diff options
Diffstat (limited to 'ANDROID_3.4.5/fs/9p/vfs_file.c')
| -rw-r--r-- | ANDROID_3.4.5/fs/9p/vfs_file.c | 789 |
1 files changed, 789 insertions, 0 deletions
diff --git a/ANDROID_3.4.5/fs/9p/vfs_file.c b/ANDROID_3.4.5/fs/9p/vfs_file.c new file mode 100644 index 00000000..fc06fd27 --- /dev/null +++ b/ANDROID_3.4.5/fs/9p/vfs_file.c @@ -0,0 +1,789 @@ +/* + * 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); + + 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, +}; + + +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, +}; |