| Message ID | 1235451952-2726-6-git-send-email-tytso@mit.edu |
|---|---|
| State | Accepted, archived |
| Headers | show |
On Feb 24, 2009 00:05 -0500, Theodore Ts'o wrote: > When closing a file that had been previously truncated, force any > delay allocated blocks that to be allocated so that if the filesystem > is mounted with data=ordered, the data blocks will be pushed out to > disk along with the journal commit. Many application programs expect > this, so we do this to avoid zero length files if the system crashes > unexpectedly. Should this only be done with "truncate-to-zero" operations, or any truncate? Some applications may do extending truncates in order to trigger file preallocation ala Windows, and we don't necessarily want to punish all of the IO for those files. Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Feb 24, 2009 at 03:13:44AM -0700, Andreas Dilger wrote: > On Feb 24, 2009 00:05 -0500, Theodore Ts'o wrote: > > When closing a file that had been previously truncated, force any > > delay allocated blocks that to be allocated so that if the filesystem > > is mounted with data=ordered, the data blocks will be pushed out to > > disk along with the journal commit. Many application programs expect > > this, so we do this to avoid zero length files if the system crashes > > unexpectedly. > > Should this only be done with "truncate-to-zero" operations, or any > truncate? Some applications may do extending truncates in order to > trigger file preallocation ala Windows, and we don't necessarily want > to punish all of the IO for those files. Agreed, we should only do this on a truncate-to-zero. I'll fix up the patch to only set EXT4_STATE_DA_ALLOC_CLOSE on truncate if inode->i_size is 0. - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 626bda7..b56245d 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -269,6 +269,7 @@ static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags) #define EXT4_STATE_NEW 0x00000002 /* inode is newly created */ #define EXT4_STATE_XATTR 0x00000004 /* has in-inode xattrs */ #define EXT4_STATE_NO_EXPAND 0x00000008 /* No space for expansion */ +#define EXT4_STATE_DA_ALLOC_CLOSE 0x00000010 /* Alloc DA blks on close */ /* Used to pass group descriptor data when online resize is done */ struct ext4_new_group_input { diff --git a/fs/ext4/file.c b/fs/ext4/file.c index f731cb5..06df827 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -33,6 +33,10 @@ */ static int ext4_release_file(struct inode *inode, struct file *filp) { + if (EXT4_I(inode)->i_state & EXT4_STATE_DA_ALLOC_CLOSE) { + ext4_alloc_da_blocks(inode); + EXT4_I(inode)->i_state &= ~EXT4_STATE_DA_ALLOC_CLOSE; + } /* if we are the last writer on the inode, drop the block reservation */ if ((filp->f_mode & FMODE_WRITE) && (atomic_read(&inode->i_writecount) == 1)) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index c66af1c..22993ca 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3871,6 +3871,8 @@ void ext4_truncate(struct inode *inode) if (!ext4_can_truncate(inode)) return; + ei->i_state |= EXT4_STATE_DA_ALLOC_CLOSE; + if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) { ext4_ext_truncate(inode); return;
When closing a file that had been previously truncated, force any delay allocated blocks that to be allocated so that if the filesystem is mounted with data=ordered, the data blocks will be pushed out to disk along with the journal commit. Many application programs expect this, so we do this to avoid zero length files if the system crashes unexpectedly. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> --- fs/ext4/ext4.h | 1 + fs/ext4/file.c | 4 ++++ fs/ext4/inode.c | 2 ++ 3 files changed, 7 insertions(+), 0 deletions(-)