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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#include <linux/mount.h>#include <linux/slab.h>#include <linux/file.h>#include <linux/uio.h>#include <linux/bio.h>#include <linux/falloc.h>#include <linux/sched/mm.h>#include <trace/events/fscache.h>#include <trace/events/netfs.h>#include "internal.h"
struct cachefiles_kiocb { struct kiocb iocb; refcount_t ki_refcnt; uoff_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;};
#define IS_ERR_VALUE_LL(x) unlikely((x) >= (unsigned long long)-MAX_ERRNO)
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, uoff_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 the extent of the * next two chunks of cached data and the next hole. */static int cachefiles_query_occupancy(struct netfs_cache_resources *cres, struct fscache_occupancy *occ){ struct cachefiles_object *object; struct inode *inode; struct file *file; uoff_t read_limit; loff_t ret; int i;
if (!fscache_wait_for_operation(cres, FSCACHE_WANT_READ)) return -ENOBUFS;
object = cachefiles_cres_object(cres); file = cachefiles_cres_file(cres); inode = file_inode(file); occ->granularity = object->volume->cache->bsize; /* Read read_limit before content_info. */ read_limit = atomic64_read_acquire(&object->read_limit);
_enter("%pD,%llu,%llx-%llx/%llx", file, inode->i_ino, occ->query_from, occ->query_to, read_limit);
if (read_limit == 0) goto done;
switch (READ_ONCE(object->content_info)) { case CACHEFILES_CONTENT_ALL: case CACHEFILES_CONTENT_SINGLE: if (read_limit > occ->query_from) { occ->cached_from[0] = 0; occ->cached_to[0] = read_limit; occ->cached_type[0] = FSCACHE_EXTENT_DATA; occ->query_from = ULLONG_MAX; } goto done; default: break; }
for (i = 0; i < ARRAY_SIZE(occ->cached_from); i++) { ret = cachefiles_inject_read_error(); if (ret == 0) ret = vfs_llseek(file, occ->query_from, SEEK_DATA); if (IS_ERR_VALUE_LL(ret)) { if (ret != -ENXIO) return ret; occ->query_from = ULLONG_MAX; goto done; } occ->cached_type[i] = FSCACHE_EXTENT_DATA; occ->cached_from[i] = ret; occ->query_from = ret;
ret = cachefiles_inject_read_error(); if (ret == 0) ret = vfs_llseek(file, occ->query_from, SEEK_HOLE); if (IS_ERR_VALUE_LL(ret)) { if (ret != -ENXIO) return ret; occ->query_from = ULLONG_MAX; goto done; } occ->cached_to[i] = ret; occ->query_from = ret; if (occ->query_from >= occ->query_to) break; }
done: _debug("query[0] %llx-%llx", occ->cached_from[0], occ->cached_to[0]); _debug("query[1] %llx-%llx", occ->cached_from[1], occ->cached_to[1]); 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, uoff_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, uoff_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);}
/* * Prepare for a write to occur. */int __cachefiles_prepare_write(struct cachefiles_object *object, struct file *file, uoff_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, cache->bsize); 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, cache->bsize);
/* 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. */ ret = cachefiles_has_space(cache, 0, *_len / cache->bsize, cachefiles_has_space_check); if (ret == 0) return 0; /* Enough space to simply overwrite the whole block */
if (ret == -ENOBUFS) trace_cachefiles_no_space(object, cachefiles_trace_write_nospace_2);
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: ret = cachefiles_has_space(cache, 0, *_len / cache->bsize, cachefiles_has_space_for_write); if (ret == -ENOBUFS) trace_cachefiles_no_space(object, cachefiles_trace_write_nospace); return ret;}
static int cachefiles_prepare_write(struct netfs_cache_resources *cres, uoff_t *_start, size_t *_len, size_t upper_len, uoff_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)) { subreq->error = -ENOBUFS; trace_netfs_sreq(subreq, netfs_sreq_trace_cache_waitfail); return netfs_prepare_write_failed(subreq); } if (!cachefiles_cres_file(cres)) { subreq->error = -ENOBUFS; trace_netfs_sreq(subreq, netfs_sreq_trace_cache_nofile); 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; uoff_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 & (cache->bsize - 1); if (off) { pre = cache->bsize - 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 & (cache->bsize - 1); size_t need = cache->bsize - part;
if (part && stream->submit_extendable_to >= need) { len += need; subreq->len += need; subreq->io_iter.count += need; } }
post = len & (cache->bsize - 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);}
/* * Collect the result of buffered writeback to the cache. This includes * copying a read to the cache. Netfslib collates the results, which might * occur out of order, and delivers them to the cache so that it can update its * content record. * * block_type is one of: * - NETFS_CACHE_COLLECT_WRITE_DATA for a contiguous block of data * - NETFS_CACHE_COLLECT_WRITE_GAP if a discontiguity was skipped * - NETFS_CACHE_COLLECT_WRITE_CANCEL for a hole due to a failed/cancelled write * * The writes we made are all rounded out at both sides to the nearest DIO * block boundary, so if the final block contains the EOF in the middle of it * (rather than at the end), padding will have been written to the file. The * backing file's filesize will have been updated if the write extended the * file; the filesize may still change due to outstanding subreqs. * * The metadata in the cache file xattr records the size of the object we have * stored, but the cache file EOF only goes up to where we've cached data to * and, furthermore, is rounded up to the nearest DIO block boundary. * * Concurrent updates should be protected against by the caller. Netfslib * holds NETFS_ICTX_WB_LOCK as a lock on writeback requests. DIO writes * invalidate the cookie and caching is kept disabled until all users have * unused the cookie. */static void cachefiles_collect_write(struct netfs_io_request *wreq, uoff_t start, size_t len, enum netfs_cache_collect block_type){ struct netfs_cache_resources *cres = &wreq->cache_resources; struct cachefiles_object *object = cachefiles_cres_object(cres); struct cachefiles_cache *cache = object->volume->cache; struct inode *inode; struct file *file = cachefiles_cres_file(cres); uoff_t read_limit; uoff_t old_size = cres->cache_i_size; uoff_t new_size; uoff_t data_to = object->object_size; uoff_t end = start + len; int ret;
if (!file) return;
inode = file_inode(file); new_size = i_size_read(inode);
_enter("%llx,%zx,%x", start, len, cache->bsize);
if (WARN_ON(old_size & (cache->bsize - 1)) || WARN_ON(new_size & (cache->bsize - 1)) || WARN_ON(start & (cache->bsize - 1)) || WARN_ON(len & (cache->bsize - 1))) { trace_cachefiles_io_error(object, inode, -EIO, cachefiles_trace_alignment_error); cachefiles_remove_object_xattr(cache, object, file->f_path.dentry); return; }
/* If this is recording a gap, due to discontiguous writes or lack of * cache space, then a hole may have been introduced into the backing * file. Treat it as a zero-length data block. */ if (block_type == NETFS_CACHE_COLLECT_WRITE_GAP || block_type == NETFS_CACHE_COLLECT_WRITE_CANCEL) { start = end; len = 0; }
/* Zeroth case: Single monolithic files are handled specially. */ if (wreq->origin == NETFS_WRITEBACK_SINGLE) { if (block_type == NETFS_CACHE_COLLECT_WRITE_GAP || block_type == NETFS_CACHE_COLLECT_WRITE_CANCEL) { trace_cachefiles_trunc(object, inode, data_to, 0, cachefiles_trunc_zap); ret = cachefiles_inject_remove_error(); if (ret == 0) ret = vfs_truncate(&file->f_path, 0); if (ret < 0) { trace_cachefiles_io_error(object, inode, ret, cachefiles_trace_trunc_error); cachefiles_io_error_obj(object, "truncate failed %d", ret); cachefiles_remove_object_xattr(cache, object, file->f_path.dentry); return; }
object->content_info = CACHEFILES_CONTENT_NO_DATA; read_limit = 0; } else { object->content_info = CACHEFILES_CONTENT_SINGLE; read_limit = len; } goto update_sizes_2; }
/* First case: The backing file was empty. */ if (old_size == 0) { if (start == 0) object->content_info = CACHEFILES_CONTENT_ALL; else object->content_info = CACHEFILES_CONTENT_BACKFS_MAP; goto update_sizes; }
/* Second case: The backing file is entirely within the old object size * and thus there can be no partial tail block to deal with in the * cache file. */ if (old_size <= data_to) { if (start > old_size) goto discontiguous; goto update_sizes; }
/* Third case: The write happened entirely within the bounds of the * current cache file's size. */ if (end <= old_size) goto update_sizes;
/* Fourth case: The write overwrote the partial tail block and extended * the file. We only need to update the object size because netfslib * rounds out/pads cache writes to whole disk blocks. */ if (start < old_size) goto update_sizes;
/* Fifth case: The write started from the end of the whole tail block * and extended the file. Just extend our notion of the filesize. */ if (start == old_size && old_size == data_to) goto update_sizes;
/* Sixth case: The write continued on from the partial tail block and * extended the file. Need to clear the gap. */ if (start == old_size && old_size > data_to) goto clear_gap;
discontiguous: /* Seventh case: The write was beyond the EOF on the cache file, so now * there's a hole in the file and we can no longer say in the metadata * that we can assume we have it all. We may also need to clear the * end of the partial tail block. */ /* TODO: For the moment, we will have to use SEEK_HOLE/SEEK_DATA. */ if (object->content_info != CACHEFILES_CONTENT_BACKFS_MAP) { object->content_info = CACHEFILES_CONTENT_BACKFS_MAP; trace_cachefiles_coherency(object, inode->i_ino, data_to, NULL, CACHEFILES_CONTENT_BACKFS_MAP, cachefiles_coherency_discontiguous); }
clear_gap: /* We need to clear any partial padding that got jumped over. It * *should* be all zeros, but shared-writable mmap exists... */ if (old_size > data_to) { trace_cachefiles_trunc(object, inode, data_to, old_size, cachefiles_trunc_clear_padding); ret = cachefiles_inject_write_error(); if (ret == 0) ret = vfs_fallocate(file, FALLOC_FL_ZERO_RANGE, data_to, old_size - data_to); if (ret < 0) { trace_cachefiles_io_error(object, inode, ret, cachefiles_trace_fallocate_error); cachefiles_io_error_obj(object, "fallocate zero pad failed %d", ret); cachefiles_remove_object_xattr(cache, object, file->f_path.dentry); return; } }
update_sizes: read_limit = umax(old_size, end);update_sizes_2: cres->cache_i_size = read_limit;
/* We need to be careful setting the object_size: we may have written * more to the cache than to the server (due to cache DIO rounding) and * the i_size set on the netfs inode may include unwritten data that * the server doesn't know about yet. */ object->object_size = umin(read_limit, wreq->i_size);
/* Raise the limit at which reads can access the file. */ /* Update read_limit after content_info */ atomic64_set_release(&object->read_limit, read_limit);}
/* * 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_write = cachefiles_prepare_write, .prepare_write_subreq = cachefiles_prepare_write_subreq, .query_occupancy = cachefiles_query_occupancy, .collect_write = cachefiles_collect_write,};
/* * 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); struct file *file;
cres->dio_size = object->volume->cache->bsize;
if (!cachefiles_cres_file(cres)) { cres->ops = &cachefiles_netfs_cache_ops; cres->object_id = object->debug_id; if (object->file) { spin_lock(&object->lock); file = object->file; if (!cres->cache_priv2 && file) { cres->cache_priv2 = get_file(file); cres->cache_i_size = i_size_read(file_inode(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;}