[PATCH v3 1/1] PNFS fix dangling DS mount
From: Olga Kornievskaia <hidden>
Date: 2017-06-30 20:05:20
Also in:
linux-fsdevel
Subsystem:
filesystems (vfs and infrastructure), nfs, sunrpc, and lockd clients, the rest · Maintainers:
Alexander Viro, Christian Brauner, Trond Myklebust, Anna Schumaker, Linus Torvalds
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 <redacted>
---
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,
--
1.8.3.1