off > start) { + off = round_up(off, cache->bsize); + len = off - start; + *_len = len; + why = cachefiles_trace_read_found_part; + goto download_and_store; + } + + to = cachefiles_inject_read_error(); + if (to == 0) + to = vfs_llseek(file, start, SEEK_HOLE); + if (to < 0 && to >= (loff_t)-MAX_ERRNO) { + trace_cachefiles_io_error(object, file_inode(file), to, + cachefiles_trace_seek_error); + why = cachefiles_trace_read_seek_error; + goto out; + } + + if (to < start + len) { + if (start + len >= i_size) + to = round_up(to, cache->bsize); + else + to = round_down(to, cache->bsize); + len = to - start; + *_len = len; + } + + why = cachefiles_trace_read_have_data; + ret = NETFS_READ_FROM_CACHE; + goto out; + +download_and_store: + __set_bit(NETFS_SREQ_COPY_TO_CACHE, _flags); +out: + cachefiles_end_secure(cache, saved_cred); +out_no_object: + trace_cachefiles_prep_read(object, start, len, *_flags, ret, why, ino, netfs_ino); + return ret; +} + +/* + * Prepare a read operation, shortening it to a cached/uncached + * boundary as appropriate. + */ +static enum netfs_io_source cachefiles_prepare_read(struct netfs_io_subrequest *subreq, + unsigned long long i_size) +{ + return cachefiles_do_prepare_read(&subreq->rreq->cache_resources, + subreq->start, &subreq->len, i_size, + &subreq->flags, subreq->rreq->inode->i_ino); +} + +/* + * Prepare for a write to occur. + */ +int __cachefiles_prepare_write(struct cachefiles_object *object, + struct file *file, + loff_t *_start, size_t *_len, size_t upper_len, + bool no_space_allocated_yet) +{ + struct cachefiles_cache *cache = object->volume->cache; + loff_t start = *_start, pos; + size_t len = *_len; + int ret; + + /* Round to DIO size */ + start = round_down(*_start, PAGE_SIZE); + if (start != *_start || *_len > upper_len) { + /* Probably asked to cache a streaming write written into the + * pagecache when the cookie was temporarily out of service to + * culling. + */ + fscache_count_dio_misfit(); + return -ENOBUFS; + } + + *_len = round_up(len, PAGE_SIZE); + + /* We need to work out whether there's sufficient disk space to perform + * the write - but we can skip that check if we have space already + * allocated. + */ + if (no_space_allocated_yet) + goto check_space; + + pos = cachefiles_inject_read_error(); + if (pos == 0) + pos = vfs_llseek(file, start, SEEK_DATA); + if (pos < 0 && pos >= (loff_t)-MAX_ERRNO) { + if (pos == -ENXIO) + goto check_space; /* Unallocated tail */ + trace_cachefiles_io_error(object, file_inode(file), pos, + cachefiles_trace_seek_error); + return pos; + } + if ((u64)pos >= (u64)start + *_len) + goto check_space; /* Unallocated region */ + + /* We have a block that's at least partially filled - if we're low on + * space, we need to see if it's fully allocated. If it's not, we may + * want to cull it. + */ + if (cachefiles_has_space(cache, 0, *_len / PAGE_SIZE, + cachefiles_has_space_check) == 0) + return 0; /* Enough space to simply overwrite the whole block */ + + pos = cachefiles_inject_read_error(); + if (pos == 0) + pos = vfs_llseek(file, start, SEEK_HOLE); + if (pos < 0 && pos >= (loff_t)-MAX_ERRNO) { + trace_cachefiles_io_error(object, file_inode(file), pos, + cachefiles_trace_seek_error); + return pos; + } + if ((u64)pos >= (u64)start + *_len) + return 0; /* Fully allocated */ + + /* Partially allocated, but insufficient space: cull. */ + fscache_count_no_write_space(); + ret = cachefiles_inject_remove_error(); + if (ret == 0) + ret = vfs_fallocate(file, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, + start, *_len); + if (ret < 0) { + trace_cachefiles_io_error(object, file_inode(file), ret, + cachefiles_trace_fallocate_error); + cachefiles_io_error_obj(object, + "CacheFiles: fallocate failed (%d)\n", ret); + ret = -EIO; + } + + return ret; + +check_space: + return cachefiles_has_space(cache, 0, *_len / PAGE_SIZE, + cachefiles_has_space_for_write); +} + +static int cachefiles_prepare_write(struct netfs_cache_resources *cres, + loff_t *_start, size_t *_len, size_t upper_len, + loff_t i_size, bool no_space_allocated_yet) +{ + struct cachefiles_object *object = cachefiles_cres_object(cres); + struct cachefiles_cache *cache = object->volume->cache; + const struct cred *saved_cred; + int ret; + + if (!cachefiles_cres_file(cres)) { + if (!fscache_wait_for_operation(cres, FSCACHE_WANT_WRITE)) + return -ENOBUFS; + if (!cachefiles_cres_file(cres)) + return -ENOBUFS; + } + + cachefiles_begin_secure(cache, &saved_cred); + ret = __cachefiles_prepare_write(object, cachefiles_cres_file(cres), + _start, _len, upper_len, + no_space_allocated_yet); + cachefiles_end_secure(cache, saved_cred); + return ret; +} + +static void cachefiles_prepare_write_subreq(struct netfs_io_subrequest *subreq) +{ + struct netfs_io_request *wreq = subreq->rreq; + struct netfs_cache_resources *cres = &wreq->cache_resources; + struct netfs_io_stream *stream = &wreq->io_streams[subreq->stream_nr]; + + _enter("W=%x[%x] %llx", wreq->debug_id, subreq->debug_index, subreq->start); + + stream->sreq_max_len = MAX_RW_COUNT; + stream->sreq_max_segs = BIO_MAX_VECS; + + if (!cachefiles_cres_file(cres)) { + if (!fscache_wait_for_operation(cres, FSCACHE_WANT_WRITE)) + return netfs_prepare_write_failed(subreq); + if (!cachefiles_cres_file(cres)) + return netfs_prepare_write_failed(subreq); + } +} + +static void cachefiles_issue_write(struct netfs_io_subrequest *subreq) +{ + struct netfs_io_request *wreq = subreq->rreq; + struct netfs_cache_resources *cres = &wreq->cache_resources; + struct cachefiles_object *object = cachefiles_cres_object(cres); + struct cachefiles_cache *cache = object->volume->cache; + struct netfs_io_stream *stream = &wreq->io_streams[subreq->stream_nr]; + const struct cred *saved_cred; + size_t off, pre, post, len = subreq->len; + loff_t start = subreq->start; + int ret; + + _enter("W=%x[%x] %llx-%llx", + wreq->debug_id, subreq->debug_index, start, start + len - 1); + + /* We need to start on the cache granularity boundary */ + off = start & (CACHEFILES_DIO_BLOCK_SIZE - 1); + if (off) { + pre = CACHEFILES_DIO_BLOCK_SIZE - off; + if (pre >= len) { + fscache_count_dio_misfit(); + netfs_write_subrequest_terminated(subreq, len); + return; + } + subreq->transferred += pre; + start += pre; + len -= pre; + iov_iter_advance(&subreq->io_iter, pre); + } + + /* We also need to end on the cache granularity boundary */ + if (start + len == wreq->i_size) { + size_t part = len % CACHEFILES_DIO_BLOCK_SIZE; + size_t need = CACHEFILES_DIO_BLOCK_SIZE - part; + + if (part && stream->submit_extendable_to >= need) { + len += need; + subreq->len += need; + subreq->io_iter.count += need; + } + } + + post = len & (CACHEFILES_DIO_BLOCK_SIZE - 1); + if (post) { + len -= post; + if (len == 0) { + fscache_count_dio_misfit(); + netfs_write_subrequest_terminated(subreq, post); + return; + } + iov_iter_truncate(&subreq->io_iter, len); + } + + trace_netfs_sreq(subreq, netfs_sreq_trace_cache_prepare); + cachefiles_begin_secure(cache, &saved_cred); + ret = __cachefiles_prepare_write(object, cachefiles_cres_file(cres), + &start, &len, len, true); + cachefiles_end_secure(cache, saved_cred); + if (ret < 0) { + netfs_write_subrequest_terminated(subreq, ret); + return; + } + + trace_netfs_sreq(subreq, netfs_sreq_trace_cache_write); + cachefiles_write(&subreq->rreq->cache_resources, + subreq->start, &subreq->io_iter, + netfs_write_subrequest_terminated, subreq); +} + +/* + * Clean up an operation. + */ +static void cachefiles_end_operation(struct netfs_cache_resources *cres) +{ + struct file *file = cachefiles_cres_file(cres); + + if (file) + fput(file); + fscache_end_cookie_access(fscache_cres_cookie(cres), fscache_access_io_end); +} + +static const struct netfs_cache_ops cachefiles_netfs_cache_ops = { + .end_operation = cachefiles_end_operation, + .read = cachefiles_read, + .write = cachefiles_write, + .issue_write = cachefiles_issue_write, + .prepare_read = cachefiles_prepare_read, + .prepare_write = cachefiles_prepare_write, + .prepare_write_subreq = cachefiles_prepare_write_subreq, + .query_occupancy = cachefiles_query_occupancy, +}; + +/* + * Open the cache file when beginning a cache operation. + */ +bool cachefiles_begin_operation(struct netfs_cache_resources *cres, + enum fscache_want_state want_state) +{ + struct cachefiles_object *object = cachefiles_cres_object(cres); + + if (!cachefiles_cres_file(cres)) { + cres->ops = &cachefiles_netfs_cache_ops; + if (object->file) { + spin_lock(&object->lock); + if (!cres->cache_priv2 && object->file) + cres->cache_priv2 = get_file(object->file); + spin_unlock(&object->lock); + } + } + + if (!cachefiles_cres_file(cres) && want_state != FSCACHE_WANT_PARAMS) { + pr_err("failed to get cres->file\n"); + return false; + } + + return true; +} -- cgit v1.3.1