Dynamically allocate XFS filesystem names

Replace the 256 byte buffer used for names in the XFS filesystem with a
dynamically allocated buffer.

The define XFS_MAXFILENAMELEN which used to be 255 has been retained,
but bumped to 1023. This value is no longer used for long-lived
allocations, but is used in chansrv_fuse.c for maintaining state
information for in-fligh I/O requests.

sesman/chansrv/chansrv_xfs.c

@@ -264,6 +264,8 @@ xfs_create_xfs_fs(mode_t umask, uid_t uid, gid_t gid)
  struct xfs_fs *xfs = g_new0(struct xfs_fs, 1);
  XFS_INODE_ALL *xino1 = NULL;
  XFS_INODE_ALL *xino2 = NULL;
+ char *xino1_name = NULL;
+ char *xino2_name = NULL;
 
  if (xfs != NULL)
  {
@@ -279,10 +281,14 @@ xfs_create_xfs_fs(mode_t umask, uid_t uid, gid_t gid)
  if (!grow_xfs(xfs, INODE_TABLE_ALLOCATION_INITIAL) ||
  xfs->inode_table == NULL ||
  (xino1 = g_new0(XFS_INODE_ALL, 1)) == NULL ||
- (xino2 = g_new0(XFS_INODE_ALL, 1)) == NULL)
+ (xino2 = g_new0(XFS_INODE_ALL, 1)) == NULL ||
+ (xino1_name = strdup(".")) == NULL ||
+ (xino2_name = strdup(".delete-pending")) == NULL)
  {
  free(xino1);
  free(xino2);
+ free(xino1_name);
+ free(xino2_name);
  xfs_delete_xfs_fs(xfs);
  xfs = NULL;
  }
@@ -306,7 +312,7 @@ xfs_create_xfs_fs(mode_t umask, uid_t uid, gid_t gid)
  xino1->pub.atime = time(0);
  xino1->pub.mtime = xino1->pub.atime;
  xino1->pub.ctime = xino1->pub.atime;
- strcpy(xino1->pub.name, ".");
+ xino1->pub.name = xino1_name;
  xino1->pub.generation = xfs->generation;
  xino1->pub.is_redirected = 0;
  xino1->pub.device_id = 0;
@@ -328,7 +334,7 @@ xfs_create_xfs_fs(mode_t umask, uid_t uid, gid_t gid)
  xino2->pub.atime = time(0);
  xino2->pub.mtime = xino2->pub.atime;
  xino2->pub.ctime = xino2->pub.atime;
- strcpy(xino2->pub.name, ".delete-pending");
+ xino2->pub.name = xino2_name;
  xino2->pub.generation = xfs->generation;
  xino2->pub.is_redirected = 0;
  xino2->pub.device_id = 0;
@@ -349,6 +355,17 @@ xfs_create_xfs_fs(mode_t umask, uid_t uid, gid_t gid)
  return xfs;
 }
 
+/* ------------------------------------------------------------------------ */
+static void
+xfs_free_inode(XFS_INODE_ALL *xino)
+{
+ if (xino != NULL)
+ {
+ free(xino->pub.name);
+ free(xino);
+ }
+}
+
 /* ------------------------------------------------------------------------ */
 void
 xfs_delete_xfs_fs(struct xfs_fs *xfs)
@@ -363,7 +380,7 @@ xfs_delete_xfs_fs(struct xfs_fs *xfs)
  size_t i;
  for (i = 0 ; i < xfs->inode_count; ++i)
  {
- free(xfs->inode_table[i]);
+ xfs_free_inode(xfs->inode_table[i]);
  }
  }
  free(xfs->inode_table);
@@ -407,9 +424,14 @@ xfs_add_entry(struct xfs_fs *xfs, fuse_ino_t parent_inum,
  if (xfs->free_count > 0 ||
  grow_xfs(xfs, INODE_TABLE_ALLOCATION_GRANULARITY))
  {
- XFS_INODE_ALL *xino = NULL;
-
- if ((xino = g_new0(XFS_INODE_ALL, 1)) != NULL)
+ XFS_INODE_ALL *xino = g_new0(XFS_INODE_ALL, 1);
+ char *cpyname = strdup(name);
+ if (xino == NULL || cpyname == NULL)
+ {
+ free(xino);
+ free(cpyname);
+ }
+ else
  {
  fuse_ino_t inum = xfs->free_list[--xfs->free_count];
  if (xfs->inode_table[inum] != NULL)
@@ -433,7 +455,7 @@ xfs_add_entry(struct xfs_fs *xfs, fuse_ino_t parent_inum,
  xino->pub.atime = time(0);
  xino->pub.mtime = xino->pub.atime;
  xino->pub.ctime = xino->pub.atime;
- strcpy(xino->pub.name, name);
+ xino->pub.name = cpyname;
  xino->pub.generation = xfs->generation;
  xino->pub.is_redirected = parent->pub.is_redirected;
  xino->pub.device_id = parent->pub.device_id;
@@ -498,7 +520,7 @@ xfs_remove_entry(struct xfs_fs *xfs, fuse_ino_t inum)
  * so that the caller can distinguish re-uses of the same inum.
  */
  ++xfs->generation;
- free(xino);
+ xfs_free_inode(xino);
  }
  }
 }
@@ -844,8 +866,15 @@ xfs_move_entry(struct xfs_fs *xfs, fuse_ino_t inum,
  XFS_INODE_ALL *xino;
  XFS_INODE_ALL *parent;
  XFS_INODE *dest;
+ char *cpyname;
 
- if (xfs_check_move_entry(xfs, inum, new_parent_inum, name))
+ /* Copy the new name. We'll either end up freeing it, or we'll
+ * use it to replace something else (which gets freed instead) */
+ if ((cpyname = strdup(name)) == NULL)
+ {
+ result = ENOMEM;
+ }
+ else if (xfs_check_move_entry(xfs, inum, new_parent_inum, name))
  {
  xino = xfs->inode_table[inum];
  parent = xfs->inode_table[new_parent_inum];
@@ -862,19 +891,31 @@ xfs_move_entry(struct xfs_fs *xfs, fuse_ino_t inum,
 
  unlink_inode_from_parent(xino);
  link_inode_into_directory_node(parent, xino);
- strcpy(xino->pub.name, name);
+
+ /* Swap the copy name and the inode name so we end up with the
+ * right name, and the old one gets freed */
+ char *t = xino->pub.name;
+ xino->pub.name = cpyname;
+ cpyname = t;
  }
  else if (strcmp(xino->pub.name, name) != 0)
  {
  /* Same directory, but name has changed */
  if ((dest = xfs_lookup_in_dir(xfs, new_parent_inum, name)) != NULL)
  {
+ /* Name collision - remove destination entry */
  xfs_remove_entry(xfs, dest->inum);
  }
- strcpy(xino->pub.name, name);
+
+ /* Swap the copy name and the inode name so we end up with the
+ * right name, and the old one gets freed */
+ char *t = xino->pub.name;
+ xino->pub.name = cpyname;
+ cpyname = t;
  }
  result = 0;
  }
+ free (cpyname);
 
  return result;
 }

sesman/chansrv/chansrv_xfs.h

@@ -29,14 +29,21 @@
 
 #include "arch.h"
 
-#define XFS_MAXFILENAMELEN 255
+/* Maximum length of filename supported (in bytes).
+ * This is a sensible limit to a filename length. It is not used by
+ * this module to allocate long-lived storage, so it can be increased
+ * if necessary */
+#define XFS_MAXFILENAMELEN 1023
 
 /*
  * Incomplete types for the public interface
  */
 struct xfs_fs;
 struct xfs_dir_handle;
 
+/**
+ * Describe an inode in the XFS filesystem
+ */
 typedef struct xfs_inode
 {
  fuse_ino_t inum; /* File serial number. */
@@ -47,7 +54,7 @@ typedef struct xfs_inode
  time_t atime; /* Time of last access. */
  time_t mtime; /* Time of last modification. */
  time_t ctime; /* Time of last status change. */
- char name[XFS_MAXFILENAMELEN + 1]; /* Short name   */
+ char *name;  /* Short name (dynamically allocated) */
  tui32 generation; /* Changes if inode is reused */
  char is_redirected; /* file is on redirected device */
  tui32 device_id; /* device ID of redirected device */