From 831441862956fffa17b9801db37e6ea1650b0f69 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Tue, 17 Jul 2007 04:03:35 -0700 Subject: Freezer: make kernel threads nonfreezable by default Currently, the freezer treats all tasks as freezable, except for the kernel threads that explicitly set the PF_NOFREEZE flag for themselves. This approach is problematic, since it requires every kernel thread to either set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't care for the freezing of tasks at all. It seems better to only require the kernel threads that want to or need to be frozen to use some freezer-related code and to remove any freezer-related code from the other (nonfreezable) kernel threads, which is done in this patch. The patch causes all kernel threads to be nonfreezable by default (ie. to have PF_NOFREEZE set by default) and introduces the set_freezable() function that should be called by the freezable kernel threads in order to unset PF_NOFREEZE. It also makes all of the currently freezable kernel threads call set_freezable(), so it shouldn't cause any (intentional) change of behaviour to appear. Additionally, it updates documentation to describe the freezing of tasks more accurately. [akpm@linux-foundation.org: build fixes] Signed-off-by: Rafael J. Wysocki Acked-by: Nigel Cunningham Cc: Pavel Machek Cc: Oleg Nesterov Cc: Gautham R Shenoy Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/jffs2/background.c | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/jffs2') diff --git a/fs/jffs2/background.c b/fs/jffs2/background.c index 0c82dfcfd246..143c5530caf3 100644 --- a/fs/jffs2/background.c +++ b/fs/jffs2/background.c @@ -81,6 +81,7 @@ static int jffs2_garbage_collect_thread(void *_c) set_user_nice(current, 10); + set_freezable(); for (;;) { allow_signal(SIGHUP); -- cgit v1.2.2 From 3bd858ab1c451725c07a805dcb315215dc85b86e Mon Sep 17 00:00:00 2001 From: Satyam Sharma Date: Tue, 17 Jul 2007 15:00:08 +0530 Subject: Introduce is_owner_or_cap() to wrap CAP_FOWNER use with fsuid check Introduce is_owner_or_cap() macro in fs.h, and convert over relevant users to it. This is done because we want to avoid bugs in the future where we check for only effective fsuid of the current task against a file's owning uid, without simultaneously checking for CAP_FOWNER as well, thus violating its semantics. [ XFS uses special macros and structures, and in general looked ... untouchable, so we leave it alone -- but it has been looked over. ] The (current->fsuid != inode->i_uid) check in generic_permission() and exec_permission_lite() is left alone, because those operations are covered by CAP_DAC_OVERRIDE and CAP_DAC_READ_SEARCH. Similarly operations falling under the purview of CAP_CHOWN and CAP_LEASE are also left alone. Signed-off-by: Satyam Sharma Cc: Al Viro Acked-by: Serge E. Hallyn Signed-off-by: Linus Torvalds --- fs/jffs2/acl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/jffs2') diff --git a/fs/jffs2/acl.c b/fs/jffs2/acl.c index a46101ee867a..65b3a1b5b88d 100644 --- a/fs/jffs2/acl.c +++ b/fs/jffs2/acl.c @@ -435,7 +435,7 @@ static int jffs2_acl_setxattr(struct inode *inode, int type, const void *value, struct posix_acl *acl; int rc; - if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER)) + if (!is_owner_or_cap(inode)) return -EPERM; if (value) { -- cgit v1.2.2 From 20c2df83d25c6a95affe6157a4c9cac4cf5ffaac Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Fri, 20 Jul 2007 10:11:58 +0900 Subject: mm: Remove slab destructors from kmem_cache_create(). Slab destructors were no longer supported after Christoph's c59def9f222d44bb7e2f0a559f2906191a0862d7 change. They've been BUGs for both slab and slub, and slob never supported them either. This rips out support for the dtor pointer from kmem_cache_create() completely and fixes up every single callsite in the kernel (there were about 224, not including the slab allocator definitions themselves, or the documentation references). Signed-off-by: Paul Mundt --- fs/jffs2/malloc.c | 18 +++++++++--------- fs/jffs2/super.c | 2 +- 2 files changed, 10 insertions(+), 10 deletions(-) (limited to 'fs/jffs2') diff --git a/fs/jffs2/malloc.c b/fs/jffs2/malloc.c index 35c1a5e30ba1..f9211252b5f1 100644 --- a/fs/jffs2/malloc.c +++ b/fs/jffs2/malloc.c @@ -33,56 +33,56 @@ int __init jffs2_create_slab_caches(void) { full_dnode_slab = kmem_cache_create("jffs2_full_dnode", sizeof(struct jffs2_full_dnode), - 0, 0, NULL, NULL); + 0, 0, NULL); if (!full_dnode_slab) goto err; raw_dirent_slab = kmem_cache_create("jffs2_raw_dirent", sizeof(struct jffs2_raw_dirent), - 0, 0, NULL, NULL); + 0, 0, NULL); if (!raw_dirent_slab) goto err; raw_inode_slab = kmem_cache_create("jffs2_raw_inode", sizeof(struct jffs2_raw_inode), - 0, 0, NULL, NULL); + 0, 0, NULL); if (!raw_inode_slab) goto err; tmp_dnode_info_slab = kmem_cache_create("jffs2_tmp_dnode", sizeof(struct jffs2_tmp_dnode_info), - 0, 0, NULL, NULL); + 0, 0, NULL); if (!tmp_dnode_info_slab) goto err; raw_node_ref_slab = kmem_cache_create("jffs2_refblock", sizeof(struct jffs2_raw_node_ref) * (REFS_PER_BLOCK + 1), - 0, 0, NULL, NULL); + 0, 0, NULL); if (!raw_node_ref_slab) goto err; node_frag_slab = kmem_cache_create("jffs2_node_frag", sizeof(struct jffs2_node_frag), - 0, 0, NULL, NULL); + 0, 0, NULL); if (!node_frag_slab) goto err; inode_cache_slab = kmem_cache_create("jffs2_inode_cache", sizeof(struct jffs2_inode_cache), - 0, 0, NULL, NULL); + 0, 0, NULL); if (!inode_cache_slab) goto err; #ifdef CONFIG_JFFS2_FS_XATTR xattr_datum_cache = kmem_cache_create("jffs2_xattr_datum", sizeof(struct jffs2_xattr_datum), - 0, 0, NULL, NULL); + 0, 0, NULL); if (!xattr_datum_cache) goto err; xattr_ref_cache = kmem_cache_create("jffs2_xattr_ref", sizeof(struct jffs2_xattr_ref), - 0, 0, NULL, NULL); + 0, 0, NULL); if (!xattr_ref_cache) goto err; #endif diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c index e220d3bd610d..be2b70c2ec16 100644 --- a/fs/jffs2/super.c +++ b/fs/jffs2/super.c @@ -192,7 +192,7 @@ static int __init init_jffs2_fs(void) sizeof(struct jffs2_inode_info), 0, (SLAB_RECLAIM_ACCOUNT| SLAB_MEM_SPREAD), - jffs2_i_init_once, NULL); + jffs2_i_init_once); if (!jffs2_inode_cachep) { printk(KERN_ERR "JFFS2 error: Failed to initialise inode cache\n"); return -ENOMEM; -- cgit v1.2.2