| /* |
| * 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/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/aio.h> |
| #include <linux/gfp.h> |
| #include <linux/swap.h> |
| |
| #include <asm/uaccess.h> |
| #include <asm/system.h> |
| |
| #include "delegation.h" |
| #include "internal.h" |
| #include "iostat.h" |
| #include "fscache.h" |
| #include "pnfs.h" |
| |
| #define NFSDBG_FACILITY NFSDBG_FILE |
| |
| static int nfs_file_open(struct inode *, struct file *); |
| static int nfs_file_release(struct inode *, struct file *); |
| static loff_t nfs_file_llseek(struct file *file, loff_t offset, int origin); |
| static int nfs_file_mmap(struct file *, struct vm_area_struct *); |
| static ssize_t nfs_file_splice_read(struct file *filp, loff_t *ppos, |
| struct pipe_inode_info *pipe, |
| size_t count, unsigned int flags); |
| static ssize_t nfs_file_read(struct kiocb *, const struct iovec *iov, |
| unsigned long nr_segs, loff_t pos); |
| static ssize_t nfs_file_splice_write(struct pipe_inode_info *pipe, |
| struct file *filp, loff_t *ppos, |
| size_t count, unsigned int flags); |
| static ssize_t nfs_file_write(struct kiocb *, const struct iovec *iov, |
| unsigned long nr_segs, loff_t pos); |
| static int nfs_file_flush(struct file *, fl_owner_t id); |
| static int nfs_file_fsync(struct file *, int datasync); |
| static int nfs_check_flags(int flags); |
| static int nfs_lock(struct file *filp, int cmd, struct file_lock *fl); |
| static int nfs_flock(struct file *filp, int cmd, struct file_lock *fl); |
| static int nfs_setlease(struct file *file, long arg, struct file_lock **fl); |
| |
| static const struct vm_operations_struct nfs_file_vm_ops; |
| |
| const struct file_operations nfs_file_operations = { |
| .llseek = nfs_file_llseek, |
| .read = do_sync_read, |
| .write = do_sync_write, |
| .aio_read = nfs_file_read, |
| .aio_write = 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 = nfs_file_splice_write, |
| .check_flags = nfs_check_flags, |
| .setlease = nfs_setlease, |
| }; |
| |
| const struct inode_operations nfs_file_inode_operations = { |
| .permission = nfs_permission, |
| .getattr = nfs_getattr, |
| .setattr = nfs_setattr, |
| }; |
| |
| #ifdef CONFIG_NFS_V3 |
| const struct inode_operations nfs3_file_inode_operations = { |
| .permission = nfs_permission, |
| .getattr = nfs_getattr, |
| .setattr = nfs_setattr, |
| .listxattr = nfs3_listxattr, |
| .getxattr = nfs3_getxattr, |
| .setxattr = nfs3_setxattr, |
| .removexattr = nfs3_removexattr, |
| }; |
| #endif /* CONFIG_NFS_v3 */ |
| |
| /* Hack for future NFS swap support */ |
| #ifndef IS_SWAPFILE |
| # define IS_SWAPFILE(inode) (0) |
| #endif |
| |
| static int nfs_check_flags(int flags) |
| { |
| if ((flags & (O_APPEND | O_DIRECT)) == (O_APPEND | O_DIRECT)) |
| return -EINVAL; |
| |
| return 0; |
| } |
| |
| /* |
| * Open file |
| */ |
| static int |
| nfs_file_open(struct inode *inode, struct file *filp) |
| { |
| int res; |
| |
| dprintk("NFS: open file(%s/%s)\n", |
| filp->f_path.dentry->d_parent->d_name.name, |
| filp->f_path.dentry->d_name.name); |
| |
| nfs_inc_stats(inode, NFSIOS_VFSOPEN); |
| res = nfs_check_flags(filp->f_flags); |
| if (res) |
| return res; |
| |
| res = nfs_open(inode, filp); |
| return res; |
| } |
| |
| static int |
| nfs_file_release(struct inode *inode, struct file *filp) |
| { |
| struct dentry *dentry = filp->f_path.dentry; |
| |
| dprintk("NFS: release(%s/%s)\n", |
| dentry->d_parent->d_name.name, |
| dentry->d_name.name); |
| |
| nfs_inc_stats(inode, NFSIOS_VFSRELEASE); |
| return nfs_release(inode, filp); |
| } |
| |
| /** |
| * 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); |
| } |
| |
| static loff_t nfs_file_llseek(struct file *filp, loff_t offset, int origin) |
| { |
| loff_t loff; |
| |
| dprintk("NFS: llseek file(%s/%s, %lld, %d)\n", |
| filp->f_path.dentry->d_parent->d_name.name, |
| filp->f_path.dentry->d_name.name, |
| offset, origin); |
| |
| /* |
| * origin == SEEK_END || SEEK_DATA || SEEK_HOLE => we must revalidate |
| * the cached file length |
| */ |
| if (origin != SEEK_SET || origin != SEEK_CUR) { |
| struct inode *inode = filp->f_mapping->host; |
| |
| int retval = nfs_revalidate_file_size(inode, filp); |
| if (retval < 0) |
| return (loff_t)retval; |
| |
| spin_lock(&inode->i_lock); |
| loff = generic_file_llseek_unlocked(filp, offset, origin); |
| spin_unlock(&inode->i_lock); |
| } else |
| loff = generic_file_llseek_unlocked(filp, offset, origin); |
| return loff; |
| } |
| |
| /* |
| * Flush all dirty pages, and check for write errors. |
| */ |
| static int |
| nfs_file_flush(struct file *file, fl_owner_t id) |
| { |
| struct dentry *dentry = file->f_path.dentry; |
| struct inode *inode = dentry->d_inode; |
| |
| dprintk("NFS: flush(%s/%s)\n", |
| dentry->d_parent->d_name.name, |
| dentry->d_name.name); |
| |
| 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); |
| } |
| |
| static ssize_t |
| nfs_file_read(struct kiocb *iocb, const struct iovec *iov, |
| unsigned long nr_segs, loff_t pos) |
| { |
| struct dentry * dentry = iocb->ki_filp->f_path.dentry; |
| struct inode * inode = dentry->d_inode; |
| ssize_t result; |
| size_t count = iov_length(iov, nr_segs); |
| |
| if (iocb->ki_filp->f_flags & O_DIRECT) |
| return nfs_file_direct_read(iocb, iov, nr_segs, pos); |
| |
| dprintk("NFS: read(%s/%s, %lu@%lu)\n", |
| dentry->d_parent->d_name.name, dentry->d_name.name, |
| (unsigned long) count, (unsigned long) pos); |
| |
| result = nfs_revalidate_mapping(inode, iocb->ki_filp->f_mapping); |
| if (!result) { |
| result = generic_file_aio_read(iocb, iov, nr_segs, pos); |
| if (result > 0) |
| nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, result); |
| } |
| return result; |
| } |
| |
| static ssize_t |
| nfs_file_splice_read(struct file *filp, loff_t *ppos, |
| struct pipe_inode_info *pipe, size_t count, |
| unsigned int flags) |
| { |
| struct dentry *dentry = filp->f_path.dentry; |
| struct inode *inode = dentry->d_inode; |
| ssize_t res; |
| |
| dprintk("NFS: splice_read(%s/%s, %lu@%Lu)\n", |
| dentry->d_parent->d_name.name, dentry->d_name.name, |
| (unsigned long) count, (unsigned long long) *ppos); |
| |
| res = nfs_revalidate_mapping(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; |
| } |
| |
| static int |
| nfs_file_mmap(struct file * file, struct vm_area_struct * vma) |
| { |
| struct dentry *dentry = file->f_path.dentry; |
| struct inode *inode = dentry->d_inode; |
| int status; |
| |
| dprintk("NFS: mmap(%s/%s)\n", |
| dentry->d_parent->d_name.name, dentry->d_name.name); |
| |
| /* 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; |
| } |
| |
| /* |
| * 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(struct file *file, int datasync) |
| { |
| struct dentry *dentry = file->f_path.dentry; |
| struct nfs_open_context *ctx = nfs_file_open_context(file); |
| struct inode *inode = dentry->d_inode; |
| int have_error, status; |
| int ret = 0; |
| |
| |
| dprintk("NFS: fsync file(%s/%s) datasync %d\n", |
| dentry->d_parent->d_name.name, dentry->d_name.name, |
| datasync); |
| |
| nfs_inc_stats(inode, NFSIOS_VFSFSYNC); |
| 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 && status < 0) |
| ret = status; |
| if (!ret && !datasync) |
| /* application has asked for meta-data sync */ |
| ret = pnfs_layoutcommit_inode(inode, true); |
| return ret; |
| } |
| |
| /* |
| * 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 ((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(%s/%s(%ld), %u@%lld)\n", |
| file->f_path.dentry->d_parent->d_name.name, |
| file->f_path.dentry->d_name.name, |
| 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(&NFS_I(mapping->host)->flags, NFS_INO_FLUSHING, |
| nfs_wait_bit_killable, TASK_KILLABLE); |
| if (ret) |
| return ret; |
| |
| 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); |
| int status; |
| |
| dfprintk(PAGECACHE, "NFS: write_end(%s/%s(%ld), %u@%lld)\n", |
| file->f_path.dentry->d_parent->d_name.name, |
| file->f_path.dentry->d_name.name, |
| 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; |
| 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 long offset) |
| { |
| dfprintk(PAGECACHE, "NFS: invalidate_page(%p, %lu)\n", page, offset); |
| |
| if (offset != 0) |
| return; |
| /* Cancel any unstarted writes on this page */ |
| nfs_wb_page_cancel(page->mapping->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); |
| |
| /* Only do I/O if gfp is a superset of GFP_KERNEL */ |
| if (mapping && (gfp & GFP_KERNEL) == GFP_KERNEL) { |
| int how = FLUSH_SYNC; |
| |
| /* Don't let kswapd deadlock waiting for OOM RPC calls */ |
| if (current_is_kswapd()) |
| how = 0; |
| nfs_commit_inode(mapping->host, how); |
| } |
| /* If PagePrivate() is set, then the page is not freeable */ |
| if (PagePrivate(page)) |
| return 0; |
| return nfs_fscache_release_page(page, gfp); |
| } |
| |
| /* |
| * 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->mapping->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); |
| } |
| |
| 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, |
| .error_remove_page = generic_error_remove_page, |
| }; |
| |
| /* |
| * 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 dentry *dentry = filp->f_path.dentry; |
| unsigned pagelen; |
| int ret = VM_FAULT_NOPAGE; |
| struct address_space *mapping; |
| |
| dfprintk(PAGECACHE, "NFS: vm_page_mkwrite(%s/%s(%ld), offset %lld)\n", |
| dentry->d_parent->d_name.name, dentry->d_name.name, |
| 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(dentry->d_inode), page); |
| |
| lock_page(page); |
| mapping = page->mapping; |
| if (mapping != dentry->d_inode->i_mapping) |
| goto out_unlock; |
| |
| 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, |
| .page_mkwrite = nfs_vm_page_mkwrite, |
| }; |
| |
| static int nfs_need_sync_write(struct file *filp, struct inode *inode) |
| { |
| struct nfs_open_context *ctx; |
| |
| if (IS_SYNC(inode) || (filp->f_flags & O_DSYNC)) |
| return 1; |
| ctx = nfs_file_open_context(filp); |
| if (test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags)) |
| return 1; |
| return 0; |
| } |
| |
| static ssize_t nfs_file_write(struct kiocb *iocb, const struct iovec *iov, |
| unsigned long nr_segs, loff_t pos) |
| { |
| struct dentry * dentry = iocb->ki_filp->f_path.dentry; |
| struct inode * inode = dentry->d_inode; |
| unsigned long written = 0; |
| ssize_t result; |
| size_t count = iov_length(iov, nr_segs); |
| |
| if (iocb->ki_filp->f_flags & O_DIRECT) |
| return nfs_file_direct_write(iocb, iov, nr_segs, pos); |
| |
| dprintk("NFS: write(%s/%s, %lu@%Ld)\n", |
| dentry->d_parent->d_name.name, dentry->d_name.name, |
| (unsigned long) count, (long long) pos); |
| |
| result = -EBUSY; |
| if (IS_SWAPFILE(inode)) |
| goto out_swapfile; |
| /* |
| * O_APPEND implies that we must revalidate the file length. |
| */ |
| if (iocb->ki_filp->f_flags & O_APPEND) { |
| result = nfs_revalidate_file_size(inode, iocb->ki_filp); |
| if (result) |
| goto out; |
| } |
| |
| result = count; |
| if (!count) |
| goto out; |
| |
| result = generic_file_aio_write(iocb, iov, nr_segs, pos); |
| if (result > 0) |
| written = result; |
| |
| /* Return error values for O_DSYNC and IS_SYNC() */ |
| if (result >= 0 && nfs_need_sync_write(iocb->ki_filp, inode)) { |
| int err = vfs_fsync(iocb->ki_filp, 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; |
| } |
| |
| static ssize_t nfs_file_splice_write(struct pipe_inode_info *pipe, |
| struct file *filp, loff_t *ppos, |
| size_t count, unsigned int flags) |
| { |
| struct dentry *dentry = filp->f_path.dentry; |
| struct inode *inode = dentry->d_inode; |
| unsigned long written = 0; |
| ssize_t ret; |
| |
| dprintk("NFS splice_write(%s/%s, %lu@%llu)\n", |
| dentry->d_parent->d_name.name, dentry->d_name.name, |
| (unsigned long) count, (unsigned long long) *ppos); |
| |
| /* |
| * The combination of splice and an O_APPEND destination is disallowed. |
| */ |
| |
| ret = generic_file_splice_write(pipe, filp, ppos, count, flags); |
| if (ret > 0) |
| written = ret; |
| |
| if (ret >= 0 && nfs_need_sync_write(filp, inode)) { |
| int err = vfs_fsync(filp, 0); |
| if (err < 0) |
| ret = err; |
| } |
| if (ret > 0) |
| nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, written); |
| return ret; |
| } |
| |
| 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_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) |
| { |
| int res = 0; |
| switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) { |
| case FL_POSIX: |
| res = posix_lock_file_wait(file, fl); |
| break; |
| case FL_FLOCK: |
| res = flock_lock_file_wait(file, fl); |
| break; |
| default: |
| BUG(); |
| } |
| return res; |
| } |
| |
| static int |
| do_unlk(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.. |
| */ |
| nfs_sync_mapping(filp->f_mapping); |
| |
| /* 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_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 |
| */ |
| static 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(%s/%s, t=%x, fl=%x, r=%lld:%lld)\n", |
| filp->f_path.dentry->d_parent->d_name.name, |
| filp->f_path.dentry->d_name.name, |
| 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; |
| } |
| |
| /* |
| * Lock a (portion of) a file |
| */ |
| static 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(%s/%s, t=%x, fl=%x)\n", |
| filp->f_path.dentry->d_parent->d_name.name, |
| filp->f_path.dentry->d_name.name, |
| fl->fl_type, fl->fl_flags); |
| |
| if (!(fl->fl_flags & FL_FLOCK)) |
| return -ENOLCK; |
| |
| if (NFS_SERVER(inode)->flags & NFS_MOUNT_LOCAL_FLOCK) |
| is_local = 1; |
| |
| /* We're simulating flock() locks using posix locks on the server */ |
| fl->fl_owner = (fl_owner_t)filp; |
| fl->fl_start = 0; |
| fl->fl_end = OFFSET_MAX; |
| |
| if (fl->fl_type == F_UNLCK) |
| return do_unlk(filp, cmd, fl, is_local); |
| return do_setlk(filp, cmd, fl, is_local); |
| } |
| |
| /* |
| * There is no protocol support for leases, so we have no way to implement |
| * them correctly in the face of opens by other clients. |
| */ |
| static int nfs_setlease(struct file *file, long arg, struct file_lock **fl) |
| { |
| dprintk("NFS: setlease(%s/%s, arg=%ld)\n", |
| file->f_path.dentry->d_parent->d_name.name, |
| file->f_path.dentry->d_name.name, arg); |
| return -EINVAL; |
| } |