static int gfs2_readpage(struct file *file, struct page *page)
{
	struct address_space *mapping = page->mapping;
	struct gfs2_inode *ip = GFS2_I(mapping->host);
	struct gfs2_holder gh;
	int error;

	unlock_page(page);
	gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh);
	error = gfs2_glock_nq_atime(&gh);
	if (unlikely(error))
		goto out;
	error = AOP_TRUNCATED_PAGE;
	lock_page(page);
	if (page->mapping == mapping && !PageUptodate(page))
		error = __gfs2_readpage(file, page);
	else
		unlock_page(page);
	gfs2_glock_dq(&gh);
out:
	gfs2_holder_uninit(&gh);
	if (error && error != AOP_TRUNCATED_PAGE)
		lock_page(page);
	return error;
}
static ssize_t gfs2_direct_IO(int rw, struct kiocb *iocb,
			      const struct iovec *iov, loff_t offset,
			      unsigned long nr_segs)
{
	struct file *file = iocb->ki_filp;
	struct inode *inode = file->f_mapping->host;
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_holder gh;
	int rv;

	/*
	 * Deferred lock, even if its a write, since we do no allocation
	 * on this path. All we need change is 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, GL_ATIME, &gh);
	rv = gfs2_glock_nq_atime(&gh);
	if (rv)
		return rv;
	rv = gfs2_ok_for_dio(ip, rw, offset);
	if (rv != 1)
		goto out; /* dio not valid, fall back to buffered i/o */

	rv = blockdev_direct_IO_no_locking(rw, iocb, inode, inode->i_sb->s_bdev,
					   iov, offset, nr_segs,
					   gfs2_get_block_direct, NULL);
out:
	gfs2_glock_dq_m(1, &gh);
	gfs2_holder_uninit(&gh);
	return rv;
}
Esempio n. 3
0
static int gfs2_mmap(struct file *file, struct vm_area_struct *vma)
{
	struct gfs2_inode *ip = GFS2_I(file->f_mapping->host);
	struct gfs2_holder i_gh;
	int error;

	gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &i_gh);
	error = gfs2_glock_nq_atime(&i_gh);
	if (error) {
		gfs2_holder_uninit(&i_gh);
		return error;
	}

	/* This is VM_MAYWRITE instead of VM_WRITE because a call
	   to mprotect() can turn on VM_WRITE later. */

	if ((vma->vm_flags & (VM_MAYSHARE | VM_MAYWRITE)) ==
	    (VM_MAYSHARE | VM_MAYWRITE))
		vma->vm_ops = &gfs2_vm_ops_sharewrite;
	else
		vma->vm_ops = &gfs2_vm_ops_private;

	gfs2_glock_dq_uninit(&i_gh);

	return error;
}
Esempio n. 4
0
static int gfs2_readpage(struct file *file, struct page *page)
{
	struct gfs2_inode *ip = GFS2_I(page->mapping->host);
	struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
	struct gfs2_file *gf = NULL;
	struct gfs2_holder gh;
	int error;
	int do_unlock = 0;

	if (likely(file != &gfs2_internal_file_sentinel)) {
		if (file) {
			gf = file->private_data;
			if (test_bit(GFF_EXLOCK, &gf->f_flags))
				/* gfs2_sharewrite_nopage has grabbed the ip->i_gl already */
				goto skip_lock;
		}
		gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME|LM_FLAG_TRY_1CB, &gh);
		do_unlock = 1;
		error = gfs2_glock_nq_atime(&gh);
		if (unlikely(error))
			goto out_unlock;
	}

skip_lock:
	if (gfs2_is_stuffed(ip)) {
		error = stuffed_readpage(ip, page);
		unlock_page(page);
	} else
		error = mpage_readpage(page, gfs2_get_block);

	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
		error = -EIO;

	if (do_unlock) {
		gfs2_glock_dq_m(1, &gh);
		gfs2_holder_uninit(&gh);
	}
out:
	return error;
out_unlock:
	unlock_page(page);
	if (error == GLR_TRYFAILED) {
		error = AOP_TRUNCATED_PAGE;
		yield();
	}
	if (do_unlock)
		gfs2_holder_uninit(&gh);
	goto out;
}
Esempio n. 5
0
/**
 * gfs2_readpages - Read a bunch of pages at once
 *
 * Some notes:
 * 1. This is only for readahead, so we can simply ignore any things
 *    which are slightly inconvenient (such as locking conflicts between
 *    the page lock and the glock) and return having done no I/O. Its
 *    obviously not something we'd want to do on too regular a basis.
 *    Any I/O we ignore at this time will be done via readpage later.
 * 2. We don't handle stuffed files here we let readpage do the honours.
 * 3. mpage_readpages() does most of the heavy lifting in the common case.
 * 4. gfs2_get_block() is relied upon to set BH_Boundary in the right places.
 * 5. We use LM_FLAG_TRY_1CB here, effectively we then have lock-ahead as
 *    well as read-ahead.
 */
static int gfs2_readpages(struct file *file, struct address_space *mapping,
			  struct list_head *pages, unsigned nr_pages)
{
	struct inode *inode = mapping->host;
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_sbd *sdp = GFS2_SB(inode);
	struct gfs2_holder gh;
	int ret = 0;
	int do_unlock = 0;

	if (likely(file != &gfs2_internal_file_sentinel)) {
		if (file) {
			struct gfs2_file *gf = file->private_data;
			if (test_bit(GFF_EXLOCK, &gf->f_flags))
				goto skip_lock;
		}
		gfs2_holder_init(ip->i_gl, LM_ST_SHARED,
				 LM_FLAG_TRY_1CB|GL_ATIME, &gh);
		do_unlock = 1;
		ret = gfs2_glock_nq_atime(&gh);
		if (ret == GLR_TRYFAILED)
			goto out_noerror;
		if (unlikely(ret))
			goto out_unlock;
	}
skip_lock:
	if (!gfs2_is_stuffed(ip))
		ret = mpage_readpages(mapping, pages, nr_pages, gfs2_get_block);

	if (do_unlock) {
		gfs2_glock_dq_m(1, &gh);
		gfs2_holder_uninit(&gh);
	}
out:
	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
		ret = -EIO;
	return ret;
out_noerror:
	ret = 0;
out_unlock:
	if (do_unlock)
		gfs2_holder_uninit(&gh);
	goto out;
}
Esempio n. 6
0
static int gfs2_get_flags(struct file *filp, u32 __user *ptr)
{
	struct inode *inode = filp->f_path.dentry->d_inode;
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_holder gh;
	int error;
	u32 fsflags;

	gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh);
	error = gfs2_glock_nq_atime(&gh);
	if (error)
		return error;

	fsflags = fsflags_cvt(gfs2_to_fsflags, ip->i_di.di_flags);
	if (put_user(fsflags, ptr))
		error = -EFAULT;

	gfs2_glock_dq_m(1, &gh);
	gfs2_holder_uninit(&gh);
	return error;
}
static int gfs2_readpages(struct file *file, struct address_space *mapping,
			  struct list_head *pages, unsigned nr_pages)
{
	struct inode *inode = mapping->host;
	struct gfs2_inode *ip = GFS2_I(inode);
	struct gfs2_sbd *sdp = GFS2_SB(inode);
	struct gfs2_holder gh;
	int ret;

	gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME, &gh);
	ret = gfs2_glock_nq_atime(&gh);
	if (unlikely(ret))
		goto out_uninit;
	if (!gfs2_is_stuffed(ip))
		ret = mpage_readpages(mapping, pages, nr_pages, gfs2_block_map);
	gfs2_glock_dq(&gh);
out_uninit:
	gfs2_holder_uninit(&gh);
	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
		ret = -EIO;
	return ret;
}
Esempio n. 8
0
static int gfs2_readpage(struct file *file, struct page *page)
{
	struct gfs2_inode *ip = GFS2_I(page->mapping->host);
	struct gfs2_holder gh;
	int error;

	gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME|LM_FLAG_TRY_1CB, &gh);
	error = gfs2_glock_nq_atime(&gh);
	if (unlikely(error)) {
		unlock_page(page);
		goto out;
	}
	error = __gfs2_readpage(file, page);
	gfs2_glock_dq(&gh);
out:
	gfs2_holder_uninit(&gh);
	if (error == GLR_TRYFAILED) {
		yield();
		return AOP_TRUNCATED_PAGE;
	}
	return error;
}
Esempio n. 9
0
static int gfs2_readdir(struct file *file, void *dirent, filldir_t filldir)
{
	struct inode *dir = file->f_mapping->host;
	struct gfs2_inode *dip = GFS2_I(dir);
	struct gfs2_holder d_gh;
	u64 offset = file->f_pos;
	int error;

	gfs2_holder_init(dip->i_gl, LM_ST_SHARED, GL_ATIME, &d_gh);
	error = gfs2_glock_nq_atime(&d_gh);
	if (error) {
		gfs2_holder_uninit(&d_gh);
		return error;
	}

	error = gfs2_dir_read(dir, &offset, dirent, filldir);

	gfs2_glock_dq_uninit(&d_gh);

	file->f_pos = offset;

	return error;
}
static int gfs2_write_begin(struct file *file, struct address_space *mapping,
			    loff_t pos, unsigned len, unsigned flags,
			    struct page **pagep, void **fsdata)
{
	struct gfs2_inode *ip = GFS2_I(mapping->host);
	struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
	unsigned int data_blocks, ind_blocks, rblocks;
	int alloc_required;
	int error = 0;
	struct gfs2_alloc *al;
	pgoff_t index = pos >> PAGE_CACHE_SHIFT;
	unsigned from = pos & (PAGE_CACHE_SIZE - 1);
	unsigned to = from + len;
	struct page *page;

	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ATIME, &ip->i_gh);
	error = gfs2_glock_nq_atime(&ip->i_gh);
	if (unlikely(error))
		goto out_uninit;

	gfs2_write_calc_reserv(ip, len, &data_blocks, &ind_blocks);
	error = gfs2_write_alloc_required(ip, pos, len, &alloc_required);
	if (error)
		goto out_unlock;

	if (alloc_required) {
		al = gfs2_alloc_get(ip);
		if (!al) {
			error = -ENOMEM;
			goto out_unlock;
		}

		error = gfs2_quota_lock_check(ip);
		if (error)
			goto out_alloc_put;

		al->al_requested = data_blocks + ind_blocks;
		error = gfs2_inplace_reserve(ip);
		if (error)
			goto out_qunlock;
	}

	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;

	error = gfs2_trans_begin(sdp, rblocks,
				 PAGE_CACHE_SIZE/sdp->sd_sb.sb_bsize);
	if (error)
		goto out_trans_fail;

	error = -ENOMEM;
	page = grab_cache_page_write_begin(mapping, index, flags);
	*pagep = page;
	if (unlikely(!page))
		goto out_endtrans;

	if (gfs2_is_stuffed(ip)) {
		error = 0;
		if (pos + len > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) {
			error = gfs2_unstuff_dinode(ip, page);
			if (error == 0)
				goto prepare_write;
		} else if (!PageUptodate(page)) {
			error = stuffed_readpage(ip, page);
		}
		goto out;
	}

prepare_write:
	error = block_prepare_write(page, from, to, gfs2_block_map);
out:
	if (error == 0)
		return 0;

	page_cache_release(page);
	if (pos + len > ip->i_inode.i_size)
		vmtruncate(&ip->i_inode, ip->i_inode.i_size);
out_endtrans:
	gfs2_trans_end(sdp);
out_trans_fail:
	if (alloc_required) {
		gfs2_inplace_release(ip);
out_qunlock:
		gfs2_quota_unlock(ip);
out_alloc_put:
		gfs2_alloc_put(ip);
	}
out_unlock:
	gfs2_glock_dq(&ip->i_gh);
out_uninit:
	gfs2_holder_uninit(&ip->i_gh);
	return error;
}
Esempio n. 11
0
static int gfs2_prepare_write(struct file *file, struct page *page,
			      unsigned from, unsigned to)
{
	struct gfs2_inode *ip = GFS2_I(page->mapping->host);
	struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
	unsigned int data_blocks, ind_blocks, rblocks;
	int alloc_required;
	int error = 0;
	loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + from;
	loff_t end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
	struct gfs2_alloc *al;
	unsigned int write_len = to - from;


	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ATIME|LM_FLAG_TRY_1CB, &ip->i_gh);
	error = gfs2_glock_nq_atime(&ip->i_gh);
	if (unlikely(error)) {
		if (error == GLR_TRYFAILED) {
			unlock_page(page);
			error = AOP_TRUNCATED_PAGE;
			yield();
		}
		goto out_uninit;
	}

	gfs2_write_calc_reserv(ip, write_len, &data_blocks, &ind_blocks);

	error = gfs2_write_alloc_required(ip, pos, write_len, &alloc_required);
	if (error)
		goto out_unlock;


	ip->i_alloc.al_requested = 0;
	if (alloc_required) {
		al = gfs2_alloc_get(ip);

		error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
		if (error)
			goto out_alloc_put;

		error = gfs2_quota_check(ip, ip->i_inode.i_uid, ip->i_inode.i_gid);
		if (error)
			goto out_qunlock;

		al->al_requested = data_blocks + ind_blocks;
		error = gfs2_inplace_reserve(ip);
		if (error)
			goto out_qunlock;
	}

	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;

	error = gfs2_trans_begin(sdp, rblocks, 0);
	if (error)
		goto out;

	if (gfs2_is_stuffed(ip)) {
		if (end > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) {
			error = gfs2_unstuff_dinode(ip, page);
			if (error == 0)
				goto prepare_write;
		} else if (!PageUptodate(page))
			error = stuffed_readpage(ip, page);
		goto out;
	}

prepare_write:
	error = block_prepare_write(page, from, to, gfs2_get_block);

out:
	if (error) {
		gfs2_trans_end(sdp);
		if (alloc_required) {
			gfs2_inplace_release(ip);
out_qunlock:
			gfs2_quota_unlock(ip);
out_alloc_put:
			gfs2_alloc_put(ip);
		}
out_unlock:
		gfs2_glock_dq_m(1, &ip->i_gh);
out_uninit:
		gfs2_holder_uninit(&ip->i_gh);
	}

	return error;
}