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-rw-r--r--fs/cachefiles/io.c420
1 files changed, 0 insertions, 420 deletions
diff --git a/fs/cachefiles/io.c b/fs/cachefiles/io.c
deleted file mode 100644
index effe37ef8629..000000000000
--- a/fs/cachefiles/io.c
+++ /dev/null
@@ -1,420 +0,0 @@
-// 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 <linux/mount.h>
-#include <linux/slab.h>
-#include <linux/file.h>
-#include <linux/uio.h>
-#include <linux/sched/mm.h>
-#include <linux/netfs.h>
-#include "internal.h"
-
-struct cachefiles_kiocb {
- struct kiocb iocb;
- refcount_t ki_refcnt;
- loff_t start;
- union {
- size_t skipped;
- size_t len;
- };
- netfs_io_terminated_t term_func;
- void *term_func_priv;
- bool was_async;
-};
-
-static inline void cachefiles_put_kiocb(struct cachefiles_kiocb *ki)
-{
- if (refcount_dec_and_test(&ki->ki_refcnt)) {
- 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);
-
- _enter("%ld", ret);
-
- if (ki->term_func) {
- if (ret >= 0)
- ret += ki->skipped;
- ki->term_func(ki->term_func_priv, ret, ki->was_async);
- }
-
- 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,
- bool seek_data,
- netfs_io_terminated_t term_func,
- void *term_func_priv)
-{
- struct cachefiles_kiocb *ki;
- struct file *file = cres->cache_priv2;
- unsigned int old_nofs;
- ssize_t ret = -ENOBUFS;
- size_t len = iov_iter_count(iter), skipped = 0;
-
- _enter("%pD,%li,%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 (seek_data) {
- loff_t off = start_pos, off2;
-
- 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.
- */
- iov_iter_zero(len, iter);
- skipped = len;
- ret = 0;
- goto presubmission_error;
- }
-
- skipped = off2 - off;
- iov_iter_zero(skipped, iter);
- }
-
- ret = -ENOBUFS;
- ki = kzalloc(sizeof(struct cachefiles_kiocb), GFP_KERNEL);
- 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_hint = ki_hint_validate(file_write_hint(file));
- ki->iocb.ki_ioprio = get_current_ioprio();
- ki->skipped = skipped;
- 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);
-
- old_nofs = memalloc_nofs_save();
- 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, false);
- return ret;
-}
-
-/*
- * 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 inode *inode = file_inode(ki->iocb.ki_filp);
-
- _enter("%ld", ret);
-
- /* Tell lockdep we inherited freeze protection from submission thread */
- __sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE);
- __sb_end_write(inode->i_sb, SB_FREEZE_WRITE);
-
- if (ki->term_func)
- ki->term_func(ki->term_func_priv, ret, ki->was_async);
-
- cachefiles_put_kiocb(ki);
-}
-
-/*
- * Initiate a write to the cache.
- */
-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)
-{
- struct cachefiles_kiocb *ki;
- struct inode *inode;
- struct file *file = cres->cache_priv2;
- unsigned int old_nofs;
- ssize_t ret = -ENOBUFS;
- size_t len = iov_iter_count(iter);
-
- _enter("%pD,%li,%llx,%zx/%llx",
- file, file_inode(file)->i_ino, start_pos, len,
- i_size_read(file_inode(file)));
-
- ki = kzalloc(sizeof(struct cachefiles_kiocb), GFP_KERNEL);
- if (!ki)
- goto presubmission_error;
-
- 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_hint = ki_hint_validate(file_write_hint(file));
- ki->iocb.ki_ioprio = get_current_ioprio();
- ki->start = start_pos;
- ki->len = len;
- 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_write_complete;
-
- /* Open-code file_start_write here to grab freeze protection, which
- * will be released by another thread in aio_complete_rw(). Fool
- * lockdep by telling it the lock got released so that it doesn't
- * complain about the held lock when we return to userspace.
- */
- inode = file_inode(file);
- __sb_start_write(inode->i_sb, SB_FREEZE_WRITE);
- __sb_writers_release(inode->i_sb, SB_FREEZE_WRITE);
-
- get_file(ki->iocb.ki_filp);
-
- old_nofs = memalloc_nofs_save();
- 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);
- 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, -ENOMEM, false);
- return -ENOMEM;
-}
-
-/*
- * Prepare a read operation, shortening it to a cached/uncached
- * boundary as appropriate.
- */
-static enum netfs_read_source cachefiles_prepare_read(struct netfs_read_subrequest *subreq,
- loff_t i_size)
-{
- struct fscache_retrieval *op = subreq->rreq->cache_resources.cache_priv;
- struct cachefiles_object *object;
- struct cachefiles_cache *cache;
- const struct cred *saved_cred;
- struct file *file = subreq->rreq->cache_resources.cache_priv2;
- loff_t off, to;
-
- _enter("%zx @%llx/%llx", subreq->len, subreq->start, i_size);
-
- object = container_of(op->op.object,
- struct cachefiles_object, fscache);
- cache = container_of(object->fscache.cache,
- struct cachefiles_cache, cache);
-
- if (!file)
- goto cache_fail_nosec;
-
- if (subreq->start >= i_size)
- return NETFS_FILL_WITH_ZEROES;
-
- cachefiles_begin_secure(cache, &saved_cred);
-
- off = vfs_llseek(file, subreq->start, SEEK_DATA);
- if (off < 0 && off >= (loff_t)-MAX_ERRNO) {
- if (off == (loff_t)-ENXIO)
- goto download_and_store;
- goto cache_fail;
- }
-
- if (off >= subreq->start + subreq->len)
- goto download_and_store;
-
- if (off > subreq->start) {
- off = round_up(off, cache->bsize);
- subreq->len = off - subreq->start;
- goto download_and_store;
- }
-
- to = vfs_llseek(file, subreq->start, SEEK_HOLE);
- if (to < 0 && to >= (loff_t)-MAX_ERRNO)
- goto cache_fail;
-
- if (to < subreq->start + subreq->len) {
- if (subreq->start + subreq->len >= i_size)
- to = round_up(to, cache->bsize);
- else
- to = round_down(to, cache->bsize);
- subreq->len = to - subreq->start;
- }
-
- cachefiles_end_secure(cache, saved_cred);
- return NETFS_READ_FROM_CACHE;
-
-download_and_store:
- if (cachefiles_has_space(cache, 0, (subreq->len + PAGE_SIZE - 1) / PAGE_SIZE) == 0)
- __set_bit(NETFS_SREQ_WRITE_TO_CACHE, &subreq->flags);
-cache_fail:
- cachefiles_end_secure(cache, saved_cred);
-cache_fail_nosec:
- return NETFS_DOWNLOAD_FROM_SERVER;
-}
-
-/*
- * Prepare for a write to occur.
- */
-static int cachefiles_prepare_write(struct netfs_cache_resources *cres,
- loff_t *_start, size_t *_len, loff_t i_size)
-{
- loff_t start = *_start;
- size_t len = *_len, down;
-
- /* Round to DIO size */
- down = start - round_down(start, PAGE_SIZE);
- *_start = start - down;
- *_len = round_up(down + len, PAGE_SIZE);
- return 0;
-}
-
-/*
- * Clean up an operation.
- */
-static void cachefiles_end_operation(struct netfs_cache_resources *cres)
-{
- struct fscache_retrieval *op = cres->cache_priv;
- struct file *file = cres->cache_priv2;
-
- _enter("");
-
- if (file)
- fput(file);
- if (op) {
- fscache_op_complete(&op->op, false);
- fscache_put_retrieval(op);
- }
-
- _leave("");
-}
-
-static const struct netfs_cache_ops cachefiles_netfs_cache_ops = {
- .end_operation = cachefiles_end_operation,
- .read = cachefiles_read,
- .write = cachefiles_write,
- .prepare_read = cachefiles_prepare_read,
- .prepare_write = cachefiles_prepare_write,
-};
-
-/*
- * Open the cache file when beginning a cache operation.
- */
-int cachefiles_begin_read_operation(struct netfs_read_request *rreq,
- struct fscache_retrieval *op)
-{
- struct cachefiles_object *object;
- struct cachefiles_cache *cache;
- struct path path;
- struct file *file;
-
- _enter("");
-
- object = container_of(op->op.object,
- struct cachefiles_object, fscache);
- cache = container_of(object->fscache.cache,
- struct cachefiles_cache, cache);
-
- path.mnt = cache->mnt;
- path.dentry = object->backer;
- file = open_with_fake_path(&path, O_RDWR | O_LARGEFILE | O_DIRECT,
- d_inode(object->backer), cache->cache_cred);
- if (IS_ERR(file))
- return PTR_ERR(file);
- if (!S_ISREG(file_inode(file)->i_mode))
- goto error_file;
- if (unlikely(!file->f_op->read_iter) ||
- unlikely(!file->f_op->write_iter)) {
- pr_notice("Cache does not support read_iter and write_iter\n");
- goto error_file;
- }
-
- fscache_get_retrieval(op);
- rreq->cache_resources.cache_priv = op;
- rreq->cache_resources.cache_priv2 = file;
- rreq->cache_resources.ops = &cachefiles_netfs_cache_ops;
- rreq->cache_resources.debug_id = object->fscache.debug_id;
- _leave("");
- return 0;
-
-error_file:
- fput(file);
- return -EIO;
-}