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);
+}