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Diffstat (limited to 'fs/inode.c')
-rw-r--r--fs/inode.c97
1 files changed, 66 insertions, 31 deletions
diff --git a/fs/inode.c b/fs/inode.c
index 205733701..d30640f7a 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -58,7 +58,6 @@ static struct hlist_head *inode_hashtable __read_mostly;
static __cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_hash_lock);
__cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_sb_list_lock);
-EXPORT_SYMBOL(inode_sb_list_lock);
/*
* Empty aops. Can be used for the cases where the user does not
@@ -153,6 +152,7 @@ int inode_init_always(struct super_block *sb, struct inode *inode)
inode->i_pipe = NULL;
inode->i_bdev = NULL;
inode->i_cdev = NULL;
+ inode->i_link = NULL;
inode->i_rdev = 0;
inode->dirtied_when = 0;
@@ -224,6 +224,7 @@ EXPORT_SYMBOL(free_inode_nonrcu);
void __destroy_inode(struct inode *inode)
{
BUG_ON(inode_has_buffers(inode));
+ inode_detach_wb(inode);
security_inode_free(inode);
fsnotify_inode_delete(inode);
locks_free_lock_context(inode->i_flctx);
@@ -831,8 +832,6 @@ unsigned int get_next_ino(void)
unsigned int *p = &get_cpu_var(last_ino);
unsigned int res = *p;
-start:
-
#ifdef CONFIG_SMP
if (unlikely((res & (LAST_INO_BATCH-1)) == 0)) {
static atomic_t shared_last_ino;
@@ -842,8 +841,10 @@ start:
}
#endif
- if (unlikely(!++res))
- goto start; /* never zero */
+ res++;
+ /* get_next_ino should not provide a 0 inode number */
+ if (unlikely(!res))
+ res++;
*p = res;
put_cpu_var(last_ino);
return res;
@@ -1589,36 +1590,47 @@ static int update_time(struct inode *inode, struct timespec *time, int flags)
* This function automatically handles read only file systems and media,
* as well as the "noatime" flag and inode specific "noatime" markers.
*/
-void touch_atime(const struct path *path)
+bool atime_needs_update(const struct path *path, struct inode *inode)
{
struct vfsmount *mnt = path->mnt;
- struct inode *inode = d_inode(path->dentry);
struct timespec now;
if (inode->i_flags & S_NOATIME)
- return;
+ return false;
if (IS_NOATIME(inode))
- return;
+ return false;
if ((inode->i_sb->s_flags & MS_NODIRATIME) && S_ISDIR(inode->i_mode))
- return;
+ return false;
if (mnt->mnt_flags & MNT_NOATIME)
- return;
+ return false;
if ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode))
- return;
+ return false;
now = current_fs_time(inode->i_sb);
if (!relatime_need_update(mnt, inode, now))
- return;
+ return false;
if (timespec_equal(&inode->i_atime, &now))
+ return false;
+
+ return true;
+}
+
+void touch_atime(const struct path *path)
+{
+ struct vfsmount *mnt = path->mnt;
+ struct inode *inode = d_inode(path->dentry);
+ struct timespec now;
+
+ if (!atime_needs_update(path, inode))
return;
if (!sb_start_write_trylock(inode->i_sb))
return;
- if (__mnt_want_write(mnt))
+ if (__mnt_want_write(mnt) != 0)
goto skip_update;
/*
* File systems can error out when updating inodes if they need to
@@ -1629,6 +1641,7 @@ void touch_atime(const struct path *path)
* We may also fail on filesystems that have the ability to make parts
* of the fs read only, e.g. subvolumes in Btrfs.
*/
+ now = current_fs_time(inode->i_sb);
update_time(inode, &now, S_ATIME);
__mnt_drop_write(mnt);
skip_update:
@@ -1665,7 +1678,31 @@ int should_remove_suid(struct dentry *dentry)
}
EXPORT_SYMBOL(should_remove_suid);
-static int __remove_suid(struct dentry *dentry, int kill)
+/*
+ * Return mask of changes for notify_change() that need to be done as a
+ * response to write or truncate. Return 0 if nothing has to be changed.
+ * Negative value on error (change should be denied).
+ */
+int dentry_needs_remove_privs(struct dentry *dentry)
+{
+ struct inode *inode = d_inode(dentry);
+ int mask = 0;
+ int ret;
+
+ if (IS_NOSEC(inode))
+ return 0;
+
+ mask = should_remove_suid(dentry);
+ ret = security_inode_need_killpriv(dentry);
+ if (ret < 0)
+ return ret;
+ if (ret)
+ mask |= ATTR_KILL_PRIV;
+ return mask;
+}
+EXPORT_SYMBOL(dentry_needs_remove_privs);
+
+static int __remove_privs(struct dentry *dentry, int kill)
{
struct iattr newattrs;
@@ -1677,33 +1714,32 @@ static int __remove_suid(struct dentry *dentry, int kill)
return notify_change(dentry, &newattrs, NULL);
}
-int file_remove_suid(struct file *file)
+/*
+ * Remove special file priviledges (suid, capabilities) when file is written
+ * to or truncated.
+ */
+int file_remove_privs(struct file *file)
{
struct dentry *dentry = file->f_path.dentry;
struct inode *inode = d_inode(dentry);
- int killsuid;
- int killpriv;
+ int kill;
int error = 0;
/* Fast path for nothing security related */
if (IS_NOSEC(inode))
return 0;
- killsuid = should_remove_suid(dentry);
- killpriv = security_inode_need_killpriv(dentry);
-
- if (killpriv < 0)
- return killpriv;
- if (killpriv)
- error = security_inode_killpriv(dentry);
- if (!error && killsuid)
- error = __remove_suid(dentry, killsuid);
+ kill = file_needs_remove_privs(file);
+ if (kill < 0)
+ return kill;
+ if (kill)
+ error = __remove_privs(dentry, kill);
if (!error)
inode_has_no_xattr(inode);
return error;
}
-EXPORT_SYMBOL(file_remove_suid);
+EXPORT_SYMBOL(file_remove_privs);
/**
* file_update_time - update mtime and ctime time
@@ -1958,9 +1994,8 @@ EXPORT_SYMBOL(inode_dio_wait);
* inode is being instantiated). The reason for the cmpxchg() loop
* --- which wouldn't be necessary if all code paths which modify
* i_flags actually followed this rule, is that there is at least one
- * code path which doesn't today --- for example,
- * __generic_file_aio_write() calls file_remove_suid() without holding
- * i_mutex --- so we use cmpxchg() out of an abundance of caution.
+ * code path which doesn't today so we use cmpxchg() out of an abundance
+ * of caution.
*
* In the long run, i_mutex is overkill, and we should probably look
* at using the i_lock spinlock to protect i_flags, and then make sure