From 41963c10c47a35185e68cb9049f7a3493c94d2d7 Mon Sep 17 00:00:00 2001 From: Benjamin Coddington Date: Mon, 22 Aug 2016 14:11:16 -0400 Subject: pnfs/blocklayout: update last_write_offset atomically with extents Block/SCSI layout write completion may add committable extents to the extent tree before updating the layout's last-written byte under the inode lock. If a sync happens before this value is updated, then prepare_layoutcommit may find and encode these extents which would produce a LAYOUTCOMMIT request whose encoded extents are larger than the request's loca_length. Fix this by using a last-written byte value that is updated atomically with the extent tree so that commitable extents always match. Signed-off-by: Benjamin Coddington Signed-off-by: Trond Myklebust --- fs/nfs/blocklayout/blocklayout.c | 2 +- fs/nfs/blocklayout/blocklayout.h | 3 ++- fs/nfs/blocklayout/extent_tree.c | 10 +++++++--- 3 files changed, 10 insertions(+), 5 deletions(-) (limited to 'fs/nfs/blocklayout') diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c index f55a4e756047..217847679f0e 100644 --- a/fs/nfs/blocklayout/blocklayout.c +++ b/fs/nfs/blocklayout/blocklayout.c @@ -346,7 +346,7 @@ static void bl_write_cleanup(struct work_struct *work) PAGE_SIZE - 1) & (loff_t)PAGE_MASK; ext_tree_mark_written(bl, start >> SECTOR_SHIFT, - (end - start) >> SECTOR_SHIFT); + (end - start) >> SECTOR_SHIFT, end); } pnfs_ld_write_done(hdr); diff --git a/fs/nfs/blocklayout/blocklayout.h b/fs/nfs/blocklayout/blocklayout.h index 18e6fd0b9506..efc007f00742 100644 --- a/fs/nfs/blocklayout/blocklayout.h +++ b/fs/nfs/blocklayout/blocklayout.h @@ -141,6 +141,7 @@ struct pnfs_block_layout { struct rb_root bl_ext_ro; spinlock_t bl_ext_lock; /* Protects list manipulation */ bool bl_scsi_layout; + u64 bl_lwb; }; static inline struct pnfs_block_layout * @@ -182,7 +183,7 @@ int ext_tree_insert(struct pnfs_block_layout *bl, int ext_tree_remove(struct pnfs_block_layout *bl, bool rw, sector_t start, sector_t end); int ext_tree_mark_written(struct pnfs_block_layout *bl, sector_t start, - sector_t len); + sector_t len, u64 lwb); bool ext_tree_lookup(struct pnfs_block_layout *bl, sector_t isect, struct pnfs_block_extent *ret, bool rw); int ext_tree_prepare_commit(struct nfs4_layoutcommit_args *arg); diff --git a/fs/nfs/blocklayout/extent_tree.c b/fs/nfs/blocklayout/extent_tree.c index 992bcb19c11e..c85fbfd2d0d9 100644 --- a/fs/nfs/blocklayout/extent_tree.c +++ b/fs/nfs/blocklayout/extent_tree.c @@ -402,7 +402,7 @@ ext_tree_split(struct rb_root *root, struct pnfs_block_extent *be, int ext_tree_mark_written(struct pnfs_block_layout *bl, sector_t start, - sector_t len) + sector_t len, u64 lwb) { struct rb_root *root = &bl->bl_ext_rw; sector_t end = start + len; @@ -471,6 +471,8 @@ ext_tree_mark_written(struct pnfs_block_layout *bl, sector_t start, } } out: + if (bl->bl_lwb < lwb) + bl->bl_lwb = lwb; spin_unlock(&bl->bl_ext_lock); __ext_put_deviceids(&tmp); @@ -518,7 +520,7 @@ static __be32 *encode_scsi_range(struct pnfs_block_extent *be, __be32 *p) } static int ext_tree_encode_commit(struct pnfs_block_layout *bl, __be32 *p, - size_t buffer_size, size_t *count) + size_t buffer_size, size_t *count, __u64 *lastbyte) { struct pnfs_block_extent *be; int ret = 0; @@ -542,6 +544,8 @@ static int ext_tree_encode_commit(struct pnfs_block_layout *bl, __be32 *p, p = encode_block_extent(be, p); be->be_tag = EXTENT_COMMITTING; } + *lastbyte = bl->bl_lwb - 1; + bl->bl_lwb = 0; spin_unlock(&bl->bl_ext_lock); return ret; @@ -564,7 +568,7 @@ ext_tree_prepare_commit(struct nfs4_layoutcommit_args *arg) arg->layoutupdate_pages = &arg->layoutupdate_page; retry: - ret = ext_tree_encode_commit(bl, start_p + 1, buffer_size, &count); + ret = ext_tree_encode_commit(bl, start_p + 1, buffer_size, &count, &arg->lastbytewritten); if (unlikely(ret)) { ext_tree_free_commitdata(arg, buffer_size); -- cgit v1.2.3-59-g8ed1b