bcachefs: Initial commit

Initially forked from drivers/md/bcache, bcachefs is a new copy-on-write
filesystem with every feature you could possibly want.

Website: https://bcachefs.org

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

1 files changed, 312 insertions, 0 deletions

diff --git a/fs/bcachefs/fs-ioctl.c b/fs/bcachefs/fs-ioctl.c
new file mode 100644
index 000000000000..895ccc79e782
--- /dev/null
+++ b/fs/bcachefs/fs-ioctl.c
@@ -0,0 +1,312 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifndef NO_BCACHEFS_FS
+
+#include "bcachefs.h"
+#include "chardev.h"
+#include "fs.h"
+#include "fs-ioctl.h"
+#include "quota.h"
+
+#include <linux/compat.h>
+#include <linux/mount.h>
+
+#define FS_IOC_GOINGDOWN	     _IOR('X', 125, __u32)
+
+/* Inode flags: */
+
+/* bcachefs inode flags -> vfs inode flags: */
+static const unsigned bch_flags_to_vfs[] = {
+	[__BCH_INODE_SYNC]	= S_SYNC,
+	[__BCH_INODE_IMMUTABLE]	= S_IMMUTABLE,
+	[__BCH_INODE_APPEND]	= S_APPEND,
+	[__BCH_INODE_NOATIME]	= S_NOATIME,
+};
+
+/* bcachefs inode flags -> FS_IOC_GETFLAGS: */
+static const unsigned bch_flags_to_uflags[] = {
+	[__BCH_INODE_SYNC]	= FS_SYNC_FL,
+	[__BCH_INODE_IMMUTABLE]	= FS_IMMUTABLE_FL,
+	[__BCH_INODE_APPEND]	= FS_APPEND_FL,
+	[__BCH_INODE_NODUMP]	= FS_NODUMP_FL,
+	[__BCH_INODE_NOATIME]	= FS_NOATIME_FL,
+};
+
+/* bcachefs inode flags -> FS_IOC_FSGETXATTR: */
+static const unsigned bch_flags_to_xflags[] = {
+	[__BCH_INODE_SYNC]	= FS_XFLAG_SYNC,
+	[__BCH_INODE_IMMUTABLE]	= FS_XFLAG_IMMUTABLE,
+	[__BCH_INODE_APPEND]	= FS_XFLAG_APPEND,
+	[__BCH_INODE_NODUMP]	= FS_XFLAG_NODUMP,
+	[__BCH_INODE_NOATIME]	= FS_XFLAG_NOATIME,
+	//[__BCH_INODE_PROJINHERIT] = FS_XFLAG_PROJINHERIT;
+};
+
+#define set_flags(_map, _in, _out)					\
+do {									\
+	unsigned _i;							\
+									\
+	for (_i = 0; _i < ARRAY_SIZE(_map); _i++)			\
+		if ((_in) & (1 << _i))					\
+			(_out) |= _map[_i];				\
+		else							\
+			(_out) &= ~_map[_i];				\
+} while (0)
+
+#define map_flags(_map, _in)						\
+({									\
+	unsigned _out = 0;						\
+									\
+	set_flags(_map, _in, _out);					\
+	_out;								\
+})
+
+#define map_flags_rev(_map, _in)					\
+({									\
+	unsigned _i, _out = 0;						\
+									\
+	for (_i = 0; _i < ARRAY_SIZE(_map); _i++)			\
+		if ((_in) & _map[_i]) {					\
+			(_out) |= 1 << _i;				\
+			(_in) &= ~_map[_i];				\
+		}							\
+	(_out);								\
+})
+
+#define map_defined(_map)						\
+({									\
+	unsigned _in = ~0;						\
+									\
+	map_flags_rev(_map, _in);					\
+})
+
+/* Set VFS inode flags from bcachefs inode: */
+void bch2_inode_flags_to_vfs(struct bch_inode_info *inode)
+{
+	set_flags(bch_flags_to_vfs, inode->ei_inode.bi_flags, inode->v.i_flags);
+}
+
+struct flags_set {
+	unsigned		mask;
+	unsigned		flags;
+
+	unsigned		projid;
+};
+
+static int bch2_inode_flags_set(struct bch_inode_info *inode,
+				struct bch_inode_unpacked *bi,
+				void *p)
+{
+	/*
+	 * We're relying on btree locking here for exclusion with other ioctl
+	 * calls - use the flags in the btree (@bi), not inode->i_flags:
+	 */
+	struct flags_set *s = p;
+	unsigned newflags = s->flags;
+	unsigned oldflags = bi->bi_flags & s->mask;
+
+	if (((newflags ^ oldflags) & (BCH_INODE_APPEND|BCH_INODE_IMMUTABLE)) &&
+	    !capable(CAP_LINUX_IMMUTABLE))
+		return -EPERM;
+
+	if (!S_ISREG(inode->v.i_mode) &&
+	    !S_ISDIR(inode->v.i_mode) &&
+	    (newflags & (BCH_INODE_NODUMP|BCH_INODE_NOATIME)) != newflags)
+		return -EINVAL;
+
+	bi->bi_flags &= ~s->mask;
+	bi->bi_flags |= newflags;
+	inode_set_ctime_current(&inode->v);
+	return 0;
+}
+
+static int bch2_ioc_getflags(struct bch_inode_info *inode, int __user *arg)
+{
+	unsigned flags = map_flags(bch_flags_to_uflags, inode->ei_inode.bi_flags);
+
+	return put_user(flags, arg);
+}
+
+static int bch2_ioc_setflags(struct bch_fs *c,
+			     struct file *file,
+			     struct bch_inode_info *inode,
+			     void __user *arg)
+{
+	struct flags_set s = { .mask = map_defined(bch_flags_to_uflags) };
+	unsigned uflags;
+	int ret;
+
+	if (get_user(uflags, (int __user *) arg))
+		return -EFAULT;
+
+	s.flags = map_flags_rev(bch_flags_to_uflags, uflags);
+	if (uflags)
+		return -EOPNOTSUPP;
+
+	ret = mnt_want_write_file(file);
+	if (ret)
+		return ret;
+
+	inode_lock(&inode->v);
+	if (!inode_owner_or_capable(file_mnt_idmap(file), &inode->v)) {
+		ret = -EACCES;
+		goto setflags_out;
+	}
+
+	mutex_lock(&inode->ei_update_lock);
+	ret = __bch2_write_inode(c, inode, bch2_inode_flags_set, &s, 0);
+
+	if (!ret)
+		bch2_inode_flags_to_vfs(inode);
+	mutex_unlock(&inode->ei_update_lock);
+
+setflags_out:
+	inode_unlock(&inode->v);
+	mnt_drop_write_file(file);
+	return ret;
+}
+
+static int bch2_ioc_fsgetxattr(struct bch_inode_info *inode,
+			       struct fsxattr __user *arg)
+{
+	struct fsxattr fa = { 0 };
+
+	fa.fsx_xflags = map_flags(bch_flags_to_xflags, inode->ei_inode.bi_flags);
+	fa.fsx_projid = inode->ei_qid.q[QTYP_PRJ];
+
+	return copy_to_user(arg, &fa, sizeof(fa));
+}
+
+static int bch2_set_projid(struct bch_fs *c,
+			   struct bch_inode_info *inode,
+			   u32 projid)
+{
+	struct bch_qid qid = inode->ei_qid;
+	int ret;
+
+	if (projid == inode->ei_qid.q[QTYP_PRJ])
+		return 0;
+
+	qid.q[QTYP_PRJ] = projid;
+
+	return bch2_quota_transfer(c, 1 << QTYP_PRJ, qid, inode->ei_qid,
+				   inode->v.i_blocks +
+				   inode->ei_quota_reserved);
+	if (ret)
+		return ret;
+
+	inode->ei_qid.q[QTYP_PRJ] = projid;
+	return 0;
+}
+
+static int fssetxattr_inode_update_fn(struct bch_inode_info *inode,
+				      struct bch_inode_unpacked *bi,
+				      void *p)
+{
+	struct flags_set *s = p;
+
+	bi->bi_project = s->projid;
+
+	return bch2_inode_flags_set(inode, bi, p);
+}
+
+static int bch2_ioc_fssetxattr(struct bch_fs *c,
+			       struct file *file,
+			       struct bch_inode_info *inode,
+			       struct fsxattr __user *arg)
+{
+	struct flags_set s = { .mask = map_defined(bch_flags_to_xflags) };
+	struct fsxattr fa;
+	int ret;
+
+	if (copy_from_user(&fa, arg, sizeof(fa)))
+		return -EFAULT;
+
+	s.flags = map_flags_rev(bch_flags_to_xflags, fa.fsx_xflags);
+	if (fa.fsx_xflags)
+		return -EOPNOTSUPP;
+
+	s.projid = fa.fsx_projid;
+
+	ret = mnt_want_write_file(file);
+	if (ret)
+		return ret;
+
+	inode_lock(&inode->v);
+	if (!inode_owner_or_capable(file_mnt_idmap(file), &inode->v)) {
+		ret = -EACCES;
+		goto err;
+	}
+
+	mutex_lock(&inode->ei_update_lock);
+	ret = bch2_set_projid(c, inode, fa.fsx_projid);
+	if (ret)
+		goto err_unlock;
+
+	ret = __bch2_write_inode(c, inode, fssetxattr_inode_update_fn, &s, 0);
+	if (!ret)
+		bch2_inode_flags_to_vfs(inode);
+err_unlock:
+	mutex_unlock(&inode->ei_update_lock);
+err:
+	inode_unlock(&inode->v);
+	mnt_drop_write_file(file);
+	return ret;
+}
+
+long bch2_fs_file_ioctl(struct file *file, unsigned cmd, unsigned long arg)
+{
+	struct bch_inode_info *inode = file_bch_inode(file);
+	struct super_block *sb = inode->v.i_sb;
+	struct bch_fs *c = sb->s_fs_info;
+
+	switch (cmd) {
+	case FS_IOC_GETFLAGS:
+		return bch2_ioc_getflags(inode, (int __user *) arg);
+
+	case FS_IOC_SETFLAGS:
+		return bch2_ioc_setflags(c, file, inode, (int __user *) arg);
+
+	case FS_IOC_FSGETXATTR:
+		return bch2_ioc_fsgetxattr(inode, (void __user *) arg);
+	case FS_IOC_FSSETXATTR:
+		return bch2_ioc_fssetxattr(c, file, inode, (void __user *) arg);
+
+	case FS_IOC_GETVERSION:
+		return -ENOTTY;
+	case FS_IOC_SETVERSION:
+		return -ENOTTY;
+
+	case FS_IOC_GOINGDOWN:
+		if (!capable(CAP_SYS_ADMIN))
+			return -EPERM;
+
+		down_write(&sb->s_umount);
+		sb->s_flags |= SB_RDONLY;
+		bch2_fs_emergency_read_only(c);
+		up_write(&sb->s_umount);
+		return 0;
+
+	default:
+		return bch2_fs_ioctl(c, cmd, (void __user *) arg);
+	}
+}
+
+#ifdef CONFIG_COMPAT
+long bch2_compat_fs_ioctl(struct file *file, unsigned cmd, unsigned long arg)
+{
+	/* These are just misnamed, they actually get/put from/to user an int */
+	switch (cmd) {
+	case FS_IOC_GETFLAGS:
+		cmd = FS_IOC_GETFLAGS;
+		break;
+	case FS_IOC32_SETFLAGS:
+		cmd = FS_IOC_SETFLAGS;
+		break;
+	default:
+		return -ENOIOCTLCMD;
+	}
+	return bch2_fs_file_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
+}
+#endif
+
+#endif /* NO_BCACHEFS_FS */