[PATCH 03/26] netfs: Update i_blocks when write committed to pagecache

David Howells
2024-03-28T16:35:23Z

Update i_blocks when i_size is updated when we finish making a write to the
pagecache to reflect the amount of space we think will be consumed.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Steve French <sfrench@samba.org>
cc: Shyam Prasad N <nspmangalore@gmail.com>
cc: Rohith Surabattula <rohiths.msft@gmail.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
---
fs/netfs/buffered_write.c | 45 +++++++++++++++++++++++++++++----------
1 file changed, 34 insertions(+), 11 deletions(-)

diff --git a/fs/netfs/buffered_write.c b/fs/netfs/buffered_write.c
index 9a0d32e4b422..c194655a6dcf 100644
--- a/fs/netfs/buffered_write.c
+++ b/fs/netfs/buffered_write.c
@@ -130,6 +130,37 @@ static struct folio *netfs_grab_folio_for_write(struct address_space *mapping,
mapping_gfp_mask(mapping));
}

+/*
+ * Update i_size and estimate the update to i_blocks to reflect the additional
+ * data written into the pagecache until we can find out from the server what
+ * the values actually are.
+ */
+static void netfs_update_i_size(struct netfs_inode *ctx, struct inode *inode,
+ loff_t i_size, loff_t pos, size_t copied)
+{
+ blkcnt_t add;
+ size_t gap;
+
+ if (ctx->ops->update_i_size) {
+ ctx->ops->update_i_size(inode, pos);
+ return;
+ }
+
+ i_size_write(inode, pos);
+#if IS_ENABLED(CONFIG_FSCACHE)
+ fscache_update_cookie(ctx->cache, NULL, &pos);
+#endif
+
+ gap = SECTOR_SIZE - (i_size & (SECTOR_SIZE - 1));
+ if (copied > gap) {
+ add = DIV_ROUND_UP(copied - gap, SECTOR_SIZE);
+
+ inode->i_blocks = min_t(blkcnt_t,
+ DIV_ROUND_UP(pos, SECTOR_SIZE),
+ inode->i_blocks + add);
+ }
+}
+
/**
* netfs_perform_write - Copy data into the pagecache.
* @iocb: The operation parameters
@@ -352,18 +383,10 @@ ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
trace_netfs_folio(folio, trace);

/* Update the inode size if we moved the EOF marker */
- i_size = i_size_read(inode);
pos += copied;
- if (pos > i_size) {
- if (ctx->ops->update_i_size) {
- ctx->ops->update_i_size(inode, pos);
- } else {
- i_size_write(inode, pos);
-#if IS_ENABLED(CONFIG_FSCACHE)
- fscache_update_cookie(ctx->cache, NULL, &pos);
-#endif
- }
- }
+ i_size = i_size_read(inode);
+ if (pos > i_size)
+ netfs_update_i_size(ctx, inode, i_size, pos, copied);
written += copied;

if (likely(!wreq)) {