vers 2 fixes unused var found by buildbot.
Patch 1 fixes an issue seen when using libaio with directio where if a read
is retried (ie due to recalled layout) we return too many bytes.
Specifically, we returned a multiple of the read size.
To reproduce, run fio with ioengine=libaio and direct=1, then revoke the
active layout. This should hit pretty easily.
Patch 2 should help notice similar issues elsewhere.
Weston Andros Adamson (2):
pnfs: set NFS_IOHDR_REDO in pnfs_read_resend_pnfs
nfs: add debug to directio "good_bytes" counting
fs/nfs/direct.c | 7 +++++--
fs/nfs/pnfs.c | 14 ++++++++------
fs/nfs/pnfs.h | 2 +-
3 files changed, 14 insertions(+), 9 deletions(-)
--
2.6.4 (Apple Git-63)
Like other resend paths, mark the (old) hdr as NFS_IOHDR_REDO. This
ensures the hdr completion function will not count the (old) hdr
as good bytes.
Also, vector the error back through the hdr->task.tk_status like other
retry calls.
This fixes a bug with the FlexFiles layout where libaio was reporting more
bytes read than requested.
Signed-off-by: Weston Andros Adamson <[email protected]>
---
fs/nfs/pnfs.c | 14 ++++++++------
fs/nfs/pnfs.h | 2 +-
2 files changed, 9 insertions(+), 7 deletions(-)
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 2fa483e6dbe2..15e5a8b3babf 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -2143,12 +2143,15 @@ pnfs_try_to_read_data(struct nfs_pgio_header *hdr,
}
/* Resend all requests through pnfs. */
-int pnfs_read_resend_pnfs(struct nfs_pgio_header *hdr)
+void pnfs_read_resend_pnfs(struct nfs_pgio_header *hdr)
{
struct nfs_pageio_descriptor pgio;
- nfs_pageio_init_read(&pgio, hdr->inode, false, hdr->completion_ops);
- return nfs_pageio_resend(&pgio, hdr);
+ if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
+ nfs_pageio_init_read(&pgio, hdr->inode, false,
+ hdr->completion_ops);
+ hdr->task.tk_status = nfs_pageio_resend(&pgio, hdr);
+ }
}
EXPORT_SYMBOL_GPL(pnfs_read_resend_pnfs);
@@ -2158,12 +2161,11 @@ pnfs_do_read(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr)
const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
struct pnfs_layout_segment *lseg = desc->pg_lseg;
enum pnfs_try_status trypnfs;
- int err = 0;
trypnfs = pnfs_try_to_read_data(hdr, call_ops, lseg);
if (trypnfs == PNFS_TRY_AGAIN)
- err = pnfs_read_resend_pnfs(hdr);
- if (trypnfs == PNFS_NOT_ATTEMPTED || err)
+ pnfs_read_resend_pnfs(hdr);
+ if (trypnfs == PNFS_NOT_ATTEMPTED || hdr->task.tk_status)
pnfs_read_through_mds(desc, hdr);
}
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 1ac1db5f6dad..7222d3a35439 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -282,7 +282,7 @@ int _pnfs_return_layout(struct inode *);
int pnfs_commit_and_return_layout(struct inode *);
void pnfs_ld_write_done(struct nfs_pgio_header *);
void pnfs_ld_read_done(struct nfs_pgio_header *);
-int pnfs_read_resend_pnfs(struct nfs_pgio_header *);
+void pnfs_read_resend_pnfs(struct nfs_pgio_header *);
struct pnfs_layout_segment *pnfs_update_layout(struct inode *ino,
struct nfs_open_context *ctx,
loff_t pos,
--
2.6.4 (Apple Git-63)
This will pop a warning if we count too many good bytes.
Signed-off-by: Weston Andros Adamson <[email protected]>
---
fs/nfs/direct.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 7a0cfd3266e5..5a31f2928530 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -87,6 +87,7 @@ struct nfs_direct_req {
int mirror_count;
ssize_t count, /* bytes actually processed */
+ max_count, /* max expected count */
bytes_left, /* bytes left to be sent */
io_start, /* start of IO */
error; /* any reported error */
@@ -123,6 +124,8 @@ nfs_direct_good_bytes(struct nfs_direct_req *dreq, struct nfs_pgio_header *hdr)
int i;
ssize_t count;
+ WARN_ON_ONCE(dreq->count >= dreq->max_count);
+
if (dreq->mirror_count == 1) {
dreq->mirrors[hdr->pgio_mirror_idx].count += hdr->good_bytes;
dreq->count += hdr->good_bytes;
@@ -593,7 +596,7 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter,
goto out_unlock;
dreq->inode = inode;
- dreq->bytes_left = count;
+ dreq->bytes_left = dreq->max_count = count;
dreq->io_start = pos;
dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp));
l_ctx = nfs_get_lock_context(dreq->ctx);
@@ -1026,7 +1029,7 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter)
goto out_unlock;
dreq->inode = inode;
- dreq->bytes_left = iov_iter_count(iter);
+ dreq->bytes_left = dreq->max_count = iov_iter_count(iter);
dreq->io_start = pos;
dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp));
l_ctx = nfs_get_lock_context(dreq->ctx);
--
2.6.4 (Apple Git-63)