linux-nfs.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jeff Layton <jlayton@poochiereds.net>
To: Trond Myklebust <trondmy@primarydata.com>,
	Anna Schumaker <Anna.Schumaker@netapp.com>
Cc: Thomas Haynes <loghyr@primarydata.com>,
	linux-nfs@vger.kernel.org, hch@lst.de
Subject: [PATCH v4 09/13] flexfiles: add kerneldoc header to nfs4_ff_layout_prepare_ds
Date: Tue, 17 May 2016 12:28:44 -0400	[thread overview]
Message-ID: <1463502528-11519-10-git-send-email-jeff.layton@primarydata.com> (raw)
In-Reply-To: <1463502528-11519-1-git-send-email-jeff.layton@primarydata.com>

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
---
 fs/nfs/flexfilelayout/flexfilelayoutdev.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/fs/nfs/flexfilelayout/flexfilelayoutdev.c b/fs/nfs/flexfilelayout/flexfilelayoutdev.c
index 5532cb14e800..b70133de9505 100644
--- a/fs/nfs/flexfilelayout/flexfilelayoutdev.c
+++ b/fs/nfs/flexfilelayout/flexfilelayoutdev.c
@@ -342,7 +342,23 @@ out:
 	return fh;
 }
 
-/* Upon return, either ds is connected, or ds is NULL */
+/**
+ * nfs4_ff_layout_prepare_ds - prepare a DS connection for an RPC call
+ * @lseg: the layout segment we're operating on
+ * @ds_idx: index of the DS to use
+ * @fail_return: return layout on connect failure?
+ *
+ * Try to prepare a DS connection to accept an RPC call. This involves
+ * selecting a mirror to use and connecting the client to it if it's not
+ * already connected.
+ *
+ * Since we only need a single functioning mirror to satisfy a read, we don't
+ * want to return the layout if there is one. For writes though, any down
+ * mirror should result in a LAYOUTRETURN. @fail_return is how we distinguish
+ * between the two cases.
+ *
+ * Returns a pointer to a connected DS object on success or NULL on failure.
+ */
 struct nfs4_pnfs_ds *
 nfs4_ff_layout_prepare_ds(struct pnfs_layout_segment *lseg, u32 ds_idx,
 			  bool fail_return)
-- 
2.5.5


  parent reply	other threads:[~2016-05-17 16:29 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-17 16:28 [PATCH v4 00/13] pnfs: layout pipelining and related fixes Jeff Layton
2016-05-17 16:28 ` [PATCH v4 01/13] pNFS/flexfile: Fix erroneous fall back to read/write through the MDS Jeff Layton
2016-05-17 16:28 ` [PATCH v4 02/13] pNFS/flexfiles: When checking for available DSes, conditionally check for MDS io Jeff Layton
2016-05-17 16:28 ` [PATCH v4 03/13] pNFS/flexfiles: When initing reads or writes, we might have to retry connecting to DSes Jeff Layton
2016-05-17 16:28 ` [PATCH v4 04/13] pnfs: don't merge new ff lsegs with ones that have LAYOUTRETURN bit set Jeff Layton
2016-05-17 16:28 ` [PATCH v4 05/13] pnfs: record sequence in pnfs_layout_segment when it's created Jeff Layton
2016-05-17 16:28 ` [PATCH v4 06/13] pnfs: keep track of the return sequence number in pnfs_layout_hdr Jeff Layton
2016-05-17 16:28 ` [PATCH v4 07/13] pnfs: only tear down lsegs that precede seqid in LAYOUTRETURN args Jeff Layton
2016-05-17 16:28 ` [PATCH v4 08/13] flexfiles: remove pointless setting of NFS_LAYOUT_RETURN_REQUESTED Jeff Layton
2016-05-17 16:28 ` Jeff Layton [this message]
2016-05-17 16:28 ` [PATCH v4 10/13] pnfs: fix bad error handling in send_layoutget Jeff Layton
2016-05-17 16:28 ` [PATCH v4 11/13] pnfs: lift retry logic from send_layoutget to pnfs_update_layout Jeff Layton
2016-05-17 16:28 ` [PATCH v4 12/13] pnfs: rework LAYOUTGET retry handling Jeff Layton
2016-06-28 12:10   ` Andrew W Elble
2016-06-28 12:22     ` Jeff Layton
2016-06-28 12:53       ` Andrew W Elble
2016-06-28 12:55         ` Trond Myklebust
2016-06-28 13:09         ` Jeff Layton
2016-05-17 16:28 ` [PATCH v4 13/13] pnfs: make pnfs_layout_process more robust Jeff Layton

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1463502528-11519-10-git-send-email-jeff.layton@primarydata.com \
    --to=jlayton@poochiereds.net \
    --cc=Anna.Schumaker@netapp.com \
    --cc=hch@lst.de \
    --cc=linux-nfs@vger.kernel.org \
    --cc=loghyr@primarydata.com \
    --cc=trondmy@primarydata.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).