diff options
Diffstat (limited to 'fs/nfs/file.c')
| -rw-r--r-- | fs/nfs/file.c | 484 |
1 files changed, 484 insertions, 0 deletions
diff --git a/fs/nfs/file.c b/fs/nfs/file.c new file mode 100644 index 000000000000..f06eee6dcff5 --- /dev/null +++ b/fs/nfs/file.c @@ -0,0 +1,484 @@ +/* + * linux/fs/nfs/file.c + * + * Copyright (C) 1992 Rick Sladkey + * + * Changes Copyright (C) 1994 by Florian La Roche + * - Do not copy data too often around in the kernel. + * - In nfs_file_read the return value of kmalloc wasn't checked. + * - Put in a better version of read look-ahead buffering. Original idea + * and implementation by Wai S Kok elekokws@ee.nus.sg. + * + * Expire cache on write to a file by Wai S Kok (Oct 1994). + * + * Total rewrite of read side for new NFS buffer cache.. Linus. + * + * nfs regular file handling functions + */ + +#include <linux/time.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/fcntl.h> +#include <linux/stat.h> +#include <linux/nfs_fs.h> +#include <linux/nfs_mount.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/pagemap.h> +#include <linux/smp_lock.h> + +#include <asm/uaccess.h> +#include <asm/system.h> + +#include "delegation.h" + +#define NFSDBG_FACILITY NFSDBG_FILE + +static int nfs_file_open(struct inode *, struct file *); +static int nfs_file_release(struct inode *, struct file *); +static int nfs_file_mmap(struct file *, struct vm_area_struct *); +static ssize_t nfs_file_sendfile(struct file *, loff_t *, size_t, read_actor_t, void *); +static ssize_t nfs_file_read(struct kiocb *, char __user *, size_t, loff_t); +static ssize_t nfs_file_write(struct kiocb *, const char __user *, size_t, loff_t); +static int nfs_file_flush(struct file *); +static int nfs_fsync(struct file *, struct dentry *dentry, int datasync); +static int nfs_check_flags(int flags); +static int nfs_lock(struct file *filp, int cmd, struct file_lock *fl); +static int nfs_flock(struct file *filp, int cmd, struct file_lock *fl); + +struct file_operations nfs_file_operations = { + .llseek = remote_llseek, + .read = do_sync_read, + .write = do_sync_write, + .aio_read = nfs_file_read, + .aio_write = nfs_file_write, + .mmap = nfs_file_mmap, + .open = nfs_file_open, + .flush = nfs_file_flush, + .release = nfs_file_release, + .fsync = nfs_fsync, + .lock = nfs_lock, + .flock = nfs_flock, + .sendfile = nfs_file_sendfile, + .check_flags = nfs_check_flags, +}; + +struct inode_operations nfs_file_inode_operations = { + .permission = nfs_permission, + .getattr = nfs_getattr, + .setattr = nfs_setattr, +}; + +/* Hack for future NFS swap support */ +#ifndef IS_SWAPFILE +# define IS_SWAPFILE(inode) (0) +#endif + +static int nfs_check_flags(int flags) +{ + if ((flags & (O_APPEND | O_DIRECT)) == (O_APPEND | O_DIRECT)) + return -EINVAL; + + return 0; +} + +/* + * Open file + */ +static int +nfs_file_open(struct inode *inode, struct file *filp) +{ + struct nfs_server *server = NFS_SERVER(inode); + int (*open)(struct inode *, struct file *); + int res; + + res = nfs_check_flags(filp->f_flags); + if (res) + return res; + + lock_kernel(); + /* Do NFSv4 open() call */ + if ((open = server->rpc_ops->file_open) != NULL) + res = open(inode, filp); + unlock_kernel(); + return res; +} + +static int +nfs_file_release(struct inode *inode, struct file *filp) +{ + /* Ensure that dirty pages are flushed out with the right creds */ + if (filp->f_mode & FMODE_WRITE) + filemap_fdatawrite(filp->f_mapping); + return NFS_PROTO(inode)->file_release(inode, filp); +} + +/* + * Flush all dirty pages, and check for write errors. + * + */ +static int +nfs_file_flush(struct file *file) +{ + struct nfs_open_context *ctx = (struct nfs_open_context *)file->private_data; + struct inode *inode = file->f_dentry->d_inode; + int status; + + dfprintk(VFS, "nfs: flush(%s/%ld)\n", inode->i_sb->s_id, inode->i_ino); + + if ((file->f_mode & FMODE_WRITE) == 0) + return 0; + lock_kernel(); + /* Ensure that data+attribute caches are up to date after close() */ + status = nfs_wb_all(inode); + if (!status) { + status = ctx->error; + ctx->error = 0; + if (!status && !nfs_have_delegation(inode, FMODE_READ)) + __nfs_revalidate_inode(NFS_SERVER(inode), inode); + } + unlock_kernel(); + return status; +} + +static ssize_t +nfs_file_read(struct kiocb *iocb, char __user * buf, size_t count, loff_t pos) +{ + struct dentry * dentry = iocb->ki_filp->f_dentry; + struct inode * inode = dentry->d_inode; + ssize_t result; + +#ifdef CONFIG_NFS_DIRECTIO + if (iocb->ki_filp->f_flags & O_DIRECT) + return nfs_file_direct_read(iocb, buf, count, pos); +#endif + + dfprintk(VFS, "nfs: read(%s/%s, %lu@%lu)\n", + dentry->d_parent->d_name.name, dentry->d_name.name, + (unsigned long) count, (unsigned long) pos); + + result = nfs_revalidate_inode(NFS_SERVER(inode), inode); + if (!result) + result = generic_file_aio_read(iocb, buf, count, pos); + return result; +} + +static ssize_t +nfs_file_sendfile(struct file *filp, loff_t *ppos, size_t count, + read_actor_t actor, void *target) +{ + struct dentry *dentry = filp->f_dentry; + struct inode *inode = dentry->d_inode; + ssize_t res; + + dfprintk(VFS, "nfs: sendfile(%s/%s, %lu@%Lu)\n", + dentry->d_parent->d_name.name, dentry->d_name.name, + (unsigned long) count, (unsigned long long) *ppos); + + res = nfs_revalidate_inode(NFS_SERVER(inode), inode); + if (!res) + res = generic_file_sendfile(filp, ppos, count, actor, target); + return res; +} + +static int +nfs_file_mmap(struct file * file, struct vm_area_struct * vma) +{ + struct dentry *dentry = file->f_dentry; + struct inode *inode = dentry->d_inode; + int status; + + dfprintk(VFS, "nfs: mmap(%s/%s)\n", + dentry->d_parent->d_name.name, dentry->d_name.name); + + status = nfs_revalidate_inode(NFS_SERVER(inode), inode); + if (!status) + status = generic_file_mmap(file, vma); + return status; +} + +/* + * Flush any dirty pages for this process, and check for write errors. + * The return status from this call provides a reliable indication of + * whether any write errors occurred for this process. + */ +static int +nfs_fsync(struct file *file, struct dentry *dentry, int datasync) +{ + struct nfs_open_context *ctx = (struct nfs_open_context *)file->private_data; + struct inode *inode = dentry->d_inode; + int status; + + dfprintk(VFS, "nfs: fsync(%s/%ld)\n", inode->i_sb->s_id, inode->i_ino); + + lock_kernel(); + status = nfs_wb_all(inode); + if (!status) { + status = ctx->error; + ctx->error = 0; + } + unlock_kernel(); + return status; +} + +/* + * This does the "real" work of the write. The generic routine has + * allocated the page, locked it, done all the page alignment stuff + * calculations etc. Now we should just copy the data from user + * space and write it back to the real medium.. + * + * If the writer ends up delaying the write, the writer needs to + * increment the page use counts until he is done with the page. + */ +static int nfs_prepare_write(struct file *file, struct page *page, unsigned offset, unsigned to) +{ + return nfs_flush_incompatible(file, page); +} + +static int nfs_commit_write(struct file *file, struct page *page, unsigned offset, unsigned to) +{ + long status; + + lock_kernel(); + status = nfs_updatepage(file, page, offset, to-offset); + unlock_kernel(); + return status; +} + +struct address_space_operations nfs_file_aops = { + .readpage = nfs_readpage, + .readpages = nfs_readpages, + .set_page_dirty = __set_page_dirty_nobuffers, + .writepage = nfs_writepage, + .writepages = nfs_writepages, + .prepare_write = nfs_prepare_write, + .commit_write = nfs_commit_write, +#ifdef CONFIG_NFS_DIRECTIO + .direct_IO = nfs_direct_IO, +#endif +}; + +/* + * Write to a file (through the page cache). + */ +static ssize_t +nfs_file_write(struct kiocb *iocb, const char __user *buf, size_t count, loff_t pos) +{ + struct dentry * dentry = iocb->ki_filp->f_dentry; + struct inode * inode = dentry->d_inode; + ssize_t result; + +#ifdef CONFIG_NFS_DIRECTIO + if (iocb->ki_filp->f_flags & O_DIRECT) + return nfs_file_direct_write(iocb, buf, count, pos); +#endif + + dfprintk(VFS, "nfs: write(%s/%s(%ld), %lu@%lu)\n", + dentry->d_parent->d_name.name, dentry->d_name.name, + inode->i_ino, (unsigned long) count, (unsigned long) pos); + + result = -EBUSY; + if (IS_SWAPFILE(inode)) + goto out_swapfile; + result = nfs_revalidate_inode(NFS_SERVER(inode), inode); + if (result) + goto out; + + result = count; + if (!count) + goto out; + + result = generic_file_aio_write(iocb, buf, count, pos); +out: + return result; + +out_swapfile: + printk(KERN_INFO "NFS: attempt to write to active swap file!\n"); + goto out; +} + +static int do_getlk(struct file *filp, int cmd, struct file_lock *fl) +{ + struct inode *inode = filp->f_mapping->host; + int status = 0; + + lock_kernel(); + /* Use local locking if mounted with "-onolock" */ + if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM)) + status = NFS_PROTO(inode)->lock(filp, cmd, fl); + else { + struct file_lock *cfl = posix_test_lock(filp, fl); + + fl->fl_type = F_UNLCK; + if (cfl != NULL) + memcpy(fl, cfl, sizeof(*fl)); + } + unlock_kernel(); + return status; +} + +static int do_vfs_lock(struct file *file, struct file_lock *fl) +{ + int res = 0; + switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) { + case FL_POSIX: + res = posix_lock_file_wait(file, fl); + break; + case FL_FLOCK: + res = flock_lock_file_wait(file, fl); + break; + default: + BUG(); + } + if (res < 0) + printk(KERN_WARNING "%s: VFS is out of sync with lock manager!\n", + __FUNCTION__); + return res; +} + +static int do_unlk(struct file *filp, int cmd, struct file_lock *fl) +{ + struct inode *inode = filp->f_mapping->host; + sigset_t oldset; + int status; + + rpc_clnt_sigmask(NFS_CLIENT(inode), &oldset); + /* + * Flush all pending writes before doing anything + * with locks.. + */ + filemap_fdatawrite(filp->f_mapping); + down(&inode->i_sem); + nfs_wb_all(inode); + up(&inode->i_sem); + filemap_fdatawait(filp->f_mapping); + + /* NOTE: special case + * If we're signalled while cleaning up locks on process exit, we + * still need to complete the unlock. + */ + lock_kernel(); + /* Use local locking if mounted with "-onolock" */ + if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM)) + status = NFS_PROTO(inode)->lock(filp, cmd, fl); + else + status = do_vfs_lock(filp, fl); + unlock_kernel(); + rpc_clnt_sigunmask(NFS_CLIENT(inode), &oldset); + return status; +} + +static int do_setlk(struct file *filp, int cmd, struct file_lock *fl) +{ + struct inode *inode = filp->f_mapping->host; + sigset_t oldset; + int status; + + rpc_clnt_sigmask(NFS_CLIENT(inode), &oldset); + /* + * Flush all pending writes before doing anything + * with locks.. + */ + status = filemap_fdatawrite(filp->f_mapping); + if (status == 0) { + down(&inode->i_sem); + status = nfs_wb_all(inode); + up(&inode->i_sem); + if (status == 0) + status = filemap_fdatawait(filp->f_mapping); + } + if (status < 0) + goto out; + + lock_kernel(); + /* Use local locking if mounted with "-onolock" */ + if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM)) { + status = NFS_PROTO(inode)->lock(filp, cmd, fl); + /* If we were signalled we still need to ensure that + * we clean up any state on the server. We therefore + * record the lock call as having succeeded in order to + * ensure that locks_remove_posix() cleans it out when + * the process exits. + */ + if (status == -EINTR || status == -ERESTARTSYS) + do_vfs_lock(filp, fl); + } else + status = do_vfs_lock(filp, fl); + unlock_kernel(); + if (status < 0) + goto out; + /* + * Make sure we clear the cache whenever we try to get the lock. + * This makes locking act as a cache coherency point. + */ + filemap_fdatawrite(filp->f_mapping); + down(&inode->i_sem); + nfs_wb_all(inode); /* we may have slept */ + up(&inode->i_sem); + filemap_fdatawait(filp->f_mapping); + nfs_zap_caches(inode); +out: + rpc_clnt_sigunmask(NFS_CLIENT(inode), &oldset); + return status; +} + +/* + * Lock a (portion of) a file + */ +static int nfs_lock(struct file *filp, int cmd, struct file_lock *fl) +{ + struct inode * inode = filp->f_mapping->host; + + dprintk("NFS: nfs_lock(f=%s/%ld, t=%x, fl=%x, r=%Ld:%Ld)\n", + inode->i_sb->s_id, inode->i_ino, + fl->fl_type, fl->fl_flags, + (long long)fl->fl_start, (long long)fl->fl_end); + + if (!inode) + return -EINVAL; + + /* No mandatory locks over NFS */ + if ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID) + return -ENOLCK; + + if (IS_GETLK(cmd)) + return do_getlk(filp, cmd, fl); + if (fl->fl_type == F_UNLCK) + return do_unlk(filp, cmd, fl); + return do_setlk(filp, cmd, fl); +} + +/* + * Lock a (portion of) a file + */ +static int nfs_flock(struct file *filp, int cmd, struct file_lock *fl) +{ + struct inode * inode = filp->f_mapping->host; + + dprintk("NFS: nfs_flock(f=%s/%ld, t=%x, fl=%x)\n", + inode->i_sb->s_id, inode->i_ino, + fl->fl_type, fl->fl_flags); + + if (!inode) + return -EINVAL; + + /* + * No BSD flocks over NFS allowed. + * Note: we could try to fake a POSIX lock request here by + * using ((u32) filp | 0x80000000) or some such as the pid. + * Not sure whether that would be unique, though, or whether + * that would break in other places. + */ + if (!(fl->fl_flags & FL_FLOCK)) + return -ENOLCK; + + /* We're simulating flock() locks using posix locks on the server */ + fl->fl_owner = (fl_owner_t)filp; + fl->fl_start = 0; + fl->fl_end = OFFSET_MAX; + + if (fl->fl_type == F_UNLCK) + return do_unlk(filp, cmd, fl); + return do_setlk(filp, cmd, fl); +} |