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| author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2006-03-20 19:44:50 +0100 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2006-03-20 19:44:50 +0100 |
| commit | deb7d638262019cbac5d15ab74ffd1c29242c7cb (patch) | |
| tree | 88095acd2d455b594f4cec08702aa9691faff2a0 /fs/nfs | |
| parent | NFSv4: Ensure the callback daemon flushes signals (diff) | |
| download | linux-deb7d638262019cbac5d15ab74ffd1c29242c7cb.tar.xz linux-deb7d638262019cbac5d15ab74ffd1c29242c7cb.zip | |
NFS: Fix a race with PG_private and nfs_release_page()
We don't need to set PG_private for readahead pages, since they never get
unlocked while I/O is in progress. However there is a small race in
nfs_readpage_release() whereby the page may be unlocked, and have
PG_private set.
Fix is to have PG_private set only for the case of writes...
Also fix a bug in nfs_clear_page_writeback(): Don't attempt to clear the
radix_tree tag if we've already deleted the radix tree entry.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs')
| -rw-r--r-- | fs/nfs/pagelist.c | 10 | ||||
| -rw-r--r-- | fs/nfs/write.c | 2 |
2 files changed, 7 insertions, 5 deletions
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index d6e076c9dbe1..106aca388ebc 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -88,7 +88,6 @@ nfs_create_request(struct nfs_open_context *ctx, struct inode *inode, BUG_ON(PagePrivate(page)); BUG_ON(!PageLocked(page)); BUG_ON(page->mapping->host != inode); - SetPagePrivate(page); req->wb_offset = offset; req->wb_pgbase = offset; req->wb_bytes = count; @@ -136,9 +135,11 @@ void nfs_clear_page_writeback(struct nfs_page *req) { struct nfs_inode *nfsi = NFS_I(req->wb_context->dentry->d_inode); - spin_lock(&nfsi->req_lock); - radix_tree_tag_clear(&nfsi->nfs_page_tree, req->wb_index, NFS_PAGE_TAG_WRITEBACK); - spin_unlock(&nfsi->req_lock); + if (req->wb_page != NULL) { + spin_lock(&nfsi->req_lock); + radix_tree_tag_clear(&nfsi->nfs_page_tree, req->wb_index, NFS_PAGE_TAG_WRITEBACK); + spin_unlock(&nfsi->req_lock); + } nfs_unlock_request(req); } @@ -153,7 +154,6 @@ void nfs_clear_request(struct nfs_page *req) { struct page *page = req->wb_page; if (page != NULL) { - ClearPagePrivate(page); page_cache_release(page); req->wb_page = NULL; } diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 647e3217c2e1..d9e5ee594572 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -429,6 +429,7 @@ static int nfs_inode_add_request(struct inode *inode, struct nfs_page *req) if (nfs_have_delegation(inode, FMODE_WRITE)) nfsi->change_attr++; } + SetPagePrivate(req->wb_page); nfsi->npages++; atomic_inc(&req->wb_count); return 0; @@ -445,6 +446,7 @@ static void nfs_inode_remove_request(struct nfs_page *req) BUG_ON (!NFS_WBACK_BUSY(req)); spin_lock(&nfsi->req_lock); + ClearPagePrivate(req->wb_page); radix_tree_delete(&nfsi->nfs_page_tree, req->wb_index); nfsi->npages--; if (!nfsi->npages) { |