diff options
Diffstat (limited to 'fs/coda/file.c')
| -rw-r--r-- | fs/coda/file.c | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/fs/coda/file.c b/fs/coda/file.c new file mode 100644 index 000000000..225ca881a --- /dev/null +++ b/fs/coda/file.c @@ -0,0 +1,240 @@ +/* + * File operations for Coda. + * Original version: (C) 1996 Peter Braam + * Rewritten for Linux 2.1: (C) 1997 Carnegie Mellon University + * + * Carnegie Mellon encourages users of this code to contribute improvements + * to the Coda project. Contact Peter Braam <coda@cs.cmu.edu>. + */ + +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/fs.h> +#include <linux/stat.h> +#include <linux/errno.h> +#include <linux/locks.h> +#include <asm/segment.h> +#include <linux/string.h> +#include <asm/uaccess.h> + +#include <linux/coda_namecache.h> +#include <linux/coda.h> +#include <linux/coda_linux.h> +#include <linux/coda_cnode.h> +#include <linux/coda_psdev.h> + +/* file operations */ +static int coda_readpage(struct inode * inode, struct page * page); +static ssize_t coda_file_read(struct file *f, char *buf, size_t count, loff_t *off); +static ssize_t coda_file_write(struct file *f, const char *buf, size_t count, loff_t *off); +static int coda_file_mmap(struct file * file, struct vm_area_struct * vma); + +/* exported from this file */ +struct inode_operations coda_file_inode_operations = { + &coda_file_operations, /* default file operations */ + NULL, /* create */ + NULL, /* lookup */ + NULL, /* link */ + NULL, /* unlink */ + NULL, /* symlink */ + NULL, /* mkdir */ + NULL, /* rmdir */ + NULL, /* mknod */ + NULL, /* rename */ + NULL, /* readlink */ + NULL, /* follow_link */ + coda_readpage, /* readpage */ + NULL, /* writepage */ + NULL, /* bmap */ + NULL, /* truncate */ + coda_permission, /* permission */ + NULL, /* smap */ + NULL, /* update page */ + NULL /* revalidate */ +}; + +struct file_operations coda_file_operations = { + NULL, /* lseek - default should work for coda */ + coda_file_read, /* read */ + coda_file_write, /* write */ + NULL, /* readdir */ + NULL, /* select - default */ + NULL, /* ioctl */ + coda_file_mmap, /* mmap */ + coda_open, /* open */ + coda_release, /* release */ + NULL, /* fsync */ +}; + +/* File file operations */ +static int coda_readpage(struct inode * inode, struct page * page) +{ + struct inode *open_inode; + struct cnode *cnp; + + ENTRY; + + cnp = ITOC(inode); + CHECK_CNODE(cnp); + + if ( ! cnp->c_ovp ) { + printk("coda_readpage: no open inode for ino %ld\n", inode->i_ino); + return -ENXIO; + } + + open_inode = cnp->c_ovp; + + CDEBUG(D_INODE, "coda ino: %ld, cached ino %ld, page offset: %lx\n", inode->i_ino, open_inode->i_ino, page->offset); + + generic_readpage(open_inode, page); + EXIT; + return 0; +} + +static int coda_file_mmap(struct file * file, struct vm_area_struct * vma) +{ + struct cnode *cnp; + cnp = ITOC(file->f_dentry->d_inode); + cnp->c_mmcount++; + + return generic_file_mmap(file, vma); +} + +static ssize_t coda_file_read(struct file *coda_file, char *buff, + size_t count, loff_t *ppos) +{ + struct cnode *cnp; + struct inode *coda_inode = coda_file->f_dentry->d_inode; + struct inode *cont_inode = NULL; + struct file cont_file; + struct dentry cont_dentry; + int result = 0; + + ENTRY; + + cnp = ITOC(coda_inode); + CHECK_CNODE(cnp); + + cont_inode = cnp->c_ovp; + if ( cont_inode == NULL ) { + printk("coda_file_read: cached inode is 0!\n"); + return -1; + } + + coda_prepare_openfile(coda_inode, coda_file, cont_inode, + &cont_file, &cont_dentry); + + if (!cont_file.f_op || ! cont_file.f_op->read) { + printk( "container file has no read in file operations.\n"); + return -1; + } + + result = cont_file.f_op->read(&cont_file , buff, count, + &(cont_file.f_pos)); + + CDEBUG(D_FILE, "ops at %x result %d, count %d, position: %d\n", + (int)cont_file.f_op, result, count, (int)cont_file.f_pos); + + coda_restore_codafile(coda_inode, coda_file, cont_inode, &cont_file); + return result; +} + + +static ssize_t coda_file_write(struct file *coda_file, const char *buff, + size_t count, loff_t *ppos) +{ + struct cnode *cnp; + struct inode *coda_inode = coda_file->f_dentry->d_inode; + struct inode *cont_inode = NULL; + struct file cont_file; + struct dentry cont_dentry; + int result = 0; + + ENTRY; + + cnp = ITOC(coda_inode); + CHECK_CNODE(cnp); + + cont_inode = cnp->c_ovp; + if ( cont_inode == NULL ) { + printk("coda_file_write: cached inode is 0!\n"); + return -1; + } + + coda_prepare_openfile(coda_inode, coda_file, cont_inode, + &cont_file, &cont_dentry); + + if (!cont_file.f_op || !cont_file.f_op->write) { + printk("coda_file_write: container file has no file ops.\n"); + return -1; + } + + cnp->c_flags &= ~C_VATTR; + + down(&cont_inode->i_sem); + result = cont_file.f_op->write(&cont_file , buff, count, + &(cont_file.f_pos)); + up(&cont_inode->i_sem); + coda_restore_codafile(coda_inode, coda_file, cont_inode, &cont_file); + + return result; +} + + + +/* + * support routines + */ + +/* instantiate the container file and dentry object to do io */ +void coda_prepare_openfile(struct inode *i, struct file *coda_file, + struct inode *cont_inode, struct file *cont_file, + struct dentry *cont_dentry) +{ + cont_file->f_pos = coda_file->f_pos; + cont_file->f_mode = coda_file->f_mode; + cont_file->f_flags = coda_file->f_flags; + cont_file->f_count = coda_file->f_count; + cont_file->f_owner = coda_file->f_owner; + cont_file->f_op = cont_inode->i_op->default_file_ops; + cont_file->f_dentry = cont_dentry; + cont_file->f_dentry->d_inode = cont_inode; + return ; +} + +/* update the Coda file & inode after I/O */ +void coda_restore_codafile(struct inode *coda_inode, struct file *coda_file, + struct inode *open_inode, struct file *open_file) +{ + coda_file->f_pos = open_file->f_pos; + /* XXX what about setting the mtime here too? */ + coda_inode->i_mtime = open_inode->i_mtime; + coda_inode->i_size = open_inode->i_size; + return; +} + +/* grab the ext2 inode of the container file */ +int coda_inode_grab(dev_t dev, ino_t ino, struct inode **ind) +{ + struct super_block *sbptr; + + sbptr = get_super(dev); + + if ( !sbptr ) { + printk("coda_inode_grab: coda_find_super returns NULL.\n"); + return -ENXIO; + } + + *ind = NULL; + *ind = iget(sbptr, ino); + + if ( *ind == NULL ) { + printk("coda_inode_grab: iget(dev: %d, ino: %ld) + returns NULL.\n", dev, ino); + return -ENOENT; + } + CDEBUG(D_FILE, "ino: %ld, ops at %x\n", ino, (int)(*ind)->i_op); + return 0; +} + |