From: Denys Vlasenko I noticed that read/write/rdwr_pipe_fops are (1) const and (2) exactly identical to xxx_fifo_fops, which are also const. Use the same struct file_operations objects for ->f_op of pipes and fifos. Size difference: # size linux-2.6.25-rc6*/*/pipe.o text data bss dec hex filename 6534 144 0 6678 1a16 linux-2.6.25-rc6/fs/pipe.o 5862 144 0 6006 1776 linux-2.6.25-rc6-pt/fs/pipe.o Signed-off-by: Denys Vlasenko Cc: Christoph Hellwig Cc: Al Viro Cc: Jens Axboe Signed-off-by: Andrew Morton --- fs/fifo.c | 8 +++--- fs/pipe.c | 51 ++++++------------------------------------- include/linux/fs.h | 6 ++--- 3 files changed, 15 insertions(+), 50 deletions(-) diff -puN fs/fifo.c~fifo-pipe-reuse-xxx_fifo_fops-for-xxx_pipe_fops fs/fifo.c --- a/fs/fifo.c~fifo-pipe-reuse-xxx_fifo_fops-for-xxx_pipe_fops +++ a/fs/fifo.c @@ -57,7 +57,7 @@ static int fifo_open(struct inode *inode * POSIX.1 says that O_NONBLOCK means return with the FIFO * opened, even when there is no process writing the FIFO. */ - filp->f_op = &read_fifo_fops; + filp->f_op = &read_pipefifo_fops; pipe->r_counter++; if (pipe->readers++ == 0) wake_up_partner(inode); @@ -86,7 +86,7 @@ static int fifo_open(struct inode *inode if ((filp->f_flags & O_NONBLOCK) && !pipe->readers) goto err; - filp->f_op = &write_fifo_fops; + filp->f_op = &write_pipefifo_fops; pipe->w_counter++; if (!pipe->writers++) wake_up_partner(inode); @@ -105,7 +105,7 @@ static int fifo_open(struct inode *inode * This implementation will NEVER block on a O_RDWR open, since * the process can at least talk to itself. */ - filp->f_op = &rdwr_fifo_fops; + filp->f_op = &rdwr_pipefifo_fops; pipe->readers++; pipe->writers++; @@ -151,5 +151,5 @@ err_nocleanup: * depending on the access mode of the file... */ const struct file_operations def_fifo_fops = { - .open = fifo_open, /* will set read or write pipe_fops */ + .open = fifo_open, /* will set read_ or write_pipefifo_fops */ }; diff -puN fs/pipe.c~fifo-pipe-reuse-xxx_fifo_fops-for-xxx_pipe_fops fs/pipe.c --- a/fs/pipe.c~fifo-pipe-reuse-xxx_fifo_fops-for-xxx_pipe_fops +++ a/fs/pipe.c @@ -777,8 +777,10 @@ pipe_rdwr_open(struct inode *inode, stru /* * The file_operations structs are not static because they * are also used in linux/fs/fifo.c to do operations on FIFOs. + * + * Pipes reuse fifos' file_operations structs. */ -const struct file_operations read_fifo_fops = { +const struct file_operations read_pipefifo_fops = { .llseek = no_llseek, .read = do_sync_read, .aio_read = pipe_read, @@ -790,7 +792,7 @@ const struct file_operations read_fifo_f .fasync = pipe_read_fasync, }; -const struct file_operations write_fifo_fops = { +const struct file_operations write_pipefifo_fops = { .llseek = no_llseek, .read = bad_pipe_r, .write = do_sync_write, @@ -802,44 +804,7 @@ const struct file_operations write_fifo_ .fasync = pipe_write_fasync, }; -const struct file_operations rdwr_fifo_fops = { - .llseek = no_llseek, - .read = do_sync_read, - .aio_read = pipe_read, - .write = do_sync_write, - .aio_write = pipe_write, - .poll = pipe_poll, - .unlocked_ioctl = pipe_ioctl, - .open = pipe_rdwr_open, - .release = pipe_rdwr_release, - .fasync = pipe_rdwr_fasync, -}; - -static const struct file_operations read_pipe_fops = { - .llseek = no_llseek, - .read = do_sync_read, - .aio_read = pipe_read, - .write = bad_pipe_w, - .poll = pipe_poll, - .unlocked_ioctl = pipe_ioctl, - .open = pipe_read_open, - .release = pipe_read_release, - .fasync = pipe_read_fasync, -}; - -static const struct file_operations write_pipe_fops = { - .llseek = no_llseek, - .read = bad_pipe_r, - .write = do_sync_write, - .aio_write = pipe_write, - .poll = pipe_poll, - .unlocked_ioctl = pipe_ioctl, - .open = pipe_write_open, - .release = pipe_write_release, - .fasync = pipe_write_fasync, -}; - -static const struct file_operations rdwr_pipe_fops = { +const struct file_operations rdwr_pipefifo_fops = { .llseek = no_llseek, .read = do_sync_read, .aio_read = pipe_read, @@ -927,7 +892,7 @@ static struct inode * get_pipe_inode(voi inode->i_pipe = pipe; pipe->readers = pipe->writers = 1; - inode->i_fop = &rdwr_pipe_fops; + inode->i_fop = &rdwr_pipefifo_fops; /* * Mark the inode dirty from the very beginning, @@ -978,7 +943,7 @@ struct file *create_write_pipe(void) d_instantiate(dentry, inode); err = -ENFILE; - f = alloc_file(pipe_mnt, dentry, FMODE_WRITE, &write_pipe_fops); + f = alloc_file(pipe_mnt, dentry, FMODE_WRITE, &write_pipefifo_fops); if (!f) goto err_dentry; f->f_mapping = inode->i_mapping; @@ -1020,7 +985,7 @@ struct file *create_read_pipe(struct fil f->f_pos = 0; f->f_flags = O_RDONLY; - f->f_op = &read_pipe_fops; + f->f_op = &read_pipefifo_fops; f->f_mode = FMODE_READ; f->f_version = 0; diff -puN include/linux/fs.h~fifo-pipe-reuse-xxx_fifo_fops-for-xxx_pipe_fops include/linux/fs.h --- a/include/linux/fs.h~fifo-pipe-reuse-xxx_fifo_fops-for-xxx_pipe_fops +++ a/include/linux/fs.h @@ -1699,9 +1699,9 @@ extern void init_special_inode(struct in extern void make_bad_inode(struct inode *); extern int is_bad_inode(struct inode *); -extern const struct file_operations read_fifo_fops; -extern const struct file_operations write_fifo_fops; -extern const struct file_operations rdwr_fifo_fops; +extern const struct file_operations read_pipefifo_fops; +extern const struct file_operations write_pipefifo_fops; +extern const struct file_operations rdwr_pipefifo_fops; extern int fs_may_remount_ro(struct super_block *); _