From 86d80f973434de24d8a807a92cd59d5ced7bd519 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Fri, 31 Jul 2015 16:24:30 -0400 Subject: [PATCH] NFSv4.1/pnfs: Fix atomicity of commit list updates 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@vger.kernel.org # v4.0+ Signed-off-by: Trond Myklebust --- fs/nfs/internal.h | 15 ++++++++++----- fs/nfs/pnfs_nfs.c | 5 +++-- fs/nfs/write.c | 29 ++++++++++++++++++++++++----- 3 files changed, 37 insertions(+), 12 deletions(-) diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h index 9b372b845f6a..1dad18105ed0 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; + if (!cinfo->dreq) { + 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); + 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..fdee9270ca15 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -767,6 +767,28 @@ nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi, return NULL; } +/** + * 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++; +} +EXPORT_SYMBOL_GPL(nfs_request_add_commit_list_locked); + /** * nfs_request_add_commit_list - add request to a commit list * @req: pointer to a struct nfs_page @@ -784,13 +806,10 @@ 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); -- 2.20.1