Hey Trond,
On 07/31/2015 04:37 PM, Trond Myklebust wrote:
> pnfs_layout_mark_request_commit() needs to ensure that it adds the
> request to the commit list atomically with all the other updates
> in order to prevent corruption to buckets[ds_commit_idx].wlseg
> due to races with pnfs_generic_clear_request_commit().
>
> Fixes: 338d00cfef07d ("pnfs: Refactor the *_layout_mark_request_commit...")
> Cc: stable@xxxxxxxxxxxxxxx # v4.0+
> Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
> ---
> fs/nfs/internal.h | 13 +++++++++----
> fs/nfs/pnfs_nfs.c | 5 +++--
> fs/nfs/write.c | 28 +++++++++++++++++++++++-----
> 3 files changed, 35 insertions(+), 11 deletions(-)
>
> diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
> index 9b372b845f6a..9553e024fa7d 100644
> --- a/fs/nfs/internal.h
> +++ b/fs/nfs/internal.h
> @@ -490,6 +490,9 @@ void nfs_retry_commit(struct list_head *page_list,
> void nfs_commitdata_release(struct nfs_commit_data *data);
> void nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst,
> struct nfs_commit_info *cinfo);
> +void nfs_request_add_commit_list_locked(struct nfs_page *req,
> + struct list_head *dst,
> + struct nfs_commit_info *cinfo);
> void nfs_request_remove_commit_list(struct nfs_page *req,
> struct nfs_commit_info *cinfo);
> void nfs_init_cinfo(struct nfs_commit_info *cinfo,
> @@ -623,13 +626,15 @@ void nfs_super_set_maxbytes(struct super_block *sb, __u64 maxfilesize)
> * Record the page as unstable and mark its inode as dirty.
> */
> static inline
> -void nfs_mark_page_unstable(struct page *page)
> +void nfs_mark_page_unstable(struct page *page, struct nfs_commit_info *cinfo)
> {
> struct inode *inode = page_file_mapping(page)->host;
>
> - inc_zone_page_state(page, NR_UNSTABLE_NFS);
> - inc_wb_stat(&inode_to_bdi(inode)->wb, WB_RECLAIMABLE);
> - __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
> + if (!cinfo->dreq) {
> + inc_zone_page_state(page, NR_UNSTABLE_NFS);
> + inc_wb_stat(&inode_to_bdi(inode)->wb, WB_RECLAIMABLE);
> + __mark_inode_dirty(inode, I_DIRTY_DATASYNC);
> + }
> }
>
> /*
> diff --git a/fs/nfs/pnfs_nfs.c b/fs/nfs/pnfs_nfs.c
> index f37e25b6311c..7a282876662f 100644
> --- a/fs/nfs/pnfs_nfs.c
> +++ b/fs/nfs/pnfs_nfs.c
> @@ -863,9 +863,10 @@ pnfs_layout_mark_request_commit(struct nfs_page *req,
> }
> set_bit(PG_COMMIT_TO_DS, &req->wb_flags);
> cinfo->ds->nwritten++;
> - spin_unlock(cinfo->lock);
>
> - nfs_request_add_commit_list(req, list, cinfo);
> + nfs_request_add_commit_list_locked(req, list, cinfo);
> + spin_unlock(cinfo->lock);
> + nfs_mark_page_unstable(req->wb_page, cinfo);
> }
> EXPORT_SYMBOL_GPL(pnfs_layout_mark_request_commit);
>
> diff --git a/fs/nfs/write.c b/fs/nfs/write.c
> index 75a35a1afa79..135a6b3aa4fb 100644
> --- a/fs/nfs/write.c
> +++ b/fs/nfs/write.c
> @@ -768,6 +768,27 @@ nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi,
> }
>
> /**
> + * nfs_request_add_commit_list_locked - add request to a commit list
> + * @req: pointer to a struct nfs_page
> + * @dst: commit list head
> + * @cinfo: holds list lock and accounting info
> + *
> + * This sets the PG_CLEAN bit, updates the cinfo count of
> + * number of outstanding requests requiring a commit as well as
> + * the MM page stats.
> + *
> + * The caller must hold the cinfo->lock, and the nfs_page lock.
> + */
> +void
> +nfs_request_add_commit_list_locked(struct nfs_page *req, struct list_head *dst,
> + struct nfs_commit_info *cinfo)
> +{
> + set_bit(PG_CLEAN, &req->wb_flags);
> + nfs_list_add_request(req, dst);
> + cinfo->mds->ncommit++;
> +}
This function also needs to be exported for pnfs to use it:
MODPOST 112 modules
ERROR: "nfs_request_add_commit_list_locked" [fs/nfs/nfsv4.ko] undefined!
scripts/Makefile.modpost:90: recipe for target '__modpost' failed
Thanks,
Anna
> +
> +/**
> * nfs_request_add_commit_list - add request to a commit list
> * @req: pointer to a struct nfs_page
> * @dst: commit list head
> @@ -784,13 +805,10 @@ void
> nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst,
> struct nfs_commit_info *cinfo)
> {
> - set_bit(PG_CLEAN, &(req)->wb_flags);
> spin_lock(cinfo->lock);
> - nfs_list_add_request(req, dst);
> - cinfo->mds->ncommit++;
> + nfs_request_add_commit_list_locked(req, dst, cinfo);
> spin_unlock(cinfo->lock);
> - if (!cinfo->dreq)
> - nfs_mark_page_unstable(req->wb_page);
> + nfs_mark_page_unstable(req->wb_page, cinfo);
> }
> EXPORT_SYMBOL_GPL(nfs_request_add_commit_list);
>
>
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