libxfs: backport inode init code from the kernel

Reorganize the userspace inode initialization code to more closely
resemble its kernel counterpart.  This is preparation to hoist the
initialization routines to libxfs.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

diff --git a/include/xfs_inode.h b/include/xfs_inode.h
index 4142c45e4e314e20b74d30a34499479b8e8ac2ce..d2f391ea872ceeb3d19673889ece5725661d4cf1 100644 (file)
--- a/include/xfs_inode.h
+++ b/include/xfs_inode.h
@@ -78,6 +78,12 @@ struct inode {
        spinlock_t              i_lock;
 };
 
+static inline void
+inode_set_iversion(struct inode *inode, uint64_t version)
+{
+       inode->i_version = version;
+}
+
 static inline uint32_t i_uid_read(struct inode *inode)
 {
        return inode->i_uid.val;
@@ -95,6 +101,18 @@ static inline void i_gid_write(struct inode *inode, gid_t gid)
        inode->i_gid.val = gid;
 }
 
+static inline void inode_fsuid_set(struct inode *inode,
+                                  struct mnt_idmap *idmap)
+{
+       inode->i_uid = make_kuid(0);
+}
+
+static inline void inode_fsgid_set(struct inode *inode,
+                                  struct mnt_idmap *idmap)
+{
+       inode->i_gid = make_kgid(0);
+}
+
 static inline void ihold(struct inode *inode)
 {
        inode->i_count++;
@@ -408,4 +426,6 @@ extern void libxfs_irele(struct xfs_inode *ip);
 
 #define XFS_DEFAULT_COWEXTSZ_HINT      32
 
+#define XFS_INHERIT_GID(pip)           (VFS_I(pip)->i_mode & S_ISGID)
+
 #endif /* __XFS_INODE_H__ */

diff --git a/include/xfs_mount.h b/include/xfs_mount.h
index a9525e4e054601e398f1fbee299bf22bf321981e..4492a2f28b11705f44b344a3d8e8b1ef52bfb1f1 100644 (file)
--- a/include/xfs_mount.h
+++ b/include/xfs_mount.h
@@ -228,6 +228,7 @@ __XFS_UNSUPP_FEAT(ikeep)
 __XFS_UNSUPP_FEAT(swalloc)
 __XFS_UNSUPP_FEAT(small_inums)
 __XFS_UNSUPP_FEAT(readonly)
+__XFS_UNSUPP_FEAT(grpid)
 
 /* Operational mount state flags */
 #define XFS_OPSTATE_INODE32            0       /* inode32 allocator active */
@@ -308,4 +309,11 @@ static inline void libxfs_buftarg_drain(struct xfs_buftarg *btp)
        cache_purge(btp->bcache);
 }
 
+struct mnt_idmap {
+       /* empty */
+};
+
+/* bogus idmapping so that mkfs can do directory inheritance correctly */
+#define libxfs_nop_idmap       ((struct mnt_idmap *)1)
+
 #endif /* __XFS_MOUNT_H__ */

diff --git a/libxfs/inode.c b/libxfs/inode.c
index 206b779a8e96da706086927e6e1484285de53370..dda9b778dc6687a09465154e350bac93abf99131 100644 (file)
--- a/libxfs/inode.c
+++ b/libxfs/inode.c
@@ -31,7 +31,7 @@
 
 /* Propagate di_flags from a parent inode to a child inode. */
 static void
-xfs_inode_propagate_flags(
+xfs_inode_inherit_flags(
        struct xfs_inode        *ip,
        const struct xfs_inode  *pip)
 {
@@ -106,35 +106,52 @@ xfs_inode_init(
        int                     times = XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG |
                                        XFS_ICHGTIME_ACCESS;
 
-       inode->i_mode = args->mode;
        if (args->flags & XFS_ICREATE_TMPFILE)
                set_nlink(inode, 0);
        else if (S_ISDIR(args->mode))
                set_nlink(inode, 2);
        else
                set_nlink(inode, 1);
-       inode->i_uid = GLOBAL_ROOT_UID;
-       inode->i_gid = GLOBAL_ROOT_GID;
-       ip->i_projid = 0;
+       inode->i_rdev = args->rdev;
+
+       if (!args->idmap || pip == NULL) {
+               /* creating a tree root, sb rooted, or detached file */
+               inode->i_uid = GLOBAL_ROOT_UID;
+               inode->i_gid = GLOBAL_ROOT_GID;
+               ip->i_projid = 0;
+               inode->i_mode = args->mode;
+       } else {
+               /* creating a child in the directory tree */
+               if (dir && !(dir->i_mode & S_ISGID) && xfs_has_grpid(mp)) {
+                       inode_fsuid_set(inode, args->idmap);
+                       inode->i_gid = dir->i_gid;
+                       inode->i_mode = args->mode;
+               } else {
+                       inode_init_owner(args->idmap, inode, dir, args->mode);
+               }
 
-       if (pip && (dir->i_mode & S_ISGID)) {
-               inode->i_gid = dir->i_gid;
-               if (S_ISDIR(args->mode))
-                       inode->i_mode |= S_ISGID;
+               /*
+                * If the group ID of the new file does not match the effective
+                * group ID or one of the supplementary group IDs, the S_ISGID
+                * bit is cleared (and only if the irix_sgid_inherit
+                * compatibility variable is set).
+                */
+               if (irix_sgid_inherit && (inode->i_mode & S_ISGID) &&
+                   !vfsgid_in_group_p(i_gid_into_vfsgid(args->idmap, inode)))
+                       inode->i_mode &= ~S_ISGID;
+
+               ip->i_projid = pip ? xfs_get_initial_prid(pip) : 0;
        }
 
-       if (pip)
-               ip->i_projid = libxfs_get_initial_prid(pip);
-
        ip->i_disk_size = 0;
        ip->i_df.if_nextents = 0;
        ASSERT(ip->i_nblocks == 0);
+
        ip->i_extsize = 0;
        ip->i_diflags = 0;
 
-       if (xfs_has_v3inodes(ip->i_mount)) {
-               inode->i_version = 1;
-               ip->i_diflags2 = ip->i_mount->m_ino_geo.new_diflags2;
+       if (xfs_has_v3inodes(mp)) {
+               inode_set_iversion(inode, 1);
                ip->i_cowextsize = 0;
                times |= XFS_ICHGTIME_CREATE;
        }
@@ -149,15 +166,14 @@ xfs_inode_init(
        case S_IFBLK:
                ip->i_df.if_format = XFS_DINODE_FMT_DEV;
                flags |= XFS_ILOG_DEV;
-               VFS_I(ip)->i_rdev = args->rdev;
                break;
        case S_IFREG:
        case S_IFDIR:
                if (pip && (pip->i_diflags & XFS_DIFLAG_ANY))
-                       xfs_inode_propagate_flags(ip, pip);
+                       xfs_inode_inherit_flags(ip, pip);
                if (pip && (pip->i_diflags2 & XFS_DIFLAG2_ANY))
                        xfs_inode_inherit_flags2(ip, pip);
-               /* FALLTHROUGH */
+               fallthrough;
        case S_IFLNK:
                ip->i_df.if_format = XFS_DINODE_FMT_EXTENTS;
                ip->i_df.if_bytes = 0;
@@ -391,6 +407,7 @@ libxfs_iget(
        VFS_I(ip)->i_count = 1;
        ip->i_ino = ino;
        ip->i_mount = mp;
+       ip->i_diflags2 = mp->m_ino_geo.new_diflags2;
        ip->i_af.if_format = XFS_DINODE_FMT_EXTENTS;
        spin_lock_init(&VFS_I(ip)->i_lock);
 
@@ -472,3 +489,18 @@ libxfs_irele(
                kmem_cache_free(xfs_inode_cache, ip);
        }
 }
+
+void inode_init_owner(struct mnt_idmap *idmap, struct inode *inode,
+                     const struct inode *dir, umode_t mode)
+{
+       inode_fsuid_set(inode, idmap);
+       if (dir && dir->i_mode & S_ISGID) {
+               inode->i_gid = dir->i_gid;
+
+               /* Directories are special, and always inherit S_ISGID */
+               if (S_ISDIR(mode))
+                       mode |= S_ISGID;
+       } else
+               inode_fsgid_set(inode, idmap);
+       inode->i_mode = mode;
+}

diff --git a/libxfs/libxfs_priv.h b/libxfs/libxfs_priv.h
index 0bf0c54ac2f7bec7dd046c115f0e0d3cf31e2e5e..ecacfff82d722b948e39459383f5fb5d535ed777 100644 (file)
--- a/libxfs/libxfs_priv.h
+++ b/libxfs/libxfs_priv.h
@@ -225,6 +225,12 @@ static inline bool WARN_ON(bool expr) {
        (inode)->i_version = (version); \
 } while (0)
 
+struct inode;
+struct mnt_idmap;
+
+void inode_init_owner(struct mnt_idmap *idmap, struct inode *inode,
+                     const struct inode *dir, umode_t mode);
+
 #define __must_check   __attribute__((__warn_unused_result__))
 
 /*
@@ -639,4 +645,8 @@ int xfs_bmap_last_extent(struct xfs_trans *tp, struct xfs_inode *ip,
 
 #define cond_resched() ((void)0)
 
+/* xfs_linux.h */
+#define irix_sgid_inherit              (false)
+#define vfsgid_in_group_p(...)         (false)
+
 #endif /* __LIBXFS_INTERNAL_XFS_H__ */