/* * 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> #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); 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, .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) { 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_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; lock_kernel(); status = NFS_PROTO(inode)->lock(filp, cmd, fl); unlock_kernel(); return status; } 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(); status = NFS_PROTO(inode)->lock(filp, cmd, fl); 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; int status; /* * 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) return status; lock_kernel(); 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) posix_lock_file(filp, fl); unlock_kernel(); if (status < 0) return status; /* * 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); return 0; } /* * Lock a (portion of) a file */ 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 (NFS_PROTO(inode)->version != 4) { /* Fake OK code if mounted without NLM support */ if (NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM) { if (IS_GETLK(cmd)) return LOCK_USE_CLNT; return 0; } } /* * 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_owner || !(fl->fl_flags & FL_POSIX)) 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); }