On Fri, Jul 18, 2014 at 4:47 PM, Lukáš Czerner <lczerner@xxxxxxxxxx> wrote: > On Fri, 18 Jul 2014, Rohan Puri wrote: > >> Date: Fri, 18 Jul 2014 16:13:21 +0530 >> From: Rohan Puri <rohan.puri15@xxxxxxxxx> >> To: Lukáš Czerner <lczerner@xxxxxxxxxx> >> Cc: hch@xxxxxxxxxxxxx, viro@xxxxxxxxxxxxxxxxxx, >> Linux FS Devel <linux-fsdevel@xxxxxxxxxxxxxxx> >> Subject: Re: [PATCH 1/2] Remove misleading comment in do_fallocate() >> >> On Fri, Jul 18, 2014 at 4:05 PM, Lukáš Czerner <lczerner@xxxxxxxxxx> wrote: >> >> > On Fri, 18 Jul 2014, Rohan Puri wrote: >> > >> > > Date: Fri, 18 Jul 2014 15:27:26 +0530 >> > > From: Rohan Puri <rohan.puri15@xxxxxxxxx> >> > > To: hch@xxxxxxxxxxxxx, viro@xxxxxxxxxxxxxxxxxx >> > > Cc: linux-fsdevel@xxxxxxxxxxxxxxx >> > > Subject: [PATCH 1/2] Remove misleading comment in do_fallocate() >> > > >> > > Preallocation for directory gets blocked at 2 places & never gets >> > propogated >> > > to the underlying file system : - >> > > >> > > - open(2) with O_DIRECTORY | O_WRONLY or O_DIRECTORY | O_RDWR >> > > at do_last()->may_open(). >> > > - open(2) with O_DIRECTORY | O_RDONLY -> fallocate(2) at do_fallocate(). >> > > >> > > Signed-off-by: Rohan Puri <rohan.puri15@xxxxxxxxx> >> > > --- >> > > fs/open.c | 4 ---- >> > > 1 file changed, 4 deletions(-) >> > > >> > > diff --git a/fs/open.c b/fs/open.c >> > > index 9d64679..5d4f372 100644 >> > > --- a/fs/open.c >> > > +++ b/fs/open.c >> > > @@ -280,10 +280,6 @@ int do_fallocate(struct file *file, int mode, >> > loff_t offset, loff_t len) >> > > if (S_ISFIFO(inode->i_mode)) >> > > return -ESPIPE; >> > > >> > > - /* >> > > - * Let individual file system decide if it supports preallocation >> > > - * for directories or not. >> > > - */ >> > >> > What's wrong about this comment ? We're only going to let through >> > regular files and directories and it's up to the file system to >> > decide what it want to support. >> > >> I agree, but AFAIK for directories we are never going to reach upto the >> file systems, since directory file opened with O_WRONLY or O_RDWR flag gets >> blocked by open(2)->do_last()->may_open() and directory with O_RDONLY gets >> blocked by do_fallocate() returning -EBADF. > > That's something that needs to be resolved when someone decides to > add fallocate support for directories. There has already been a > small discussion about that idea. > > So I think that the comment is just fine from the fallocate > perspective. sounds good. Thanks Lukas for clarification :) > > -Lukas > >> So this comment is misleading in terms that for directory we never go to >> file systems during fallocate. >> >> > >> > -Lukas >> > >> > > if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode)) >> > > return -ENODEV; >> > > >> > > >> > >> >> - Rohan >> - Rohan -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
