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-rw-r--r--fs/gfs2/file.c1624
1 files changed, 1624 insertions, 0 deletions
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
new file mode 100644
index 000000000..f2700477a
--- /dev/null
+++ b/fs/gfs2/file.c
@@ -0,0 +1,1624 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
+ * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
+ */
+
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/compat.h>
+#include <linux/completion.h>
+#include <linux/buffer_head.h>
+#include <linux/pagemap.h>
+#include <linux/uio.h>
+#include <linux/blkdev.h>
+#include <linux/mm.h>
+#include <linux/mount.h>
+#include <linux/fs.h>
+#include <linux/filelock.h>
+#include <linux/gfs2_ondisk.h>
+#include <linux/falloc.h>
+#include <linux/swap.h>
+#include <linux/crc32.h>
+#include <linux/writeback.h>
+#include <linux/uaccess.h>
+#include <linux/dlm.h>
+#include <linux/dlm_plock.h>
+#include <linux/delay.h>
+#include <linux/backing-dev.h>
+#include <linux/fileattr.h>
+
+#include "gfs2.h"
+#include "incore.h"
+#include "bmap.h"
+#include "aops.h"
+#include "dir.h"
+#include "glock.h"
+#include "glops.h"
+#include "inode.h"
+#include "log.h"
+#include "meta_io.h"
+#include "quota.h"
+#include "rgrp.h"
+#include "trans.h"
+#include "util.h"
+
+/**
+ * gfs2_llseek - seek to a location in a file
+ * @file: the file
+ * @offset: the offset
+ * @whence: Where to seek from (SEEK_SET, SEEK_CUR, or SEEK_END)
+ *
+ * SEEK_END requires the glock for the file because it references the
+ * file's size.
+ *
+ * Returns: The new offset, or errno
+ */
+
+static loff_t gfs2_llseek(struct file *file, loff_t offset, int whence)
+{
+ struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
+ struct gfs2_holder i_gh;
+ loff_t error;
+
+ switch (whence) {
+ case SEEK_END:
+ error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
+ &i_gh);
+ if (!error) {
+ error = generic_file_llseek(file, offset, whence);
+ gfs2_glock_dq_uninit(&i_gh);
+ }
+ break;
+
+ case SEEK_DATA:
+ error = gfs2_seek_data(file, offset);
+ break;
+
+ case SEEK_HOLE:
+ error = gfs2_seek_hole(file, offset);
+ break;
+
+ case SEEK_CUR:
+ case SEEK_SET:
+ /*
+ * These don't reference inode->i_size and don't depend on the
+ * block mapping, so we don't need the glock.
+ */
+ error = generic_file_llseek(file, offset, whence);
+ break;
+ default:
+ error = -EINVAL;
+ }
+
+ return error;
+}
+
+/**
+ * gfs2_readdir - Iterator for a directory
+ * @file: The directory to read from
+ * @ctx: What to feed directory entries to
+ *
+ * Returns: errno
+ */
+
+static int gfs2_readdir(struct file *file, struct dir_context *ctx)
+{
+ struct inode *dir = file->f_mapping->host;
+ struct gfs2_inode *dip = GFS2_I(dir);
+ struct gfs2_holder d_gh;
+ int error;
+
+ error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
+ if (error)
+ return error;
+
+ error = gfs2_dir_read(dir, ctx, &file->f_ra);
+
+ gfs2_glock_dq_uninit(&d_gh);
+
+ return error;
+}
+
+/*
+ * struct fsflag_gfs2flag
+ *
+ * The FS_JOURNAL_DATA_FL flag maps to GFS2_DIF_INHERIT_JDATA for directories,
+ * and to GFS2_DIF_JDATA for non-directories.
+ */
+static struct {
+ u32 fsflag;
+ u32 gfsflag;
+} fsflag_gfs2flag[] = {
+ {FS_SYNC_FL, GFS2_DIF_SYNC},
+ {FS_IMMUTABLE_FL, GFS2_DIF_IMMUTABLE},
+ {FS_APPEND_FL, GFS2_DIF_APPENDONLY},
+ {FS_NOATIME_FL, GFS2_DIF_NOATIME},
+ {FS_INDEX_FL, GFS2_DIF_EXHASH},
+ {FS_TOPDIR_FL, GFS2_DIF_TOPDIR},
+ {FS_JOURNAL_DATA_FL, GFS2_DIF_JDATA | GFS2_DIF_INHERIT_JDATA},
+};
+
+static inline u32 gfs2_gfsflags_to_fsflags(struct inode *inode, u32 gfsflags)
+{
+ int i;
+ u32 fsflags = 0;
+
+ if (S_ISDIR(inode->i_mode))
+ gfsflags &= ~GFS2_DIF_JDATA;
+ else
+ gfsflags &= ~GFS2_DIF_INHERIT_JDATA;
+
+ for (i = 0; i < ARRAY_SIZE(fsflag_gfs2flag); i++)
+ if (gfsflags & fsflag_gfs2flag[i].gfsflag)
+ fsflags |= fsflag_gfs2flag[i].fsflag;
+ return fsflags;
+}
+
+int gfs2_fileattr_get(struct dentry *dentry, struct fileattr *fa)
+{
+ struct inode *inode = d_inode(dentry);
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct gfs2_holder gh;
+ int error;
+ u32 fsflags;
+
+ if (d_is_special(dentry))
+ return -ENOTTY;
+
+ gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
+ error = gfs2_glock_nq(&gh);
+ if (error)
+ goto out_uninit;
+
+ fsflags = gfs2_gfsflags_to_fsflags(inode, ip->i_diskflags);
+
+ fileattr_fill_flags(fa, fsflags);
+
+ gfs2_glock_dq(&gh);
+out_uninit:
+ gfs2_holder_uninit(&gh);
+ return error;
+}
+
+void gfs2_set_inode_flags(struct inode *inode)
+{
+ struct gfs2_inode *ip = GFS2_I(inode);
+ unsigned int flags = inode->i_flags;
+
+ flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_NOSEC);
+ if ((ip->i_eattr == 0) && !is_sxid(inode->i_mode))
+ flags |= S_NOSEC;
+ if (ip->i_diskflags & GFS2_DIF_IMMUTABLE)
+ flags |= S_IMMUTABLE;
+ if (ip->i_diskflags & GFS2_DIF_APPENDONLY)
+ flags |= S_APPEND;
+ if (ip->i_diskflags & GFS2_DIF_NOATIME)
+ flags |= S_NOATIME;
+ if (ip->i_diskflags & GFS2_DIF_SYNC)
+ flags |= S_SYNC;
+ inode->i_flags = flags;
+}
+
+/* Flags that can be set by user space */
+#define GFS2_FLAGS_USER_SET (GFS2_DIF_JDATA| \
+ GFS2_DIF_IMMUTABLE| \
+ GFS2_DIF_APPENDONLY| \
+ GFS2_DIF_NOATIME| \
+ GFS2_DIF_SYNC| \
+ GFS2_DIF_TOPDIR| \
+ GFS2_DIF_INHERIT_JDATA)
+
+/**
+ * do_gfs2_set_flags - set flags on an inode
+ * @inode: The inode
+ * @reqflags: The flags to set
+ * @mask: Indicates which flags are valid
+ *
+ */
+static int do_gfs2_set_flags(struct inode *inode, u32 reqflags, u32 mask)
+{
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct gfs2_sbd *sdp = GFS2_SB(inode);
+ struct buffer_head *bh;
+ struct gfs2_holder gh;
+ int error;
+ u32 new_flags, flags;
+
+ error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
+ if (error)
+ return error;
+
+ error = 0;
+ flags = ip->i_diskflags;
+ new_flags = (flags & ~mask) | (reqflags & mask);
+ if ((new_flags ^ flags) == 0)
+ goto out;
+
+ if (!IS_IMMUTABLE(inode)) {
+ error = gfs2_permission(&nop_mnt_idmap, inode, MAY_WRITE);
+ if (error)
+ goto out;
+ }
+ if ((flags ^ new_flags) & GFS2_DIF_JDATA) {
+ if (new_flags & GFS2_DIF_JDATA)
+ gfs2_log_flush(sdp, ip->i_gl,
+ GFS2_LOG_HEAD_FLUSH_NORMAL |
+ GFS2_LFC_SET_FLAGS);
+ error = filemap_fdatawrite(inode->i_mapping);
+ if (error)
+ goto out;
+ error = filemap_fdatawait(inode->i_mapping);
+ if (error)
+ goto out;
+ if (new_flags & GFS2_DIF_JDATA)
+ gfs2_ordered_del_inode(ip);
+ }
+ error = gfs2_trans_begin(sdp, RES_DINODE, 0);
+ if (error)
+ goto out;
+ error = gfs2_meta_inode_buffer(ip, &bh);
+ if (error)
+ goto out_trans_end;
+ inode_set_ctime_current(inode);
+ gfs2_trans_add_meta(ip->i_gl, bh);
+ ip->i_diskflags = new_flags;
+ gfs2_dinode_out(ip, bh->b_data);
+ brelse(bh);
+ gfs2_set_inode_flags(inode);
+ gfs2_set_aops(inode);
+out_trans_end:
+ gfs2_trans_end(sdp);
+out:
+ gfs2_glock_dq_uninit(&gh);
+ return error;
+}
+
+int gfs2_fileattr_set(struct mnt_idmap *idmap,
+ struct dentry *dentry, struct fileattr *fa)
+{
+ struct inode *inode = d_inode(dentry);
+ u32 fsflags = fa->flags, gfsflags = 0;
+ u32 mask;
+ int i;
+
+ if (d_is_special(dentry))
+ return -ENOTTY;
+
+ if (fileattr_has_fsx(fa))
+ return -EOPNOTSUPP;
+
+ for (i = 0; i < ARRAY_SIZE(fsflag_gfs2flag); i++) {
+ if (fsflags & fsflag_gfs2flag[i].fsflag) {
+ fsflags &= ~fsflag_gfs2flag[i].fsflag;
+ gfsflags |= fsflag_gfs2flag[i].gfsflag;
+ }
+ }
+ if (fsflags || gfsflags & ~GFS2_FLAGS_USER_SET)
+ return -EINVAL;
+
+ mask = GFS2_FLAGS_USER_SET;
+ if (S_ISDIR(inode->i_mode)) {
+ mask &= ~GFS2_DIF_JDATA;
+ } else {
+ /* The GFS2_DIF_TOPDIR flag is only valid for directories. */
+ if (gfsflags & GFS2_DIF_TOPDIR)
+ return -EINVAL;
+ mask &= ~(GFS2_DIF_TOPDIR | GFS2_DIF_INHERIT_JDATA);
+ }
+
+ return do_gfs2_set_flags(inode, gfsflags, mask);
+}
+
+static int gfs2_getlabel(struct file *filp, char __user *label)
+{
+ struct inode *inode = file_inode(filp);
+ struct gfs2_sbd *sdp = GFS2_SB(inode);
+
+ if (copy_to_user(label, sdp->sd_sb.sb_locktable, GFS2_LOCKNAME_LEN))
+ return -EFAULT;
+
+ return 0;
+}
+
+static long gfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+ switch(cmd) {
+ case FITRIM:
+ return gfs2_fitrim(filp, (void __user *)arg);
+ case FS_IOC_GETFSLABEL:
+ return gfs2_getlabel(filp, (char __user *)arg);
+ }
+
+ return -ENOTTY;
+}
+
+#ifdef CONFIG_COMPAT
+static long gfs2_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+ switch(cmd) {
+ /* Keep this list in sync with gfs2_ioctl */
+ case FITRIM:
+ case FS_IOC_GETFSLABEL:
+ break;
+ default:
+ return -ENOIOCTLCMD;
+ }
+
+ return gfs2_ioctl(filp, cmd, (unsigned long)compat_ptr(arg));
+}
+#else
+#define gfs2_compat_ioctl NULL
+#endif
+
+/**
+ * gfs2_size_hint - Give a hint to the size of a write request
+ * @filep: The struct file
+ * @offset: The file offset of the write
+ * @size: The length of the write
+ *
+ * When we are about to do a write, this function records the total
+ * write size in order to provide a suitable hint to the lower layers
+ * about how many blocks will be required.
+ *
+ */
+
+static void gfs2_size_hint(struct file *filep, loff_t offset, size_t size)
+{
+ struct inode *inode = file_inode(filep);
+ struct gfs2_sbd *sdp = GFS2_SB(inode);
+ struct gfs2_inode *ip = GFS2_I(inode);
+ size_t blks = (size + sdp->sd_sb.sb_bsize - 1) >> sdp->sd_sb.sb_bsize_shift;
+ int hint = min_t(size_t, INT_MAX, blks);
+
+ if (hint > atomic_read(&ip->i_sizehint))
+ atomic_set(&ip->i_sizehint, hint);
+}
+
+/**
+ * gfs2_allocate_page_backing - Allocate blocks for a write fault
+ * @page: The (locked) page to allocate backing for
+ * @length: Size of the allocation
+ *
+ * We try to allocate all the blocks required for the page in one go. This
+ * might fail for various reasons, so we keep trying until all the blocks to
+ * back this page are allocated. If some of the blocks are already allocated,
+ * that is ok too.
+ */
+static int gfs2_allocate_page_backing(struct page *page, unsigned int length)
+{
+ u64 pos = page_offset(page);
+
+ do {
+ struct iomap iomap = { };
+
+ if (gfs2_iomap_alloc(page->mapping->host, pos, length, &iomap))
+ return -EIO;
+
+ if (length < iomap.length)
+ iomap.length = length;
+ length -= iomap.length;
+ pos += iomap.length;
+ } while (length > 0);
+
+ return 0;
+}
+
+/**
+ * gfs2_page_mkwrite - Make a shared, mmap()ed, page writable
+ * @vmf: The virtual memory fault containing the page to become writable
+ *
+ * When the page becomes writable, we need to ensure that we have
+ * blocks allocated on disk to back that page.
+ */
+
+static vm_fault_t gfs2_page_mkwrite(struct vm_fault *vmf)
+{
+ struct page *page = vmf->page;
+ struct inode *inode = file_inode(vmf->vma->vm_file);
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct gfs2_sbd *sdp = GFS2_SB(inode);
+ struct gfs2_alloc_parms ap = { .aflags = 0, };
+ u64 offset = page_offset(page);
+ unsigned int data_blocks, ind_blocks, rblocks;
+ vm_fault_t ret = VM_FAULT_LOCKED;
+ struct gfs2_holder gh;
+ unsigned int length;
+ loff_t size;
+ int err;
+
+ sb_start_pagefault(inode->i_sb);
+
+ gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
+ err = gfs2_glock_nq(&gh);
+ if (err) {
+ ret = vmf_fs_error(err);
+ goto out_uninit;
+ }
+
+ /* Check page index against inode size */
+ size = i_size_read(inode);
+ if (offset >= size) {
+ ret = VM_FAULT_SIGBUS;
+ goto out_unlock;
+ }
+
+ /* Update file times before taking page lock */
+ file_update_time(vmf->vma->vm_file);
+
+ /* page is wholly or partially inside EOF */
+ if (size - offset < PAGE_SIZE)
+ length = size - offset;
+ else
+ length = PAGE_SIZE;
+
+ gfs2_size_hint(vmf->vma->vm_file, offset, length);
+
+ set_bit(GLF_DIRTY, &ip->i_gl->gl_flags);
+ set_bit(GIF_SW_PAGED, &ip->i_flags);
+
+ /*
+ * iomap_writepage / iomap_writepages currently don't support inline
+ * files, so always unstuff here.
+ */
+
+ if (!gfs2_is_stuffed(ip) &&
+ !gfs2_write_alloc_required(ip, offset, length)) {
+ lock_page(page);
+ if (!PageUptodate(page) || page->mapping != inode->i_mapping) {
+ ret = VM_FAULT_NOPAGE;
+ unlock_page(page);
+ }
+ goto out_unlock;
+ }
+
+ err = gfs2_rindex_update(sdp);
+ if (err) {
+ ret = vmf_fs_error(err);
+ goto out_unlock;
+ }
+
+ gfs2_write_calc_reserv(ip, length, &data_blocks, &ind_blocks);
+ ap.target = data_blocks + ind_blocks;
+ err = gfs2_quota_lock_check(ip, &ap);
+ if (err) {
+ ret = vmf_fs_error(err);
+ goto out_unlock;
+ }
+ err = gfs2_inplace_reserve(ip, &ap);
+ if (err) {
+ ret = vmf_fs_error(err);
+ goto out_quota_unlock;
+ }
+
+ rblocks = RES_DINODE + ind_blocks;
+ if (gfs2_is_jdata(ip))
+ rblocks += data_blocks ? data_blocks : 1;
+ if (ind_blocks || data_blocks) {
+ rblocks += RES_STATFS + RES_QUOTA;
+ rblocks += gfs2_rg_blocks(ip, data_blocks + ind_blocks);
+ }
+ err = gfs2_trans_begin(sdp, rblocks, 0);
+ if (err) {
+ ret = vmf_fs_error(err);
+ goto out_trans_fail;
+ }
+
+ /* Unstuff, if required, and allocate backing blocks for page */
+ if (gfs2_is_stuffed(ip)) {
+ err = gfs2_unstuff_dinode(ip);
+ if (err) {
+ ret = vmf_fs_error(err);
+ goto out_trans_end;
+ }
+ }
+
+ lock_page(page);
+ /* If truncated, we must retry the operation, we may have raced
+ * with the glock demotion code.
+ */
+ if (!PageUptodate(page) || page->mapping != inode->i_mapping) {
+ ret = VM_FAULT_NOPAGE;
+ goto out_page_locked;
+ }
+
+ err = gfs2_allocate_page_backing(page, length);
+ if (err)
+ ret = vmf_fs_error(err);
+
+out_page_locked:
+ if (ret != VM_FAULT_LOCKED)
+ unlock_page(page);
+out_trans_end:
+ gfs2_trans_end(sdp);
+out_trans_fail:
+ gfs2_inplace_release(ip);
+out_quota_unlock:
+ gfs2_quota_unlock(ip);
+out_unlock:
+ gfs2_glock_dq(&gh);
+out_uninit:
+ gfs2_holder_uninit(&gh);
+ if (ret == VM_FAULT_LOCKED) {
+ set_page_dirty(page);
+ wait_for_stable_page(page);
+ }
+ sb_end_pagefault(inode->i_sb);
+ return ret;
+}
+
+static vm_fault_t gfs2_fault(struct vm_fault *vmf)
+{
+ struct inode *inode = file_inode(vmf->vma->vm_file);
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct gfs2_holder gh;
+ vm_fault_t ret;
+ int err;
+
+ gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
+ err = gfs2_glock_nq(&gh);
+ if (err) {
+ ret = vmf_fs_error(err);
+ goto out_uninit;
+ }
+ ret = filemap_fault(vmf);
+ gfs2_glock_dq(&gh);
+out_uninit:
+ gfs2_holder_uninit(&gh);
+ return ret;
+}
+
+static const struct vm_operations_struct gfs2_vm_ops = {
+ .fault = gfs2_fault,
+ .map_pages = filemap_map_pages,
+ .page_mkwrite = gfs2_page_mkwrite,
+};
+
+/**
+ * gfs2_mmap
+ * @file: The file to map
+ * @vma: The VMA which described the mapping
+ *
+ * There is no need to get a lock here unless we should be updating
+ * atime. We ignore any locking errors since the only consequence is
+ * a missed atime update (which will just be deferred until later).
+ *
+ * Returns: 0
+ */
+
+static int gfs2_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
+
+ if (!(file->f_flags & O_NOATIME) &&
+ !IS_NOATIME(&ip->i_inode)) {
+ struct gfs2_holder i_gh;
+ int error;
+
+ error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
+ &i_gh);
+ if (error)
+ return error;
+ /* grab lock to update inode */
+ gfs2_glock_dq_uninit(&i_gh);
+ file_accessed(file);
+ }
+ vma->vm_ops = &gfs2_vm_ops;
+
+ return 0;
+}
+
+/**
+ * gfs2_open_common - This is common to open and atomic_open
+ * @inode: The inode being opened
+ * @file: The file being opened
+ *
+ * This maybe called under a glock or not depending upon how it has
+ * been called. We must always be called under a glock for regular
+ * files, however. For other file types, it does not matter whether
+ * we hold the glock or not.
+ *
+ * Returns: Error code or 0 for success
+ */
+
+int gfs2_open_common(struct inode *inode, struct file *file)
+{
+ struct gfs2_file *fp;
+ int ret;
+
+ if (S_ISREG(inode->i_mode)) {
+ ret = generic_file_open(inode, file);
+ if (ret)
+ return ret;
+
+ if (!gfs2_is_jdata(GFS2_I(inode)))
+ file->f_mode |= FMODE_CAN_ODIRECT;
+ }
+
+ fp = kzalloc(sizeof(struct gfs2_file), GFP_NOFS);
+ if (!fp)
+ return -ENOMEM;
+
+ mutex_init(&fp->f_fl_mutex);
+
+ gfs2_assert_warn(GFS2_SB(inode), !file->private_data);
+ file->private_data = fp;
+ if (file->f_mode & FMODE_WRITE) {
+ ret = gfs2_qa_get(GFS2_I(inode));
+ if (ret)
+ goto fail;
+ }
+ return 0;
+
+fail:
+ kfree(file->private_data);
+ file->private_data = NULL;
+ return ret;
+}
+
+/**
+ * gfs2_open - open a file
+ * @inode: the inode to open
+ * @file: the struct file for this opening
+ *
+ * After atomic_open, this function is only used for opening files
+ * which are already cached. We must still get the glock for regular
+ * files to ensure that we have the file size uptodate for the large
+ * file check which is in the common code. That is only an issue for
+ * regular files though.
+ *
+ * Returns: errno
+ */
+
+static int gfs2_open(struct inode *inode, struct file *file)
+{
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct gfs2_holder i_gh;
+ int error;
+ bool need_unlock = false;
+
+ if (S_ISREG(ip->i_inode.i_mode)) {
+ error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY,
+ &i_gh);
+ if (error)
+ return error;
+ need_unlock = true;
+ }
+
+ error = gfs2_open_common(inode, file);
+
+ if (need_unlock)
+ gfs2_glock_dq_uninit(&i_gh);
+
+ return error;
+}
+
+/**
+ * gfs2_release - called to close a struct file
+ * @inode: the inode the struct file belongs to
+ * @file: the struct file being closed
+ *
+ * Returns: errno
+ */
+
+static int gfs2_release(struct inode *inode, struct file *file)
+{
+ struct gfs2_inode *ip = GFS2_I(inode);
+
+ kfree(file->private_data);
+ file->private_data = NULL;
+
+ if (file->f_mode & FMODE_WRITE) {
+ if (gfs2_rs_active(&ip->i_res))
+ gfs2_rs_delete(ip);
+ gfs2_qa_put(ip);
+ }
+ return 0;
+}
+
+/**
+ * gfs2_fsync - sync the dirty data for a file (across the cluster)
+ * @file: the file that points to the dentry
+ * @start: the start position in the file to sync
+ * @end: the end position in the file to sync
+ * @datasync: set if we can ignore timestamp changes
+ *
+ * We split the data flushing here so that we don't wait for the data
+ * until after we've also sent the metadata to disk. Note that for
+ * data=ordered, we will write & wait for the data at the log flush
+ * stage anyway, so this is unlikely to make much of a difference
+ * except in the data=writeback case.
+ *
+ * If the fdatawrite fails due to any reason except -EIO, we will
+ * continue the remainder of the fsync, although we'll still report
+ * the error at the end. This is to match filemap_write_and_wait_range()
+ * behaviour.
+ *
+ * Returns: errno
+ */
+
+static int gfs2_fsync(struct file *file, loff_t start, loff_t end,
+ int datasync)
+{
+ struct address_space *mapping = file->f_mapping;
+ struct inode *inode = mapping->host;
+ int sync_state = inode->i_state & I_DIRTY;
+ struct gfs2_inode *ip = GFS2_I(inode);
+ int ret = 0, ret1 = 0;
+
+ if (mapping->nrpages) {
+ ret1 = filemap_fdatawrite_range(mapping, start, end);
+ if (ret1 == -EIO)
+ return ret1;
+ }
+
+ if (!gfs2_is_jdata(ip))
+ sync_state &= ~I_DIRTY_PAGES;
+ if (datasync)
+ sync_state &= ~I_DIRTY_SYNC;
+
+ if (sync_state) {
+ ret = sync_inode_metadata(inode, 1);
+ if (ret)
+ return ret;
+ if (gfs2_is_jdata(ip))
+ ret = file_write_and_wait(file);
+ if (ret)
+ return ret;
+ gfs2_ail_flush(ip->i_gl, 1);
+ }
+
+ if (mapping->nrpages)
+ ret = file_fdatawait_range(file, start, end);
+
+ return ret ? ret : ret1;
+}
+
+static inline bool should_fault_in_pages(struct iov_iter *i,
+ struct kiocb *iocb,
+ size_t *prev_count,
+ size_t *window_size)
+{
+ size_t count = iov_iter_count(i);
+ size_t size, offs;
+
+ if (!count)
+ return false;
+ if (!user_backed_iter(i))
+ return false;
+
+ /*
+ * Try to fault in multiple pages initially. When that doesn't result
+ * in any progress, fall back to a single page.
+ */
+ size = PAGE_SIZE;
+ offs = offset_in_page(iocb->ki_pos);
+ if (*prev_count != count) {
+ size_t nr_dirtied;
+
+ nr_dirtied = max(current->nr_dirtied_pause -
+ current->nr_dirtied, 8);
+ size = min_t(size_t, SZ_1M, nr_dirtied << PAGE_SHIFT);
+ }
+
+ *prev_count = count;
+ *window_size = size - offs;
+ return true;
+}
+
+static ssize_t gfs2_file_direct_read(struct kiocb *iocb, struct iov_iter *to,
+ struct gfs2_holder *gh)
+{
+ struct file *file = iocb->ki_filp;
+ struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
+ size_t prev_count = 0, window_size = 0;
+ size_t read = 0;
+ ssize_t ret;
+
+ /*
+ * In this function, we disable page faults when we're holding the
+ * inode glock while doing I/O. If a page fault occurs, we indicate
+ * that the inode glock may be dropped, fault in the pages manually,
+ * and retry.
+ *
+ * Unlike generic_file_read_iter, for reads, iomap_dio_rw can trigger
+ * physical as well as manual page faults, and we need to disable both
+ * kinds.
+ *
+ * For direct I/O, gfs2 takes the inode glock in deferred mode. This
+ * locking mode is compatible with other deferred holders, so multiple
+ * processes and nodes can do direct I/O to a file at the same time.
+ * There's no guarantee that reads or writes will be atomic. Any
+ * coordination among readers and writers needs to happen externally.
+ */
+
+ if (!iov_iter_count(to))
+ return 0; /* skip atime */
+
+ gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, gh);
+retry:
+ ret = gfs2_glock_nq(gh);
+ if (ret)
+ goto out_uninit;
+ pagefault_disable();
+ to->nofault = true;
+ ret = iomap_dio_rw(iocb, to, &gfs2_iomap_ops, NULL,
+ IOMAP_DIO_PARTIAL, NULL, read);
+ to->nofault = false;
+ pagefault_enable();
+ if (ret <= 0 && ret != -EFAULT)
+ goto out_unlock;
+ /* No increment (+=) because iomap_dio_rw returns a cumulative value. */
+ if (ret > 0)
+ read = ret;
+
+ if (should_fault_in_pages(to, iocb, &prev_count, &window_size)) {
+ gfs2_glock_dq(gh);
+ window_size -= fault_in_iov_iter_writeable(to, window_size);
+ if (window_size)
+ goto retry;
+ }
+out_unlock:
+ if (gfs2_holder_queued(gh))
+ gfs2_glock_dq(gh);
+out_uninit:
+ gfs2_holder_uninit(gh);
+ /* User space doesn't expect partial success. */
+ if (ret < 0)
+ return ret;
+ return read;
+}
+
+static ssize_t gfs2_file_direct_write(struct kiocb *iocb, struct iov_iter *from,
+ struct gfs2_holder *gh)
+{
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file->f_mapping->host;
+ struct gfs2_inode *ip = GFS2_I(inode);
+ size_t prev_count = 0, window_size = 0;
+ size_t written = 0;
+ bool enough_retries;
+ ssize_t ret;
+
+ /*
+ * In this function, we disable page faults when we're holding the
+ * inode glock while doing I/O. If a page fault occurs, we indicate
+ * that the inode glock may be dropped, fault in the pages manually,
+ * and retry.
+ *
+ * For writes, iomap_dio_rw only triggers manual page faults, so we
+ * don't need to disable physical ones.
+ */
+
+ /*
+ * Deferred lock, even if its a write, since we do no allocation on
+ * this path. All we need to change is the atime, and this lock mode
+ * ensures that other nodes have flushed their buffered read caches
+ * (i.e. their page cache entries for this inode). We do not,
+ * unfortunately, have the option of only flushing a range like the
+ * VFS does.
+ */
+ gfs2_holder_init(ip->i_gl, LM_ST_DEFERRED, 0, gh);
+retry:
+ ret = gfs2_glock_nq(gh);
+ if (ret)
+ goto out_uninit;
+ /* Silently fall back to buffered I/O when writing beyond EOF */
+ if (iocb->ki_pos + iov_iter_count(from) > i_size_read(&ip->i_inode))
+ goto out_unlock;
+
+ from->nofault = true;
+ ret = iomap_dio_rw(iocb, from, &gfs2_iomap_ops, NULL,
+ IOMAP_DIO_PARTIAL, NULL, written);
+ from->nofault = false;
+ if (ret <= 0) {
+ if (ret == -ENOTBLK)
+ ret = 0;
+ if (ret != -EFAULT)
+ goto out_unlock;
+ }
+ /* No increment (+=) because iomap_dio_rw returns a cumulative value. */
+ if (ret > 0)
+ written = ret;
+
+ enough_retries = prev_count == iov_iter_count(from) &&
+ window_size <= PAGE_SIZE;
+ if (should_fault_in_pages(from, iocb, &prev_count, &window_size)) {
+ gfs2_glock_dq(gh);
+ window_size -= fault_in_iov_iter_readable(from, window_size);
+ if (window_size) {
+ if (!enough_retries)
+ goto retry;
+ /* fall back to buffered I/O */
+ ret = 0;
+ }
+ }
+out_unlock:
+ if (gfs2_holder_queued(gh))
+ gfs2_glock_dq(gh);
+out_uninit:
+ gfs2_holder_uninit(gh);
+ /* User space doesn't expect partial success. */
+ if (ret < 0)
+ return ret;
+ return written;
+}
+
+static ssize_t gfs2_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
+{
+ struct gfs2_inode *ip;
+ struct gfs2_holder gh;
+ size_t prev_count = 0, window_size = 0;
+ size_t read = 0;
+ ssize_t ret;
+
+ /*
+ * In this function, we disable page faults when we're holding the
+ * inode glock while doing I/O. If a page fault occurs, we indicate
+ * that the inode glock may be dropped, fault in the pages manually,
+ * and retry.
+ */
+
+ if (iocb->ki_flags & IOCB_DIRECT)
+ return gfs2_file_direct_read(iocb, to, &gh);
+
+ pagefault_disable();
+ iocb->ki_flags |= IOCB_NOIO;
+ ret = generic_file_read_iter(iocb, to);
+ iocb->ki_flags &= ~IOCB_NOIO;
+ pagefault_enable();
+ if (ret >= 0) {
+ if (!iov_iter_count(to))
+ return ret;
+ read = ret;
+ } else if (ret != -EFAULT) {
+ if (ret != -EAGAIN)
+ return ret;
+ if (iocb->ki_flags & IOCB_NOWAIT)
+ return ret;
+ }
+ ip = GFS2_I(iocb->ki_filp->f_mapping->host);
+ gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
+retry:
+ ret = gfs2_glock_nq(&gh);
+ if (ret)
+ goto out_uninit;
+ pagefault_disable();
+ ret = generic_file_read_iter(iocb, to);
+ pagefault_enable();
+ if (ret <= 0 && ret != -EFAULT)
+ goto out_unlock;
+ if (ret > 0)
+ read += ret;
+
+ if (should_fault_in_pages(to, iocb, &prev_count, &window_size)) {
+ gfs2_glock_dq(&gh);
+ window_size -= fault_in_iov_iter_writeable(to, window_size);
+ if (window_size)
+ goto retry;
+ }
+out_unlock:
+ if (gfs2_holder_queued(&gh))
+ gfs2_glock_dq(&gh);
+out_uninit:
+ gfs2_holder_uninit(&gh);
+ return read ? read : ret;
+}
+
+static ssize_t gfs2_file_buffered_write(struct kiocb *iocb,
+ struct iov_iter *from,
+ struct gfs2_holder *gh)
+{
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file_inode(file);
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct gfs2_sbd *sdp = GFS2_SB(inode);
+ struct gfs2_holder *statfs_gh = NULL;
+ size_t prev_count = 0, window_size = 0;
+ size_t orig_count = iov_iter_count(from);
+ size_t written = 0;
+ ssize_t ret;
+
+ /*
+ * In this function, we disable page faults when we're holding the
+ * inode glock while doing I/O. If a page fault occurs, we indicate
+ * that the inode glock may be dropped, fault in the pages manually,
+ * and retry.
+ */
+
+ if (inode == sdp->sd_rindex) {
+ statfs_gh = kmalloc(sizeof(*statfs_gh), GFP_NOFS);
+ if (!statfs_gh)
+ return -ENOMEM;
+ }
+
+ gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, gh);
+ if (should_fault_in_pages(from, iocb, &prev_count, &window_size)) {
+retry:
+ window_size -= fault_in_iov_iter_readable(from, window_size);
+ if (!window_size) {
+ ret = -EFAULT;
+ goto out_uninit;
+ }
+ from->count = min(from->count, window_size);
+ }
+ ret = gfs2_glock_nq(gh);
+ if (ret)
+ goto out_uninit;
+
+ if (inode == sdp->sd_rindex) {
+ struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
+
+ ret = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE,
+ GL_NOCACHE, statfs_gh);
+ if (ret)
+ goto out_unlock;
+ }
+
+ pagefault_disable();
+ ret = iomap_file_buffered_write(iocb, from, &gfs2_iomap_ops);
+ pagefault_enable();
+ if (ret > 0)
+ written += ret;
+
+ if (inode == sdp->sd_rindex)
+ gfs2_glock_dq_uninit(statfs_gh);
+
+ if (ret <= 0 && ret != -EFAULT)
+ goto out_unlock;
+
+ from->count = orig_count - written;
+ if (should_fault_in_pages(from, iocb, &prev_count, &window_size)) {
+ gfs2_glock_dq(gh);
+ goto retry;
+ }
+out_unlock:
+ if (gfs2_holder_queued(gh))
+ gfs2_glock_dq(gh);
+out_uninit:
+ gfs2_holder_uninit(gh);
+ kfree(statfs_gh);
+ from->count = orig_count - written;
+ return written ? written : ret;
+}
+
+/**
+ * gfs2_file_write_iter - Perform a write to a file
+ * @iocb: The io context
+ * @from: The data to write
+ *
+ * We have to do a lock/unlock here to refresh the inode size for
+ * O_APPEND writes, otherwise we can land up writing at the wrong
+ * offset. There is still a race, but provided the app is using its
+ * own file locking, this will make O_APPEND work as expected.
+ *
+ */
+
+static ssize_t gfs2_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
+{
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file_inode(file);
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct gfs2_holder gh;
+ ssize_t ret;
+
+ gfs2_size_hint(file, iocb->ki_pos, iov_iter_count(from));
+
+ if (iocb->ki_flags & IOCB_APPEND) {
+ ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
+ if (ret)
+ return ret;
+ gfs2_glock_dq_uninit(&gh);
+ }
+
+ inode_lock(inode);
+ ret = generic_write_checks(iocb, from);
+ if (ret <= 0)
+ goto out_unlock;
+
+ ret = file_remove_privs(file);
+ if (ret)
+ goto out_unlock;
+
+ ret = file_update_time(file);
+ if (ret)
+ goto out_unlock;
+
+ if (iocb->ki_flags & IOCB_DIRECT) {
+ struct address_space *mapping = file->f_mapping;
+ ssize_t buffered, ret2;
+
+ ret = gfs2_file_direct_write(iocb, from, &gh);
+ if (ret < 0 || !iov_iter_count(from))
+ goto out_unlock;
+
+ iocb->ki_flags |= IOCB_DSYNC;
+ buffered = gfs2_file_buffered_write(iocb, from, &gh);
+ if (unlikely(buffered <= 0)) {
+ if (!ret)
+ ret = buffered;
+ goto out_unlock;
+ }
+
+ /*
+ * We need to ensure that the page cache pages are written to
+ * disk and invalidated to preserve the expected O_DIRECT
+ * semantics. If the writeback or invalidate fails, only report
+ * the direct I/O range as we don't know if the buffered pages
+ * made it to disk.
+ */
+ ret2 = generic_write_sync(iocb, buffered);
+ invalidate_mapping_pages(mapping,
+ (iocb->ki_pos - buffered) >> PAGE_SHIFT,
+ (iocb->ki_pos - 1) >> PAGE_SHIFT);
+ if (!ret || ret2 > 0)
+ ret += ret2;
+ } else {
+ ret = gfs2_file_buffered_write(iocb, from, &gh);
+ if (likely(ret > 0))
+ ret = generic_write_sync(iocb, ret);
+ }
+
+out_unlock:
+ inode_unlock(inode);
+ return ret;
+}
+
+static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len,
+ int mode)
+{
+ struct super_block *sb = inode->i_sb;
+ struct gfs2_inode *ip = GFS2_I(inode);
+ loff_t end = offset + len;
+ struct buffer_head *dibh;
+ int error;
+
+ error = gfs2_meta_inode_buffer(ip, &dibh);
+ if (unlikely(error))
+ return error;
+
+ gfs2_trans_add_meta(ip->i_gl, dibh);
+
+ if (gfs2_is_stuffed(ip)) {
+ error = gfs2_unstuff_dinode(ip);
+ if (unlikely(error))
+ goto out;
+ }
+
+ while (offset < end) {
+ struct iomap iomap = { };
+
+ error = gfs2_iomap_alloc(inode, offset, end - offset, &iomap);
+ if (error)
+ goto out;
+ offset = iomap.offset + iomap.length;
+ if (!(iomap.flags & IOMAP_F_NEW))
+ continue;
+ error = sb_issue_zeroout(sb, iomap.addr >> inode->i_blkbits,
+ iomap.length >> inode->i_blkbits,
+ GFP_NOFS);
+ if (error) {
+ fs_err(GFS2_SB(inode), "Failed to zero data buffers\n");
+ goto out;
+ }
+ }
+out:
+ brelse(dibh);
+ return error;
+}
+
+/**
+ * calc_max_reserv() - Reverse of write_calc_reserv. Given a number of
+ * blocks, determine how many bytes can be written.
+ * @ip: The inode in question.
+ * @len: Max cap of bytes. What we return in *len must be <= this.
+ * @data_blocks: Compute and return the number of data blocks needed
+ * @ind_blocks: Compute and return the number of indirect blocks needed
+ * @max_blocks: The total blocks available to work with.
+ *
+ * Returns: void, but @len, @data_blocks and @ind_blocks are filled in.
+ */
+static void calc_max_reserv(struct gfs2_inode *ip, loff_t *len,
+ unsigned int *data_blocks, unsigned int *ind_blocks,
+ unsigned int max_blocks)
+{
+ loff_t max = *len;
+ const struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+ unsigned int tmp, max_data = max_blocks - 3 * (sdp->sd_max_height - 1);
+
+ for (tmp = max_data; tmp > sdp->sd_diptrs;) {
+ tmp = DIV_ROUND_UP(tmp, sdp->sd_inptrs);
+ max_data -= tmp;
+ }
+
+ *data_blocks = max_data;
+ *ind_blocks = max_blocks - max_data;
+ *len = ((loff_t)max_data - 3) << sdp->sd_sb.sb_bsize_shift;
+ if (*len > max) {
+ *len = max;
+ gfs2_write_calc_reserv(ip, max, data_blocks, ind_blocks);
+ }
+}
+
+static long __gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
+{
+ struct inode *inode = file_inode(file);
+ struct gfs2_sbd *sdp = GFS2_SB(inode);
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct gfs2_alloc_parms ap = { .aflags = 0, };
+ unsigned int data_blocks = 0, ind_blocks = 0, rblocks;
+ loff_t bytes, max_bytes, max_blks;
+ int error;
+ const loff_t pos = offset;
+ const loff_t count = len;
+ loff_t bsize_mask = ~((loff_t)sdp->sd_sb.sb_bsize - 1);
+ loff_t next = (offset + len - 1) >> sdp->sd_sb.sb_bsize_shift;
+ loff_t max_chunk_size = UINT_MAX & bsize_mask;
+
+ next = (next + 1) << sdp->sd_sb.sb_bsize_shift;
+
+ offset &= bsize_mask;
+
+ len = next - offset;
+ bytes = sdp->sd_max_rg_data * sdp->sd_sb.sb_bsize / 2;
+ if (!bytes)
+ bytes = UINT_MAX;
+ bytes &= bsize_mask;
+ if (bytes == 0)
+ bytes = sdp->sd_sb.sb_bsize;
+
+ gfs2_size_hint(file, offset, len);
+
+ gfs2_write_calc_reserv(ip, PAGE_SIZE, &data_blocks, &ind_blocks);
+ ap.min_target = data_blocks + ind_blocks;
+
+ while (len > 0) {
+ if (len < bytes)
+ bytes = len;
+ if (!gfs2_write_alloc_required(ip, offset, bytes)) {
+ len -= bytes;
+ offset += bytes;
+ continue;
+ }
+
+ /* We need to determine how many bytes we can actually
+ * fallocate without exceeding quota or going over the
+ * end of the fs. We start off optimistically by assuming
+ * we can write max_bytes */
+ max_bytes = (len > max_chunk_size) ? max_chunk_size : len;
+
+ /* Since max_bytes is most likely a theoretical max, we
+ * calculate a more realistic 'bytes' to serve as a good
+ * starting point for the number of bytes we may be able
+ * to write */
+ gfs2_write_calc_reserv(ip, bytes, &data_blocks, &ind_blocks);
+ ap.target = data_blocks + ind_blocks;
+
+ error = gfs2_quota_lock_check(ip, &ap);
+ if (error)
+ return error;
+ /* ap.allowed tells us how many blocks quota will allow
+ * us to write. Check if this reduces max_blks */
+ max_blks = UINT_MAX;
+ if (ap.allowed)
+ max_blks = ap.allowed;
+
+ error = gfs2_inplace_reserve(ip, &ap);
+ if (error)
+ goto out_qunlock;
+
+ /* check if the selected rgrp limits our max_blks further */
+ if (ip->i_res.rs_reserved < max_blks)
+ max_blks = ip->i_res.rs_reserved;
+
+ /* Almost done. Calculate bytes that can be written using
+ * max_blks. We also recompute max_bytes, data_blocks and
+ * ind_blocks */
+ calc_max_reserv(ip, &max_bytes, &data_blocks,
+ &ind_blocks, max_blks);
+
+ rblocks = RES_DINODE + ind_blocks + RES_STATFS + RES_QUOTA +
+ RES_RG_HDR + gfs2_rg_blocks(ip, data_blocks + ind_blocks);
+ if (gfs2_is_jdata(ip))
+ rblocks += data_blocks ? data_blocks : 1;
+
+ error = gfs2_trans_begin(sdp, rblocks,
+ PAGE_SIZE >> inode->i_blkbits);
+ if (error)
+ goto out_trans_fail;
+
+ error = fallocate_chunk(inode, offset, max_bytes, mode);
+ gfs2_trans_end(sdp);
+
+ if (error)
+ goto out_trans_fail;
+
+ len -= max_bytes;
+ offset += max_bytes;
+ gfs2_inplace_release(ip);
+ gfs2_quota_unlock(ip);
+ }
+
+ if (!(mode & FALLOC_FL_KEEP_SIZE) && (pos + count) > inode->i_size)
+ i_size_write(inode, pos + count);
+ file_update_time(file);
+ mark_inode_dirty(inode);
+
+ if ((file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host))
+ return vfs_fsync_range(file, pos, pos + count - 1,
+ (file->f_flags & __O_SYNC) ? 0 : 1);
+ return 0;
+
+out_trans_fail:
+ gfs2_inplace_release(ip);
+out_qunlock:
+ gfs2_quota_unlock(ip);
+ return error;
+}
+
+static long gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
+{
+ struct inode *inode = file_inode(file);
+ struct gfs2_sbd *sdp = GFS2_SB(inode);
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct gfs2_holder gh;
+ int ret;
+
+ if (mode & ~(FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE))
+ return -EOPNOTSUPP;
+ /* fallocate is needed by gfs2_grow to reserve space in the rindex */
+ if (gfs2_is_jdata(ip) && inode != sdp->sd_rindex)
+ return -EOPNOTSUPP;
+
+ inode_lock(inode);
+
+ gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
+ ret = gfs2_glock_nq(&gh);
+ if (ret)
+ goto out_uninit;
+
+ if (!(mode & FALLOC_FL_KEEP_SIZE) &&
+ (offset + len) > inode->i_size) {
+ ret = inode_newsize_ok(inode, offset + len);
+ if (ret)
+ goto out_unlock;
+ }
+
+ ret = get_write_access(inode);
+ if (ret)
+ goto out_unlock;
+
+ if (mode & FALLOC_FL_PUNCH_HOLE) {
+ ret = __gfs2_punch_hole(file, offset, len);
+ } else {
+ ret = __gfs2_fallocate(file, mode, offset, len);
+ if (ret)
+ gfs2_rs_deltree(&ip->i_res);
+ }
+
+ put_write_access(inode);
+out_unlock:
+ gfs2_glock_dq(&gh);
+out_uninit:
+ gfs2_holder_uninit(&gh);
+ inode_unlock(inode);
+ return ret;
+}
+
+static ssize_t gfs2_file_splice_write(struct pipe_inode_info *pipe,
+ struct file *out, loff_t *ppos,
+ size_t len, unsigned int flags)
+{
+ ssize_t ret;
+
+ gfs2_size_hint(out, *ppos, len);
+
+ ret = iter_file_splice_write(pipe, out, ppos, len, flags);
+ return ret;
+}
+
+#ifdef CONFIG_GFS2_FS_LOCKING_DLM
+
+/**
+ * gfs2_lock - acquire/release a posix lock on a file
+ * @file: the file pointer
+ * @cmd: either modify or retrieve lock state, possibly wait
+ * @fl: type and range of lock
+ *
+ * Returns: errno
+ */
+
+static int gfs2_lock(struct file *file, int cmd, struct file_lock *fl)
+{
+ struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
+ struct gfs2_sbd *sdp = GFS2_SB(file->f_mapping->host);
+ struct lm_lockstruct *ls = &sdp->sd_lockstruct;
+
+ if (!(fl->fl_flags & FL_POSIX))
+ return -ENOLCK;
+ if (unlikely(gfs2_withdrawn(sdp))) {
+ if (fl->fl_type == F_UNLCK)
+ locks_lock_file_wait(file, fl);
+ return -EIO;
+ }
+ if (cmd == F_CANCELLK)
+ return dlm_posix_cancel(ls->ls_dlm, ip->i_no_addr, file, fl);
+ else if (IS_GETLK(cmd))
+ return dlm_posix_get(ls->ls_dlm, ip->i_no_addr, file, fl);
+ else if (fl->fl_type == F_UNLCK)
+ return dlm_posix_unlock(ls->ls_dlm, ip->i_no_addr, file, fl);
+ else
+ return dlm_posix_lock(ls->ls_dlm, ip->i_no_addr, file, cmd, fl);
+}
+
+static void __flock_holder_uninit(struct file *file, struct gfs2_holder *fl_gh)
+{
+ struct gfs2_glock *gl = gfs2_glock_hold(fl_gh->gh_gl);
+
+ /*
+ * Make sure gfs2_glock_put() won't sleep under the file->f_lock
+ * spinlock.
+ */
+
+ spin_lock(&file->f_lock);
+ gfs2_holder_uninit(fl_gh);
+ spin_unlock(&file->f_lock);
+ gfs2_glock_put(gl);
+}
+
+static int do_flock(struct file *file, int cmd, struct file_lock *fl)
+{
+ struct gfs2_file *fp = file->private_data;
+ struct gfs2_holder *fl_gh = &fp->f_fl_gh;
+ struct gfs2_inode *ip = GFS2_I(file_inode(file));
+ struct gfs2_glock *gl;
+ unsigned int state;
+ u16 flags;
+ int error = 0;
+ int sleeptime;
+
+ state = (fl->fl_type == F_WRLCK) ? LM_ST_EXCLUSIVE : LM_ST_SHARED;
+ flags = GL_EXACT | GL_NOPID;
+ if (!IS_SETLKW(cmd))
+ flags |= LM_FLAG_TRY_1CB;
+
+ mutex_lock(&fp->f_fl_mutex);
+
+ if (gfs2_holder_initialized(fl_gh)) {
+ struct file_lock request;
+ if (fl_gh->gh_state == state)
+ goto out;
+ locks_init_lock(&request);
+ request.fl_type = F_UNLCK;
+ request.fl_flags = FL_FLOCK;
+ locks_lock_file_wait(file, &request);
+ gfs2_glock_dq(fl_gh);
+ gfs2_holder_reinit(state, flags, fl_gh);
+ } else {
+ error = gfs2_glock_get(GFS2_SB(&ip->i_inode), ip->i_no_addr,
+ &gfs2_flock_glops, CREATE, &gl);
+ if (error)
+ goto out;
+ spin_lock(&file->f_lock);
+ gfs2_holder_init(gl, state, flags, fl_gh);
+ spin_unlock(&file->f_lock);
+ gfs2_glock_put(gl);
+ }
+ for (sleeptime = 1; sleeptime <= 4; sleeptime <<= 1) {
+ error = gfs2_glock_nq(fl_gh);
+ if (error != GLR_TRYFAILED)
+ break;
+ fl_gh->gh_flags &= ~LM_FLAG_TRY_1CB;
+ fl_gh->gh_flags |= LM_FLAG_TRY;
+ msleep(sleeptime);
+ }
+ if (error) {
+ __flock_holder_uninit(file, fl_gh);
+ if (error == GLR_TRYFAILED)
+ error = -EAGAIN;
+ } else {
+ error = locks_lock_file_wait(file, fl);
+ gfs2_assert_warn(GFS2_SB(&ip->i_inode), !error);
+ }
+
+out:
+ mutex_unlock(&fp->f_fl_mutex);
+ return error;
+}
+
+static void do_unflock(struct file *file, struct file_lock *fl)
+{
+ struct gfs2_file *fp = file->private_data;
+ struct gfs2_holder *fl_gh = &fp->f_fl_gh;
+
+ mutex_lock(&fp->f_fl_mutex);
+ locks_lock_file_wait(file, fl);
+ if (gfs2_holder_initialized(fl_gh)) {
+ gfs2_glock_dq(fl_gh);
+ __flock_holder_uninit(file, fl_gh);
+ }
+ mutex_unlock(&fp->f_fl_mutex);
+}
+
+/**
+ * gfs2_flock - acquire/release a flock lock on a file
+ * @file: the file pointer
+ * @cmd: either modify or retrieve lock state, possibly wait
+ * @fl: type and range of lock
+ *
+ * Returns: errno
+ */
+
+static int gfs2_flock(struct file *file, int cmd, struct file_lock *fl)
+{
+ if (!(fl->fl_flags & FL_FLOCK))
+ return -ENOLCK;
+
+ if (fl->fl_type == F_UNLCK) {
+ do_unflock(file, fl);
+ return 0;
+ } else {
+ return do_flock(file, cmd, fl);
+ }
+}
+
+const struct file_operations gfs2_file_fops = {
+ .llseek = gfs2_llseek,
+ .read_iter = gfs2_file_read_iter,
+ .write_iter = gfs2_file_write_iter,
+ .iopoll = iocb_bio_iopoll,
+ .unlocked_ioctl = gfs2_ioctl,
+ .compat_ioctl = gfs2_compat_ioctl,
+ .mmap = gfs2_mmap,
+ .open = gfs2_open,
+ .release = gfs2_release,
+ .fsync = gfs2_fsync,
+ .lock = gfs2_lock,
+ .flock = gfs2_flock,
+ .splice_read = copy_splice_read,
+ .splice_write = gfs2_file_splice_write,
+ .setlease = simple_nosetlease,
+ .fallocate = gfs2_fallocate,
+};
+
+const struct file_operations gfs2_dir_fops = {
+ .iterate_shared = gfs2_readdir,
+ .unlocked_ioctl = gfs2_ioctl,
+ .compat_ioctl = gfs2_compat_ioctl,
+ .open = gfs2_open,
+ .release = gfs2_release,
+ .fsync = gfs2_fsync,
+ .lock = gfs2_lock,
+ .flock = gfs2_flock,
+ .llseek = default_llseek,
+};
+
+#endif /* CONFIG_GFS2_FS_LOCKING_DLM */
+
+const struct file_operations gfs2_file_fops_nolock = {
+ .llseek = gfs2_llseek,
+ .read_iter = gfs2_file_read_iter,
+ .write_iter = gfs2_file_write_iter,
+ .iopoll = iocb_bio_iopoll,
+ .unlocked_ioctl = gfs2_ioctl,
+ .compat_ioctl = gfs2_compat_ioctl,
+ .mmap = gfs2_mmap,
+ .open = gfs2_open,
+ .release = gfs2_release,
+ .fsync = gfs2_fsync,
+ .splice_read = copy_splice_read,
+ .splice_write = gfs2_file_splice_write,
+ .setlease = generic_setlease,
+ .fallocate = gfs2_fallocate,
+};
+
+const struct file_operations gfs2_dir_fops_nolock = {
+ .iterate_shared = gfs2_readdir,
+ .unlocked_ioctl = gfs2_ioctl,
+ .compat_ioctl = gfs2_compat_ioctl,
+ .open = gfs2_open,
+ .release = gfs2_release,
+ .fsync = gfs2_fsync,
+ .llseek = default_llseek,
+};
+
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-19 01:10:31 +0000