diff options
Diffstat (limited to 'fs/inode.c')
| -rw-r--r-- | fs/inode.c | 108 |
1 files changed, 87 insertions, 21 deletions
diff --git a/fs/inode.c b/fs/inode.c index b33ba8e021c..6eecb7ff0b9 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -105,7 +105,7 @@ long get_nr_dirty_inodes(void) * Handle nr_inode sysctl */ #ifdef CONFIG_SYSCTL -int proc_nr_inodes(ctl_table *table, int write, +int proc_nr_inodes(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { inodes_stat.nr_inodes = get_nr_inodes(); @@ -503,6 +503,7 @@ void clear_inode(struct inode *inode) */ spin_lock_irq(&inode->i_data.tree_lock); BUG_ON(inode->i_data.nrpages); + BUG_ON(inode->i_data.nrshadows); spin_unlock_irq(&inode->i_data.tree_lock); BUG_ON(!list_empty(&inode->i_data.private_list)); BUG_ON(!(inode->i_state & I_FREEING)); @@ -548,8 +549,7 @@ static void evict(struct inode *inode) if (op->evict_inode) { op->evict_inode(inode); } else { - if (inode->i_data.nrpages) - truncate_inode_pages(&inode->i_data, 0); + truncate_inode_pages_final(&inode->i_data); clear_inode(inode); } if (S_ISBLK(inode->i_mode) && inode->i_bdev) @@ -773,15 +773,11 @@ static struct inode *find_inode(struct super_block *sb, repeat: hlist_for_each_entry(inode, head, i_hash) { - spin_lock(&inode->i_lock); - if (inode->i_sb != sb) { - spin_unlock(&inode->i_lock); + if (inode->i_sb != sb) continue; - } - if (!test(inode, data)) { - spin_unlock(&inode->i_lock); + if (!test(inode, data)) continue; - } + spin_lock(&inode->i_lock); if (inode->i_state & (I_FREEING|I_WILL_FREE)) { __wait_on_freeing_inode(inode); goto repeat; @@ -804,15 +800,11 @@ static struct inode *find_inode_fast(struct super_block *sb, repeat: hlist_for_each_entry(inode, head, i_hash) { - spin_lock(&inode->i_lock); - if (inode->i_ino != ino) { - spin_unlock(&inode->i_lock); + if (inode->i_ino != ino) continue; - } - if (inode->i_sb != sb) { - spin_unlock(&inode->i_lock); + if (inode->i_sb != sb) continue; - } + spin_lock(&inode->i_lock); if (inode->i_state & (I_FREEING|I_WILL_FREE)) { __wait_on_freeing_inode(inode); goto repeat; @@ -951,6 +943,41 @@ void unlock_new_inode(struct inode *inode) EXPORT_SYMBOL(unlock_new_inode); /** + * lock_two_nondirectories - take two i_mutexes on non-directory objects + * + * Lock any non-NULL argument that is not a directory. + * Zero, one or two objects may be locked by this function. + * + * @inode1: first inode to lock + * @inode2: second inode to lock + */ +void lock_two_nondirectories(struct inode *inode1, struct inode *inode2) +{ + if (inode1 > inode2) + swap(inode1, inode2); + + if (inode1 && !S_ISDIR(inode1->i_mode)) + mutex_lock(&inode1->i_mutex); + if (inode2 && !S_ISDIR(inode2->i_mode) && inode2 != inode1) + mutex_lock_nested(&inode2->i_mutex, I_MUTEX_NONDIR2); +} +EXPORT_SYMBOL(lock_two_nondirectories); + +/** + * unlock_two_nondirectories - release locks from lock_two_nondirectories() + * @inode1: first inode to unlock + * @inode2: second inode to unlock + */ +void unlock_two_nondirectories(struct inode *inode1, struct inode *inode2) +{ + if (inode1 && !S_ISDIR(inode1->i_mode)) + mutex_unlock(&inode1->i_mutex); + if (inode2 && !S_ISDIR(inode2->i_mode) && inode2 != inode1) + mutex_unlock(&inode2->i_mutex); +} +EXPORT_SYMBOL(unlock_two_nondirectories); + +/** * iget5_locked - obtain an inode from a mounted file system * @sb: super block of file system * @hashval: hash value (usually inode number) to get @@ -1575,7 +1602,11 @@ static int __remove_suid(struct dentry *dentry, int kill) struct iattr newattrs; newattrs.ia_valid = ATTR_FORCE | kill; - return notify_change(dentry, &newattrs); + /* + * Note we call this on write, so notify_change will not + * encounter any conflicting delegations: + */ + return notify_change(dentry, &newattrs, NULL); } int file_remove_suid(struct file *file) @@ -1808,14 +1839,18 @@ EXPORT_SYMBOL(inode_init_owner); * inode_owner_or_capable - check current task permissions to inode * @inode: inode being checked * - * Return true if current either has CAP_FOWNER to the inode, or - * owns the file. + * Return true if current either has CAP_FOWNER in a namespace with the + * inode owner uid mapped, or owns the file. */ bool inode_owner_or_capable(const struct inode *inode) { + struct user_namespace *ns; + if (uid_eq(current_fsuid(), inode->i_uid)) return true; - if (inode_capable(inode, CAP_FOWNER)) + + ns = current_user_ns(); + if (ns_capable(ns, CAP_FOWNER) && kuid_has_mapping(ns, inode->i_uid)) return true; return false; } @@ -1867,3 +1902,34 @@ void inode_dio_done(struct inode *inode) wake_up_bit(&inode->i_state, __I_DIO_WAKEUP); } EXPORT_SYMBOL(inode_dio_done); + +/* + * inode_set_flags - atomically set some inode flags + * + * Note: the caller should be holding i_mutex, or else be sure that + * they have exclusive access to the inode structure (i.e., while the + * 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. + * + * 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 + * it is so documented in include/linux/fs.h and that all code follows + * the locking convention!! + */ +void inode_set_flags(struct inode *inode, unsigned int flags, + unsigned int mask) +{ + unsigned int old_flags, new_flags; + + WARN_ON_ONCE(flags & ~mask); + do { + old_flags = ACCESS_ONCE(inode->i_flags); + new_flags = (old_flags & ~mask) | flags; + } while (unlikely(cmpxchg(&inode->i_flags, old_flags, + new_flags) != old_flags)); +} +EXPORT_SYMBOL(inode_set_flags); |