From 11de3b11e08cac26d59e88efaf4e316701883552 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Wed, 1 Dec 2010 14:17:06 -0500 Subject: [PATCH] NFS: Fix a memory leak in nfs_readdir We need to ensure that the entries in the nfs_cache_array get cleared when the page is removed from the page cache. To do so, we use the freepage address_space operation. Change nfs_readdir_clear_array to use kmap_atomic(), so that the function can be safely called from all contexts. Finally, modify the cache_page_release helper to call nfs_readdir_clear_array directly, when dealing with an anonymous page from 'uncached_readdir'. Signed-off-by: Trond Myklebust --- fs/nfs/dir.c | 18 +++++++++--------- fs/nfs/inode.c | 1 + include/linux/nfs_fs.h | 1 + 3 files changed, 11 insertions(+), 9 deletions(-) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index e03537ff9350..d529e0e99efa 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -57,7 +57,7 @@ static int nfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *); static int nfs_fsync_dir(struct file *, int); static loff_t nfs_llseek_dir(struct file *, loff_t, int); -static int nfs_readdir_clear_array(struct page*, gfp_t); +static void nfs_readdir_clear_array(struct page*); const struct file_operations nfs_dir_operations = { .llseek = nfs_llseek_dir, @@ -83,8 +83,8 @@ const struct inode_operations nfs_dir_inode_operations = { .setattr = nfs_setattr, }; -const struct address_space_operations nfs_dir_addr_space_ops = { - .releasepage = nfs_readdir_clear_array, +const struct address_space_operations nfs_dir_aops = { + .freepage = nfs_readdir_clear_array, }; #ifdef CONFIG_NFS_V3 @@ -214,17 +214,15 @@ void nfs_readdir_release_array(struct page *page) * we are freeing strings created by nfs_add_to_readdir_array() */ static -int nfs_readdir_clear_array(struct page *page, gfp_t mask) +void nfs_readdir_clear_array(struct page *page) { - struct nfs_cache_array *array = nfs_readdir_get_array(page); + struct nfs_cache_array *array; int i; - if (IS_ERR(array)) - return PTR_ERR(array); + array = kmap_atomic(page, KM_USER0); for (i = 0; i < array->size; i++) kfree(array->array[i].string.name); - nfs_readdir_release_array(page); - return 0; + kunmap_atomic(array, KM_USER0); } /* @@ -639,6 +637,8 @@ int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page* page) static void cache_page_release(nfs_readdir_descriptor_t *desc) { + if (!desc->page->mapping) + nfs_readdir_clear_array(desc->page); page_cache_release(desc->page); desc->page = NULL; } diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 314f57164602..e67e31c73416 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -289,6 +289,7 @@ nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr) } else if (S_ISDIR(inode->i_mode)) { inode->i_op = NFS_SB(sb)->nfs_client->rpc_ops->dir_inode_ops; inode->i_fop = &nfs_dir_operations; + inode->i_data.a_ops = &nfs_dir_aops; if (nfs_server_capable(inode, NFS_CAP_READDIRPLUS)) set_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags); /* Deal with crossing mountpoints */ diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h index c66fdb7d6998..29d504d5d1c3 100644 --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -401,6 +401,7 @@ extern const struct inode_operations nfs3_file_inode_operations; #endif /* CONFIG_NFS_V3 */ extern const struct file_operations nfs_file_operations; extern const struct address_space_operations nfs_file_aops; +extern const struct address_space_operations nfs_dir_aops; static inline struct nfs_open_context *nfs_file_open_context(struct file *filp) { -- 2.11.0