| Message ID | 20240208172024.23625-5-shikemeng@huaweicloud.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Fixes and cleanups to fs-writeback | expand |
On Fri, 2024-02-09 at 01:20 +0800, Kemeng Shi wrote: > I_DIRTY_ALL consists of I_DIRTY_TIME and I_DIRTY, so I_DIRTY_TIME must > be set when any bit of I_DIRTY_ALL is set but I_DIRTY is not set. /s/any bit of/some bit in/ > > Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed by: Tim Chen <tim.c.chen@linux.intel.com> > --- > fs/fs-writeback.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c > index 2619f74ced70..b61bf2075931 100644 > --- a/fs/fs-writeback.c > +++ b/fs/fs-writeback.c > @@ -1788,7 +1788,7 @@ static int writeback_single_inode(struct inode *inode, > else if (!(inode->i_state & I_SYNC_QUEUED)) { > if ((inode->i_state & I_DIRTY)) > redirty_tail_locked(inode, wb); > - else if (inode->i_state & I_DIRTY_TIME) { > + else { > inode->dirtied_when = jiffies; > inode_io_list_move_locked(inode, > wb,
On Fri, Feb 09, 2024 at 01:20:21AM +0800, Kemeng Shi wrote: > I_DIRTY_ALL consists of I_DIRTY_TIME and I_DIRTY, so I_DIRTY_TIME must > be set when any bit of I_DIRTY_ALL is set but I_DIRTY is not set. > > Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> > --- > fs/fs-writeback.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c > index 2619f74ced70..b61bf2075931 100644 > --- a/fs/fs-writeback.c > +++ b/fs/fs-writeback.c > @@ -1788,7 +1788,7 @@ static int writeback_single_inode(struct inode *inode, > else if (!(inode->i_state & I_SYNC_QUEUED)) { > if ((inode->i_state & I_DIRTY)) > redirty_tail_locked(inode, wb); > - else if (inode->i_state & I_DIRTY_TIME) { > + else { > inode->dirtied_when = jiffies; > inode_io_list_move_locked(inode, > wb, NAK. The code is correct and the behaviour that is intended it obvious from the code as it stands. It is -incorrect- to move any inode that does not have I_DIRTY_TIME to the wb->b_dirty_time list. By removing the I_DIRTY_TIME guard from this code, you are leaving a nasty, undocumented logic trap in the code that somebody is guaranteed to trip over into in the future. That's making the code worse, not better.... -Dave.
on 2/10/2024 8:46 AM, Dave Chinner wrote: > On Fri, Feb 09, 2024 at 01:20:21AM +0800, Kemeng Shi wrote: >> I_DIRTY_ALL consists of I_DIRTY_TIME and I_DIRTY, so I_DIRTY_TIME must >> be set when any bit of I_DIRTY_ALL is set but I_DIRTY is not set. >> >> Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> >> --- >> fs/fs-writeback.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c >> index 2619f74ced70..b61bf2075931 100644 >> --- a/fs/fs-writeback.c >> +++ b/fs/fs-writeback.c >> @@ -1788,7 +1788,7 @@ static int writeback_single_inode(struct inode *inode, >> else if (!(inode->i_state & I_SYNC_QUEUED)) { >> if ((inode->i_state & I_DIRTY)) >> redirty_tail_locked(inode, wb); >> - else if (inode->i_state & I_DIRTY_TIME) { >> + else { >> inode->dirtied_when = jiffies; >> inode_io_list_move_locked(inode, >> wb, > > NAK. > > The code is correct and the behaviour that is intended it obvious > from the code as it stands. > > It is -incorrect- to move any inode that does not have I_DIRTY_TIME > to the wb->b_dirty_time list. By removing the I_DIRTY_TIME guard > from this code, you are leaving a nasty, undocumented logic trap in > the code that somebody is guaranteed to trip over into in the > future. That's making the code worse, not better.... Sure, I will remove this one in next version. Thanks for the explanation. > > -Dave. >
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 2619f74ced70..b61bf2075931 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -1788,7 +1788,7 @@ static int writeback_single_inode(struct inode *inode, else if (!(inode->i_state & I_SYNC_QUEUED)) { if ((inode->i_state & I_DIRTY)) redirty_tail_locked(inode, wb); - else if (inode->i_state & I_DIRTY_TIME) { + else { inode->dirtied_when = jiffies; inode_io_list_move_locked(inode, wb,
I_DIRTY_ALL consists of I_DIRTY_TIME and I_DIRTY, so I_DIRTY_TIME must be set when any bit of I_DIRTY_ALL is set but I_DIRTY is not set. Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> --- fs/fs-writeback.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)