On 06/30/2017 03:52 PM, Olga Kornievskaia wrote:
> There is a regression by commit 8d40b0f14846 ("NFS filelayout:call
> GETDEVICEINFO after pnfs_layout_process completes"). It leaves the
> DS mount dangling.
>
> Previously, filelayout_alloc_sec() would call filelayout_check_layout()
> which would call nfs4_find_get_deviceid which ups the count on the
> device_id. It's only called once and it's matched by the
> filelayout_free_lseg() that calls nfs4_fl_put_deviceid().
>
> After that patch, each read/write ends up calling nfs4_find_get_deviceid
> and there is no balance for that. Instead, do nfs4_fl_put_deviceid()
> in the filelayout's .pg_cleanup and remove it from filelayout_free_lseg.
>
> But we still need a reference to hold over the lifetime of the segment.
> For every new lseg that's created we need to take a reference on deviceid
> that uses it. It will be released in the "free_lseg" routine.
>
> Signed-off-by: Olga Kornievskaia <kolga@xxxxxxxxxx>
Tested-by: Steve Dickson <steved@xxxxxxxxxx>
steved.
> ---
> fs/nfs/filelayout/filelayout.c | 21 +++++++++++++++++----
> fs/nfs/flexfilelayout/flexfilelayout.c | 9 ++++++---
> fs/nfs/pnfs.c | 13 ++++++++++---
> fs/nfs/pnfs.h | 3 ++-
> 4 files changed, 35 insertions(+), 11 deletions(-)
>
> diff --git a/fs/nfs/filelayout/filelayout.c b/fs/nfs/filelayout/filelayout.c
> index 1cf85d6..86d694e 100644
> --- a/fs/nfs/filelayout/filelayout.c
> +++ b/fs/nfs/filelayout/filelayout.c
> @@ -909,9 +909,10 @@ static void _filelayout_free_lseg(struct nfs4_filelayout_segment *fl)
> struct pnfs_layout_hdr *lo;
> struct nfs4_filelayout_segment *fl;
> int status;
> + bool new_layout = false;
>
> lseg = pnfs_update_layout(ino, ctx, pos, count, iomode, strict_iomode,
> - gfp_flags);
> + gfp_flags, &new_layout);
> if (!lseg)
> lseg = ERR_PTR(-ENOMEM);
> if (IS_ERR(lseg))
> @@ -924,7 +925,8 @@ static void _filelayout_free_lseg(struct nfs4_filelayout_segment *fl)
> if (status) {
> pnfs_put_lseg(lseg);
> lseg = ERR_PTR(status);
> - }
> + } else if (new_layout)
> + nfs4_get_deviceid(&fl->dsaddr->id_node);
> out:
> return lseg;
> }
> @@ -991,18 +993,29 @@ static void _filelayout_free_lseg(struct nfs4_filelayout_segment *fl)
> nfs_pageio_reset_write_mds(pgio);
> }
>
> +static void filelayout_pg_cleanup(struct nfs_pageio_descriptor *desc)
> +{
> + if (desc->pg_lseg) {
> + struct nfs4_filelayout_segment *fl =
> + FILELAYOUT_LSEG(desc->pg_lseg);
> +
> + nfs4_fl_put_deviceid(fl->dsaddr);
> + }
> + pnfs_generic_pg_cleanup(desc);
> +}
> +
> static const struct nfs_pageio_ops filelayout_pg_read_ops = {
> .pg_init = filelayout_pg_init_read,
> .pg_test = filelayout_pg_test,
> .pg_doio = pnfs_generic_pg_readpages,
> - .pg_cleanup = pnfs_generic_pg_cleanup,
> + .pg_cleanup = filelayout_pg_cleanup,
> };
>
> static const struct nfs_pageio_ops filelayout_pg_write_ops = {
> .pg_init = filelayout_pg_init_write,
> .pg_test = filelayout_pg_test,
> .pg_doio = pnfs_generic_pg_writepages,
> - .pg_cleanup = pnfs_generic_pg_cleanup,
> + .pg_cleanup = filelayout_pg_cleanup,
> };
>
> static u32 select_bucket_index(struct nfs4_filelayout_segment *fl, u32 j)
> diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c b/fs/nfs/flexfilelayout/flexfilelayout.c
> index 23542dc..53a4a19 100644
> --- a/fs/nfs/flexfilelayout/flexfilelayout.c
> +++ b/fs/nfs/flexfilelayout/flexfilelayout.c
> @@ -820,7 +820,8 @@ static bool ff_layout_has_rw_segments(struct pnfs_layout_hdr *layout)
> NFS4_MAX_UINT64,
> IOMODE_READ,
> strict_iomode,
> - GFP_KERNEL);
> + GFP_KERNEL,
> + NULL);
> if (IS_ERR(pgio->pg_lseg)) {
> pgio->pg_error = PTR_ERR(pgio->pg_lseg);
> pgio->pg_lseg = NULL;
> @@ -904,7 +905,8 @@ static bool ff_layout_has_rw_segments(struct pnfs_layout_hdr *layout)
> NFS4_MAX_UINT64,
> IOMODE_RW,
> false,
> - GFP_NOFS);
> + GFP_NOFS,
> + NULL);
> if (IS_ERR(pgio->pg_lseg)) {
> pgio->pg_error = PTR_ERR(pgio->pg_lseg);
> pgio->pg_lseg = NULL;
> @@ -960,7 +962,8 @@ static bool ff_layout_has_rw_segments(struct pnfs_layout_hdr *layout)
> NFS4_MAX_UINT64,
> IOMODE_RW,
> false,
> - GFP_NOFS);
> + GFP_NOFS,
> + NULL);
> if (IS_ERR(pgio->pg_lseg)) {
> pgio->pg_error = PTR_ERR(pgio->pg_lseg);
> pgio->pg_lseg = NULL;
> diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
> index c383d09..fb011c6 100644
> --- a/fs/nfs/pnfs.c
> +++ b/fs/nfs/pnfs.c
> @@ -1698,7 +1698,8 @@ struct pnfs_layout_segment *
> u64 count,
> enum pnfs_iomode iomode,
> bool strict_iomode,
> - gfp_t gfp_flags)
> + gfp_t gfp_flags,
> + bool *new)
> {
> struct pnfs_layout_range arg = {
> .iomode = iomode,
> @@ -1764,8 +1765,12 @@ struct pnfs_layout_segment *
> if (lseg) {
> trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
> PNFS_UPDATE_LAYOUT_FOUND_CACHED);
> + if (new)
> + *new = false;
> goto out_unlock;
> }
> + if (new)
> + *new = true;
>
> if (!nfs4_valid_open_stateid(ctx->state)) {
> trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
> @@ -2126,7 +2131,8 @@ void pnfs_error_mark_layout_for_return(struct inode *inode,
> rd_size,
> IOMODE_READ,
> false,
> - GFP_KERNEL);
> + GFP_KERNEL,
> + NULL);
> if (IS_ERR(pgio->pg_lseg)) {
> pgio->pg_error = PTR_ERR(pgio->pg_lseg);
> pgio->pg_lseg = NULL;
> @@ -2153,7 +2159,8 @@ void pnfs_error_mark_layout_for_return(struct inode *inode,
> wb_size,
> IOMODE_RW,
> false,
> - GFP_NOFS);
> + GFP_NOFS,
> + NULL);
> if (IS_ERR(pgio->pg_lseg)) {
> pgio->pg_error = PTR_ERR(pgio->pg_lseg);
> pgio->pg_lseg = NULL;
> diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
> index 99731e3..978fab0 100644
> --- a/fs/nfs/pnfs.h
> +++ b/fs/nfs/pnfs.h
> @@ -291,7 +291,8 @@ struct pnfs_layout_segment *pnfs_update_layout(struct inode *ino,
> u64 count,
> enum pnfs_iomode iomode,
> bool strict_iomode,
> - gfp_t gfp_flags);
> + gfp_t gfp_flags,
> + bool *new);
> void pnfs_layoutreturn_free_lsegs(struct pnfs_layout_hdr *lo,
> const nfs4_stateid *arg_stateid,
> const struct pnfs_layout_range *range,
>
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