diff options
author | 2015-08-04 12:17:53 -0700 | |
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committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/fs/nfs/file.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/fs/nfs/file.c')
-rw-r--r-- | kernel/fs/nfs/file.c | 947 |
1 files changed, 947 insertions, 0 deletions
diff --git a/kernel/fs/nfs/file.c b/kernel/fs/nfs/file.c new file mode 100644 index 000000000..8b8d83a52 --- /dev/null +++ b/kernel/fs/nfs/file.c @@ -0,0 +1,947 @@ +/* + * 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); + return nfs_release(inode, filp); +} +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. + */ +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; + + /* + * If we're holding a write delegation, then just start the i/o + * but don't wait for completion (or send a commit). + */ + if (NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE)) + return filemap_fdatawrite(file->f_mapping); + + /* Flush writes to the server and return any errors */ + return vfs_fsync(file, 0); +} +EXPORT_SYMBOL_GPL(nfs_file_flush); + +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. + */ +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; +} +EXPORT_SYMBOL_GPL(nfs_file_fsync_commit); + +static 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); + + nfs_inode_dio_wait(inode); + do { + ret = filemap_write_and_wait_range(inode->i_mapping, start, end); + if (ret != 0) + break; + mutex_lock(&inode->i_mutex); + ret = nfs_file_fsync_commit(file, start, end, datasync); + mutex_unlock(&inode->i_mutex); + /* + * 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; +} + +/* + * 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 + */ + nfs_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 __GFP_WAIT is set. 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 ((gfp & __GFP_WAIT) && + !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 (test_bit(NFS_INO_COMMIT, &nfsi->flags)) { + *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); +} + +#ifdef CONFIG_NFS_SWAP +static int nfs_swap_activate(struct swap_info_struct *sis, struct file *file, + sector_t *span) +{ + int ret; + struct rpc_clnt *clnt = NFS_CLIENT(file->f_mapping->host); + + *span = sis->pages; + + rcu_read_lock(); + ret = xs_swapper(rcu_dereference(clnt->cl_xprt), 1); + rcu_read_unlock(); + + return ret; +} + +static void nfs_swap_deactivate(struct file *file) +{ + struct rpc_clnt *clnt = NFS_CLIENT(file->f_mapping->host); + + rcu_read_lock(); + xs_swapper(rcu_dereference(clnt->cl_xprt), 0); + rcu_read_unlock(); +} +#endif + +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, +#ifdef CONFIG_NFS_SWAP + .swap_activate = nfs_swap_activate, + .swap_deactivate = nfs_swap_deactivate, +#endif +}; + +/* + * 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_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) || + 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 for O_DSYNC and IS_SYNC() */ + if (result >= 0 && nfs_need_sync_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) +{ + 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; + 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->io_count); + 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); |