| Message ID | 20240830-vfs-file-f_version-v1-19-6d3e4816aa7b@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | file: remove f_version | expand |
On Fri 30-08-24 15:05:00, Christian Brauner wrote: > Pipes use f_version to defer poll notifications until a write has been > observed. Since multiple file's refer to the same struct pipe_inode_info > in their ->private_data moving it into their isn't feasible since we > would need to introduce an additional pointer indirection. > > However, since pipes don't require f_pos_lock we placed a new f_pipe > member into a union with f_pos_lock that pipes can use. This is similar > to what we already do for struct inode where we have additional fields > per file type. This will allow us to fully remove f_version in the next > step. > > Signed-off-by: Christian Brauner <brauner@kernel.org> Looks good. Feel free to add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > fs/pipe.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/fs/pipe.c b/fs/pipe.c > index 7dff2aa50a6d..b8f1943c57b9 100644 > --- a/fs/pipe.c > +++ b/fs/pipe.c > @@ -686,7 +686,7 @@ pipe_poll(struct file *filp, poll_table *wait) > if (filp->f_mode & FMODE_READ) { > if (!pipe_empty(head, tail)) > mask |= EPOLLIN | EPOLLRDNORM; > - if (!pipe->writers && filp->f_version != pipe->w_counter) > + if (!pipe->writers && filp->f_pipe != pipe->w_counter) > mask |= EPOLLHUP; > } > > @@ -1108,7 +1108,7 @@ static int fifo_open(struct inode *inode, struct file *filp) > bool is_pipe = inode->i_sb->s_magic == PIPEFS_MAGIC; > int ret; > > - filp->f_version = 0; > + filp->f_pipe = 0; > > spin_lock(&inode->i_lock); > if (inode->i_pipe) { > @@ -1155,7 +1155,7 @@ static int fifo_open(struct inode *inode, struct file *filp) > if ((filp->f_flags & O_NONBLOCK)) { > /* suppress EPOLLHUP until we have > * seen a writer */ > - filp->f_version = pipe->w_counter; > + filp->f_pipe = pipe->w_counter; > } else { > if (wait_for_partner(pipe, &pipe->w_counter)) > goto err_rd; > > -- > 2.45.2 >
diff --git a/fs/pipe.c b/fs/pipe.c index 7dff2aa50a6d..b8f1943c57b9 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -686,7 +686,7 @@ pipe_poll(struct file *filp, poll_table *wait) if (filp->f_mode & FMODE_READ) { if (!pipe_empty(head, tail)) mask |= EPOLLIN | EPOLLRDNORM; - if (!pipe->writers && filp->f_version != pipe->w_counter) + if (!pipe->writers && filp->f_pipe != pipe->w_counter) mask |= EPOLLHUP; } @@ -1108,7 +1108,7 @@ static int fifo_open(struct inode *inode, struct file *filp) bool is_pipe = inode->i_sb->s_magic == PIPEFS_MAGIC; int ret; - filp->f_version = 0; + filp->f_pipe = 0; spin_lock(&inode->i_lock); if (inode->i_pipe) { @@ -1155,7 +1155,7 @@ static int fifo_open(struct inode *inode, struct file *filp) if ((filp->f_flags & O_NONBLOCK)) { /* suppress EPOLLHUP until we have * seen a writer */ - filp->f_version = pipe->w_counter; + filp->f_pipe = pipe->w_counter; } else { if (wait_for_partner(pipe, &pipe->w_counter)) goto err_rd;
Pipes use f_version to defer poll notifications until a write has been observed. Since multiple file's refer to the same struct pipe_inode_info in their ->private_data moving it into their isn't feasible since we would need to introduce an additional pointer indirection. However, since pipes don't require f_pos_lock we placed a new f_pipe member into a union with f_pos_lock that pipes can use. This is similar to what we already do for struct inode where we have additional fields per file type. This will allow us to fully remove f_version in the next step. Signed-off-by: Christian Brauner <brauner@kernel.org> --- fs/pipe.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)