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authorDavid Howells <dhowells@redhat.com>2022-01-14 18:39:55 +0100
committerDavid Howells <dhowells@redhat.com>2023-12-28 10:45:23 +0100
commit016dc8516aec8719641e7aaaacd78d344759178e (patch)
tree15cc93a54ddfa05ffc558b1bff50aa655ce926ce /mm
parentnetfs: Allocate multipage folios in the writepath (diff)
downloadlinux-016dc8516aec8719641e7aaaacd78d344759178e.tar.xz
linux-016dc8516aec8719641e7aaaacd78d344759178e.zip
netfs: Implement unbuffered/DIO read support
Implement support for unbuffered and DIO reads in the netfs library, utilising the existing read helper code to do block splitting and individual queuing. The code also handles extraction of the destination buffer from the supplied iterator, allowing async unbuffered reads to take place. The read will be split up according to the rsize setting and, if supplied, the ->clamp_length() method. Note that the next subrequest will be issued as soon as issue_op returns, without waiting for previous ones to finish. The network filesystem needs to pause or handle queuing them if it doesn't want to fire them all at the server simultaneously. Once all the subrequests have finished, the state will be assessed and the amount of data to be indicated as having being obtained will be determined. As the subrequests may finish in any order, if an intermediate subrequest is short, any further subrequests may be copied into the buffer and then abandoned. In the future, this will also take care of doing an unbuffered read from encrypted content, with the decryption being done by the library. Signed-off-by: David Howells <dhowells@redhat.com> cc: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org
Diffstat (limited to 'mm')
-rw-r--r--mm/filemap.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/mm/filemap.c b/mm/filemap.c
index f1c8c278310f..1c5271ed0cc0 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2678,6 +2678,7 @@ int kiocb_write_and_wait(struct kiocb *iocb, size_t count)
return filemap_write_and_wait_range(mapping, pos, end);
}
+EXPORT_SYMBOL_GPL(kiocb_write_and_wait);
int kiocb_invalidate_pages(struct kiocb *iocb, size_t count)
{