diff options
| author | Jeff Layton <jlayton@poochiereds.net> | 2015-11-25 21:43:14 +0300 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@primarydata.com> | 2015-11-25 23:32:13 +0300 |
| commit | 4f2e9dce0c6348a95eaa56ade9bab18572221088 (patch) | |
| tree | 2e208da8a6585afccab9d942f3fed755073efafe /fs/nfs | |
| parent | c812012f9ca7cf89c9e1a1cd512e6c3b5be04b85 (diff) | |
| download | linux-4f2e9dce0c6348a95eaa56ade9bab18572221088.tar.xz | |
nfs4: resend LAYOUTGET when there is a race that changes the seqid
pnfs_layout_process will check the returned layout stateid against what
the kernel has in-core. If it turns out that the stateid we received is
older, then we should resend the LAYOUTGET instead of falling back to
MDS I/O.
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Cc: stable@vger.kernel.org # 3.18+
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Diffstat (limited to 'fs/nfs')
| -rw-r--r-- | fs/nfs/pnfs.c | 56 |
1 files changed, 31 insertions, 25 deletions
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index 93496c059837..5a8ae2125b50 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -872,33 +872,38 @@ send_layoutget(struct pnfs_layout_hdr *lo, dprintk("--> %s\n", __func__); - lgp = kzalloc(sizeof(*lgp), gfp_flags); - if (lgp == NULL) - return NULL; + /* + * Synchronously retrieve layout information from server and + * store in lseg. If we race with a concurrent seqid morphing + * op, then re-send the LAYOUTGET. + */ + do { + lgp = kzalloc(sizeof(*lgp), gfp_flags); + if (lgp == NULL) + return NULL; + + i_size = i_size_read(ino); + + lgp->args.minlength = PAGE_CACHE_SIZE; + if (lgp->args.minlength > range->length) + lgp->args.minlength = range->length; + if (range->iomode == IOMODE_READ) { + if (range->offset >= i_size) + lgp->args.minlength = 0; + else if (i_size - range->offset < lgp->args.minlength) + lgp->args.minlength = i_size - range->offset; + } + lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE; + lgp->args.range = *range; + lgp->args.type = server->pnfs_curr_ld->id; + lgp->args.inode = ino; + lgp->args.ctx = get_nfs_open_context(ctx); + lgp->gfp_flags = gfp_flags; + lgp->cred = lo->plh_lc_cred; - i_size = i_size_read(ino); + lseg = nfs4_proc_layoutget(lgp, gfp_flags); + } while (lseg == ERR_PTR(-EAGAIN)); - lgp->args.minlength = PAGE_CACHE_SIZE; - if (lgp->args.minlength > range->length) - lgp->args.minlength = range->length; - if (range->iomode == IOMODE_READ) { - if (range->offset >= i_size) - lgp->args.minlength = 0; - else if (i_size - range->offset < lgp->args.minlength) - lgp->args.minlength = i_size - range->offset; - } - lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE; - lgp->args.range = *range; - lgp->args.type = server->pnfs_curr_ld->id; - lgp->args.inode = ino; - lgp->args.ctx = get_nfs_open_context(ctx); - lgp->gfp_flags = gfp_flags; - lgp->cred = lo->plh_lc_cred; - - /* Synchronously retrieve layout information from server and - * store in lseg. - */ - lseg = nfs4_proc_layoutget(lgp, gfp_flags); if (IS_ERR(lseg)) { switch (PTR_ERR(lseg)) { case -ENOMEM: @@ -1687,6 +1692,7 @@ pnfs_layout_process(struct nfs4_layoutget *lgp) /* existing state ID, make sure the sequence number matches. */ if (pnfs_layout_stateid_blocked(lo, &res->stateid)) { dprintk("%s forget reply due to sequence\n", __func__); + status = -EAGAIN; goto out_forget_reply; } pnfs_set_layout_stateid(lo, &res->stateid, false); |