From 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 27 Apr 2024 12:05:51 +0200 Subject: Adding upstream version 5.10.209. Signed-off-by: Daniel Baumann --- fs/nfs/file.c | 874 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 874 insertions(+) create mode 100644 fs/nfs/file.c (limited to 'fs/nfs/file.c') diff --git a/fs/nfs/file.c b/fs/nfs/file.c new file mode 100644 index 000000000..7be1a7f7f --- /dev/null +++ b/fs/nfs/file.c @@ -0,0 +1,874 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include "delegation.h" +#include "internal.h" +#include "iostat.h" +#include "fscache.h" +#include "pnfs.h" + +#include "nfstrace.h" + +#define NFSDBG_FACILITY NFSDBG_FILE + +static const struct vm_operations_struct nfs_file_vm_ops; + +/* Hack for future NFS swap support */ +#ifndef IS_SWAPFILE +# define IS_SWAPFILE(inode) (0) +#endif + +int nfs_check_flags(int flags) +{ + if ((flags & (O_APPEND | O_DIRECT)) == (O_APPEND | O_DIRECT)) + return -EINVAL; + + return 0; +} +EXPORT_SYMBOL_GPL(nfs_check_flags); + +/* + * Open file + */ +static int +nfs_file_open(struct inode *inode, struct file *filp) +{ + int res; + + dprintk("NFS: open file(%pD2)\n", filp); + + nfs_inc_stats(inode, NFSIOS_VFSOPEN); + res = nfs_check_flags(filp->f_flags); + if (res) + return res; + + res = nfs_open(inode, filp); + return res; +} + +int +nfs_file_release(struct inode *inode, struct file *filp) +{ + dprintk("NFS: release(%pD2)\n", filp); + + nfs_inc_stats(inode, NFSIOS_VFSRELEASE); + nfs_file_clear_open_context(filp); + return 0; +} +EXPORT_SYMBOL_GPL(nfs_file_release); + +/** + * nfs_revalidate_size - Revalidate the file size + * @inode: pointer to inode struct + * @filp: 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); + + if (filp->f_flags & O_DIRECT) + goto force_reval; + if (nfs_check_cache_invalid(inode, NFS_INO_REVAL_PAGECACHE)) + goto force_reval; + return 0; +force_reval: + return __nfs_revalidate_inode(server, inode); +} + +loff_t nfs_file_llseek(struct file *filp, loff_t offset, int whence) +{ + dprintk("NFS: llseek file(%pD2, %lld, %d)\n", + filp, offset, whence); + + /* + * whence == SEEK_END || SEEK_DATA || SEEK_HOLE => we must revalidate + * the cached file length + */ + if (whence != SEEK_SET && whence != SEEK_CUR) { + struct inode *inode = filp->f_mapping->host; + + int retval = nfs_revalidate_file_size(inode, filp); + if (retval < 0) + return (loff_t)retval; + } + + return generic_file_llseek(filp, offset, whence); +} +EXPORT_SYMBOL_GPL(nfs_file_llseek); + +/* + * Flush all dirty pages, and check for write errors. + */ +static int +nfs_file_flush(struct file *file, fl_owner_t id) +{ + struct inode *inode = file_inode(file); + errseq_t since; + + dprintk("NFS: flush(%pD2)\n", file); + + nfs_inc_stats(inode, NFSIOS_VFSFLUSH); + if ((file->f_mode & FMODE_WRITE) == 0) + return 0; + + /* Flush writes to the server and return any errors */ + since = filemap_sample_wb_err(file->f_mapping); + nfs_wb_all(inode); + return filemap_check_wb_err(file->f_mapping, since); +} + +ssize_t +nfs_file_read(struct kiocb *iocb, struct iov_iter *to) +{ + struct inode *inode = file_inode(iocb->ki_filp); + ssize_t result; + + if (iocb->ki_flags & IOCB_DIRECT) + return nfs_file_direct_read(iocb, to, false); + + dprintk("NFS: read(%pD2, %zu@%lu)\n", + iocb->ki_filp, + iov_iter_count(to), (unsigned long) iocb->ki_pos); + + nfs_start_io_read(inode); + result = nfs_revalidate_mapping(inode, iocb->ki_filp->f_mapping); + if (!result) { + result = generic_file_read_iter(iocb, to); + if (result > 0) + nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, result); + } + nfs_end_io_read(inode); + return result; +} +EXPORT_SYMBOL_GPL(nfs_file_read); + +int +nfs_file_mmap(struct file * file, struct vm_area_struct * vma) +{ + struct inode *inode = file_inode(file); + int status; + + dprintk("NFS: mmap(%pD2)\n", file); + + /* Note: generic_file_mmap() returns ENOSYS on nommu systems + * so we call that before revalidating the mapping + */ + status = generic_file_mmap(file, vma); + if (!status) { + vma->vm_ops = &nfs_file_vm_ops; + status = nfs_revalidate_mapping(inode, file->f_mapping); + } + return status; +} +EXPORT_SYMBOL_GPL(nfs_file_mmap); + +/* + * 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_file_fsync_commit(struct file *file, int datasync) +{ + struct inode *inode = file_inode(file); + int ret, ret2; + + dprintk("NFS: fsync file(%pD2) datasync %d\n", file, datasync); + + nfs_inc_stats(inode, NFSIOS_VFSFSYNC); + ret = nfs_commit_inode(inode, FLUSH_SYNC); + ret2 = file_check_and_advance_wb_err(file); + if (ret2 < 0) + return ret2; + return ret; +} + +int +nfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync) +{ + struct nfs_open_context *ctx = nfs_file_open_context(file); + struct inode *inode = file_inode(file); + int ret; + + trace_nfs_fsync_enter(inode); + + for (;;) { + ret = file_write_and_wait_range(file, start, end); + if (ret != 0) + break; + ret = nfs_file_fsync_commit(file, datasync); + if (ret != 0) + break; + ret = pnfs_sync_inode(inode, !!datasync); + if (ret != 0) + break; + if (!test_and_clear_bit(NFS_CONTEXT_RESEND_WRITES, &ctx->flags)) + break; + /* + * If nfs_file_fsync_commit detected a server reboot, then + * resend all dirty pages that might have been covered by + * the NFS_CONTEXT_RESEND_WRITES flag + */ + start = 0; + end = LLONG_MAX; + } + + trace_nfs_fsync_exit(inode, ret); + return ret; +} +EXPORT_SYMBOL_GPL(nfs_file_fsync); + +/* + * Decide whether a read/modify/write cycle may be more efficient + * then a modify/write/read cycle when writing to a page in the + * page cache. + * + * Some pNFS layout drivers can only read/write at a certain block + * granularity like all block devices and therefore we must perform + * read/modify/write whenever a page hasn't read yet and the data + * to be written there is not aligned to a block boundary and/or + * smaller than the block size. + * + * The modify/write/read cycle may occur if a page is read before + * being completely filled by the writer. In this situation, the + * page must be completely written to stable storage on the server + * before it can be refilled by reading in the page from the server. + * This can lead to expensive, small, FILE_SYNC mode writes being + * done. + * + * It may be more efficient to read the page first if the file is + * open for reading in addition to writing, the page is not marked + * as Uptodate, it is not dirty or waiting to be committed, + * indicating that it was previously allocated and then modified, + * that there were valid bytes of data in that range of the file, + * and that the new data won't completely replace the old data in + * that range of the file. + */ +static bool nfs_full_page_write(struct page *page, loff_t pos, unsigned int len) +{ + unsigned int pglen = nfs_page_length(page); + unsigned int offset = pos & (PAGE_SIZE - 1); + unsigned int end = offset + len; + + return !pglen || (end >= pglen && !offset); +} + +static bool nfs_want_read_modify_write(struct file *file, struct page *page, + loff_t pos, unsigned int len) +{ + /* + * Up-to-date pages, those with ongoing or full-page write + * don't need read/modify/write + */ + if (PageUptodate(page) || PagePrivate(page) || + nfs_full_page_write(page, pos, len)) + return false; + + if (pnfs_ld_read_whole_page(file->f_mapping->host)) + return true; + /* Open for reading too? */ + if (file->f_mode & FMODE_READ) + return true; + return false; +} + +/* + * This does the "real" work of the write. We must allocate and lock the + * page to be sent back to the generic routine, which then copies the + * data from user space. + * + * 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_write_begin(struct file *file, struct address_space *mapping, + loff_t pos, unsigned len, unsigned flags, + struct page **pagep, void **fsdata) +{ + int ret; + pgoff_t index = pos >> PAGE_SHIFT; + struct page *page; + int once_thru = 0; + + dfprintk(PAGECACHE, "NFS: write_begin(%pD2(%lu), %u@%lld)\n", + file, mapping->host->i_ino, len, (long long) pos); + +start: + page = grab_cache_page_write_begin(mapping, index, flags); + if (!page) + return -ENOMEM; + *pagep = page; + + ret = nfs_flush_incompatible(file, page); + if (ret) { + unlock_page(page); + put_page(page); + } else if (!once_thru && + nfs_want_read_modify_write(file, page, pos, len)) { + once_thru = 1; + ret = nfs_readpage(file, page); + put_page(page); + if (!ret) + goto start; + } + return ret; +} + +static int nfs_write_end(struct file *file, struct address_space *mapping, + loff_t pos, unsigned len, unsigned copied, + struct page *page, void *fsdata) +{ + unsigned offset = pos & (PAGE_SIZE - 1); + struct nfs_open_context *ctx = nfs_file_open_context(file); + int status; + + dfprintk(PAGECACHE, "NFS: write_end(%pD2(%lu), %u@%lld)\n", + file, mapping->host->i_ino, len, (long long) pos); + + /* + * Zero any uninitialised parts of the page, and then mark the page + * as up to date if it turns out that we're extending the file. + */ + if (!PageUptodate(page)) { + unsigned pglen = nfs_page_length(page); + unsigned end = offset + copied; + + if (pglen == 0) { + zero_user_segments(page, 0, offset, + end, PAGE_SIZE); + SetPageUptodate(page); + } else if (end >= pglen) { + zero_user_segment(page, end, PAGE_SIZE); + if (offset == 0) + SetPageUptodate(page); + } else + zero_user_segment(page, pglen, PAGE_SIZE); + } + + status = nfs_updatepage(file, page, offset, copied); + + unlock_page(page); + put_page(page); + + if (status < 0) + return status; + NFS_I(mapping->host)->write_io += copied; + + if (nfs_ctx_key_to_expire(ctx, mapping->host)) + nfs_wb_all(mapping->host); + + return copied; +} + +/* + * Partially or wholly invalidate a page + * - Release the private state associated with a page if undergoing complete + * page invalidation + * - Called if either PG_private or PG_fscache is set on the page + * - Caller holds page lock + */ +static void nfs_invalidate_page(struct page *page, unsigned int offset, + unsigned int length) +{ + dfprintk(PAGECACHE, "NFS: invalidate_page(%p, %u, %u)\n", + page, offset, length); + + if (offset != 0 || length < PAGE_SIZE) + return; + /* Cancel any unstarted writes on this page */ + nfs_wb_page_cancel(page_file_mapping(page)->host, page); + + nfs_fscache_invalidate_page(page, page->mapping->host); +} + +/* + * Attempt to release the private state associated with a page + * - Called if either PG_private or PG_fscache is set on the page + * - Caller holds page lock + * - Return true (may release page) or false (may not) + */ +static int nfs_release_page(struct page *page, gfp_t gfp) +{ + dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page); + + /* If PagePrivate() is set, then the page is not freeable */ + if (PagePrivate(page)) + return 0; + return nfs_fscache_release_page(page, gfp); +} + +static void nfs_check_dirty_writeback(struct page *page, + bool *dirty, bool *writeback) +{ + struct nfs_inode *nfsi; + struct address_space *mapping = page_file_mapping(page); + + if (!mapping || PageSwapCache(page)) + return; + + /* + * Check if an unstable page is currently being committed and + * if so, have the VM treat it as if the page is under writeback + * so it will not block due to pages that will shortly be freeable. + */ + nfsi = NFS_I(mapping->host); + if (atomic_read(&nfsi->commit_info.rpcs_out)) { + *writeback = true; + return; + } + + /* + * If PagePrivate() is set, then the page is not freeable and as the + * inode is not being committed, it's not going to be cleaned in the + * near future so treat it as dirty + */ + if (PagePrivate(page)) + *dirty = true; +} + +/* + * Attempt to clear the private state associated with a page when an error + * occurs that requires the cached contents of an inode to be written back or + * destroyed + * - Called if either PG_private or fscache is set on the page + * - Caller holds page lock + * - Return 0 if successful, -error otherwise + */ +static int nfs_launder_page(struct page *page) +{ + struct inode *inode = page_file_mapping(page)->host; + struct nfs_inode *nfsi = NFS_I(inode); + + dfprintk(PAGECACHE, "NFS: launder_page(%ld, %llu)\n", + inode->i_ino, (long long)page_offset(page)); + + nfs_fscache_wait_on_page_write(nfsi, page); + return nfs_wb_page(inode, page); +} + +static int nfs_swap_activate(struct swap_info_struct *sis, struct file *file, + sector_t *span) +{ + unsigned long blocks; + long long isize; + struct inode *inode = file_inode(file); + struct rpc_clnt *clnt = NFS_CLIENT(inode); + struct nfs_client *cl = NFS_SERVER(inode)->nfs_client; + + spin_lock(&inode->i_lock); + blocks = inode->i_blocks; + isize = inode->i_size; + spin_unlock(&inode->i_lock); + if (blocks*512 < isize) { + pr_warn("swap activate: swapfile has holes\n"); + return -EINVAL; + } + + *span = sis->pages; + + + if (cl->rpc_ops->enable_swap) + cl->rpc_ops->enable_swap(inode); + + return rpc_clnt_swap_activate(clnt); +} + +static void nfs_swap_deactivate(struct file *file) +{ + struct inode *inode = file_inode(file); + struct rpc_clnt *clnt = NFS_CLIENT(inode); + struct nfs_client *cl = NFS_SERVER(inode)->nfs_client; + + rpc_clnt_swap_deactivate(clnt); + if (cl->rpc_ops->disable_swap) + cl->rpc_ops->disable_swap(file_inode(file)); +} + +const struct address_space_operations nfs_file_aops = { + .readpage = nfs_readpage, + .readpages = nfs_readpages, + .set_page_dirty = __set_page_dirty_nobuffers, + .writepage = nfs_writepage, + .writepages = nfs_writepages, + .write_begin = nfs_write_begin, + .write_end = nfs_write_end, + .invalidatepage = nfs_invalidate_page, + .releasepage = nfs_release_page, + .direct_IO = nfs_direct_IO, +#ifdef CONFIG_MIGRATION + .migratepage = nfs_migrate_page, +#endif + .launder_page = nfs_launder_page, + .is_dirty_writeback = nfs_check_dirty_writeback, + .error_remove_page = generic_error_remove_page, + .swap_activate = nfs_swap_activate, + .swap_deactivate = nfs_swap_deactivate, +}; + +/* + * Notification that a PTE pointing to an NFS page is about to be made + * writable, implying that someone is about to modify the page through a + * shared-writable mapping + */ +static vm_fault_t nfs_vm_page_mkwrite(struct vm_fault *vmf) +{ + struct page *page = vmf->page; + struct file *filp = vmf->vma->vm_file; + struct inode *inode = file_inode(filp); + unsigned pagelen; + vm_fault_t ret = VM_FAULT_NOPAGE; + struct address_space *mapping; + + dfprintk(PAGECACHE, "NFS: vm_page_mkwrite(%pD2(%lu), offset %lld)\n", + filp, filp->f_mapping->host->i_ino, + (long long)page_offset(page)); + + sb_start_pagefault(inode->i_sb); + + /* make sure the cache has finished storing the page */ + nfs_fscache_wait_on_page_write(NFS_I(inode), page); + + wait_on_bit_action(&NFS_I(inode)->flags, NFS_INO_INVALIDATING, + nfs_wait_bit_killable, TASK_KILLABLE); + + lock_page(page); + mapping = page_file_mapping(page); + if (mapping != inode->i_mapping) + goto out_unlock; + + wait_on_page_writeback(page); + + pagelen = nfs_page_length(page); + if (pagelen == 0) + goto out_unlock; + + ret = VM_FAULT_LOCKED; + if (nfs_flush_incompatible(filp, page) == 0 && + nfs_updatepage(filp, page, 0, pagelen) == 0) + goto out; + + ret = VM_FAULT_SIGBUS; +out_unlock: + unlock_page(page); +out: + sb_end_pagefault(inode->i_sb); + return ret; +} + +static const struct vm_operations_struct nfs_file_vm_ops = { + .fault = filemap_fault, + .map_pages = filemap_map_pages, + .page_mkwrite = nfs_vm_page_mkwrite, +}; + +static int nfs_need_check_write(struct file *filp, struct inode *inode, + int error) +{ + struct nfs_open_context *ctx; + + ctx = nfs_file_open_context(filp); + if (nfs_error_is_fatal_on_server(error) || + nfs_ctx_key_to_expire(ctx, inode)) + return 1; + return 0; +} + +ssize_t nfs_file_write(struct kiocb *iocb, struct iov_iter *from) +{ + struct file *file = iocb->ki_filp; + struct inode *inode = file_inode(file); + unsigned long written = 0; + ssize_t result; + errseq_t since; + int error; + + result = nfs_key_timeout_notify(file, inode); + if (result) + return result; + + if (iocb->ki_flags & IOCB_DIRECT) + return nfs_file_direct_write(iocb, from, false); + + dprintk("NFS: write(%pD2, %zu@%Ld)\n", + file, iov_iter_count(from), (long long) iocb->ki_pos); + + if (IS_SWAPFILE(inode)) + goto out_swapfile; + /* + * O_APPEND implies that we must revalidate the file length. + */ + if (iocb->ki_flags & IOCB_APPEND) { + result = nfs_revalidate_file_size(inode, file); + if (result) + goto out; + } + if (iocb->ki_pos > i_size_read(inode)) + nfs_revalidate_mapping(inode, file->f_mapping); + + since = filemap_sample_wb_err(file->f_mapping); + nfs_start_io_write(inode); + result = generic_write_checks(iocb, from); + if (result > 0) { + current->backing_dev_info = inode_to_bdi(inode); + result = generic_perform_write(file, from, iocb->ki_pos); + current->backing_dev_info = NULL; + } + nfs_end_io_write(inode); + if (result <= 0) + goto out; + + written = result; + iocb->ki_pos += written; + result = generic_write_sync(iocb, written); + if (result < 0) + goto out; + + /* Return error values */ + error = filemap_check_wb_err(file->f_mapping, since); + if (nfs_need_check_write(file, inode, error)) { + int err = nfs_wb_all(inode); + if (err < 0) + result = err; + } + nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, written); +out: + return result; + +out_swapfile: + printk(KERN_INFO "NFS: attempt to write to active swap file!\n"); + return -ETXTBSY; +} +EXPORT_SYMBOL_GPL(nfs_file_write); + +static int +do_getlk(struct file *filp, int cmd, struct file_lock *fl, int is_local) +{ + struct inode *inode = filp->f_mapping->host; + int status = 0; + unsigned int saved_type = fl->fl_type; + + /* Try local locking first */ + posix_test_lock(filp, fl); + if (fl->fl_type != F_UNLCK) { + /* found a conflict */ + goto out; + } + fl->fl_type = saved_type; + + if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ)) + goto out_noconflict; + + if (is_local) + goto out_noconflict; + + status = NFS_PROTO(inode)->lock(filp, cmd, fl); +out: + return status; +out_noconflict: + fl->fl_type = F_UNLCK; + goto out; +} + +static int +do_unlk(struct file *filp, int cmd, struct file_lock *fl, int is_local) +{ + struct inode *inode = filp->f_mapping->host; + struct nfs_lock_context *l_ctx; + int status; + + /* + * Flush all pending writes before doing anything + * with locks.. + */ + nfs_wb_all(inode); + + l_ctx = nfs_get_lock_context(nfs_file_open_context(filp)); + if (!IS_ERR(l_ctx)) { + status = nfs_iocounter_wait(l_ctx); + nfs_put_lock_context(l_ctx); + /* NOTE: special case + * If we're signalled while cleaning up locks on process exit, we + * still need to complete the unlock. + */ + if (status < 0 && !(fl->fl_flags & FL_CLOSE)) + return status; + } + + /* + * Use local locking if mounted with "-onolock" or with appropriate + * "-olocal_lock=" + */ + if (!is_local) + status = NFS_PROTO(inode)->lock(filp, cmd, fl); + else + status = locks_lock_file_wait(filp, fl); + return status; +} + +static int +do_setlk(struct file *filp, int cmd, struct file_lock *fl, int is_local) +{ + 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; + + /* + * Use local locking if mounted with "-onolock" or with appropriate + * "-olocal_lock=" + */ + if (!is_local) + status = NFS_PROTO(inode)->lock(filp, cmd, fl); + else + status = locks_lock_file_wait(filp, fl); + if (status < 0) + goto out; + + /* + * Invalidate cache to prevent missing any changes. If + * the file is mapped, clear the page cache as well so + * those mappings will be loaded. + * + * This makes locking act as a cache coherency point. + */ + nfs_sync_mapping(filp->f_mapping); + if (!NFS_PROTO(inode)->have_delegation(inode, FMODE_READ)) { + nfs_zap_caches(inode); + if (mapping_mapped(filp->f_mapping)) + nfs_revalidate_mapping(inode, filp->f_mapping); + } +out: + return status; +} + +/* + * Lock a (portion of) a file + */ +int nfs_lock(struct file *filp, int cmd, struct file_lock *fl) +{ + struct inode *inode = filp->f_mapping->host; + int ret = -ENOLCK; + int is_local = 0; + + dprintk("NFS: lock(%pD2, t=%x, fl=%x, r=%lld:%lld)\n", + filp, 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 (__mandatory_lock(inode) && fl->fl_type != F_UNLCK) + goto out_err; + + if (NFS_SERVER(inode)->flags & NFS_MOUNT_LOCAL_FCNTL) + is_local = 1; + + if (NFS_PROTO(inode)->lock_check_bounds != NULL) { + ret = NFS_PROTO(inode)->lock_check_bounds(fl); + if (ret < 0) + goto out_err; + } + + if (IS_GETLK(cmd)) + ret = do_getlk(filp, cmd, fl, is_local); + else if (fl->fl_type == F_UNLCK) + ret = do_unlk(filp, cmd, fl, is_local); + else + ret = do_setlk(filp, cmd, fl, is_local); +out_err: + return ret; +} +EXPORT_SYMBOL_GPL(nfs_lock); + +/* + * Lock a (portion of) a file + */ +int nfs_flock(struct file *filp, int cmd, struct file_lock *fl) +{ + struct inode *inode = filp->f_mapping->host; + int is_local = 0; + + dprintk("NFS: flock(%pD2, t=%x, fl=%x)\n", + filp, fl->fl_type, fl->fl_flags); + + if (!(fl->fl_flags & FL_FLOCK)) + return -ENOLCK; + + /* + * The NFSv4 protocol doesn't support LOCK_MAND, which is not part of + * any standard. In principle we might be able to support LOCK_MAND + * on NFSv2/3 since NLMv3/4 support DOS share modes, but for now the + * NFS code is not set up for it. + */ + if (fl->fl_type & LOCK_MAND) + return -EINVAL; + + if (NFS_SERVER(inode)->flags & NFS_MOUNT_LOCAL_FLOCK) + is_local = 1; + + /* We're simulating flock() locks using posix locks on the server */ + if (fl->fl_type == F_UNLCK) + return do_unlk(filp, cmd, fl, is_local); + return do_setlk(filp, cmd, fl, is_local); +} +EXPORT_SYMBOL_GPL(nfs_flock); + +const struct file_operations nfs_file_operations = { + .llseek = nfs_file_llseek, + .read_iter = nfs_file_read, + .write_iter = nfs_file_write, + .mmap = nfs_file_mmap, + .open = nfs_file_open, + .flush = nfs_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, +}; +EXPORT_SYMBOL_GPL(nfs_file_operations); -- cgit v1.2.3