// SPDX-License-Identifier: GPL-2.0 /* * linux/fs/nfs/file.c * * Copyright (C) 1992 Rick Sladkey */ #include <linux/fs.h> #include <linux/file.h> #include <linux/falloc.h> #include <linux/nfs_fs.h> #include "delegation.h" #include "internal.h" #include "iostat.h" #include "fscache.h" #include "pnfs.h" #include "nfstrace.h" #ifdef CONFIG_NFS_V4_2 #include "nfs42.h" #endif #define NFSDBG_FACILITY NFSDBG_FILE static int nfs4_file_open(struct inode *inode, struct file *filp) { struct nfs_open_context *ctx; struct dentry *dentry = file_dentry(filp); struct dentry *parent = NULL; struct inode *dir; unsigned openflags = filp->f_flags; struct iattr attr; int err; /* * If no cached dentry exists or if it's negative, NFSv4 handled the * opens in ->lookup() or ->create(). * * We only get this far for a cached positive dentry. We skipped * revalidation, so handle it here by dropping the dentry and returning * -EOPENSTALE. The VFS will retry the lookup/create/open. */ dprintk("NFS: open file(%pd2)\n", dentry); err = nfs_check_flags(openflags); if (err) return err; if ((openflags & O_ACCMODE) == 3) openflags--; /* We can't create new files here */ openflags &= ~(O_CREAT|O_EXCL); parent = dget_parent(dentry); dir = d_inode(parent); ctx = alloc_nfs_open_context(file_dentry(filp), filp->f_mode, filp); err = PTR_ERR(ctx); if (IS_ERR(ctx)) goto out; attr.ia_valid = ATTR_OPEN; if (openflags & O_TRUNC) { attr.ia_valid |= ATTR_SIZE; attr.ia_size = 0; filemap_write_and_wait(inode->i_mapping); } inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, &attr, NULL); if (IS_ERR(inode)) { err = PTR_ERR(inode); switch (err) { case -EPERM: case -EACCES: case -EDQUOT: case -ENOSPC: case -EROFS: goto out_put_ctx; default: goto out_drop; } } if (inode != d_inode(dentry)) goto out_drop; nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); nfs_file_set_open_context(filp, ctx); nfs_fscache_open_file(inode, filp); err = 0; out_put_ctx: put_nfs_open_context(ctx); out: dput(parent); return err; out_drop: d_drop(dentry); err = -EOPENSTALE; goto out_put_ctx; } /* * Flush all dirty pages, and check for write errors. */ static int nfs4_file_flush(struct file *file, fl_owner_t id) { struct inode *inode = file_inode(file); dprintk("NFS: flush(%pD2)\n", file); nfs_inc_stats(inode, NFSIOS_VFSFLUSH); if ((file->f_mode & FMODE_WRITE) == 0) return 0; /* * If we're holding a write delegation, then check if we're required * to flush the i/o on close. If not, then just start the i/o now. */ if (!nfs4_delegation_flush_on_close(inode)) return filemap_fdatawrite(file->f_mapping); /* Flush writes to the server and return any errors */ return vfs_fsync(file, 0); } #ifdef CONFIG_NFS_V4_2 static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in, struct file *file_out, loff_t pos_out, size_t count, unsigned int flags) { if (file_inode(file_in) == file_inode(file_out)) return -EINVAL; return nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count); } static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence) { loff_t ret; switch (whence) { case SEEK_HOLE: case SEEK_DATA: ret = nfs42_proc_llseek(filep, offset, whence); if (ret != -ENOTSUPP) return ret; /* Fall through */ default: return nfs_file_llseek(filep, offset, whence); } } static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t len) { struct inode *inode = file_inode(filep); long ret; if (!S_ISREG(inode->i_mode)) return -EOPNOTSUPP; if ((mode != 0) && (mode != (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE))) return -EOPNOTSUPP; ret = inode_newsize_ok(inode, offset + len); if (ret < 0) return ret; if (mode & FALLOC_FL_PUNCH_HOLE) return nfs42_proc_deallocate(filep, offset, len); return nfs42_proc_allocate(filep, offset, len); } static loff_t nfs42_remap_file_range(struct file *src_file, loff_t src_off, struct file *dst_file, loff_t dst_off, loff_t count, unsigned int remap_flags) { struct inode *dst_inode = file_inode(dst_file); struct nfs_server *server = NFS_SERVER(dst_inode); struct inode *src_inode = file_inode(src_file); unsigned int bs = server->clone_blksize; bool same_inode = false; int ret; if (remap_flags & ~REMAP_FILE_ADVISORY) return -EINVAL; /* check alignment w.r.t. clone_blksize */ ret = -EINVAL; if (bs) { if (!IS_ALIGNED(src_off, bs) || !IS_ALIGNED(dst_off, bs)) goto out; if (!IS_ALIGNED(count, bs) && i_size_read(src_inode) != (src_off + count)) goto out; } if (src_inode == dst_inode) same_inode = true; /* XXX: do we lock at all? what if server needs CB_RECALL_LAYOUT? */ if (same_inode) { inode_lock(src_inode); } else if (dst_inode < src_inode) { inode_lock_nested(dst_inode, I_MUTEX_PARENT); inode_lock_nested(src_inode, I_MUTEX_CHILD); } else { inode_lock_nested(src_inode, I_MUTEX_PARENT); inode_lock_nested(dst_inode, I_MUTEX_CHILD); } /* flush all pending writes on both src and dst so that server * has the latest data */ ret = nfs_sync_inode(src_inode); if (ret) goto out_unlock; ret = nfs_sync_inode(dst_inode); if (ret) goto out_unlock; ret = nfs42_proc_clone(src_file, dst_file, src_off, dst_off, count); /* truncate inode page cache of the dst range so that future reads can fetch * new data from server */ if (!ret) truncate_inode_pages_range(&dst_inode->i_data, dst_off, dst_off + count - 1); out_unlock: if (same_inode) { inode_unlock(src_inode); } else if (dst_inode < src_inode) { inode_unlock(src_inode); inode_unlock(dst_inode); } else { inode_unlock(dst_inode); inode_unlock(src_inode); } out: return ret < 0 ? ret : count; } #endif /* CONFIG_NFS_V4_2 */ const struct file_operations nfs4_file_operations = { .read_iter = nfs_file_read, .write_iter = nfs_file_write, .mmap = nfs_file_mmap, .open = nfs4_file_open, .flush = nfs4_file_flush, .release = nfs_file_release, .fsync = nfs_file_fsync, .lock = nfs_lock, .flock = nfs_flock, .splice_read = generic_file_splice_read, .splice_write = iter_file_splice_write, .check_flags = nfs_check_flags, .setlease = simple_nosetlease, #ifdef CONFIG_NFS_V4_2 .copy_file_range = nfs4_copy_file_range, .llseek = nfs4_file_llseek, .fallocate = nfs42_fallocate, .remap_file_range = nfs42_remap_file_range, #else .llseek = nfs_file_llseek, #endif };