On Fri, Aug 20, 2021 at 10:59:28AM +0300, Nikolay Borisov wrote: > > > On 18.08.21 г. 0:06, Omar Sandoval wrote: > > From: Omar Sandoval <osandov@xxxxxx> > > > > Encoded I/O in Btrfs needs to check a write with a given logical size > > without an iov_iter that matches that size (because the iov_iter we have > > is for the compressed data). So, factor out the parts of > > generic_write_check() that expect an iov_iter into a new > > __generic_write_checks() function and export that. > > > > Signed-off-by: Omar Sandoval <osandov@xxxxxx> > > --- > > fs/read_write.c | 40 ++++++++++++++++++++++------------------ > > include/linux/fs.h | 1 + > > 2 files changed, 23 insertions(+), 18 deletions(-) > > > > diff --git a/fs/read_write.c b/fs/read_write.c > > index 0029ff2b0ca8..3bddd5ee7f64 100644 > > --- a/fs/read_write.c > > +++ b/fs/read_write.c > > @@ -1633,6 +1633,26 @@ int generic_write_check_limits(struct file *file, loff_t pos, loff_t *count) > > return 0; > > } > > > > +/* Like generic_write_checks(), but takes size of write instead of iter. */ > > +int __generic_write_checks(struct kiocb *iocb, loff_t *count) > > +{ > > + struct file *file = iocb->ki_filp; > > + struct inode *inode = file->f_mapping->host; > > + > > + if (IS_SWAPFILE(inode)) > > + return -ETXTBSY; > > Missing 'if(!count) return 0' from original code ? Good catch, thanks.