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authorAlexey Dobriyan <adobriyan@gmail.com>2009-03-25 22:48:06 +0300
committerAlexey Dobriyan <adobriyan@gmail.com>2009-03-31 01:14:44 +0400
commit99b76233803beab302123d243eea9e41149804f3 (patch)
tree398178210fe66845ccd6fa4258ba762a87e023ad /fs
parent3dec7f59c370c7b58184d63293c3dc984d475840 (diff)
proc 2/2: remove struct proc_dir_entry::owner
Setting ->owner as done currently (pde->owner = THIS_MODULE) is racy as correctly noted at bug #12454. Someone can lookup entry with NULL ->owner, thus not pinning enything, and release it later resulting in module refcount underflow. We can keep ->owner and supply it at registration time like ->proc_fops and ->data. But this leaves ->owner as easy-manipulative field (just one C assignment) and somebody will forget to unpin previous/pin current module when switching ->owner. ->proc_fops is declared as "const" which should give some thoughts. ->read_proc/->write_proc were just fixed to not require ->owner for protection. rmmod'ed directories will be empty and return "." and ".." -- no harm. And directories with tricky enough readdir and lookup shouldn't be modular. We definitely don't want such modular code. Removing ->owner will also make PDE smaller. So, let's nuke it. Kudos to Jeff Layton for reminding about this, let's say, oversight. http://bugzilla.kernel.org/show_bug.cgi?id=12454 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Diffstat (limited to 'fs')
-rw-r--r--fs/afs/proc.c1
-rw-r--r--fs/cifs/cifs_debug.c1
-rw-r--r--fs/jfs/jfs_debug.c1
-rw-r--r--fs/nfs/client.c2
-rw-r--r--fs/proc/inode.c19
-rw-r--r--fs/proc/proc_tty.c1
-rw-r--r--fs/reiserfs/procfs.c5
7 files changed, 4 insertions, 26 deletions
diff --git a/fs/afs/proc.c b/fs/afs/proc.c
index 7578c1ab9e0..8630615e57f 100644
--- a/fs/afs/proc.c
+++ b/fs/afs/proc.c
@@ -146,7 +146,6 @@ int afs_proc_init(void)
proc_afs = proc_mkdir("fs/afs", NULL);
if (!proc_afs)
goto error_dir;
- proc_afs->owner = THIS_MODULE;
p = proc_create("cells", 0, proc_afs, &afs_proc_cells_fops);
if (!p)
diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c
index 877e4d9a115..7f19fefd3d4 100644
--- a/fs/cifs/cifs_debug.c
+++ b/fs/cifs/cifs_debug.c
@@ -404,7 +404,6 @@ cifs_proc_init(void)
if (proc_fs_cifs == NULL)
return;
- proc_fs_cifs->owner = THIS_MODULE;
proc_create("DebugData", 0, proc_fs_cifs, &cifs_debug_data_proc_fops);
#ifdef CONFIG_CIFS_STATS
diff --git a/fs/jfs/jfs_debug.c b/fs/jfs/jfs_debug.c
index 6a73de84bce..dd824d9b0b1 100644
--- a/fs/jfs/jfs_debug.c
+++ b/fs/jfs/jfs_debug.c
@@ -90,7 +90,6 @@ void jfs_proc_init(void)
if (!(base = proc_mkdir("fs/jfs", NULL)))
return;
- base->owner = THIS_MODULE;
for (i = 0; i < NPROCENT; i++)
proc_create(Entries[i].name, 0, base, Entries[i].proc_fops);
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 574158ae239..2277421656e 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -1606,8 +1606,6 @@ int __init nfs_fs_proc_init(void)
if (!proc_fs_nfs)
goto error_0;
- proc_fs_nfs->owner = THIS_MODULE;
-
/* a file of servers with which we're dealing */
p = proc_create("servers", S_IFREG|S_IRUGO,
proc_fs_nfs, &nfs_server_list_fops);
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index e11dc22c651..d78ade30554 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -58,11 +58,8 @@ static void proc_delete_inode(struct inode *inode)
/* Let go of any associated proc directory entry */
de = PROC_I(inode)->pde;
- if (de) {
- if (de->owner)
- module_put(de->owner);
+ if (de)
de_put(de);
- }
if (PROC_I(inode)->sysctl)
sysctl_head_put(PROC_I(inode)->sysctl);
clear_inode(inode);
@@ -449,12 +446,9 @@ struct inode *proc_get_inode(struct super_block *sb, unsigned int ino,
{
struct inode * inode;
- if (!try_module_get(de->owner))
- goto out_mod;
-
inode = iget_locked(sb, ino);
if (!inode)
- goto out_ino;
+ return NULL;
if (inode->i_state & I_NEW) {
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
PROC_I(inode)->fd = 0;
@@ -485,16 +479,9 @@ struct inode *proc_get_inode(struct super_block *sb, unsigned int ino,
}
}
unlock_new_inode(inode);
- } else {
- module_put(de->owner);
+ } else
de_put(de);
- }
return inode;
-
-out_ino:
- module_put(de->owner);
-out_mod:
- return NULL;
}
int proc_fill_super(struct super_block *s)
diff --git a/fs/proc/proc_tty.c b/fs/proc/proc_tty.c
index d153946d6d1..4a9e0f65ae6 100644
--- a/fs/proc/proc_tty.c
+++ b/fs/proc/proc_tty.c
@@ -152,7 +152,6 @@ void proc_tty_register_driver(struct tty_driver *driver)
if (!ent)
return;
ent->read_proc = driver->ops->read_proc;
- ent->owner = driver->owner;
ent->data = driver;
driver->proc_entry = ent;
diff --git a/fs/reiserfs/procfs.c b/fs/reiserfs/procfs.c
index d5066400638..9229e5514a4 100644
--- a/fs/reiserfs/procfs.c
+++ b/fs/reiserfs/procfs.c
@@ -492,7 +492,6 @@ int reiserfs_proc_info_init(struct super_block *sb)
spin_lock_init(&__PINFO(sb).lock);
REISERFS_SB(sb)->procdir = proc_mkdir(b, proc_info_root);
if (REISERFS_SB(sb)->procdir) {
- REISERFS_SB(sb)->procdir->owner = THIS_MODULE;
REISERFS_SB(sb)->procdir->data = sb;
add_file(sb, "version", show_version);
add_file(sb, "super", show_super);
@@ -556,9 +555,7 @@ int reiserfs_proc_info_global_init(void)
{
if (proc_info_root == NULL) {
proc_info_root = proc_mkdir(proc_info_root_name, NULL);
- if (proc_info_root) {
- proc_info_root->owner = THIS_MODULE;
- } else {
+ if (!proc_info_root) {
reiserfs_warning(NULL, "cannot create /proc/%s",
proc_info_root_name);
return 1;