diff options
author | David Howells <dhowells@redhat.com> | 2022-02-21 12:38:17 +0100 |
---|---|---|
committer | David Howells <dhowells@redhat.com> | 2023-12-28 10:45:24 +0100 |
commit | 153a9961b551101cd38e94e26cd92fbfd198b19b (patch) | |
tree | 4d45c248dbdaf8ded00848164de353f239f8bac9 /fs | |
parent | netfs: Implement unbuffered/DIO read support (diff) | |
download | linux-153a9961b551101cd38e94e26cd92fbfd198b19b.tar.xz linux-153a9961b551101cd38e94e26cd92fbfd198b19b.zip |
netfs: Implement unbuffered/DIO write support
Implement support for unbuffered writes and direct I/O writes. If the
write is misaligned with respect to the fscrypt block size, then RMW cycles
are performed if necessary. DIO writes are a special case of unbuffered
writes with extra restriction imposed, such as block size alignment
requirements.
Also provide a field that can tell the code to add some extra space onto
the bounce buffer for use by the filesystem in the case of a
content-encrypted file.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Diffstat (limited to 'fs')
-rw-r--r-- | fs/afs/inode.c | 2 | ||||
-rw-r--r-- | fs/netfs/Makefile | 1 | ||||
-rw-r--r-- | fs/netfs/direct_write.c | 166 | ||||
-rw-r--r-- | fs/netfs/internal.h | 6 | ||||
-rw-r--r-- | fs/netfs/io.c | 2 | ||||
-rw-r--r-- | fs/netfs/main.c | 12 | ||||
-rw-r--r-- | fs/netfs/objects.c | 6 | ||||
-rw-r--r-- | fs/netfs/output.c | 30 |
8 files changed, 216 insertions, 9 deletions
diff --git a/fs/afs/inode.c b/fs/afs/inode.c index 6f375f0cf650..37485ae31471 100644 --- a/fs/afs/inode.c +++ b/fs/afs/inode.c @@ -250,7 +250,7 @@ static void afs_apply_status(struct afs_operation *op, * what's on the server. */ vnode->netfs.remote_i_size = status->size; - if (change_size) { + if (change_size || status->size > i_size_read(inode)) { afs_set_i_size(vnode, status->size); inode_set_ctime_to_ts(inode, t); inode_set_atime_to_ts(inode, t); diff --git a/fs/netfs/Makefile b/fs/netfs/Makefile index e968ab1eca40..d4d1d799819e 100644 --- a/fs/netfs/Makefile +++ b/fs/netfs/Makefile @@ -4,6 +4,7 @@ netfs-y := \ buffered_read.o \ buffered_write.o \ direct_read.o \ + direct_write.o \ io.o \ iterator.o \ locking.o \ diff --git a/fs/netfs/direct_write.c b/fs/netfs/direct_write.c new file mode 100644 index 000000000000..bb0c2718f57b --- /dev/null +++ b/fs/netfs/direct_write.c @@ -0,0 +1,166 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Unbuffered and direct write support. + * + * Copyright (C) 2023 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include <linux/export.h> +#include <linux/uio.h> +#include "internal.h" + +static void netfs_cleanup_dio_write(struct netfs_io_request *wreq) +{ + struct inode *inode = wreq->inode; + unsigned long long end = wreq->start + wreq->len; + + if (!wreq->error && + i_size_read(inode) < end) { + if (wreq->netfs_ops->update_i_size) + wreq->netfs_ops->update_i_size(inode, end); + else + i_size_write(inode, end); + } +} + +/* + * Perform an unbuffered write where we may have to do an RMW operation on an + * encrypted file. This can also be used for direct I/O writes. + */ +ssize_t netfs_unbuffered_write_iter_locked(struct kiocb *iocb, struct iov_iter *iter, + struct netfs_group *netfs_group) +{ + struct netfs_io_request *wreq; + unsigned long long start = iocb->ki_pos; + unsigned long long end = start + iov_iter_count(iter); + ssize_t ret, n; + bool async = !is_sync_kiocb(iocb); + + _enter(""); + + /* We're going to need a bounce buffer if what we transmit is going to + * be different in some way to the source buffer, e.g. because it gets + * encrypted/compressed or because it needs expanding to a block size. + */ + // TODO + + _debug("uw %llx-%llx", start, end); + + wreq = netfs_alloc_request(iocb->ki_filp->f_mapping, iocb->ki_filp, + start, end - start, + iocb->ki_flags & IOCB_DIRECT ? + NETFS_DIO_WRITE : NETFS_UNBUFFERED_WRITE); + if (IS_ERR(wreq)) + return PTR_ERR(wreq); + + { + /* If this is an async op and we're not using a bounce buffer, + * we have to save the source buffer as the iterator is only + * good until we return. In such a case, extract an iterator + * to represent as much of the the output buffer as we can + * manage. Note that the extraction might not be able to + * allocate a sufficiently large bvec array and may shorten the + * request. + */ + if (async || user_backed_iter(iter)) { + n = netfs_extract_user_iter(iter, wreq->len, &wreq->iter, 0); + if (n < 0) { + ret = n; + goto out; + } + wreq->direct_bv = (struct bio_vec *)wreq->iter.bvec; + wreq->direct_bv_count = n; + wreq->direct_bv_unpin = iov_iter_extract_will_pin(iter); + wreq->len = iov_iter_count(&wreq->iter); + } else { + wreq->iter = *iter; + } + + wreq->io_iter = wreq->iter; + } + + /* Copy the data into the bounce buffer and encrypt it. */ + // TODO + + /* Dispatch the write. */ + __set_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags); + if (async) + wreq->iocb = iocb; + wreq->cleanup = netfs_cleanup_dio_write; + ret = netfs_begin_write(wreq, is_sync_kiocb(iocb), + iocb->ki_flags & IOCB_DIRECT ? + netfs_write_trace_dio_write : + netfs_write_trace_unbuffered_write); + if (ret < 0) { + _debug("begin = %zd", ret); + goto out; + } + + if (!async) { + trace_netfs_rreq(wreq, netfs_rreq_trace_wait_ip); + wait_on_bit(&wreq->flags, NETFS_RREQ_IN_PROGRESS, + TASK_UNINTERRUPTIBLE); + + ret = wreq->error; + _debug("waited = %zd", ret); + if (ret == 0) { + ret = wreq->transferred; + iocb->ki_pos += ret; + } + } else { + ret = -EIOCBQUEUED; + } + +out: + netfs_put_request(wreq, false, netfs_rreq_trace_put_return); + return ret; +} + +/** + * netfs_unbuffered_write_iter - Unbuffered write to a file + * @iocb: IO state structure + * @from: iov_iter with data to write + * + * Do an unbuffered write to a file, writing the data directly to the server + * and not lodging the data in the pagecache. + * + * Return: + * * Negative error code if no data has been written at all of + * vfs_fsync_range() failed for a synchronous write + * * Number of bytes written, even for truncated writes + */ +ssize_t netfs_unbuffered_write_iter(struct kiocb *iocb, struct iov_iter *from) +{ + struct file *file = iocb->ki_filp; + struct inode *inode = file->f_mapping->host; + struct netfs_inode *ictx = netfs_inode(inode); + ssize_t ret; + + _enter("%llx,%zx,%llx", iocb->ki_pos, iov_iter_count(from), i_size_read(inode)); + + trace_netfs_write_iter(iocb, from); + + ret = netfs_start_io_direct(inode); + if (ret < 0) + return ret; + ret = generic_write_checks(iocb, from); + if (ret < 0) + goto out; + ret = file_remove_privs(file); + if (ret < 0) + goto out; + ret = file_update_time(file); + if (ret < 0) + goto out; + ret = kiocb_invalidate_pages(iocb, iov_iter_count(from)); + if (ret < 0) + goto out; + + fscache_invalidate(netfs_i_cookie(ictx), NULL, i_size_read(inode), + FSCACHE_INVAL_DIO_WRITE); + ret = netfs_unbuffered_write_iter_locked(iocb, from, NULL); +out: + netfs_end_io_direct(inode); + return ret; +} +EXPORT_SYMBOL(netfs_unbuffered_write_iter); diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h index 886c2e8f841f..2de4f826dbe4 100644 --- a/fs/netfs/internal.h +++ b/fs/netfs/internal.h @@ -27,6 +27,12 @@ int netfs_prefetch_for_write(struct file *file, struct folio *folio, size_t offset, size_t len); /* + * direct_write.c + */ +ssize_t netfs_unbuffered_write_iter_locked(struct kiocb *iocb, struct iov_iter *iter, + struct netfs_group *netfs_group); + +/* * io.c */ int netfs_begin_read(struct netfs_io_request *rreq, bool sync); diff --git a/fs/netfs/io.c b/fs/netfs/io.c index c972415c8aad..01c7ff27228e 100644 --- a/fs/netfs/io.c +++ b/fs/netfs/io.c @@ -645,7 +645,7 @@ static bool netfs_rreq_submit_slice(struct netfs_io_request *rreq, subreq->debug_index = (*_debug_index)++; subreq->start = rreq->start + rreq->submitted; - subreq->len = rreq->len - rreq->submitted; + subreq->len = io_iter->count; _debug("slice %llx,%zx,%zx", subreq->start, subreq->len, rreq->submitted); list_add_tail(&subreq->rreq_link, &rreq->subrequests); diff --git a/fs/netfs/main.c b/fs/netfs/main.c index abb8857486ee..8e4db9ff40c4 100644 --- a/fs/netfs/main.c +++ b/fs/netfs/main.c @@ -26,11 +26,13 @@ LIST_HEAD(netfs_io_requests); DEFINE_SPINLOCK(netfs_proc_lock); static const char *netfs_origins[nr__netfs_io_origin] = { - [NETFS_READAHEAD] = "RA", - [NETFS_READPAGE] = "RP", - [NETFS_READ_FOR_WRITE] = "RW", - [NETFS_WRITEBACK] = "WB", - [NETFS_DIO_READ] = "DR", + [NETFS_READAHEAD] = "RA", + [NETFS_READPAGE] = "RP", + [NETFS_READ_FOR_WRITE] = "RW", + [NETFS_WRITEBACK] = "WB", + [NETFS_UNBUFFERED_WRITE] = "UW", + [NETFS_DIO_READ] = "DR", + [NETFS_DIO_WRITE] = "DW", }; /* diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c index 7153f24e8034..93f1d7431199 100644 --- a/fs/netfs/objects.c +++ b/fs/netfs/objects.c @@ -20,8 +20,10 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping, struct inode *inode = file ? file_inode(file) : mapping->host; struct netfs_inode *ctx = netfs_inode(inode); struct netfs_io_request *rreq; - bool is_dio = (origin == NETFS_DIO_READ); - bool cached = is_dio && netfs_is_cache_enabled(ctx); + bool is_unbuffered = (origin == NETFS_UNBUFFERED_WRITE || + origin == NETFS_DIO_READ || + origin == NETFS_DIO_WRITE); + bool cached = !is_unbuffered && netfs_is_cache_enabled(ctx); int ret; rreq = kzalloc(ctx->ops->io_request_size ?: sizeof(struct netfs_io_request), diff --git a/fs/netfs/output.c b/fs/netfs/output.c index 2ad0fd8c32be..560cbcea0c0a 100644 --- a/fs/netfs/output.c +++ b/fs/netfs/output.c @@ -74,12 +74,22 @@ static void netfs_write_terminated(struct netfs_io_request *wreq, bool was_async { struct netfs_io_subrequest *subreq; struct netfs_inode *ctx = netfs_inode(wreq->inode); + size_t transferred = 0; _enter("R=%x[]", wreq->debug_id); trace_netfs_rreq(wreq, netfs_rreq_trace_write_done); list_for_each_entry(subreq, &wreq->subrequests, rreq_link) { + if (subreq->error || subreq->transferred == 0) + break; + transferred += subreq->transferred; + if (subreq->transferred < subreq->len) + break; + } + wreq->transferred = transferred; + + list_for_each_entry(subreq, &wreq->subrequests, rreq_link) { if (!subreq->error) continue; switch (subreq->source) { @@ -110,11 +120,28 @@ static void netfs_write_terminated(struct netfs_io_request *wreq, bool was_async wreq->cleanup(wreq); + if (wreq->origin == NETFS_DIO_WRITE && + wreq->mapping->nrpages) { + pgoff_t first = wreq->start >> PAGE_SHIFT; + pgoff_t last = (wreq->start + wreq->transferred - 1) >> PAGE_SHIFT; + invalidate_inode_pages2_range(wreq->mapping, first, last); + } + + if (wreq->origin == NETFS_DIO_WRITE) + inode_dio_end(wreq->inode); + _debug("finished"); trace_netfs_rreq(wreq, netfs_rreq_trace_wake_ip); clear_bit_unlock(NETFS_RREQ_IN_PROGRESS, &wreq->flags); wake_up_bit(&wreq->flags, NETFS_RREQ_IN_PROGRESS); + if (wreq->iocb) { + wreq->iocb->ki_pos += transferred; + if (wreq->iocb->ki_complete) + wreq->iocb->ki_complete( + wreq->iocb, wreq->error ? wreq->error : transferred); + } + netfs_clear_subrequests(wreq, was_async); netfs_put_request(wreq, was_async, netfs_rreq_trace_put_complete); } @@ -329,6 +356,9 @@ int netfs_begin_write(struct netfs_io_request *wreq, bool may_wait, return -EIO; } + if (wreq->origin == NETFS_DIO_WRITE) + inode_dio_begin(wreq->inode); + wreq->io_iter = wreq->iter; /* ->outstanding > 0 carries a ref */ |