/* * linux/fs/9p/vfs_file.c * * This file contians vfs file ops for 9P2000. * * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com> * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 * as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to: * Free Software Foundation * 51 Franklin Street, Fifth Floor * Boston, MA 02111-1301 USA * */ #include <linux/module.h> #include <linux/errno.h> #include <linux/fs.h> #include <linux/sched.h> #include <linux/file.h> #include <linux/stat.h> #include <linux/string.h> #include <linux/inet.h> #include <linux/list.h> #include <linux/pagemap.h> #include <linux/utsname.h> #include <asm/uaccess.h> #include <linux/idr.h> #include <net/9p/9p.h> #include <net/9p/client.h> #include "v9fs.h" #include "v9fs_vfs.h" #include "fid.h" #include "cache.h" static const struct vm_operations_struct v9fs_file_vm_ops; /** * v9fs_file_open - open a file (or directory) * @inode: inode to be opened * @file: file being opened * */ int v9fs_file_open(struct inode *inode, struct file *file) { int err; struct v9fs_inode *v9inode; struct v9fs_session_info *v9ses; struct p9_fid *fid; int omode; p9_debug(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, file); v9inode = V9FS_I(inode); v9ses = v9fs_inode2v9ses(inode); if (v9fs_proto_dotl(v9ses)) omode = v9fs_open_to_dotl_flags(file->f_flags); else omode = v9fs_uflags2omode(file->f_flags, v9fs_proto_dotu(v9ses)); fid = file->private_data; if (!fid) { fid = v9fs_fid_clone(file->f_path.dentry); if (IS_ERR(fid)) return PTR_ERR(fid); err = p9_client_open(fid, omode); if (err < 0) { p9_client_clunk(fid); return err; } if (file->f_flags & O_TRUNC) { i_size_write(inode, 0); inode->i_blocks = 0; } if ((file->f_flags & O_APPEND) && (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses))) generic_file_llseek(file, 0, SEEK_END); } file->private_data = fid; mutex_lock(&v9inode->v_mutex); if (v9ses->cache && !v9inode->writeback_fid && ((file->f_flags & O_ACCMODE) != O_RDONLY)) { /* * clone a fid and add it to writeback_fid * we do it during open time instead of * page dirty time via write_begin/page_mkwrite * because we want write after unlink usecase * to work. */ fid = v9fs_writeback_fid(file->f_path.dentry); if (IS_ERR(fid)) { err = PTR_ERR(fid); mutex_unlock(&v9inode->v_mutex); goto out_error; } v9inode->writeback_fid = (void *) fid; } mutex_unlock(&v9inode->v_mutex); #ifdef CONFIG_9P_FSCACHE if (v9ses->cache) v9fs_cache_inode_set_cookie(inode, file); #endif return 0; out_error: p9_client_clunk(file->private_data); file->private_data = NULL; return err; } /** * v9fs_file_lock - lock a file (or directory) * @filp: file to be locked * @cmd: lock command * @fl: file lock structure * * Bugs: this looks like a local only lock, we should extend into 9P * by using open exclusive */ static int v9fs_file_lock(struct file *filp, int cmd, struct file_lock *fl) { int res = 0; struct inode *inode = filp->f_path.dentry->d_inode; p9_debug(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl); /* No mandatory locks */ if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK) return -ENOLCK; if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) { filemap_write_and_wait(inode->i_mapping); invalidate_mapping_pages(&inode->i_data, 0, -1); } return res; } static int v9fs_file_do_lock(struct file *filp, int cmd, struct file_lock *fl) { struct p9_flock flock; struct p9_fid *fid; uint8_t status; int res = 0; unsigned char fl_type; fid = filp->private_data; BUG_ON(fid == NULL); if ((fl->fl_flags & FL_POSIX) != FL_POSIX) BUG(); res = posix_lock_file_wait(filp, fl); if (res < 0) goto out; /* convert posix lock to p9 tlock args */ memset(&flock, 0, sizeof(flock)); /* map the lock type */ switch (fl->fl_type) { case F_RDLCK: flock.type = P9_LOCK_TYPE_RDLCK; break; case F_WRLCK: flock.type = P9_LOCK_TYPE_WRLCK; break; case F_UNLCK: flock.type = P9_LOCK_TYPE_UNLCK; break; } flock.start = fl->fl_start; if (fl->fl_end == OFFSET_MAX) flock.length = 0; else flock.length = fl->fl_end - fl->fl_start + 1; flock.proc_id = fl->fl_pid; flock.client_id = utsname()->nodename; if (IS_SETLKW(cmd)) flock.flags = P9_LOCK_FLAGS_BLOCK; /* * if its a blocked request and we get P9_LOCK_BLOCKED as the status * for lock request, keep on trying */ for (;;) { res = p9_client_lock_dotl(fid, &flock, &status); if (res < 0) break; if (status != P9_LOCK_BLOCKED) break; if (status == P9_LOCK_BLOCKED && !IS_SETLKW(cmd)) break; if (schedule_timeout_interruptible(P9_LOCK_TIMEOUT) != 0) break; } /* map 9p status to VFS status */ switch (status) { case P9_LOCK_SUCCESS: res = 0; break; case P9_LOCK_BLOCKED: res = -EAGAIN; break; case P9_LOCK_ERROR: case P9_LOCK_GRACE: res = -ENOLCK; break; default: BUG(); } /* * incase server returned error for lock request, revert * it locally */ if (res < 0 && fl->fl_type != F_UNLCK) { fl_type = fl->fl_type; fl->fl_type = F_UNLCK; res = posix_lock_file_wait(filp, fl); fl->fl_type = fl_type; } out: return res; } static int v9fs_file_getlock(struct file *filp, struct file_lock *fl) { struct p9_getlock glock; struct p9_fid *fid; int res = 0; fid = filp->private_data; BUG_ON(fid == NULL); posix_test_lock(filp, fl); /* * if we have a conflicting lock locally, no need to validate * with server */ if (fl->fl_type != F_UNLCK) return res; /* convert posix lock to p9 tgetlock args */ memset(&glock, 0, sizeof(glock)); glock.type = P9_LOCK_TYPE_UNLCK; glock.start = fl->fl_start; if (fl->fl_end == OFFSET_MAX) glock.length = 0; else glock.length = fl->fl_end - fl->fl_start + 1; glock.proc_id = fl->fl_pid; glock.client_id = utsname()->nodename; res = p9_client_getlock_dotl(fid, &glock); if (res < 0) return res; /* map 9p lock type to os lock type */ switch (glock.type) { case P9_LOCK_TYPE_RDLCK: fl->fl_type = F_RDLCK; break; case P9_LOCK_TYPE_WRLCK: fl->fl_type = F_WRLCK; break; case P9_LOCK_TYPE_UNLCK: fl->fl_type = F_UNLCK; break; } if (glock.type != P9_LOCK_TYPE_UNLCK) { fl->fl_start = glock.start; if (glock.length == 0) fl->fl_end = OFFSET_MAX; else fl->fl_end = glock.start + glock.length - 1; fl->fl_pid = glock.proc_id; } return res; } /** * v9fs_file_lock_dotl - lock a file (or directory) * @filp: file to be locked * @cmd: lock command * @fl: file lock structure * */ static int v9fs_file_lock_dotl(struct file *filp, int cmd, struct file_lock *fl) { struct inode *inode = filp->f_path.dentry->d_inode; int ret = -ENOLCK; p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %s\n", filp, cmd, fl, filp->f_path.dentry->d_name.name); /* No mandatory locks */ if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK) goto out_err; if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) { filemap_write_and_wait(inode->i_mapping); invalidate_mapping_pages(&inode->i_data, 0, -1); } if (IS_SETLK(cmd) || IS_SETLKW(cmd)) ret = v9fs_file_do_lock(filp, cmd, fl); else if (IS_GETLK(cmd)) ret = v9fs_file_getlock(filp, fl); else ret = -EINVAL; out_err: return ret; } /** * v9fs_file_flock_dotl - lock a file * @filp: file to be locked * @cmd: lock command * @fl: file lock structure * */ static int v9fs_file_flock_dotl(struct file *filp, int cmd, struct file_lock *fl) { struct inode *inode = filp->f_path.dentry->d_inode; int ret = -ENOLCK; p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %s\n", filp, cmd, fl, filp->f_path.dentry->d_name.name); /* No mandatory locks */ if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK) goto out_err; if (!(fl->fl_flags & FL_FLOCK)) goto out_err; if ((IS_SETLK(cmd) || IS_SETLKW(cmd)) && fl->fl_type != F_UNLCK) { filemap_write_and_wait(inode->i_mapping); invalidate_mapping_pages(&inode->i_data, 0, -1); } /* Convert flock to posix lock */ fl->fl_owner = (fl_owner_t)filp; fl->fl_start = 0; fl->fl_end = OFFSET_MAX; fl->fl_flags |= FL_POSIX; fl->fl_flags ^= FL_FLOCK; if (IS_SETLK(cmd) | IS_SETLKW(cmd)) ret = v9fs_file_do_lock(filp, cmd, fl); else ret = -EINVAL; out_err: return ret; } /** * v9fs_fid_readn - read from a fid * @fid: fid to read * @data: data buffer to read data into * @udata: user data buffer to read data into * @count: size of buffer * @offset: offset at which to read data * */ ssize_t v9fs_fid_readn(struct p9_fid *fid, char *data, char __user *udata, u32 count, u64 offset) { int n, total, size; p9_debug(P9_DEBUG_VFS, "fid %d offset %llu count %d\n", fid->fid, (long long unsigned)offset, count); n = 0; total = 0; size = fid->iounit ? fid->iounit : fid->clnt->msize - P9_IOHDRSZ; do { n = p9_client_read(fid, data, udata, offset, count); if (n <= 0) break; if (data) data += n; if (udata) udata += n; offset += n; count -= n; total += n; } while (count > 0 && n == size); if (n < 0) total = n; return total; } /** * v9fs_file_readn - read from a file * @filp: file pointer to read * @data: data buffer to read data into * @udata: user data buffer to read data into * @count: size of buffer * @offset: offset at which to read data * */ ssize_t v9fs_file_readn(struct file *filp, char *data, char __user *udata, u32 count, u64 offset) { return v9fs_fid_readn(filp->private_data, data, udata, count, offset); } /** * v9fs_file_read - read from a file * @filp: file pointer to read * @udata: user data buffer to read data into * @count: size of buffer * @offset: offset at which to read data * */ static ssize_t v9fs_file_read(struct file *filp, char __user *udata, size_t count, loff_t * offset) { int ret; struct p9_fid *fid; size_t size; p9_debug(P9_DEBUG_VFS, "count %zu offset %lld\n", count, *offset); fid = filp->private_data; size = fid->iounit ? fid->iounit : fid->clnt->msize - P9_IOHDRSZ; if (count > size) ret = v9fs_file_readn(filp, NULL, udata, count, *offset); else ret = p9_client_read(fid, NULL, udata, *offset, count); if (ret > 0) *offset += ret; return ret; } ssize_t v9fs_file_write_internal(struct inode *inode, struct p9_fid *fid, const char __user *data, size_t count, loff_t *offset, int invalidate) { int n; loff_t i_size; size_t total = 0; struct p9_client *clnt; loff_t origin = *offset; unsigned long pg_start, pg_end; p9_debug(P9_DEBUG_VFS, "data %p count %d offset %x\n", data, (int)count, (int)*offset); clnt = fid->clnt; do { n = p9_client_write(fid, NULL, data+total, origin+total, count); if (n <= 0) break; count -= n; total += n; } while (count > 0); if (invalidate && (total > 0)) { pg_start = origin >> PAGE_CACHE_SHIFT; pg_end = (origin + total - 1) >> PAGE_CACHE_SHIFT; if (inode->i_mapping && inode->i_mapping->nrpages) invalidate_inode_pages2_range(inode->i_mapping, pg_start, pg_end); *offset += total; i_size = i_size_read(inode); if (*offset > i_size) { inode_add_bytes(inode, *offset - i_size); i_size_write(inode, *offset); } } if (n < 0) return n; return total; } /** * v9fs_file_write - write to a file * @filp: file pointer to write * @data: data buffer to write data from * @count: size of buffer * @offset: offset at which to write data * */ static ssize_t v9fs_file_write(struct file *filp, const char __user * data, size_t count, loff_t *offset) { ssize_t retval = 0; loff_t origin = *offset; retval = generic_write_checks(filp, &origin, &count, 0); if (retval) goto out; retval = -EINVAL; if ((ssize_t) count < 0) goto out; retval = 0; if (!count) goto out; retval = v9fs_file_write_internal(filp->f_path.dentry->d_inode, filp->private_data, data, count, &origin, 1); /* update offset on successful write */ if (retval > 0) *offset = origin; out: return retval; } static int v9fs_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync) { struct p9_fid *fid; struct inode *inode = filp->f_mapping->host; struct p9_wstat wstat; int retval; retval = filemap_write_and_wait_range(inode->i_mapping, start, end); if (retval) return retval; mutex_lock(&inode->i_mutex); p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync); fid = filp->private_data; v9fs_blank_wstat(&wstat); retval = p9_client_wstat(fid, &wstat); mutex_unlock(&inode->i_mutex); return retval; } int v9fs_file_fsync_dotl(struct file *filp, loff_t start, loff_t end, int datasync) { struct p9_fid *fid; struct inode *inode = filp->f_mapping->host; int retval; retval = filemap_write_and_wait_range(inode->i_mapping, start, end); if (retval) return retval; mutex_lock(&inode->i_mutex); p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync); fid = filp->private_data; retval = p9_client_fsync(fid, datasync); mutex_unlock(&inode->i_mutex); return retval; } static int v9fs_file_mmap(struct file *file, struct vm_area_struct *vma) { int retval; retval = generic_file_mmap(file, vma); if (!retval) vma->vm_ops = &v9fs_file_vm_ops; return retval; } static int v9fs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) { struct v9fs_inode *v9inode; struct page *page = vmf->page; struct file *filp = vma->vm_file; struct inode *inode = filp->f_path.dentry->d_inode; p9_debug(P9_DEBUG_VFS, "page %p fid %lx\n", page, (unsigned long)filp->private_data); /* Update file times before taking page lock */ file_update_time(filp); v9inode = V9FS_I(inode); /* make sure the cache has finished storing the page */ v9fs_fscache_wait_on_page_write(inode, page); BUG_ON(!v9inode->writeback_fid); lock_page(page); if (page->mapping != inode->i_mapping) goto out_unlock; return VM_FAULT_LOCKED; out_unlock: unlock_page(page); return VM_FAULT_NOPAGE; } static ssize_t v9fs_direct_read(struct file *filp, char __user *udata, size_t count, loff_t *offsetp) { loff_t size, offset; struct inode *inode; struct address_space *mapping; offset = *offsetp; mapping = filp->f_mapping; inode = mapping->host; if (!count) return 0; size = i_size_read(inode); if (offset < size) filemap_write_and_wait_range(mapping, offset, offset + count - 1); return v9fs_file_read(filp, udata, count, offsetp); } /** * v9fs_cached_file_read - read from a file * @filp: file pointer to read * @udata: user data buffer to read data into * @count: size of buffer * @offset: offset at which to read data * */ static ssize_t v9fs_cached_file_read(struct file *filp, char __user *data, size_t count, loff_t *offset) { if (filp->f_flags & O_DIRECT) return v9fs_direct_read(filp, data, count, offset); return do_sync_read(filp, data, count, offset); } static ssize_t v9fs_direct_write(struct file *filp, const char __user * data, size_t count, loff_t *offsetp) { loff_t offset; ssize_t retval; struct inode *inode; struct address_space *mapping; offset = *offsetp; mapping = filp->f_mapping; inode = mapping->host; if (!count) return 0; mutex_lock(&inode->i_mutex); retval = filemap_write_and_wait_range(mapping, offset, offset + count - 1); if (retval) goto err_out; /* * After a write we want buffered reads to be sure to go to disk to get * the new data. We invalidate clean cached page from the region we're * about to write. We do this *before* the write so that if we fail * here we fall back to buffered write */ if (mapping->nrpages) { pgoff_t pg_start = offset >> PAGE_CACHE_SHIFT; pgoff_t pg_end = (offset + count - 1) >> PAGE_CACHE_SHIFT; retval = invalidate_inode_pages2_range(mapping, pg_start, pg_end); /* * If a page can not be invalidated, fall back * to buffered write. */ if (retval) { if (retval == -EBUSY) goto buff_write; goto err_out; } } retval = v9fs_file_write(filp, data, count, offsetp); err_out: mutex_unlock(&inode->i_mutex); return retval; buff_write: mutex_unlock(&inode->i_mutex); return do_sync_write(filp, data, count, offsetp); } /** * v9fs_cached_file_write - write to a file * @filp: file pointer to write * @data: data buffer to write data from * @count: size of buffer * @offset: offset at which to write data * */ static ssize_t v9fs_cached_file_write(struct file *filp, const char __user * data, size_t count, loff_t *offset) { if (filp->f_flags & O_DIRECT) return v9fs_direct_write(filp, data, count, offset); return do_sync_write(filp, data, count, offset); } static const struct vm_operations_struct v9fs_file_vm_ops = { .fault = filemap_fault, .page_mkwrite = v9fs_vm_page_mkwrite, .remap_pages = generic_file_remap_pages, }; const struct file_operations v9fs_cached_file_operations = { .llseek = generic_file_llseek, .read = v9fs_cached_file_read, .write = v9fs_cached_file_write, .aio_read = generic_file_aio_read, .aio_write = generic_file_aio_write, .open = v9fs_file_open, .release = v9fs_dir_release, .lock = v9fs_file_lock, .mmap = v9fs_file_mmap, .fsync = v9fs_file_fsync, }; const struct file_operations v9fs_cached_file_operations_dotl = { .llseek = generic_file_llseek, .read = v9fs_cached_file_read, .write = v9fs_cached_file_write, .aio_read = generic_file_aio_read, .aio_write = generic_file_aio_write, .open = v9fs_file_open, .release = v9fs_dir_release, .lock = v9fs_file_lock_dotl, .flock = v9fs_file_flock_dotl, .mmap = v9fs_file_mmap, .fsync = v9fs_file_fsync_dotl, }; const struct file_operations v9fs_file_operations = { .llseek = generic_file_llseek, .read = v9fs_file_read, .write = v9fs_file_write, .open = v9fs_file_open, .release = v9fs_dir_release, .lock = v9fs_file_lock, .mmap = generic_file_readonly_mmap, .fsync = v9fs_file_fsync, }; const struct file_operations v9fs_file_operations_dotl = { .llseek = generic_file_llseek, .read = v9fs_file_read, .write = v9fs_file_write, .open = v9fs_file_open, .release = v9fs_dir_release, .lock = v9fs_file_lock_dotl, .flock = v9fs_file_flock_dotl, .mmap = generic_file_readonly_mmap, .fsync = v9fs_file_fsync_dotl, };