From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- fs/9p/vfs_file.c | 608 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 608 insertions(+) create mode 100644 fs/9p/vfs_file.c (limited to 'fs/9p/vfs_file.c') diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c new file mode 100644 index 0000000000..11cd8d23f6 --- /dev/null +++ b/fs/9p/vfs_file.c @@ -0,0 +1,608 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file contians vfs file ops for 9P2000. + * + * Copyright (C) 2004 by Eric Van Hensbergen + * Copyright (C) 2002 by Ron Minnich + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "v9fs.h" +#include "v9fs_vfs.h" +#include "fid.h" +#include "cache.h" + +static const struct vm_operations_struct v9fs_mmap_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_session_info *v9ses; + struct p9_fid *fid; + int omode; + + p9_debug(P9_DEBUG_VFS, "inode: %p file: %p\n", inode, file); + 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_dentry(file)); + if (IS_ERR(fid)) + return PTR_ERR(fid); + + if ((v9ses->cache & CACHE_WRITEBACK) && (omode & P9_OWRITE)) { + int writeback_omode = (omode & ~P9_OWRITE) | P9_ORDWR; + + p9_debug(P9_DEBUG_CACHE, "write-only file with writeback enabled, try opening O_RDWR\n"); + err = p9_client_open(fid, writeback_omode); + if (err < 0) { + p9_debug(P9_DEBUG_CACHE, "could not open O_RDWR, disabling caches\n"); + err = p9_client_open(fid, omode); + fid->mode |= P9L_DIRECT; + } + } else { + err = p9_client_open(fid, omode); + } + if (err < 0) { + p9_fid_put(fid); + return err; + } + 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; + } + +#ifdef CONFIG_9P_FSCACHE + if (v9ses->cache & CACHE_FSCACHE) + fscache_use_cookie(v9fs_inode_cookie(V9FS_I(inode)), + file->f_mode & FMODE_WRITE); +#endif + v9fs_fid_add_modes(fid, v9ses->flags, v9ses->cache, file->f_flags); + v9fs_open_fid_add(inode, &fid); + return 0; +} + +/** + * 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) +{ + struct inode *inode = file_inode(filp); + + p9_debug(P9_DEBUG_VFS, "filp: %p lock: %p\n", filp, fl); + + 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 0; +} + +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 = P9_LOCK_ERROR; + int res = 0; + unsigned char fl_type; + struct v9fs_session_info *v9ses; + + fid = filp->private_data; + BUG_ON(fid == NULL); + + BUG_ON((fl->fl_flags & FL_POSIX) != FL_POSIX); + + res = locks_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 = fid->clnt->name; + if (IS_SETLKW(cmd)) + flock.flags = P9_LOCK_FLAGS_BLOCK; + + v9ses = v9fs_inode2v9ses(file_inode(filp)); + + /* + * 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) + goto out_unlock; + + if (status != P9_LOCK_BLOCKED) + break; + if (status == P9_LOCK_BLOCKED && !IS_SETLKW(cmd)) + break; + if (schedule_timeout_interruptible(v9ses->session_lock_timeout) + != 0) + break; + /* + * p9_client_lock_dotl overwrites flock.client_id with the + * server message, free and reuse the client name + */ + if (flock.client_id != fid->clnt->name) { + kfree(flock.client_id); + flock.client_id = fid->clnt->name; + } + } + + /* map 9p status to VFS status */ + switch (status) { + case P9_LOCK_SUCCESS: + res = 0; + break; + case P9_LOCK_BLOCKED: + res = -EAGAIN; + break; + default: + WARN_ONCE(1, "unknown lock status code: %d\n", status); + fallthrough; + case P9_LOCK_ERROR: + case P9_LOCK_GRACE: + res = -ENOLCK; + break; + } + +out_unlock: + /* + * 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; + /* Even if this fails we want to return the remote error */ + locks_lock_file_wait(filp, fl); + fl->fl_type = fl_type; + } + if (flock.client_id != fid->clnt->name) + kfree(flock.client_id); +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 = fid->clnt->name; + + res = p9_client_getlock_dotl(fid, &glock); + if (res < 0) + goto out; + /* 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; + } +out: + if (glock.client_id != fid->clnt->name) + kfree(glock.client_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 = file_inode(filp); + int ret = -ENOLCK; + + p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n", + filp, cmd, fl, filp); + + 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; + 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 = file_inode(filp); + int ret = -ENOLCK; + + p9_debug(P9_DEBUG_VFS, "filp: %p cmd:%d lock: %p name: %pD\n", + filp, cmd, fl, filp); + + 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_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_file_read_iter - read from a file + * @iocb: The operation parameters + * @to: The buffer to read into + * + */ +static ssize_t +v9fs_file_read_iter(struct kiocb *iocb, struct iov_iter *to) +{ + struct p9_fid *fid = iocb->ki_filp->private_data; + int ret, err = 0; + + p9_debug(P9_DEBUG_VFS, "fid %d count %zu offset %lld\n", + fid->fid, iov_iter_count(to), iocb->ki_pos); + + if (!(fid->mode & P9L_DIRECT)) { + p9_debug(P9_DEBUG_VFS, "(cached)\n"); + return generic_file_read_iter(iocb, to); + } + + if (iocb->ki_filp->f_flags & O_NONBLOCK) + ret = p9_client_read_once(fid, iocb->ki_pos, to, &err); + else + ret = p9_client_read(fid, iocb->ki_pos, to, &err); + if (!ret) + return err; + + iocb->ki_pos += ret; + return ret; +} + +/* + * v9fs_file_splice_read - splice-read from a file + * @in: The 9p file to read from + * @ppos: Where to find/update the file position + * @pipe: The pipe to splice into + * @len: The maximum amount of data to splice + * @flags: SPLICE_F_* flags + */ +static ssize_t v9fs_file_splice_read(struct file *in, loff_t *ppos, + struct pipe_inode_info *pipe, + size_t len, unsigned int flags) +{ + struct p9_fid *fid = in->private_data; + + p9_debug(P9_DEBUG_VFS, "fid %d count %zu offset %lld\n", + fid->fid, len, *ppos); + + if (fid->mode & P9L_DIRECT) + return copy_splice_read(in, ppos, pipe, len, flags); + return filemap_splice_read(in, ppos, pipe, len, flags); +} + +/** + * v9fs_file_write_iter - write to a file + * @iocb: The operation parameters + * @from: The data to write + * + */ +static ssize_t +v9fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from) +{ + struct file *file = iocb->ki_filp; + struct p9_fid *fid = file->private_data; + ssize_t retval; + loff_t origin; + int err = 0; + + p9_debug(P9_DEBUG_VFS, "fid %d\n", fid->fid); + + if (!(fid->mode & (P9L_DIRECT | P9L_NOWRITECACHE))) { + p9_debug(P9_DEBUG_CACHE, "(cached)\n"); + return generic_file_write_iter(iocb, from); + } + + retval = generic_write_checks(iocb, from); + if (retval <= 0) + return retval; + + origin = iocb->ki_pos; + retval = p9_client_write(file->private_data, iocb->ki_pos, from, &err); + if (retval > 0) { + struct inode *inode = file_inode(file); + loff_t i_size; + unsigned long pg_start, pg_end; + + pg_start = origin >> PAGE_SHIFT; + pg_end = (origin + retval - 1) >> PAGE_SHIFT; + if (inode->i_mapping && inode->i_mapping->nrpages) + invalidate_inode_pages2_range(inode->i_mapping, + pg_start, pg_end); + iocb->ki_pos += retval; + i_size = i_size_read(inode); + if (iocb->ki_pos > i_size) { + inode_add_bytes(inode, iocb->ki_pos - i_size); + /* + * Need to serialize against i_size_write() in + * v9fs_stat2inode() + */ + v9fs_i_size_write(inode, iocb->ki_pos); + } + return retval; + } + return err; +} + +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 = file_write_and_wait_range(filp, start, end); + if (retval) + return retval; + + inode_lock(inode); + 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); + inode_unlock(inode); + + 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 = file_write_and_wait_range(filp, start, end); + if (retval) + return retval; + + inode_lock(inode); + p9_debug(P9_DEBUG_VFS, "filp %p datasync %x\n", filp, datasync); + + fid = filp->private_data; + + retval = p9_client_fsync(fid, datasync); + inode_unlock(inode); + + return retval; +} + +static int +v9fs_file_mmap(struct file *filp, struct vm_area_struct *vma) +{ + int retval; + struct inode *inode = file_inode(filp); + struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode); + + p9_debug(P9_DEBUG_MMAP, "filp :%p\n", filp); + + if (!(v9ses->cache & CACHE_WRITEBACK)) { + p9_debug(P9_DEBUG_CACHE, "(read-only mmap mode)"); + return generic_file_readonly_mmap(filp, vma); + } + + retval = generic_file_mmap(filp, vma); + if (!retval) + vma->vm_ops = &v9fs_mmap_file_vm_ops; + + return retval; +} + +static vm_fault_t +v9fs_vm_page_mkwrite(struct vm_fault *vmf) +{ + struct folio *folio = page_folio(vmf->page); + struct file *filp = vmf->vma->vm_file; + struct inode *inode = file_inode(filp); + + + p9_debug(P9_DEBUG_VFS, "folio %p fid %lx\n", + folio, (unsigned long)filp->private_data); + + /* Wait for the page to be written to the cache before we allow it to + * be modified. We then assume the entire page will need writing back. + */ +#ifdef CONFIG_9P_FSCACHE + if (folio_test_fscache(folio) && + folio_wait_fscache_killable(folio) < 0) + return VM_FAULT_NOPAGE; +#endif + + /* Update file times before taking page lock */ + file_update_time(filp); + + if (folio_lock_killable(folio) < 0) + return VM_FAULT_RETRY; + if (folio_mapping(folio) != inode->i_mapping) + goto out_unlock; + folio_wait_stable(folio); + + return VM_FAULT_LOCKED; +out_unlock: + folio_unlock(folio); + return VM_FAULT_NOPAGE; +} + +static void v9fs_mmap_vm_close(struct vm_area_struct *vma) +{ + struct inode *inode; + + struct writeback_control wbc = { + .nr_to_write = LONG_MAX, + .sync_mode = WB_SYNC_ALL, + .range_start = (loff_t)vma->vm_pgoff * PAGE_SIZE, + /* absolute end, byte at end included */ + .range_end = (loff_t)vma->vm_pgoff * PAGE_SIZE + + (vma->vm_end - vma->vm_start - 1), + }; + + if (!(vma->vm_flags & VM_SHARED)) + return; + + p9_debug(P9_DEBUG_VFS, "9p VMA close, %p, flushing", vma); + + inode = file_inode(vma->vm_file); + filemap_fdatawrite_wbc(inode->i_mapping, &wbc); +} + +static const struct vm_operations_struct v9fs_mmap_file_vm_ops = { + .close = v9fs_mmap_vm_close, + .fault = filemap_fault, + .map_pages = filemap_map_pages, + .page_mkwrite = v9fs_vm_page_mkwrite, +}; + +const struct file_operations v9fs_file_operations = { + .llseek = generic_file_llseek, + .read_iter = v9fs_file_read_iter, + .write_iter = v9fs_file_write_iter, + .open = v9fs_file_open, + .release = v9fs_dir_release, + .lock = v9fs_file_lock, + .mmap = generic_file_readonly_mmap, + .splice_read = v9fs_file_splice_read, + .splice_write = iter_file_splice_write, + .fsync = v9fs_file_fsync, +}; + +const struct file_operations v9fs_file_operations_dotl = { + .llseek = generic_file_llseek, + .read_iter = v9fs_file_read_iter, + .write_iter = v9fs_file_write_iter, + .open = v9fs_file_open, + .release = v9fs_dir_release, + .lock = v9fs_file_lock_dotl, + .flock = v9fs_file_flock_dotl, + .mmap = v9fs_file_mmap, + .splice_read = v9fs_file_splice_read, + .splice_write = iter_file_splice_write, + .fsync = v9fs_file_fsync_dotl, +}; -- cgit v1.2.3