| /* |
| * 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 <linux/module.h> |
| #include <linux/time.h> |
| #include <linux/kernel.h> |
| #include <linux/errno.h> |
| #include <linux/fcntl.h> |
| #include <linux/stat.h> |
| #include <linux/nfs_fs.h> |
| #include <linux/nfs_mount.h> |
| #include <linux/mm.h> |
| #include <linux/pagemap.h> |
| #include <linux/gfp.h> |
| #include <linux/swap.h> |
| |
| #include <asm/uaccess.h> |
| |
| #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 |
| * @file - 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); |
| struct nfs_inode *nfsi = NFS_I(inode); |
| |
| if (nfs_have_delegated_attributes(inode)) |
| goto out_noreval; |
| |
| if (filp->f_flags & O_DIRECT) |
| goto force_reval; |
| if (nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE) |
| goto force_reval; |
| if (nfs_attribute_timeout(inode)) |
| goto force_reval; |
| out_noreval: |
| 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); |
| |
| 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 */ |
| return vfs_fsync(file, 0); |
| } |
| |
| 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, iocb->ki_pos); |
| |
| dprintk("NFS: read(%pD2, %zu@%lu)\n", |
| iocb->ki_filp, |
| iov_iter_count(to), (unsigned long) iocb->ki_pos); |
| |
| result = nfs_revalidate_mapping_protected(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); |
| } |
| return result; |
| } |
| EXPORT_SYMBOL_GPL(nfs_file_read); |
| |
| ssize_t |
| nfs_file_splice_read(struct file *filp, loff_t *ppos, |
| struct pipe_inode_info *pipe, size_t count, |
| unsigned int flags) |
| { |
| struct inode *inode = file_inode(filp); |
| ssize_t res; |
| |
| dprintk("NFS: splice_read(%pD2, %lu@%Lu)\n", |
| filp, (unsigned long) count, (unsigned long long) *ppos); |
| |
| res = nfs_revalidate_mapping_protected(inode, filp->f_mapping); |
| if (!res) { |
| res = generic_file_splice_read(filp, ppos, pipe, count, flags); |
| if (res > 0) |
| nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, res); |
| } |
| return res; |
| } |
| EXPORT_SYMBOL_GPL(nfs_file_splice_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. |
| * |
| * Notice that it clears the NFS_CONTEXT_ERROR_WRITE before synching to |
| * disk, but it retrieves and clears ctx->error after synching, despite |
| * the two being set at the same time in nfs_context_set_write_error(). |
| * This is because the former is used to notify the _next_ call to |
| * nfs_file_write() that a write error occurred, and hence cause it to |
| * fall back to doing a synchronous write. |
| */ |
| static int |
| nfs_file_fsync_commit(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 have_error, do_resend, status; |
| int ret = 0; |
| |
| dprintk("NFS: fsync file(%pD2) datasync %d\n", file, datasync); |
| |
| nfs_inc_stats(inode, NFSIOS_VFSFSYNC); |
| do_resend = test_and_clear_bit(NFS_CONTEXT_RESEND_WRITES, &ctx->flags); |
| have_error = test_and_clear_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags); |
| status = nfs_commit_inode(inode, FLUSH_SYNC); |
| have_error |= test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags); |
| if (have_error) { |
| ret = xchg(&ctx->error, 0); |
| if (ret) |
| goto out; |
| } |
| if (status < 0) { |
| ret = status; |
| goto out; |
| } |
| do_resend |= test_bit(NFS_CONTEXT_RESEND_WRITES, &ctx->flags); |
| if (do_resend) |
| ret = -EAGAIN; |
| out: |
| return ret; |
| } |
| |
| int |
| nfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync) |
| { |
| int ret; |
| struct inode *inode = file_inode(file); |
| |
| trace_nfs_fsync_enter(inode); |
| |
| inode_dio_wait(inode); |
| do { |
| ret = filemap_write_and_wait_range(inode->i_mapping, start, end); |
| if (ret != 0) |
| break; |
| inode_lock(inode); |
| ret = nfs_file_fsync_commit(file, start, end, datasync); |
| if (!ret) |
| ret = pnfs_sync_inode(inode, !!datasync); |
| inode_unlock(inode); |
| /* |
| * 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; |
| } while (ret == -EAGAIN); |
| |
| 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. |
| * |
| * 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 int nfs_want_read_modify_write(struct file *file, struct page *page, |
| loff_t pos, unsigned len) |
| { |
| unsigned int pglen = nfs_page_length(page); |
| unsigned int offset = pos & (PAGE_CACHE_SIZE - 1); |
| unsigned int end = offset + len; |
| |
| if (pnfs_ld_read_whole_page(file->f_mapping->host)) { |
| if (!PageUptodate(page)) |
| return 1; |
| return 0; |
| } |
| |
| if ((file->f_mode & FMODE_READ) && /* open for read? */ |
| !PageUptodate(page) && /* Uptodate? */ |
| !PagePrivate(page) && /* i/o request already? */ |
| pglen && /* valid bytes of file? */ |
| (end < pglen || offset)) /* replace all valid bytes? */ |
| return 1; |
| return 0; |
| } |
| |
| /* |
| * 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_CACHE_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: |
| /* |
| * Prevent starvation issues if someone is doing a consistency |
| * sync-to-disk |
| */ |
| ret = wait_on_bit_action(&NFS_I(mapping->host)->flags, NFS_INO_FLUSHING, |
| nfs_wait_bit_killable, TASK_KILLABLE); |
| if (ret) |
| return ret; |
| /* |
| * Wait for O_DIRECT to complete |
| */ |
| inode_dio_wait(mapping->host); |
| |
| 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); |
| page_cache_release(page); |
| } else if (!once_thru && |
| nfs_want_read_modify_write(file, page, pos, len)) { |
| once_thru = 1; |
| ret = nfs_readpage(file, page); |
| page_cache_release(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_CACHE_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 + len; |
| |
| if (pglen == 0) { |
| zero_user_segments(page, 0, offset, |
| end, PAGE_CACHE_SIZE); |
| SetPageUptodate(page); |
| } else if (end >= pglen) { |
| zero_user_segment(page, end, PAGE_CACHE_SIZE); |
| if (offset == 0) |
| SetPageUptodate(page); |
| } else |
| zero_user_segment(page, pglen, PAGE_CACHE_SIZE); |
| } |
| |
| status = nfs_updatepage(file, page, offset, copied); |
| |
| unlock_page(page); |
| page_cache_release(page); |
| |
| if (status < 0) |
| return status; |
| NFS_I(mapping->host)->write_io += copied; |
| |
| if (nfs_ctx_key_to_expire(ctx)) { |
| status = nfs_wb_all(mapping->host); |
| if (status < 0) |
| return status; |
| } |
| |
| 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_CACHE_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) |
| { |
| struct address_space *mapping = page->mapping; |
| |
| dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page); |
| |
| /* Always try to initiate a 'commit' if relevant, but only |
| * wait for it if the caller allows blocking. Even then, |
| * only wait 1 second and only if the 'bdi' is not congested. |
| * Waiting indefinitely can cause deadlocks when the NFS |
| * server is on this machine, when a new TCP connection is |
| * needed and in other rare cases. There is no particular |
| * need to wait extensively here. A short wait has the |
| * benefit that someone else can worry about the freezer. |
| */ |
| if (mapping) { |
| struct nfs_server *nfss = NFS_SERVER(mapping->host); |
| nfs_commit_inode(mapping->host, 0); |
| if (gfpflags_allow_blocking(gfp) && |
| !bdi_write_congested(&nfss->backing_dev_info)) { |
| wait_on_page_bit_killable_timeout(page, PG_private, |
| HZ); |
| if (PagePrivate(page)) |
| set_bdi_congested(&nfss->backing_dev_info, |
| BLK_RW_ASYNC); |
| } |
| } |
| /* 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_launder_page(inode, page); |
| } |
| |
| static int nfs_swap_activate(struct swap_info_struct *sis, struct file *file, |
| sector_t *span) |
| { |
| struct rpc_clnt *clnt = NFS_CLIENT(file->f_mapping->host); |
| |
| *span = sis->pages; |
| |
| return rpc_clnt_swap_activate(clnt); |
| } |
| |
| static void nfs_swap_deactivate(struct file *file) |
| { |
| struct rpc_clnt *clnt = NFS_CLIENT(file->f_mapping->host); |
| |
| rpc_clnt_swap_deactivate(clnt); |
| } |
| |
| 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, |
| .migratepage = nfs_migrate_page, |
| .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 int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) |
| { |
| struct page *page = vmf->page; |
| struct file *filp = vma->vm_file; |
| struct inode *inode = file_inode(filp); |
| unsigned pagelen; |
| int 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)); |
| |
| /* 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: |
| 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) |
| { |
| struct nfs_open_context *ctx; |
| |
| ctx = nfs_file_open_context(filp); |
| if (test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags) || |
| nfs_ctx_key_to_expire(ctx)) |
| 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; |
| size_t count = iov_iter_count(from); |
| |
| result = nfs_key_timeout_notify(file, inode); |
| if (result) |
| return result; |
| |
| if (iocb->ki_flags & IOCB_DIRECT) { |
| result = generic_write_checks(iocb, from); |
| if (result <= 0) |
| return result; |
| return nfs_file_direct_write(iocb, from); |
| } |
| |
| dprintk("NFS: write(%pD2, %zu@%Ld)\n", |
| file, count, (long long) iocb->ki_pos); |
| |
| result = -EBUSY; |
| 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; |
| } |
| |
| result = count; |
| if (!count) |
| goto out; |
| |
| result = generic_file_write_iter(iocb, from); |
| if (result > 0) |
| written = result; |
| |
| /* Return error values */ |
| if (result >= 0 && nfs_need_check_write(file, inode)) { |
| int err = vfs_fsync(file, 0); |
| if (err < 0) |
| result = err; |
| } |
| if (result > 0) |
| nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, written); |
| out: |
| return result; |
| |
| out_swapfile: |
| printk(KERN_INFO "NFS: attempt to write to active swap file!\n"); |
| goto out; |
| } |
| 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_vfs_lock(struct file *file, struct file_lock *fl) |
| { |
| return locks_lock_file_wait(file, fl); |
| } |
| |
| 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.. |
| */ |
| vfs_fsync(filp, 0); |
| |
| 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); |
| if (status < 0) |
| return status; |
| } |
| |
| /* NOTE: special case |
| * If we're signalled while cleaning up locks on process exit, we |
| * still need to complete the unlock. |
| */ |
| /* |
| * 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 = do_vfs_lock(filp, fl); |
| return status; |
| } |
| |
| static int |
| is_time_granular(struct timespec *ts) { |
| return ((ts->tv_sec == 0) && (ts->tv_nsec <= 1000)); |
| } |
| |
| 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 = do_vfs_lock(filp, fl); |
| if (status < 0) |
| goto out; |
| |
| /* |
| * Revalidate the cache if the server has time stamps granular |
| * enough to detect subsecond changes. Otherwise, clear the |
| * cache to prevent missing any changes. |
| * |
| * This makes locking act as a cache coherency point. |
| */ |
| nfs_sync_mapping(filp->f_mapping); |
| if (!NFS_PROTO(inode)->have_delegation(inode, FMODE_READ)) { |
| if (is_time_granular(&NFS_SERVER(inode)->time_delta)) |
| __nfs_revalidate_inode(NFS_SERVER(inode), inode); |
| else |
| nfs_zap_caches(inode); |
| } |
| 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 = nfs_file_splice_read, |
| .splice_write = iter_file_splice_write, |
| .check_flags = nfs_check_flags, |
| .setlease = simple_nosetlease, |
| }; |
| EXPORT_SYMBOL_GPL(nfs_file_operations); |