Re: [Jfs-discussion] [PATCH] fs/jfs: TRIM support for JFS Filesystem
Brought to you by:
blaschke-oss,
shaggyk
From: Dave K. <dav...@or...> - 2012-08-01 20:07:39
|
On 08/01/2012 02:29 PM, Tino Reichardt wrote: > * Dave Kleikamp <dav...@or...> wrote: >> On 07/28/2012 06:08 AM, Tino Reichardt wrote: >>> + tt->nblocks = 0; /* mark the current end */ >>> + for (tt = totrim; tt->nblocks != 0; tt++) { >>> + if (!(JFS_SBI(sb)->flag & JFS_DISCARD)) { >>> + /* not needed, when online discard is used */ >> >> Why enter the function at all if JFS_DISCARD is set? But is this really >> true? Removing files or file fragments that are smaller than >> minblks_trim will fail to discard them dynamically. > > The other FS can also trim via fstrim(8) when mounted with discard > option :) It is important, that a user can discard all free blocks, even > when mounting with discard option. The FS could also be mounted several > times without discard option, and then there are some ranges, where the > device isn't informed about these ranges. So the batched discard ioctl() > is then the only way to change that. > > > The comment there was also a bit updated, here is it: > > /* when mounted with online discard, dbFree() will > * call jfs_issue_discard() itself */ Ah. This comments makes it clear. I was forgetting that dbFree will handle this. Thanks, Dave |