xfs: pack icreate initialization parameters into a separate structure

Callers that want to create an inode currently pass all possible file
attribute values for the new inode into xfs_init_new_inode as ten
separate parameters.  This causes two code maintenance issues: first, we
have large multi-line call sites which programmers must read carefully
to make sure they did not accidentally invert a value.  Second, all
three file id parameters must be passed separately to the quota
functions; any discrepancy results in quota count errors.

Clean this up by creating a new icreate_args structure to hold all this
information, some helpers to initialize them properly, and make the
callers pass this structure through to the creation function, whose name
we shorten to xfs_icreate.  This eliminates the issues, enables us to
keep the inode init code in sync with userspace via libxfs, and is
needed for future metadata directory tree management.

(A subsequent cleanup will also fix the quota alloc calls.)

Signed-off-by: Darrick J. Wong <djwong@kernel.org>

diff --git a/include/xfs_inode.h b/include/xfs_inode.h
index 7dcad0616b1c21d896cc085e337085996af5b904..ecb41f821af1685efc924d03faab68a440941fac 100644 (file)
--- a/include/xfs_inode.h
+++ b/include/xfs_inode.h
@@ -7,6 +7,36 @@
 #ifndef __XFS_INODE_H__
 #define __XFS_INODE_H__
 
+/*
+ * Borrow the kernel's uid/gid types.  These are used by xfs_inode_util.h, so
+ * they must come first in the header file.
+ */
+
+typedef struct {
+       uid_t val;
+} kuid_t;
+
+typedef struct {
+       gid_t val;
+} kgid_t;
+
+static inline kuid_t make_kuid(uid_t uid)
+{
+       kuid_t  v = { .val = uid };
+       return v;
+}
+
+static inline kgid_t make_kgid(gid_t gid)
+{
+       kgid_t  v = { .val = gid };
+       return v;
+}
+
+#define KUIDT_INIT(value) (kuid_t){ value }
+#define KGIDT_INIT(value) (kgid_t){ value }
+#define GLOBAL_ROOT_UID KUIDT_INIT(0)
+#define GLOBAL_ROOT_GID KGIDT_INIT(0)
+
 /* These match kernel side includes */
 #include "xfs_inode_buf.h"
 #include "xfs_inode_fork.h"
@@ -34,8 +64,8 @@ static inline bool IS_I_VERSION(const struct inode *inode) { return false; }
  */
 struct inode {
        mode_t                  i_mode;
-       uint32_t                i_uid;
-       uint32_t                i_gid;
+       kuid_t                  i_uid;
+       kgid_t                  i_gid;
        uint32_t                i_nlink;
        xfs_dev_t               i_rdev;  /* This actually holds xfs_dev_t */
        unsigned int            i_count;
@@ -50,19 +80,19 @@ struct inode {
 
 static inline uint32_t i_uid_read(struct inode *inode)
 {
-       return inode->i_uid;
+       return inode->i_uid.val;
 }
 static inline uint32_t i_gid_read(struct inode *inode)
 {
-       return inode->i_gid;
+       return inode->i_gid.val;
 }
-static inline void i_uid_write(struct inode *inode, uint32_t uid)
+static inline void i_uid_write(struct inode *inode, uid_t uid)
 {
-       inode->i_uid = uid;
+       inode->i_uid.val = uid;
 }
-static inline void i_gid_write(struct inode *inode, uint32_t gid)
+static inline void i_gid_write(struct inode *inode, gid_t gid)
 {
-       inode->i_gid = gid;
+       inode->i_gid.val = gid;
 }
 
 static inline void ihold(struct inode *inode)

diff --git a/libxfs/inode.c b/libxfs/inode.c
index 2af7e8fe9001878beaa908ed29b39911389b896b..9ccc22adffdf17f15bf9716e20aa3bfd70562423 100644 (file)
--- a/libxfs/inode.c
+++ b/libxfs/inode.c
@@ -82,18 +82,16 @@ libxfs_bumplink(
  * caller locked exclusively.
  */
 static int
-libxfs_init_new_inode(
+libxfs_icreate(
        struct xfs_trans        *tp,
-       struct xfs_inode        *pip,
        xfs_ino_t               ino,
-       umode_t                 mode,
-       xfs_nlink_t             nlink,
-       dev_t                   rdev,
-       struct cred             *cr,
-       struct fsxattr          *fsx,
+       const struct xfs_icreate_args *args,
        struct xfs_inode        **ipp)
 {
        struct xfs_mount        *mp = tp->t_mountp;
+       struct xfs_inode        *pip = args->pip;
+       struct inode            *dir = pip ? VFS_I(pip) : NULL;
+       struct inode            *inode;
        struct xfs_inode        *ip;
        unsigned int            flags;
        int                     error;
@@ -103,48 +101,47 @@ libxfs_init_new_inode(
                return error;
        ASSERT(ip != NULL);
 
-       VFS_I(ip)->i_mode = mode;
-       set_nlink(VFS_I(ip), nlink);
-       i_uid_write(VFS_I(ip), cr->cr_uid);
-       i_gid_write(VFS_I(ip), cr->cr_gid);
-       ip->i_projid = pip ? 0 : fsx->fsx_projid;
+       inode = VFS_I(ip);
+       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;
        xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG | XFS_ICHGTIME_MOD);
 
-       if (pip && (VFS_I(pip)->i_mode & S_ISGID)) {
-               if (!(cr->cr_flags & CRED_FORCE_GID))
-                       VFS_I(ip)->i_gid = VFS_I(pip)->i_gid;
-               if ((VFS_I(pip)->i_mode & S_ISGID) && (mode & S_IFMT) == S_IFDIR)
-                       VFS_I(ip)->i_mode |= S_ISGID;
+       if (pip && (dir->i_mode & S_ISGID)) {
+               inode->i_gid = dir->i_gid;
+               if (S_ISDIR(args->mode))
+                       inode->i_mode |= S_ISGID;
        }
 
        ip->i_disk_size = 0;
        ip->i_df.if_nextents = 0;
        ASSERT(ip->i_nblocks == 0);
-       ip->i_extsize = pip ? 0 : fsx->fsx_extsize;
-       ip->i_diflags = pip ? 0 : xfs_flags2diflags(ip, fsx->fsx_xflags);
+       ip->i_extsize = 0;
+       ip->i_diflags = 0;
 
        if (xfs_has_v3inodes(ip->i_mount)) {
-               VFS_I(ip)->i_version = 1;
+               inode->i_version = 1;
                ip->i_diflags2 = ip->i_mount->m_ino_geo.new_diflags2;
-               if (!pip)
-                       ip->i_diflags2 = xfs_flags2diflags2(ip,
-                                                       fsx->fsx_xflags);
-               ip->i_crtime = inode_get_mtime(VFS_I(ip)); /* struct copy */
-               ip->i_cowextsize = pip ? 0 : fsx->fsx_cowextsize;
+               ip->i_crtime = inode_get_mtime(inode); /* struct copy */
+               ip->i_cowextsize = 0;
        }
 
        flags = XFS_ILOG_CORE;
-       switch (mode & S_IFMT) {
+       switch (args->mode & S_IFMT) {
        case S_IFIFO:
        case S_IFSOCK:
-               /* doesn't make sense to set an rdev for these */
-               rdev = 0;
-               /* FALLTHROUGH */
        case S_IFCHR:
        case S_IFBLK:
                ip->i_df.if_format = XFS_DINODE_FMT_DEV;
                flags |= XFS_ILOG_DEV;
-               VFS_I(ip)->i_rdev = rdev;
+               VFS_I(ip)->i_rdev = args->rdev;
                break;
        case S_IFREG:
        case S_IFDIR:
@@ -161,10 +158,16 @@ libxfs_init_new_inode(
        }
 
        /*
-        * If we're going to set a parent pointer on this file, we need to
-        * create an attr fork to receive that parent pointer.
+        * If we need to create attributes immediately after allocating the
+        * inode, initialise an empty attribute fork right now. We use the
+        * default fork offset for attributes here as we don't know exactly what
+        * size or how many attributes we might be adding. We can do this
+        * safely here because we know the data fork is completely empty and
+        * this saves us from needing to run a separate transaction to set the
+        * fork offset in the immediate future.
         */
-       if (pip && xfs_has_parent(mp)) {
+       if ((args->flags & XFS_ICREATE_INIT_XATTRS) &&
+           (xfs_has_attr(tp->t_mountp) || xfs_has_attr2(tp->t_mountp))) {
                ip->i_forkoff = xfs_default_attroffset(ip) >> 3;
                xfs_ifork_init_attr(ip, XFS_DINODE_FMT_EXTENTS, 0);
 
@@ -270,10 +273,27 @@ libxfs_dir_ialloc(
        struct fsxattr          *fsx,
        struct xfs_inode        **ipp)
 {
+       struct xfs_icreate_args args = {
+               .pip            = dp,
+               .mode           = mode,
+       };
+       struct xfs_inode        *ip;
+       struct inode            *inode;
        xfs_ino_t               parent_ino = dp ? dp->i_ino : 0;
        xfs_ino_t               ino;
        int                     error;
 
+       if (dp && xfs_has_parent(dp->i_mount))
+               args.flags |= XFS_ICREATE_INIT_XATTRS;
+
+       /* Only devices get rdev numbers */
+       switch (mode & S_IFMT) {
+       case S_IFCHR:
+       case S_IFBLK:
+               args.rdev = rdev;
+               break;
+       }
+
        /*
         * Call the space management code to pick the on-disk inode to be
         * allocated.
@@ -282,8 +302,32 @@ libxfs_dir_ialloc(
        if (error)
                return error;
 
-       return libxfs_init_new_inode(*tpp, dp, ino, mode, nlink, rdev, cr,
-                               fsx, ipp);
+       error = libxfs_icreate(*tpp, ino, &args, &ip);
+       if (error)
+               return error;
+
+       inode = VFS_I(ip);
+       i_uid_write(inode, cr->cr_uid);
+       if (cr->cr_flags & CRED_FORCE_GID)
+               i_gid_write(inode, cr->cr_gid);
+       set_nlink(inode, nlink);
+
+       /* If there is no parent dir, initialize the file from fsxattr data. */
+       if (dp == NULL) {
+               ip->i_projid = fsx->fsx_projid;
+               ip->i_extsize = fsx->fsx_extsize;
+               ip->i_diflags = xfs_flags2diflags(ip, fsx->fsx_xflags);
+
+               if (xfs_has_v3inodes(ip->i_mount)) {
+                       ip->i_diflags2 = xfs_flags2diflags2(ip,
+                                                       fsx->fsx_xflags);
+                       ip->i_cowextsize = fsx->fsx_cowextsize;
+               }
+       }
+
+       xfs_trans_log_inode(*tpp, ip, XFS_ILOG_CORE);
+       *ipp = ip;
+       return 0;
 }
 
 /*

diff --git a/libxfs/xfs_inode_util.h b/libxfs/xfs_inode_util.h
index f7e4d5a8235dda8562621db20faf27248a6fe70f..9226482fdee8cea668a2730c89e172256b350ec4 100644 (file)
--- a/libxfs/xfs_inode_util.h
+++ b/libxfs/xfs_inode_util.h
@@ -13,4 +13,26 @@ uint32_t     xfs_ip2xflags(struct xfs_inode *ip);
 
 prid_t         xfs_get_initial_prid(struct xfs_inode *dp);
 
+/*
+ * File creation context.
+ *
+ * Due to our only partial reliance on the VFS to propagate uid and gid values
+ * according to accepted Unix behaviors, callers must initialize idmap to the
+ * correct idmapping structure to get the correct inheritance behaviors when
+ * XFS_MOUNT_GRPID is set.
+ *
+ * To create files detached from the directory tree (e.g. quota inodes), set
+ * idmap to NULL.  To create a tree root, set pip to NULL.
+ */
+struct xfs_icreate_args {
+       struct mnt_idmap        *idmap;
+       struct xfs_inode        *pip;   /* parent inode or null */
+       dev_t                   rdev;
+       umode_t                 mode;
+
+#define XFS_ICREATE_TMPFILE    (1U << 0)  /* create an unlinked file */
+#define XFS_ICREATE_INIT_XATTRS        (1U << 1)  /* will set xattrs immediately */
+       uint16_t                flags;
+};
+
 #endif /* __XFS_INODE_UTIL_H__ */