| Message ID | 20180412150826.20988-12-mszeredi@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Apr 12, 2018 at 6:08 PM, Miklos Szeredi <mszeredi@redhat.com> wrote: > Implement stacked reading. > I couldn't decipher the meaning of "readd" in the subject of this and other file ops pacthes?? > Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> > --- > fs/overlayfs/file.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 56 insertions(+) > > diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c > index 409b542ff30c..a19429c5965d 100644 > --- a/fs/overlayfs/file.c > +++ b/fs/overlayfs/file.c > @@ -9,6 +9,7 @@ > #include <linux/cred.h> > #include <linux/file.h> > #include <linux/xattr.h> > +#include <linux/uio.h> > #include "overlayfs.h" > > static struct file *ovl_open_realfile(const struct file *file) > @@ -129,8 +130,63 @@ static loff_t ovl_llseek(struct file *file, loff_t offset, int whence) > i_size_read(realinode)); > } > > +static void ovl_file_accessed(struct file *file) > +{ > + struct inode *inode = file_inode(file); > + > + if ((file->f_flags & O_NOATIME) || !ovl_inode_upper(inode)) > + return; > + > + ovl_copytimes(inode); > + touch_atime(&file->f_path); > +} > + > +static rwf_t ovl_iocb_to_rwf(struct kiocb *iocb) > +{ > + int ifl = iocb->ki_flags; > + rwf_t flags = 0; > + > + if (ifl & IOCB_NOWAIT) > + flags |= RWF_NOWAIT; > + if (ifl & IOCB_HIPRI) > + flags |= RWF_HIPRI; > + if (ifl & IOCB_DSYNC) > + flags |= RWF_DSYNC; > + if (ifl & IOCB_SYNC) > + flags |= RWF_SYNC; > + > + return flags; > +} > + > +static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter) > +{ > + struct file *file = iocb->ki_filp; > + struct fd real; > + const struct cred *old_cred; > + ssize_t ret; > + > + if (!iov_iter_count(iter)) > + return 0; > + > + ret = ovl_real_file(file, &real); > + if (ret) > + return ret; > + > + old_cred = ovl_override_creds(file_inode(file)->i_sb); > + ret = vfs_iter_read(real.file, iter, &iocb->ki_pos, > + ovl_iocb_to_rwf(iocb)); > + revert_creds(old_cred); > + > + ovl_file_accessed(file); > + > + fdput(real); I find it confusing that the name of ovl_real_file() does not suggest it may take a reference, so this fdput() looks unbalanced. All other ovl_XXX_{real,upper,lower} helpers do not take a reference. Perhaps something along the lines of ovl_file_real_fdget(). Thanks, Amir.
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c index 409b542ff30c..a19429c5965d 100644 --- a/fs/overlayfs/file.c +++ b/fs/overlayfs/file.c @@ -9,6 +9,7 @@ #include <linux/cred.h> #include <linux/file.h> #include <linux/xattr.h> +#include <linux/uio.h> #include "overlayfs.h" static struct file *ovl_open_realfile(const struct file *file) @@ -129,8 +130,63 @@ static loff_t ovl_llseek(struct file *file, loff_t offset, int whence) i_size_read(realinode)); } +static void ovl_file_accessed(struct file *file) +{ + struct inode *inode = file_inode(file); + + if ((file->f_flags & O_NOATIME) || !ovl_inode_upper(inode)) + return; + + ovl_copytimes(inode); + touch_atime(&file->f_path); +} + +static rwf_t ovl_iocb_to_rwf(struct kiocb *iocb) +{ + int ifl = iocb->ki_flags; + rwf_t flags = 0; + + if (ifl & IOCB_NOWAIT) + flags |= RWF_NOWAIT; + if (ifl & IOCB_HIPRI) + flags |= RWF_HIPRI; + if (ifl & IOCB_DSYNC) + flags |= RWF_DSYNC; + if (ifl & IOCB_SYNC) + flags |= RWF_SYNC; + + return flags; +} + +static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter) +{ + struct file *file = iocb->ki_filp; + struct fd real; + const struct cred *old_cred; + ssize_t ret; + + if (!iov_iter_count(iter)) + return 0; + + ret = ovl_real_file(file, &real); + if (ret) + return ret; + + old_cred = ovl_override_creds(file_inode(file)->i_sb); + ret = vfs_iter_read(real.file, iter, &iocb->ki_pos, + ovl_iocb_to_rwf(iocb)); + revert_creds(old_cred); + + ovl_file_accessed(file); + + fdput(real); + + return ret; +} + const struct file_operations ovl_file_operations = { .open = ovl_open, .release = ovl_release, .llseek = ovl_llseek, + .read_iter = ovl_read_iter, };
Implement stacked reading. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> --- fs/overlayfs/file.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+)