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-rw-r--r--fs/nfs/file.c484
1 files changed, 484 insertions, 0 deletions
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
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+++ b/fs/nfs/file.c
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+/*
+ * 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);
+}