From 7ada4db88634429f4da690ad1c4eb73c93085f0c Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Mon, 21 Nov 2011 12:11:32 +0100 Subject: vfs: count unlinked inodes Add a new counter to the superblock that keeps track of unlinked but not yet deleted inodes. Do not WARN_ON if set_nlink is called with zero count, just do a ratelimited printk. This happens on xfs and probably other filesystems after an unclean shutdown when the filesystem reads inodes which already have zero i_nlink. Reported by Christoph Hellwig. Signed-off-by: Miklos Szeredi Tested-by: Toshiyuki Okajima Signed-off-by: Al Viro --- include/linux/fs.h | 61 +++++++----------------------------------------------- 1 file changed, 7 insertions(+), 54 deletions(-) (limited to 'include/linux/fs.h') diff --git a/include/linux/fs.h b/include/linux/fs.h index 7b8a681b1ef4..8ac40921f5ac 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1483,6 +1483,9 @@ struct super_block { struct shrinker s_shrink; /* per-sb shrinker handle */ + /* Number of inodes with nlink == 0 but still referenced */ + atomic_long_t s_remove_count; + /* Being remounted read-only */ int s_readonly_remount; }; @@ -1768,31 +1771,10 @@ static inline void mark_inode_dirty_sync(struct inode *inode) __mark_inode_dirty(inode, I_DIRTY_SYNC); } -/** - * set_nlink - directly set an inode's link count - * @inode: inode - * @nlink: new nlink (should be non-zero) - * - * This is a low-level filesystem helper to replace any - * direct filesystem manipulation of i_nlink. - */ -static inline void set_nlink(struct inode *inode, unsigned int nlink) -{ - inode->__i_nlink = nlink; -} - -/** - * inc_nlink - directly increment an inode's link count - * @inode: inode - * - * This is a low-level filesystem helper to replace any - * direct filesystem manipulation of i_nlink. Currently, - * it is only here for parity with dec_nlink(). - */ -static inline void inc_nlink(struct inode *inode) -{ - inode->__i_nlink++; -} +extern void inc_nlink(struct inode *inode); +extern void drop_nlink(struct inode *inode); +extern void clear_nlink(struct inode *inode); +extern void set_nlink(struct inode *inode, unsigned int nlink); static inline void inode_inc_link_count(struct inode *inode) { @@ -1800,35 +1782,6 @@ static inline void inode_inc_link_count(struct inode *inode) mark_inode_dirty(inode); } -/** - * drop_nlink - directly drop an inode's link count - * @inode: inode - * - * This is a low-level filesystem helper to replace any - * direct filesystem manipulation of i_nlink. In cases - * where we are attempting to track writes to the - * filesystem, a decrement to zero means an imminent - * write when the file is truncated and actually unlinked - * on the filesystem. - */ -static inline void drop_nlink(struct inode *inode) -{ - inode->__i_nlink--; -} - -/** - * clear_nlink - directly zero an inode's link count - * @inode: inode - * - * This is a low-level filesystem helper to replace any - * direct filesystem manipulation of i_nlink. See - * drop_nlink() for why we care about i_nlink hitting zero. - */ -static inline void clear_nlink(struct inode *inode) -{ - inode->__i_nlink = 0; -} - static inline void inode_dec_link_count(struct inode *inode) { drop_nlink(inode); -- cgit v1.2.2