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-rw-r--r--fs/netfs/buffered_write.c69
-rw-r--r--fs/netfs/internal.h3
-rw-r--r--fs/netfs/main.c1
-rw-r--r--fs/netfs/objects.c1
-rw-r--r--fs/netfs/output.c90
-rw-r--r--include/linux/netfs.h2
-rw-r--r--include/trace/events/netfs.h8
7 files changed, 162 insertions, 12 deletions
diff --git a/fs/netfs/buffered_write.c b/fs/netfs/buffered_write.c
index 50be8fe3ca43..6ca6c4bde5eb 100644
--- a/fs/netfs/buffered_write.c
+++ b/fs/netfs/buffered_write.c
@@ -26,6 +26,8 @@ enum netfs_how_to_modify {
NETFS_FLUSH_CONTENT, /* Flush incompatible content. */
};
+static void netfs_cleanup_buffered_write(struct netfs_io_request *wreq);
+
static void netfs_set_group(struct folio *folio, struct netfs_group *netfs_group)
{
if (netfs_group && !folio_get_private(folio))
@@ -133,6 +135,14 @@ ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
struct inode *inode = file_inode(file);
struct address_space *mapping = inode->i_mapping;
struct netfs_inode *ctx = netfs_inode(inode);
+ struct writeback_control wbc = {
+ .sync_mode = WB_SYNC_NONE,
+ .for_sync = true,
+ .nr_to_write = LONG_MAX,
+ .range_start = iocb->ki_pos,
+ .range_end = iocb->ki_pos + iter->count,
+ };
+ struct netfs_io_request *wreq = NULL;
struct netfs_folio *finfo;
struct folio *folio;
enum netfs_how_to_modify howto;
@@ -143,6 +153,30 @@ ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
size_t max_chunk = PAGE_SIZE << MAX_PAGECACHE_ORDER;
bool maybe_trouble = false;
+ if (unlikely(test_bit(NETFS_ICTX_WRITETHROUGH, &ctx->flags) ||
+ iocb->ki_flags & (IOCB_DSYNC | IOCB_SYNC))
+ ) {
+ if (pos < i_size_read(inode)) {
+ ret = filemap_write_and_wait_range(mapping, pos, pos + iter->count);
+ if (ret < 0) {
+ goto out;
+ }
+ }
+
+ wbc_attach_fdatawrite_inode(&wbc, mapping->host);
+
+ wreq = netfs_begin_writethrough(iocb, iter->count);
+ if (IS_ERR(wreq)) {
+ wbc_detach_inode(&wbc);
+ ret = PTR_ERR(wreq);
+ wreq = NULL;
+ goto out;
+ }
+ if (!is_sync_kiocb(iocb))
+ wreq->iocb = iocb;
+ wreq->cleanup = netfs_cleanup_buffered_write;
+ }
+
do {
size_t flen;
size_t offset; /* Offset into pagecache folio */
@@ -315,7 +349,25 @@ ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
}
written += copied;
- folio_mark_dirty(folio);
+ if (likely(!wreq)) {
+ folio_mark_dirty(folio);
+ } else {
+ if (folio_test_dirty(folio))
+ /* Sigh. mmap. */
+ folio_clear_dirty_for_io(folio);
+ /* We make multiple writes to the folio... */
+ if (!folio_test_writeback(folio)) {
+ folio_wait_fscache(folio);
+ folio_start_writeback(folio);
+ folio_start_fscache(folio);
+ if (wreq->iter.count == 0)
+ trace_netfs_folio(folio, netfs_folio_trace_wthru);
+ else
+ trace_netfs_folio(folio, netfs_folio_trace_wthru_plus);
+ }
+ netfs_advance_writethrough(wreq, copied,
+ offset + copied == flen);
+ }
retry:
folio_unlock(folio);
folio_put(folio);
@@ -325,17 +377,14 @@ ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
} while (iov_iter_count(iter));
out:
- if (likely(written)) {
- /* Flush and wait for a write that requires immediate synchronisation. */
- if (iocb->ki_flags & (IOCB_DSYNC | IOCB_SYNC)) {
- _debug("dsync");
- ret = filemap_fdatawait_range(mapping, iocb->ki_pos,
- iocb->ki_pos + written);
- }
-
- iocb->ki_pos += written;
+ if (unlikely(wreq)) {
+ ret = netfs_end_writethrough(wreq, iocb);
+ wbc_detach_inode(&wbc);
+ if (ret == -EIOCBQUEUED)
+ return ret;
}
+ iocb->ki_pos += written;
_leave(" = %zd [%zd]", written, ret);
return written ? written : ret;
diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h
index 2de4f826dbe4..d2d63120ac60 100644
--- a/fs/netfs/internal.h
+++ b/fs/netfs/internal.h
@@ -101,6 +101,9 @@ static inline void netfs_see_request(struct netfs_io_request *rreq,
*/
int netfs_begin_write(struct netfs_io_request *wreq, bool may_wait,
enum netfs_write_trace what);
+struct netfs_io_request *netfs_begin_writethrough(struct kiocb *iocb, size_t len);
+int netfs_advance_writethrough(struct netfs_io_request *wreq, size_t copied, bool to_page_end);
+int netfs_end_writethrough(struct netfs_io_request *wreq, struct kiocb *iocb);
/*
* stats.c
diff --git a/fs/netfs/main.c b/fs/netfs/main.c
index 473f889e1bd1..81a13071b258 100644
--- a/fs/netfs/main.c
+++ b/fs/netfs/main.c
@@ -30,6 +30,7 @@ static const char *netfs_origins[nr__netfs_io_origin] = {
[NETFS_READPAGE] = "RP",
[NETFS_READ_FOR_WRITE] = "RW",
[NETFS_WRITEBACK] = "WB",
+ [NETFS_WRITETHROUGH] = "WT",
[NETFS_LAUNDER_WRITE] = "LW",
[NETFS_UNBUFFERED_WRITE] = "UW",
[NETFS_DIO_READ] = "DR",
diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c
index b4e3bd836e5d..610ceb5bd86c 100644
--- a/fs/netfs/objects.c
+++ b/fs/netfs/objects.c
@@ -41,6 +41,7 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
rreq->i_size = i_size_read(inode);
rreq->debug_id = atomic_inc_return(&debug_ids);
INIT_LIST_HEAD(&rreq->subrequests);
+ INIT_WORK(&rreq->work, NULL);
refcount_set(&rreq->ref, 1);
__set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
diff --git a/fs/netfs/output.c b/fs/netfs/output.c
index cc9065733b42..625eb68f3e5a 100644
--- a/fs/netfs/output.c
+++ b/fs/netfs/output.c
@@ -386,3 +386,93 @@ int netfs_begin_write(struct netfs_io_request *wreq, bool may_wait,
TASK_UNINTERRUPTIBLE);
return wreq->error;
}
+
+/*
+ * Begin a write operation for writing through the pagecache.
+ */
+struct netfs_io_request *netfs_begin_writethrough(struct kiocb *iocb, size_t len)
+{
+ struct netfs_io_request *wreq;
+ struct file *file = iocb->ki_filp;
+
+ wreq = netfs_alloc_request(file->f_mapping, file, iocb->ki_pos, len,
+ NETFS_WRITETHROUGH);
+ if (IS_ERR(wreq))
+ return wreq;
+
+ trace_netfs_write(wreq, netfs_write_trace_writethrough);
+
+ __set_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags);
+ iov_iter_xarray(&wreq->iter, ITER_SOURCE, &wreq->mapping->i_pages, wreq->start, 0);
+ wreq->io_iter = wreq->iter;
+
+ /* ->outstanding > 0 carries a ref */
+ netfs_get_request(wreq, netfs_rreq_trace_get_for_outstanding);
+ atomic_set(&wreq->nr_outstanding, 1);
+ return wreq;
+}
+
+static void netfs_submit_writethrough(struct netfs_io_request *wreq, bool final)
+{
+ struct netfs_inode *ictx = netfs_inode(wreq->inode);
+ unsigned long long start;
+ size_t len;
+
+ if (!test_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags))
+ return;
+
+ start = wreq->start + wreq->submitted;
+ len = wreq->iter.count - wreq->submitted;
+ if (!final) {
+ len /= wreq->wsize; /* Round to number of maximum packets */
+ len *= wreq->wsize;
+ }
+
+ ictx->ops->create_write_requests(wreq, start, len);
+ wreq->submitted += len;
+}
+
+/*
+ * Advance the state of the write operation used when writing through the
+ * pagecache. Data has been copied into the pagecache that we need to append
+ * to the request. If we've added more than wsize then we need to create a new
+ * subrequest.
+ */
+int netfs_advance_writethrough(struct netfs_io_request *wreq, size_t copied, bool to_page_end)
+{
+ _enter("ic=%zu sb=%zu ws=%u cp=%zu tp=%u",
+ wreq->iter.count, wreq->submitted, wreq->wsize, copied, to_page_end);
+
+ wreq->iter.count += copied;
+ wreq->io_iter.count += copied;
+ if (to_page_end && wreq->io_iter.count - wreq->submitted >= wreq->wsize)
+ netfs_submit_writethrough(wreq, false);
+
+ return wreq->error;
+}
+
+/*
+ * End a write operation used when writing through the pagecache.
+ */
+int netfs_end_writethrough(struct netfs_io_request *wreq, struct kiocb *iocb)
+{
+ int ret = -EIOCBQUEUED;
+
+ _enter("ic=%zu sb=%zu ws=%u",
+ wreq->iter.count, wreq->submitted, wreq->wsize);
+
+ if (wreq->submitted < wreq->io_iter.count)
+ netfs_submit_writethrough(wreq, true);
+
+ if (atomic_dec_and_test(&wreq->nr_outstanding))
+ netfs_write_terminated(wreq, false);
+
+ if (is_sync_kiocb(iocb)) {
+ wait_on_bit(&wreq->flags, NETFS_RREQ_IN_PROGRESS,
+ TASK_UNINTERRUPTIBLE);
+ ret = wreq->error;
+ }
+
+ netfs_put_request(wreq, false, netfs_rreq_trace_put_return);
+ return ret;
+}
diff --git a/include/linux/netfs.h b/include/linux/netfs.h
index 29c66acad925..8a2dd882a781 100644
--- a/include/linux/netfs.h
+++ b/include/linux/netfs.h
@@ -139,6 +139,7 @@ struct netfs_inode {
unsigned long flags;
#define NETFS_ICTX_ODIRECT 0 /* The file has DIO in progress */
#define NETFS_ICTX_UNBUFFERED 1 /* I/O should not use the pagecache */
+#define NETFS_ICTX_WRITETHROUGH 2 /* Write-through caching */
};
/*
@@ -227,6 +228,7 @@ enum netfs_io_origin {
NETFS_READPAGE, /* This read is a synchronous read */
NETFS_READ_FOR_WRITE, /* This read is to prepare a write */
NETFS_WRITEBACK, /* This write was triggered by writepages */
+ NETFS_WRITETHROUGH, /* This write was made by netfs_perform_write() */
NETFS_LAUNDER_WRITE, /* This is triggered by ->launder_folio() */
NETFS_UNBUFFERED_WRITE, /* This is an unbuffered write */
NETFS_DIO_READ, /* This is a direct I/O read */
diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h
index cc998798e20a..447a8c21cf57 100644
--- a/include/trace/events/netfs.h
+++ b/include/trace/events/netfs.h
@@ -27,13 +27,15 @@
EM(netfs_write_trace_dio_write, "DIO-WRITE") \
EM(netfs_write_trace_launder, "LAUNDER ") \
EM(netfs_write_trace_unbuffered_write, "UNB-WRITE") \
- E_(netfs_write_trace_writeback, "WRITEBACK")
+ EM(netfs_write_trace_writeback, "WRITEBACK") \
+ E_(netfs_write_trace_writethrough, "WRITETHRU")
#define netfs_rreq_origins \
EM(NETFS_READAHEAD, "RA") \
EM(NETFS_READPAGE, "RP") \
EM(NETFS_READ_FOR_WRITE, "RW") \
EM(NETFS_WRITEBACK, "WB") \
+ EM(NETFS_WRITETHROUGH, "WT") \
EM(NETFS_LAUNDER_WRITE, "LW") \
EM(NETFS_UNBUFFERED_WRITE, "UW") \
EM(NETFS_DIO_READ, "DR") \
@@ -136,7 +138,9 @@
EM(netfs_folio_trace_redirty, "redirty") \
EM(netfs_folio_trace_redirtied, "redirtied") \
EM(netfs_folio_trace_store, "store") \
- E_(netfs_folio_trace_store_plus, "store+")
+ EM(netfs_folio_trace_store_plus, "store+") \
+ EM(netfs_folio_trace_wthru, "wthru") \
+ E_(netfs_folio_trace_wthru_plus, "wthru+")
#ifndef __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY
#define __NETFS_DECLARE_TRACE_ENUMS_ONCE_ONLY