diff options
Diffstat (limited to 'include/linux/fs.h')
-rw-r--r-- | include/linux/fs.h | 36 |
1 files changed, 16 insertions, 20 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index 77a9750..cca1919 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1587,7 +1587,7 @@ struct super_operations { * until that flag is cleared. I_WILL_FREE, I_FREEING and I_CLEAR are set at * various stages of removing an inode. * - * Two bits are used for locking and completion notification, I_LOCK and I_SYNC. + * Two bits are used for locking and completion notification, I_NEW and I_SYNC. * * I_DIRTY_SYNC Inode is dirty, but doesn't have to be written on * fdatasync(). i_atime is the usual cause. @@ -1596,8 +1596,14 @@ struct super_operations { * don't have to write inode on fdatasync() when only * mtime has changed in it. * I_DIRTY_PAGES Inode has dirty pages. Inode itself may be clean. - * I_NEW get_new_inode() sets i_state to I_LOCK|I_NEW. Both - * are cleared by unlock_new_inode(), called from iget(). + * I_NEW Serves as both a mutex and completion notification. + * New inodes set I_NEW. If two processes both create + * the same inode, one of them will release its inode and + * wait for I_NEW to be released before returning. + * Inodes in I_WILL_FREE, I_FREEING or I_CLEAR state can + * also cause waiting on I_NEW, without I_NEW actually + * being set. find_inode() uses this to prevent returning + * nearly-dead inodes. * I_WILL_FREE Must be set when calling write_inode_now() if i_count * is zero. I_FREEING must be set when I_WILL_FREE is * cleared. @@ -1611,20 +1617,11 @@ struct super_operations { * prohibited for many purposes. iget() must wait for * the inode to be completely released, then create it * anew. Other functions will just ignore such inodes, - * if appropriate. I_LOCK is used for waiting. + * if appropriate. I_NEW is used for waiting. * - * I_LOCK Serves as both a mutex and completion notification. - * New inodes set I_LOCK. If two processes both create - * the same inode, one of them will release its inode and - * wait for I_LOCK to be released before returning. - * Inodes in I_WILL_FREE, I_FREEING or I_CLEAR state can - * also cause waiting on I_LOCK, without I_LOCK actually - * being set. find_inode() uses this to prevent returning - * nearly-dead inodes. - * I_SYNC Similar to I_LOCK, but limited in scope to writeback - * of inode dirty data. Having a separate lock for this - * purpose reduces latency and prevents some filesystem- - * specific deadlocks. + * I_SYNC Synchonized write of dirty inode data. The bits is + * set during data writeback, and cleared with a wakeup + * on the bit address once it is done. * * Q: What is the difference between I_WILL_FREE and I_FREEING? * Q: igrab() only checks on (I_FREEING|I_WILL_FREE). Should it also check on @@ -1633,13 +1630,12 @@ struct super_operations { #define I_DIRTY_SYNC 1 #define I_DIRTY_DATASYNC 2 #define I_DIRTY_PAGES 4 -#define I_NEW 8 +#define __I_NEW 3 +#define I_NEW (1 << __I_NEW) #define I_WILL_FREE 16 #define I_FREEING 32 #define I_CLEAR 64 -#define __I_LOCK 7 -#define I_LOCK (1 << __I_LOCK) -#define __I_SYNC 8 +#define __I_SYNC 7 #define I_SYNC (1 << __I_SYNC) #define I_DIRTY (I_DIRTY_SYNC | I_DIRTY_DATASYNC | I_DIRTY_PAGES) |