]> wimlib.net Git - wimlib/blobdiff - src/mount.c
hardlinks (IN PROGRESS)
[wimlib] / src / mount.c
index f3043c2b5a7e26f910d9c4f51840290fd9e416d1..364d84dcd0d3d77f2e784ea2716876ce2e3c51fe 100644 (file)
@@ -32,6 +32,7 @@
 #include "sha1.h"
 #include "lookup_table.h"
 #include "xml.h"
+#include "io.h"
 #include "timestamp.h"
 #include <stdlib.h>
 #include <unistd.h>
 #include <ftw.h>
 #include <mqueue.h>
 
+struct wimlib_fd {
+       int staging_fd;
+       u64 hard_link_group;
+       struct lookup_table_entry *lte;
+};
+
 /* The WIMStruct for the mounted WIM. */
 static WIMStruct *w;
 
@@ -65,6 +72,63 @@ static int mount_flags;
 static const char *mount_dir;
 
 
+static inline int get_lookup_flags()
+{
+       if (mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_WINDOWS)
+               return LOOKUP_FLAG_ADS_OK;
+       else
+               return 0;
+}
+
+static inline int flags_writable(int open_flags)
+{
+       return open_flags & (O_RDWR | O_WRONLY);
+}
+
+static int alloc_fd(struct lookup_table_entry *lte, struct wimlib_fd **fd_ret)
+{
+       struct wimlib_fd *fds, *fd;
+       if (lte->num_opened_fds == lte->num_allocated_fds) {
+               if (lte->num_allocated_fds > 0xffff - 8)
+                       return -ENFILE;
+               
+               fds = CALLOC(lte->num_allocated_fds + 8, sizeof(struct wimlib_fd));
+               if (!fds)
+                       return -ENOMEM;
+               memcpy(fds, lte->fds,
+                      lte->num_allocated_fds * sizeof(struct wimlib_fd));
+               FREE(lte->fds);
+               lte->fds = fds;
+       }
+       fd = lte->fds;
+       while (1) {
+               if (!fd->lte) {
+                       fd->hard_link_group = 0;
+                       fd->staging_fd = -1;
+                       fd->lte = lte;
+                       *fd_ret = fd;
+                       return 0;
+               }
+               fd++;
+       }
+}
+
+static int close_fd(struct wimlib_fd *fd)
+{
+       struct lookup_table_entry *lte = fd->lte;
+       wimlib_assert(lte);
+       wimlib_assert(lte->num_opened_fds);
+
+       u16 idx = fd - lte->fds;
+       if (lte->staging_file_name && fd->staging_fd != -1)
+               if (close(fd->staging_fd) != 0)
+                       return -errno;
+       if (--lte->num_opened_fds == 0 && lte->refcnt == 0)
+               free_lookup_table_entry(lte);
+       fd->lte = NULL;
+       return 0;
+}
+
 /* 
  * Creates a randomly named staging directory and returns its name into the
  * static variable staging_dir_name.
@@ -299,13 +363,15 @@ static int wimfs_access(const char *path, int mask)
 
 /* Closes the staging file descriptor associated with the lookup table entry, if
  * it is opened. */
-static int close_staging_file(struct lookup_table_entry *lte, void *ignore)
+static int close_lte_fds(struct lookup_table_entry *lte, void *ignore)
 {
-       if (lte->staging_file_name && lte->staging_num_times_opened) {
-               if (close(lte->staging_fd) != 0) {
-                       ERROR_WITH_ERRNO("Failed close file `%s'",
-                                        lte->staging_file_name);
-                       return WIMLIB_ERR_WRITE;
+       for (u16 i = 0; i < lte->num_opened_fds; i++) {
+               if (lte->fds[i].lte && lte->fds[i].staging_fd != -1) {
+                       if (close(lte->fds[i].staging_fd) != 0) {
+                               ERROR_WITH_ERRNO("Failed close file `%s'",
+                                                lte->staging_file_name);
+                               return WIMLIB_ERR_WRITE;
+                       }
                }
        }
        return 0;
@@ -316,35 +382,40 @@ static int close_staging_file(struct lookup_table_entry *lte, void *ignore)
  * file.  Updates the SHA1 sum in the dentry and the lookup table entry.  If
  * there is already a lookup table entry with the same checksum, increment its
  * reference count and destroy the lookup entry with the updated checksum. */
-static int calculate_sha1sum_for_staging_file(struct dentry *dentry, void *lookup_table)
+static int calculate_sha1sum_for_staging_file(struct dentry *dentry,
+                                             void *_lookup_table)
 {
-       struct lookup_table *table;
-       struct lookup_table_entry *lte; 
-       struct lookup_table_entry *existing;
-       int ret;
-
-       table = lookup_table;
-       lte = lookup_resource(table, dentry->hash);
-       
-       if (lte && lte->staging_file_name) {
-
-               DEBUG("Calculating SHA1 hash for file `%s'",
-                     dentry->file_name_utf8);
-               ret = sha1sum(lte->staging_file_name, dentry->hash);
-               if (ret != 0)
-                       return ret;
-
-               lookup_table_unlink(table, lte);
-               memcpy(lte->hash, dentry->hash, WIM_HASH_SIZE);
-               existing = lookup_resource(table, dentry->hash);
-               if (existing) {
-                       DEBUG("Merging duplicate lookup table entries for file "
-                             "`%s'", dentry->file_name_utf8);
-                       free_lookup_table_entry(lte);
-                       existing->refcnt++;
-               } else {
-                       lookup_table_insert(table, lte);
+       struct lookup_table *lookup_table =  _lookup_table;
+       u8 *hash = dentry->hash;
+       u16 i = 0;
+       while (1) {
+               struct lookup_table_entry *lte = __lookup_resource(lookup_table, hash);
+               if (lte && lte->staging_file_name) {
+                       struct lookup_table_entry *existing;
+                       int ret;
+
+                       DEBUG("Calculating SHA1 hash for file `%s'",
+                             dentry->file_name_utf8);
+                       ret = sha1sum(lte->staging_file_name, lte->hash);
+                       if (ret != 0)
+                               return ret;
+
+                       lookup_table_unlink(lookup_table, lte);
+                       memcpy(hash, lte->hash, WIM_HASH_SIZE);
+                       existing = __lookup_resource(lookup_table, hash);
+                       if (existing) {
+                               DEBUG("Merging duplicate lookup table entries for file "
+                                     "`%s'", dentry->file_name_utf8);
+                               free_lookup_table_entry(lte);
+                               existing->refcnt++;
+                       } else {
+                               lookup_table_insert(lookup_table, lte);
+                       }
                }
+               if (i == dentry->num_ads)
+                       break;
+               hash = dentry->ads_entries[i].hash;
+               i++;
        }
        return 0;
 }
@@ -359,7 +430,7 @@ static int rebuild_wim(WIMStruct *w, bool check_integrity)
 
        DEBUG("Closing all staging file descriptors.");
        /* Close all the staging file descriptors. */
-       ret = for_lookup_table_entry(w->lookup_table, close_staging_file, NULL);
+       ret = for_lookup_table_entry(w->lookup_table, close_lte_fds, NULL);
        if (ret != 0) {
                ERROR("Failed to close all staging files");
                return ret;
@@ -495,7 +566,7 @@ static int wimfs_mkdir(const char *path, mode_t mode)
                return -EEXIST;
 
        newdir = new_dentry(basename);
-       newdir->attributes |= WIM_FILE_ATTRIBUTE_DIRECTORY;
+       newdir->attributes |= FILE_ATTRIBUTE_DIRECTORY;
        link_dentry(newdir, parent);
        return 0;
 }
@@ -508,7 +579,7 @@ static int wimfs_mkdir(const char *path, mode_t mode)
  * @return:  The file descriptor for the new file.  Returns -1 and sets errno on
  *             error, for any reason possible from the creat() function.
  */
-static int create_staging_file(char **name_ret)
+static int create_staging_file(char **name_ret, int open_flags)
 {
        size_t name_len;
        char *name;
@@ -523,29 +594,28 @@ static int create_staging_file(char **name_ret)
                return -1;
        }
 
-       memcpy(name, staging_dir_name, staging_dir_name_len);
-       name[staging_dir_name_len] = '/';
-       randomize_char_array_with_alnum(name + staging_dir_name_len + 1,
-                                       WIM_HASH_SIZE);
-       name[name_len] = '\0';
+       do {
+
+               memcpy(name, staging_dir_name, staging_dir_name_len);
+               name[staging_dir_name_len] = '/';
+               randomize_char_array_with_alnum(name + staging_dir_name_len + 1,
+                                               WIM_HASH_SIZE);
+               name[name_len] = '\0';
 
 
        /* Just in case, verify that the randomly generated name doesn't name an
         * existing file, and try again if so  */
-       if (stat(name, &stbuf) == 0) {
-               /* stat succeeded-- the file must exist. Try another name. */
-               FREE(name);
-               return create_staging_file(name_ret);
-       } else {
-               if (errno != ENOENT)
-                       /* other error! */
-                       return -1;
-               /* doesn't exist--- ok */
-       }
+       } while (stat(name, &stbuf) == 0);
+
+       if (errno != ENOENT)
+               /* other error! */
+               return -1;
 
-       DEBUG("Creating staging file '%s'", name);
+       /* doesn't exist--- ok */
 
-       fd = creat(name, 0600); 
+       DEBUG("Creating staging file `%s'", name);
+
+       fd = open(name, open_flags | O_CREAT | O_TRUNC, 0600); 
        if (fd == -1) {
                errno_save = errno;
                FREE(name);
@@ -556,113 +626,113 @@ static int create_staging_file(char **name_ret)
        return fd;
 }
 
-/* Creates a regular file.  This is done in the staging directory.  */
+/* Creates a regular file. */
 static int wimfs_mknod(const char *path, mode_t mode, dev_t rdev)
 {
-       struct dentry *parent, *dentry;
-       const char *basename;
-       struct lookup_table_entry *lte;
-       char *tmpfile_name;
-       int fd;
-       int err;
-
-       /* Make sure that the parent of @path exists and is a directory, and
-        * that the dentry named by @path does not already exist.  */
-       parent = get_parent_dentry(w, path);
-       if (!parent)
-               return -ENOENT;
-       if (!dentry_is_directory(parent))
-               return -ENOTDIR;
-       basename = path_basename(path);
-       if (get_dentry_child_with_name(parent, path))
-               return -EEXIST;
-
-       dentry = new_dentry(basename);
-
-       /* XXX fill in a temporary random hash value- really should check for
-        * duplicates */
-       randomize_byte_array(dentry->hash, WIM_HASH_SIZE);
-
-       /* Create a lookup table entry having the same hash value */
-       lte = new_lookup_table_entry();
-       lte->staging_num_times_opened = 0;
-       lte->resource_entry.original_size = 0;
-       memcpy(lte->hash, dentry->hash, WIM_HASH_SIZE);
-
-       fd = create_staging_file(&tmpfile_name);
-
-       if (fd == -1)
-               goto mknod_error;
-
-       if (close(fd) != 0)
-               goto mknod_error;
-
-       lte->staging_file_name = tmpfile_name;
+       const char *stream_name;
+       if ((mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_WINDOWS)
+            && (stream_name = path_stream_name(path))) {
+               struct ads_entry *new_entry;
+               struct dentry *dentry;
+
+               dentry = get_dentry(w, path);
+               if (!dentry || !dentry_is_regular_file(dentry))
+                       return -ENOENT;
+               if (dentry_get_ads_entry(dentry, stream_name))
+                       return -EEXIST;
+               new_entry = dentry_add_ads(dentry, stream_name);
+               if (!new_entry)
+                       return -ENOENT;
+       } else {
+               struct dentry *dentry, *parent;
+               const char *basename;
 
-       /* Insert the lookup table entry, and link the new dentry with its
-        * parent. */
-       lookup_table_insert(w->lookup_table, lte);
-       link_dentry(dentry, parent);
+               /* Make sure that the parent of @path exists and is a directory, and
+                * that the dentry named by @path does not already exist.  */
+               parent = get_parent_dentry(w, path);
+               if (!parent)
+                       return -ENOENT;
+               if (!dentry_is_directory(parent))
+                       return -ENOTDIR;
+               basename = path_basename(path);
+               if (get_dentry_child_with_name(parent, path))
+                       return -EEXIST;
+
+               dentry = new_dentry(basename);
+               link_dentry(dentry, parent);
+       }
        return 0;
-mknod_error:
-       err = errno;
-       free_lookup_table_entry(lte);
-       return -err;
 }
 
+
 /* Open a file.  */
 static int wimfs_open(const char *path, struct fuse_file_info *fi)
 {
        struct dentry *dentry;
        struct lookup_table_entry *lte;
-       
-       dentry = get_dentry(w, path);
+       u8 *dentry_hash;
+       int ret;
+       struct wimlib_fd *fd;
 
-       if (!dentry)
-               return -EEXIST;
-       if (dentry_is_directory(dentry))
-               return -EISDIR;
-       lte = wim_lookup_resource(w, dentry);
+       ret = lookup_resource(w, path, get_lookup_flags(), &dentry, &lte,
+                             &dentry_hash);
+       if (ret != 0)
+               return ret;
 
        if (lte) {
-               /* If this file is in the staging directory and the file is not
-                * currently open, open it. */
-               if (lte->staging_file_name && lte->staging_num_times_opened == 0) {
-                       lte->staging_fd = open(lte->staging_file_name, O_RDWR);
-                       if (lte->staging_fd == -1)
+               /* Common case--- there's a lookup table entry for a file.
+                * Allocate a new file descriptor for it. */
+
+               ret = alloc_fd(lte, &fd);
+               if (ret != 0)
+                       return ret;
+
+               /* The file resource may be in the staging directory (read-write
+                * mounts only) or in the WIM.  If it's in the staging
+                * directory, we need to open a native file descriptor for the
+                * corresponding file.  Otherwise, we can read the file resource
+                * directly from the WIM file if we are opening it read-only,
+                * but we need to extract the resource to the staging directory
+                * if we are opening it writable. */
+               if (lte->staging_file_name) {
+                       fd->staging_fd = open(lte->staging_file_name, fi->flags);
+                       if (fd->staging_fd == -1) {
+                               close_fd(fd);
                                return -errno;
-                       lte->staging_offset = 0;
+                       }
+               } else if (flags_writable(fi->flags)) {
+
+                       ret = extract_resource_to_staging_dir(lte,
+                                                             lte->resource_entry.original_size);
                }
        } else {
-               /* no lookup table entry, so the file must be empty.  Create a
-                * lookup table entry for the file, unless it's a read-only
-                * filesystem.  */
+               /* Empty file with no lookup-table entry.  This is fine if it's
+                * a read-only filesystem.  Otherwise we need to create a lookup
+                * table entry so that we can keep track of the file descriptors
+                * (this is important in case someone opens the file for
+                * writing) */
+               if (!(mount_flags & WIMLIB_MOUNT_FLAG_READWRITE)) {
+                       fi->fd = 0;
+                       return 0;
+               }
                char *tmpfile_name;
                int fd;
 
-               if (!staging_dir_name) /* Read-only filesystem */
-                       return 0;
+               fd = create_staging_file(&tmpfile_name, O_RDWR);
+               if (fd == -1)
+                       return -errno;
 
                lte = new_lookup_table_entry();
                if (!lte)
                        return -ENOMEM;
 
-               fd = create_staging_file(&tmpfile_name);
-
-               if (fd == -1) {
-                       int err = errno;
-                       free(lte);
-                       return -err;
-               }
-               lte->resource_entry.original_size = 0;
                randomize_byte_array(lte->hash, WIM_HASH_SIZE);
-               memcpy(dentry->hash, lte->hash, WIM_HASH_SIZE);
+               memcpy(dentry_hash, lte->hash, WIM_HASH_SIZE);
                lte->staging_file_name = tmpfile_name;
                lte->staging_fd = fd;
-               lte->staging_offset = 0;
                lookup_table_insert(w->lookup_table, lte);
        }
-       lte->staging_num_times_opened++;
+       fi->fd = (uint64_t)fd;
        return 0;
 }
 
@@ -674,6 +744,7 @@ static int wimfs_opendir(const char *path, struct fuse_file_info *fi)
        dentry = get_dentry(w, path);
        if (!dentry || !dentry_is_directory(dentry))
                return -ENOTDIR;
+       fi->fd = (uint64_t)dentry;
        return 0;
 }
 
@@ -682,46 +753,25 @@ static int wimfs_opendir(const char *path, struct fuse_file_info *fi)
  * Read data from a file in the WIM or in the staging directory. 
  */
 static int wimfs_read(const char *path, char *buf, size_t size, 
-               off_t offset, struct fuse_file_info *fi)
+                     off_t offset, struct fuse_file_info *fi)
 {
-       struct dentry *dentry;
-       struct lookup_table_entry *lte;
-       
-       dentry = get_dentry(w, path);
-
-       if (!dentry)
-               return -EEXIST;
+       struct wimlib_fd *fd = (struct wimlib_fd*)fi->fh;
 
-       if (!dentry_is_regular_file(dentry))
-               return -EISDIR;
+       wimlib_assert(fd->lte);
+       wimlib_assert(fd->lte->staging_dir_name);
 
-       lte = wim_lookup_resource(w, dentry);
+       if (fd->lte->staging_file_name) {
+               /* Read from staging file */
 
-       if (!lte)
-               return 0;
-
-       if (lte->staging_file_name) {
+               wimlib_assert(fd->staging_fd != -1);
 
-               /* Read from staging */
-               int fd;
-               off_t cur_offset;
                ssize_t ret;
 
-               if (lte->staging_num_times_opened == 0)
-                       return -EBADF;
-
-               fd = lte->staging_fd;
-               cur_offset = lte->staging_offset;
-               if (cur_offset != offset)
-                       if (lseek(fd, offset, SEEK_SET) == -1)
-                               return -errno;
-               lte->staging_offset = offset;
-
-               ret = read(fd, buf, size);
+               if (lseek(fd->staging_fd, offset, SEEK_SET) == -1)
+                       return -errno;
+               ret = read(fd->staging_fd, buf, size);
                if (ret == -1)
                        return -errno;
-               lte->staging_offset = offset + ret;
-
                return ret;
        } else {
 
@@ -753,18 +803,7 @@ static int wimfs_read(const char *path, char *buf, size_t size,
 static int wimfs_readdir(const char *path, void *buf, fuse_fill_dir_t filler, 
                                off_t offset, struct fuse_file_info *fi)
 {
-       struct dentry *parent;
-       struct dentry *child;
-       struct stat st;
-
-       parent = get_dentry(w, path);
-
-       if (!parent)
-               return -EEXIST;
-
-       if (!dentry_is_directory(parent))
-               return -ENOTDIR;
-
+       struct dentry *parent = (struct dentry*) fi->fh;
        filler(buf, ".", NULL, 0);
        filler(buf, "..", NULL, 0);
 
@@ -774,38 +813,38 @@ static int wimfs_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
                return 0;
 
        do {
-               memset(&st, 0, sizeof(st));
-               if (filler(buf, child->file_name_utf8, &st, 0))
+               if (filler(buf, child->file_name_utf8, NULL, 0))
                        return 0;
                child = child->next;
        } while (child != parent->children);
        return 0;
 }
 
-/* Close a file. */
-static int wimfs_release(const char *path, struct fuse_file_info *fi)
+
+static int wimfs_readlink(const char *path, char *buf, size_t buf_len)
 {
-       struct dentry *dentry;
-       struct lookup_table_entry *lte;
+       struct dentry *dentry = get_dentry(w, path);
        int ret;
-       
-       dentry = get_dentry(w, path);
        if (!dentry)
-               return -EEXIST;
-       lte = wim_lookup_resource(w, dentry);
+               return -ENOENT;
+       if (!dentry_is_symlink(dentry))
+               return -EINVAL;
 
-       if (!lte)
-               return 0;
-       
-       if (lte->staging_num_times_opened == 0)
-               return -EBADF;
+       ret = dentry_readlink(dentry, buf, buf_len, w);
+       if (ret > 0)
+               ret = 0;
+       return ret;
+}
 
-       if (--lte->staging_num_times_opened == 0 && lte->staging_file_name) {
-               ret = close(lte->staging_fd);
-               if (ret != 0)
-                       return -errno;
-       }
-       return 0;
+/* Close a file. */
+static int wimfs_release(const char *path, struct fuse_file_info *fi)
+{
+       int ret;
+       struct wimlib_fd *fd = (struct wimlib_fd*)fi->fh;
+       
+       wimlib_assert(fd->lte);
+       wimlib_assert(fd->num_opened_fds);
+       return close_fd(fd);
 }
 
 /* Renames a file or directory.  See rename (3) */
@@ -858,36 +897,36 @@ static int wimfs_rmdir(const char *path)
        
        dentry = get_dentry(w, path);
        if (!dentry)
-               return -EEXIST;
+               return -ENOENT;
 
        if (!dentry_is_empty_directory(dentry))
-               return -EEXIST;
+               return -ENOTEMPTY;
 
        unlink_dentry(dentry);
        free_dentry(dentry);
        return 0;
 }
 
-/* Extracts the resource corresponding to @dentry and its lookup table entry
- * @lte to a file in the staging directory.  The lookup table entry for @dentry
- * is updated to point to the new file.  If @lte has multiple dentries
- * referencing it, a new lookup table entry is created and the hash of @dentry
- * is changed to point to the new lookup table entry.
- *
+/* 
+ * Extract a WIM resource to the staging directory.
  * Only @size bytes are extracted, to support truncating the file. 
  *
- * Returns the negative error code on failure.
+ * We need to:
+ * - Create a staging file for the WIM resource
+ * - Extract the resource to it
+ * - Create a new lte for the file resource
+ * - Transfer fds from the old lte to the new lte, but
+ *   only if they share the same hard link group as this
+ *   dentry
  */
-static int extract_resource_to_staging_dir(struct dentry *dentry, 
-                                          struct lookup_table_entry *lte, 
+static int extract_resource_to_staging_dir(struct lookup_table_entry *lte,
                                           u64 size)
 {
-       int fd;
-       bool ret;
        char *staging_file_name;
+       int ret;
+       int fd;
        struct lookup_table_entry *new_lte;
-
-       /* File in WIM.  Copy it to the staging directory. */
+       
        fd = create_staging_file(&staging_file_name);
        if (fd == -1)
                return -errno;
@@ -903,7 +942,13 @@ static int extract_resource_to_staging_dir(struct dentry *dentry,
                return ret;
        }
 
-       if (lte->refcnt != 1) {
+       /* XXX
+        * Need to figure out how to avoid creating orphan lookup table entries.
+        * XXX
+        */
+       if (lte->refcnt == 1) {
+               new_lte = lte;
+       } else {
                /* Need to make a new lookup table entry if we are
                 * changing only one copy of a hardlinked entry */
                lte->refcnt--;
@@ -911,8 +956,8 @@ static int extract_resource_to_staging_dir(struct dentry *dentry,
                new_lte = new_lookup_table_entry();
                if (!new_lte)
                        return -ENOMEM;
-               randomize_byte_array(dentry->hash, WIM_HASH_SIZE);
-               memcpy(new_lte->hash, dentry->hash, WIM_HASH_SIZE);
+               randomize_byte_array(dentry_hash, WIM_HASH_SIZE);
+               memcpy(new_lte->hash, dentry_hash, WIM_HASH_SIZE);
 
                new_lte->resource_entry.flags = 0;
                new_lte->staging_num_times_opened = lte->staging_num_times_opened;
@@ -938,14 +983,17 @@ static int wimfs_truncate(const char *path, off_t size)
        struct dentry *dentry;
        struct lookup_table_entry *lte;
        int ret;
+       u8 *dentry_hash;
+       
+       ret = lookup_resource(w, path, get_lookup_flags(), &dentry,
+                             &lte, &dentry_hash);
 
-       dentry = get_dentry(w, path);
-       if (!dentry)
-               return -EEXIST;
-       lte = wim_lookup_resource(w, dentry);
+       if (ret != 0)
+               return ret;
 
        if (!lte) /* Already a zero-length file */
                return 0;
+
        if (lte->staging_file_name) {
                /* File on disk.  Call POSIX API */
                if (lte->staging_num_times_opened != 0)
@@ -956,12 +1004,12 @@ static int wimfs_truncate(const char *path, off_t size)
                        return -errno;
                dentry_update_all_timestamps(dentry);
                lte->resource_entry.original_size = size;
-               return 0;
        } else {
                /* File in WIM.  Extract it to the staging directory, but only
                 * the first @size bytes of it. */
-               return extract_resource_to_staging_dir(dentry, lte, size);
+               ret = extract_resource_to_staging_dir(dentry_hash, lte, size);
        }
+       return ret;
 }
 
 /* Remove a regular file */
@@ -969,27 +1017,52 @@ static int wimfs_unlink(const char *path)
 {
        struct dentry *dentry;
        struct lookup_table_entry *lte;
+       int ret;
+       u8 *dentry_hash;
        
-       dentry = get_dentry(w, path);
-       if (!dentry)
-               return -EEXIST;
+       ret = lookup_resource(w, path, get_lookup_flags(), &dentry,
+                             &lte, &dentry_hash);
 
-       if (!dentry_is_regular_file(dentry))
-               return -EEXIST;
+       if (ret != 0)
+               return ret;
 
-       lte = wim_lookup_resource(w, dentry);
-       if (lte) {
-               if (lte->staging_file_name)
-                       if (unlink(lte->staging_file_name) != 0)
-                               return -errno;
-               lookup_table_decrement_refcnt(w->lookup_table, dentry->hash);
-       }
+       if (lte && lte->staging_file_name)
+               if (unlink(lte->staging_file_name) != 0)
+                       return -errno;
 
-       unlink_dentry(dentry);
-       free_dentry(dentry);
+       if (dentry_hash == dentry->hash) {
+               /* We are removing the full dentry including all alternate data
+                * streams. */
+               const u8 *hash = dentry->hash;
+               u16 i = 0;
+               while (1) {
+                       lookup_table_decrement_refcnt(w->lookup_table, hash);
+                       if (i == dentry->num_ads)
+                               break;
+                       hash = dentry->ads_entries[i].hash;
+                       i++;
+               }
+
+               unlink_dentry(dentry);
+               free_dentry(dentry);
+       } else {
+               /* We are removing an alternate data stream. */
+               struct ads_entry *cur_entry = dentry->ads_entries;
+               while (cur_entry->hash != dentry_hash)
+                       cur_entry++;
+               lookup_table_decrement_refcnt(w->lookup_table, cur_entry->hash);
+               
+               dentry_remove_ads(dentry, cur_entry);
+       }
+       /* Beware: The lookup table entry(s) may still be referenced by users
+        * that have opened the corresponding streams.  They are freed later in
+        * wimfs_release() when the last file user has closed the stream. */
        return 0;
 }
 
+/* Change the timestamp on a file dentry. 
+ *
+ * There is no distinction between a file and its alternate data streams here.  */
 static int wimfs_utimens(const char *path, const struct timespec tv[2])
 {
        struct dentry *dentry = get_dentry(w, path);
@@ -1004,61 +1077,43 @@ static int wimfs_utimens(const char *path, const struct timespec tv[2])
        return 0;
 }
 
-/* Writes to a file in the WIM filesystem. */
+/* Writes to a file in the WIM filesystem. 
+ * It may be an alternate data stream, but here we don't even notice because we
+ * just get a lookup table entry. */
 static int wimfs_write(const char *path, const char *buf, size_t size, 
-                               off_t offset, struct fuse_file_info *fi)
+                      off_t offset, struct fuse_file_info *fi)
 {
-       struct dentry *dentry;
-       struct lookup_table_entry *lte;
-       ssize_t ret;
-
-       dentry = get_dentry(w, path);
-       if (!dentry)
-               return -EEXIST;
-       lte = wim_lookup_resource(w, dentry);
+       struct wimlib_fd *fd = (struct wimlib_fd*)fi->fh;
+       int ret;
 
-       if (!lte) /* this should not happen */
-               return -EEXIST;
+       wimlib_assert(fd->lte);
+       wimlib_assert(fd->lte->staging_dir_name);
+       wimlib_assert(fd->staging_fd != -1);
 
-       if (lte->staging_num_times_opened == 0)
-               return -EBADF;
-       if (lte->staging_file_name) {
-
-               /* File in staging directory. We can write to it directly. */
+       /* Seek to correct position in file if needed. */
+       if (lte->staging_offset != offset) {
+               if (lseek(lte->staging_fd, offset, SEEK_SET) == -1)
+                       return -errno;
+               lte->staging_offset = offset;
+       }
 
-               /* Seek to correct position in file if needed. */
-               if (lte->staging_offset != offset) {
-                       if (lseek(lte->staging_fd, offset, SEEK_SET) == -1)
-                               return -errno;
-                       lte->staging_offset = offset;
-               }
+       /* Write the data. */
+       ret = write(lte->staging_fd, buf, size);
+       if (ret == -1)
+               return -errno;
 
-               /* Write the data. */
-               ret = write(lte->staging_fd, buf, size);
-               if (ret == -1)
-                       return -errno;
+       /* Adjust the stored offset of staging_fd. */
+       lte->staging_offset = offset + ret;
 
-               /* Adjust the stored offset of staging_fd. */
-               lte->staging_offset = offset + ret;
+       /* Increase file size if needed. */
+       if (lte->resource_entry.original_size < lte->staging_offset)
+               lte->resource_entry.original_size = lte->staging_offset;
 
-               /* Increase file size if needed. */
-               if (lte->resource_entry.original_size < lte->staging_offset)
-                       lte->resource_entry.original_size = lte->staging_offset;
+       /* The file has been modified, so all its timestamps must be
+        * updated. */
+       dentry_update_all_timestamps(dentry);
 
-               /* The file has been modified, so all its timestamps must be
-                * updated. */
-               dentry_update_all_timestamps(dentry);
-               return ret;
-       } else {
-               /* File in the WIM.  We must extract it to the staging directory
-                * before it can be written to. */
-               ret = extract_resource_to_staging_dir(dentry, lte, 
-                                       lte->resource_entry.original_size);
-               if (ret != 0)
-                       return ret;
-               else
-                       return wimfs_write(path, buf, size, offset, fi);
-       }
+       return ret;
 }
 
 
@@ -1072,6 +1127,7 @@ static struct fuse_operations wimfs_oper = {
        .opendir  = wimfs_opendir,
        .read     = wimfs_read,
        .readdir  = wimfs_readdir,
+       .readlink = wimfs_readlink,
        .release  = wimfs_release,
        .rename   = wimfs_rename,
        .rmdir    = wimfs_rmdir,
@@ -1105,6 +1161,11 @@ WIMLIBAPI int wimlib_mount(WIMStruct *wim, int image, const char *dir,
        if (flags & WIMLIB_MOUNT_FLAG_READWRITE)
                wim_get_current_image_metadata(wim)->modified = true;
 
+       if (!(flags & (WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_NONE |
+                      WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR |
+                      WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_WINDOWS)))
+               flags |= WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR;
+
        mount_dir = dir;
        working_directory = getcwd(NULL, 0);
        if (!working_directory) {