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Commit 86d80f97 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

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: 338d00cf ("pnfs: Refactor the *_layout_mark_request_commit...")
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
parent 74d33293

fs/nfs/internal.h

+10 −5
Original line number Diff line number Diff line
@@ -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,
@@ -623,14 +626,16 @@ 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)

{

	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);

	}

}



/*

 * Determine the number of bytes of data the page contains

fs/nfs/pnfs_nfs.c

+3 −2
Original line number Diff line number Diff line
@@ -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);

fs/nfs/write.c

+24 −5
Original line number Diff line number Diff line
@@ -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);