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-rw-r--r--fs/nfs/file.c904
1 files changed, 904 insertions, 0 deletions
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
new file mode 100644
index 0000000000..3f97688104
--- /dev/null
+++ b/fs/nfs/file.c
@@ -0,0 +1,904 @@
+// 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 <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 <linux/uaccess.h>
+#include <linux/filelock.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;
+
+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);
+ if (res == 0)
+ filp->f_mode |= FMODE_CAN_ODIRECT;
+ 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);
+ nfs_fscache_release_file(inode, filp);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(nfs_file_release);
+
+/**
+ * nfs_revalidate_file_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_INVALID_SIZE))
+ 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);
+
+ssize_t
+nfs_file_splice_read(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe,
+ size_t len, unsigned int flags)
+{
+ struct inode *inode = file_inode(in);
+ ssize_t result;
+
+ dprintk("NFS: splice_read(%pD2, %zu@%llu)\n", in, len, *ppos);
+
+ nfs_start_io_read(inode);
+ result = nfs_revalidate_mapping(inode, in->f_mapping);
+ if (!result) {
+ result = filemap_splice_read(in, ppos, pipe, len, flags);
+ if (result > 0)
+ nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, result);
+ }
+ nfs_end_io_read(inode);
+ return result;
+}
+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.
+ */
+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 inode *inode = file_inode(file);
+ struct nfs_inode *nfsi = NFS_I(inode);
+ long save_nredirtied = atomic_long_read(&nfsi->redirtied_pages);
+ long nredirtied;
+ 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;
+ nredirtied = atomic_long_read(&nfsi->redirtied_pages);
+ if (nredirtied == save_nredirtied)
+ break;
+ save_nredirtied = nredirtied;
+ }
+
+ 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_folio_is_full_write(struct folio *folio, loff_t pos,
+ unsigned int len)
+{
+ unsigned int pglen = nfs_folio_length(folio);
+ unsigned int offset = offset_in_folio(folio, pos);
+ unsigned int end = offset + len;
+
+ return !pglen || (end >= pglen && !offset);
+}
+
+static bool nfs_want_read_modify_write(struct file *file, struct folio *folio,
+ loff_t pos, unsigned int len)
+{
+ /*
+ * Up-to-date pages, those with ongoing or full-page write
+ * don't need read/modify/write
+ */
+ if (folio_test_uptodate(folio) || folio_test_private(folio) ||
+ nfs_folio_is_full_write(folio, pos, len))
+ return false;
+
+ if (pnfs_ld_read_whole_page(file_inode(file)))
+ 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, struct page **pagep,
+ void **fsdata)
+{
+ struct folio *folio;
+ int once_thru = 0;
+ int ret;
+
+ dfprintk(PAGECACHE, "NFS: write_begin(%pD2(%lu), %u@%lld)\n",
+ file, mapping->host->i_ino, len, (long long) pos);
+
+start:
+ folio = __filemap_get_folio(mapping, pos >> PAGE_SHIFT, FGP_WRITEBEGIN,
+ mapping_gfp_mask(mapping));
+ if (IS_ERR(folio))
+ return PTR_ERR(folio);
+ *pagep = &folio->page;
+
+ ret = nfs_flush_incompatible(file, folio);
+ if (ret) {
+ folio_unlock(folio);
+ folio_put(folio);
+ } else if (!once_thru &&
+ nfs_want_read_modify_write(file, folio, pos, len)) {
+ once_thru = 1;
+ ret = nfs_read_folio(file, folio);
+ folio_put(folio);
+ 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)
+{
+ struct nfs_open_context *ctx = nfs_file_open_context(file);
+ struct folio *folio = page_folio(page);
+ unsigned offset = offset_in_folio(folio, pos);
+ 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 (!folio_test_uptodate(folio)) {
+ size_t fsize = folio_size(folio);
+ unsigned pglen = nfs_folio_length(folio);
+ unsigned end = offset + copied;
+
+ if (pglen == 0) {
+ folio_zero_segments(folio, 0, offset, end, fsize);
+ folio_mark_uptodate(folio);
+ } else if (end >= pglen) {
+ folio_zero_segment(folio, end, fsize);
+ if (offset == 0)
+ folio_mark_uptodate(folio);
+ } else
+ folio_zero_segment(folio, pglen, fsize);
+ }
+
+ status = nfs_update_folio(file, folio, offset, copied);
+
+ folio_unlock(folio);
+ folio_put(folio);
+
+ 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_folio(struct folio *folio, size_t offset,
+ size_t length)
+{
+ struct inode *inode = folio_file_mapping(folio)->host;
+ dfprintk(PAGECACHE, "NFS: invalidate_folio(%lu, %zu, %zu)\n",
+ folio->index, offset, length);
+
+ if (offset != 0 || length < folio_size(folio))
+ return;
+ /* Cancel any unstarted writes on this page */
+ nfs_wb_folio_cancel(inode, folio);
+ folio_wait_fscache(folio);
+ trace_nfs_invalidate_folio(inode, folio);
+}
+
+/*
+ * Attempt to release the private state associated with a folio
+ * - Called if either private or fscache flags are set on the folio
+ * - Caller holds folio lock
+ * - Return true (may release folio) or false (may not)
+ */
+static bool nfs_release_folio(struct folio *folio, gfp_t gfp)
+{
+ dfprintk(PAGECACHE, "NFS: release_folio(%p)\n", folio);
+
+ /* If the private flag is set, then the folio is not freeable */
+ if (folio_test_private(folio)) {
+ if ((current_gfp_context(gfp) & GFP_KERNEL) != GFP_KERNEL ||
+ current_is_kswapd())
+ return false;
+ if (nfs_wb_folio(folio_file_mapping(folio)->host, folio) < 0)
+ return false;
+ }
+ return nfs_fscache_release_folio(folio, gfp);
+}
+
+static void nfs_check_dirty_writeback(struct folio *folio,
+ bool *dirty, bool *writeback)
+{
+ struct nfs_inode *nfsi;
+ struct address_space *mapping = folio->mapping;
+
+ /*
+ * Check if an unstable folio is currently being committed and
+ * if so, have the VM treat it as if the folio is under writeback
+ * so it will not block due to folios that will shortly be freeable.
+ */
+ nfsi = NFS_I(mapping->host);
+ if (atomic_read(&nfsi->commit_info.rpcs_out)) {
+ *writeback = true;
+ return;
+ }
+
+ /*
+ * If the private flag is set, then the folio 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 (folio_test_private(folio))
+ *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_folio(struct folio *folio)
+{
+ struct inode *inode = folio->mapping->host;
+ int ret;
+
+ dfprintk(PAGECACHE, "NFS: launder_folio(%ld, %llu)\n",
+ inode->i_ino, folio_pos(folio));
+
+ folio_wait_fscache(folio);
+ ret = nfs_wb_folio(inode, folio);
+ trace_nfs_launder_folio_done(inode, folio, ret);
+ return ret;
+}
+
+static int nfs_swap_activate(struct swap_info_struct *sis, struct file *file,
+ sector_t *span)
+{
+ unsigned long blocks;
+ long long isize;
+ int ret;
+ 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;
+ }
+
+ ret = rpc_clnt_swap_activate(clnt);
+ if (ret)
+ return ret;
+ ret = add_swap_extent(sis, 0, sis->max, 0);
+ if (ret < 0) {
+ rpc_clnt_swap_deactivate(clnt);
+ return ret;
+ }
+
+ *span = sis->pages;
+
+ if (cl->rpc_ops->enable_swap)
+ cl->rpc_ops->enable_swap(inode);
+
+ sis->flags |= SWP_FS_OPS;
+ return ret;
+}
+
+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 = {
+ .read_folio = nfs_read_folio,
+ .readahead = nfs_readahead,
+ .dirty_folio = filemap_dirty_folio,
+ .writepage = nfs_writepage,
+ .writepages = nfs_writepages,
+ .write_begin = nfs_write_begin,
+ .write_end = nfs_write_end,
+ .invalidate_folio = nfs_invalidate_folio,
+ .release_folio = nfs_release_folio,
+ .migrate_folio = nfs_migrate_folio,
+ .launder_folio = nfs_launder_folio,
+ .is_dirty_writeback = nfs_check_dirty_writeback,
+ .error_remove_page = generic_error_remove_page,
+ .swap_activate = nfs_swap_activate,
+ .swap_deactivate = nfs_swap_deactivate,
+ .swap_rw = nfs_swap_rw,
+};
+
+/*
+ * 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 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;
+ struct folio *folio = page_folio(vmf->page);
+
+ dfprintk(PAGECACHE, "NFS: vm_page_mkwrite(%pD2(%lu), offset %lld)\n",
+ filp, filp->f_mapping->host->i_ino,
+ (long long)folio_file_pos(folio));
+
+ sb_start_pagefault(inode->i_sb);
+
+ /* make sure the cache has finished storing the page */
+ if (folio_test_fscache(folio) &&
+ folio_wait_fscache_killable(folio) < 0) {
+ ret = VM_FAULT_RETRY;
+ goto out;
+ }
+
+ wait_on_bit_action(&NFS_I(inode)->flags, NFS_INO_INVALIDATING,
+ nfs_wait_bit_killable,
+ TASK_KILLABLE|TASK_FREEZABLE_UNSAFE);
+
+ folio_lock(folio);
+ mapping = folio_file_mapping(folio);
+ if (mapping != inode->i_mapping)
+ goto out_unlock;
+
+ folio_wait_writeback(folio);
+
+ pagelen = nfs_folio_length(folio);
+ if (pagelen == 0)
+ goto out_unlock;
+
+ ret = VM_FAULT_LOCKED;
+ if (nfs_flush_incompatible(filp, folio) == 0 &&
+ nfs_update_folio(filp, folio, 0, pagelen) == 0)
+ goto out;
+
+ ret = VM_FAULT_SIGBUS;
+out_unlock:
+ folio_unlock(folio);
+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,
+};
+
+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 int mntflags = NFS_SERVER(inode)->flags;
+ ssize_t result, written;
+ 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 || iocb->ki_pos > i_size_read(inode)) {
+ result = nfs_revalidate_file_size(inode, file);
+ if (result)
+ return result;
+ }
+
+ nfs_clear_invalid_mapping(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)
+ result = generic_perform_write(iocb, from);
+ nfs_end_io_write(inode);
+ if (result <= 0)
+ goto out;
+
+ written = result;
+ nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, written);
+
+ if (mntflags & NFS_MOUNT_WRITE_EAGER) {
+ result = filemap_fdatawrite_range(file->f_mapping,
+ iocb->ki_pos - written,
+ iocb->ki_pos - 1);
+ if (result < 0)
+ goto out;
+ }
+ if (mntflags & NFS_MOUNT_WRITE_WAIT) {
+ filemap_fdatawait_range(file->f_mapping,
+ iocb->ki_pos - written,
+ iocb->ki_pos - 1);
+ }
+ result = generic_write_sync(iocb, written);
+ if (result < 0)
+ return result;
+
+out:
+ /* Return error values */
+ error = filemap_check_wb_err(file->f_mapping, since);
+ switch (error) {
+ default:
+ break;
+ case -EDQUOT:
+ case -EFBIG:
+ case -ENOSPC:
+ nfs_wb_all(inode);
+ error = file_check_and_advance_wb_err(file);
+ if (error < 0)
+ result = error;
+ }
+ 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);
+
+ if (fl->fl_flags & FL_RECLAIM)
+ return -ENOGRACE;
+
+ 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;
+
+ 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);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-13 15:59:11 +0000