| /* |
| * 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 <linux/aio.h> |
| |
| #include <asm/uaccess.h> |
| #include <asm/system.h> |
| |
| #include "delegation.h" |
| #include "iostat.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 loff_t nfs_file_llseek(struct file *file, loff_t offset, int origin); |
| static int nfs_file_mmap(struct file *, struct vm_area_struct *); |
| static ssize_t nfs_file_splice_read(struct file *filp, loff_t *ppos, |
| struct pipe_inode_info *pipe, |
| size_t count, unsigned int flags); |
| static ssize_t nfs_file_read(struct kiocb *, const struct iovec *iov, |
| unsigned long nr_segs, loff_t pos); |
| static ssize_t nfs_file_write(struct kiocb *, const struct iovec *iov, |
| unsigned long nr_segs, loff_t pos); |
| static int nfs_file_flush(struct file *, fl_owner_t id); |
| 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); |
| static int nfs_setlease(struct file *file, long arg, struct file_lock **fl); |
| |
| const struct file_operations nfs_file_operations = { |
| .llseek = nfs_file_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, |
| .splice_read = nfs_file_splice_read, |
| .check_flags = nfs_check_flags, |
| .setlease = nfs_setlease, |
| }; |
| |
| const struct inode_operations nfs_file_inode_operations = { |
| .permission = nfs_permission, |
| .getattr = nfs_getattr, |
| .setattr = nfs_setattr, |
| }; |
| |
| #ifdef CONFIG_NFS_V3 |
| const struct inode_operations nfs3_file_inode_operations = { |
| .permission = nfs_permission, |
| .getattr = nfs_getattr, |
| .setattr = nfs_setattr, |
| .listxattr = nfs3_listxattr, |
| .getxattr = nfs3_getxattr, |
| .setxattr = nfs3_setxattr, |
| .removexattr = nfs3_removexattr, |
| }; |
| #endif /* CONFIG_NFS_v3 */ |
| |
| /* 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) |
| { |
| int res; |
| |
| res = nfs_check_flags(filp->f_flags); |
| if (res) |
| return res; |
| |
| nfs_inc_stats(inode, NFSIOS_VFSOPEN); |
| lock_kernel(); |
| res = NFS_PROTO(inode)->file_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); |
| nfs_inc_stats(inode, NFSIOS_VFSRELEASE); |
| return NFS_PROTO(inode)->file_release(inode, filp); |
| } |
| |
| /** |
| * nfs_revalidate_size - Revalidate the file size |
| * @inode - pointer to inode struct |
| * @file - pointer to struct file |
| * |
| * Revalidates the file length. This is basically a wrapper around |
| * nfs_revalidate_inode() that takes into account the fact that we may |
| * have cached writes (in which case we don't care about the server's |
| * idea of what the file length is), or O_DIRECT (in which case we |
| * shouldn't trust the cache). |
| */ |
| static int nfs_revalidate_file_size(struct inode *inode, struct file *filp) |
| { |
| struct nfs_server *server = NFS_SERVER(inode); |
| struct nfs_inode *nfsi = NFS_I(inode); |
| |
| if (server->flags & NFS_MOUNT_NOAC) |
| goto force_reval; |
| if (filp->f_flags & O_DIRECT) |
| goto force_reval; |
| if (nfsi->npages != 0) |
| return 0; |
| if (!(nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE) && !nfs_attribute_timeout(inode)) |
| return 0; |
| force_reval: |
| return __nfs_revalidate_inode(server, inode); |
| } |
| |
| static loff_t nfs_file_llseek(struct file *filp, loff_t offset, int origin) |
| { |
| /* origin == SEEK_END => we must revalidate the cached file length */ |
| if (origin == SEEK_END) { |
| struct inode *inode = filp->f_mapping->host; |
| int retval = nfs_revalidate_file_size(inode, filp); |
| if (retval < 0) |
| return (loff_t)retval; |
| } |
| return remote_llseek(filp, offset, origin); |
| } |
| |
| /* |
| * Flush all dirty pages, and check for write errors. |
| * |
| */ |
| static int |
| nfs_file_flush(struct file *file, fl_owner_t id) |
| { |
| struct nfs_open_context *ctx = (struct nfs_open_context *)file->private_data; |
| struct inode *inode = file->f_path.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; |
| nfs_inc_stats(inode, NFSIOS_VFSFLUSH); |
| 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, const struct iovec *iov, |
| unsigned long nr_segs, loff_t pos) |
| { |
| struct dentry * dentry = iocb->ki_filp->f_path.dentry; |
| struct inode * inode = dentry->d_inode; |
| ssize_t result; |
| size_t count = iov_length(iov, nr_segs); |
| |
| #ifdef CONFIG_NFS_DIRECTIO |
| if (iocb->ki_filp->f_flags & O_DIRECT) |
| return nfs_file_direct_read(iocb, iov, nr_segs, 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_mapping(inode, iocb->ki_filp->f_mapping); |
| nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, count); |
| if (!result) |
| result = generic_file_aio_read(iocb, iov, nr_segs, pos); |
| return result; |
| } |
| |
| static ssize_t |
| nfs_file_splice_read(struct file *filp, loff_t *ppos, |
| struct pipe_inode_info *pipe, size_t count, |
| unsigned int flags) |
| { |
| struct dentry *dentry = filp->f_path.dentry; |
| struct inode *inode = dentry->d_inode; |
| ssize_t res; |
| |
| dfprintk(VFS, "nfs: splice_read(%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_mapping(inode, filp->f_mapping); |
| if (!res) |
| res = generic_file_splice_read(filp, ppos, pipe, count, flags); |
| return res; |
| } |
| |
| static int |
| nfs_file_mmap(struct file * file, struct vm_area_struct * vma) |
| { |
| struct dentry *dentry = file->f_path.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_mapping(inode, file->f_mapping); |
| 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); |
| |
| nfs_inc_stats(inode, NFSIOS_VFSFSYNC); |
| 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; |
| } |
| |
| static void nfs_invalidate_page(struct page *page, unsigned long offset) |
| { |
| if (offset != 0) |
| return; |
| /* Cancel any unstarted writes on this page */ |
| nfs_wb_page_priority(page->mapping->host, page, FLUSH_INVALIDATE); |
| } |
| |
| static int nfs_release_page(struct page *page, gfp_t gfp) |
| { |
| /* If PagePrivate() is set, then the page is not freeable */ |
| return 0; |
| } |
| |
| static int nfs_launder_page(struct page *page) |
| { |
| return nfs_wb_page(page->mapping->host, page); |
| } |
| |
| const struct address_space_operations nfs_file_aops = { |
| .readpage = nfs_readpage, |
| .readpages = nfs_readpages, |
| .set_page_dirty = nfs_set_page_dirty, |
| .writepage = nfs_writepage, |
| .writepages = nfs_writepages, |
| .prepare_write = nfs_prepare_write, |
| .commit_write = nfs_commit_write, |
| .invalidatepage = nfs_invalidate_page, |
| .releasepage = nfs_release_page, |
| #ifdef CONFIG_NFS_DIRECTIO |
| .direct_IO = nfs_direct_IO, |
| #endif |
| .launder_page = nfs_launder_page, |
| }; |
| |
| static ssize_t nfs_file_write(struct kiocb *iocb, const struct iovec *iov, |
| unsigned long nr_segs, loff_t pos) |
| { |
| struct dentry * dentry = iocb->ki_filp->f_path.dentry; |
| struct inode * inode = dentry->d_inode; |
| ssize_t result; |
| size_t count = iov_length(iov, nr_segs); |
| |
| #ifdef CONFIG_NFS_DIRECTIO |
| if (iocb->ki_filp->f_flags & O_DIRECT) |
| return nfs_file_direct_write(iocb, iov, nr_segs, pos); |
| #endif |
| |
| dfprintk(VFS, "nfs: write(%s/%s(%ld), %lu@%Ld)\n", |
| dentry->d_parent->d_name.name, dentry->d_name.name, |
| inode->i_ino, (unsigned long) count, (long long) pos); |
| |
| result = -EBUSY; |
| if (IS_SWAPFILE(inode)) |
| goto out_swapfile; |
| /* |
| * O_APPEND implies that we must revalidate the file length. |
| */ |
| if (iocb->ki_filp->f_flags & O_APPEND) { |
| result = nfs_revalidate_file_size(inode, iocb->ki_filp); |
| if (result) |
| goto out; |
| } |
| |
| result = count; |
| if (!count) |
| goto out; |
| |
| nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, count); |
| result = generic_file_aio_write(iocb, iov, nr_segs, pos); |
| /* Return error values for O_SYNC and IS_SYNC() */ |
| if (result >= 0 && (IS_SYNC(inode) || (iocb->ki_filp->f_flags & O_SYNC))) { |
| int err = nfs_fsync(iocb->ki_filp, dentry, 1); |
| if (err < 0) |
| result = err; |
| } |
| 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(); |
| /* Try local locking first */ |
| if (posix_test_lock(filp, fl)) { |
| goto out; |
| } |
| |
| if (nfs_have_delegation(inode, FMODE_READ)) |
| goto out_noconflict; |
| |
| if (NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM) |
| goto out_noconflict; |
| |
| status = NFS_PROTO(inode)->lock(filp, cmd, fl); |
| out: |
| unlock_kernel(); |
| return status; |
| out_noconflict: |
| fl->fl_type = F_UNLCK; |
| goto out; |
| } |
| |
| 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) |
| dprintk(KERN_WARNING "%s: VFS is out of sync with lock manager" |
| " - error %d!\n", |
| __FUNCTION__, res); |
| return res; |
| } |
| |
| static int do_unlk(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.. |
| */ |
| nfs_sync_mapping(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(); |
| 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 = nfs_sync_mapping(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. |
| */ |
| nfs_sync_mapping(filp->f_mapping); |
| nfs_zap_caches(inode); |
| out: |
| 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); |
| nfs_inc_stats(inode, NFSIOS_VFSLOCK); |
| |
| /* No mandatory locks over NFS */ |
| if ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID && |
| fl->fl_type != F_UNLCK) |
| 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) |
| { |
| dprintk("NFS: nfs_flock(f=%s/%ld, t=%x, fl=%x)\n", |
| filp->f_path.dentry->d_inode->i_sb->s_id, |
| filp->f_path.dentry->d_inode->i_ino, |
| fl->fl_type, fl->fl_flags); |
| |
| /* |
| * 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); |
| } |
| |
| static int nfs_setlease(struct file *file, long arg, struct file_lock **fl) |
| { |
| /* |
| * There is no protocol support for leases, so we have no way |
| * to implement them correctly in the face of opens by other |
| * clients. |
| */ |
| return -EINVAL; |
| } |