diff options
Diffstat (limited to 'sys/ufs')
| -rw-r--r-- | sys/ufs/ufs/ufs_extern.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/sys/ufs/ufs/ufs_extern.h b/sys/ufs/ufs/ufs_extern.h index cc6078065e7f..a28fcffabd2e 100644 --- a/sys/ufs/ufs/ufs_extern.h +++ b/sys/ufs/ufs/ufs_extern.h @@ -119,6 +119,13 @@ void softdep_revert_rmdir(struct inode *, struct inode *); * * Note: The general vfs code typically limits the sequential heuristic * count to 127. See sequential_heuristic() in kern/vfs_vnops.c + * + * The BA_CLRBUF flag specifies that the existing content of the block + * will not be completely overwritten by the caller, so buffers for new + * blocks must be cleared and buffers for existing blocks must be read. + * When BA_CLRBUF is not set the buffer will be completely overwritten + * and there is no reason to clear them or to spend I/O fetching existing + * data. The BA_CLRBUF flag is handled in the UFS_BALLOC() functions. */ #define BA_CLRBUF 0x00010000 /* Clear invalid areas of buffer. */ #define BA_METAONLY 0x00020000 /* Return indirect block buffer. */ |