Implement XATTR interface to ADS in wimfs
authorEric Biggers <ebiggers3@gmail.com>
Sat, 25 Aug 2012 05:13:31 +0000 (00:13 -0500)
committerEric Biggers <ebiggers3@gmail.com>
Sat, 25 Aug 2012 05:13:31 +0000 (00:13 -0500)
src/dentry.c
src/mount.c
src/resource.c

index d8b3e60edd156a68e4c532131b0b437537b1c824..c84a95655100cd80c634ad542ae7480d6ada93de 100644 (file)
@@ -99,13 +99,18 @@ void dentry_update_all_timestamps(struct dentry *dentry)
 struct ads_entry *dentry_get_ads_entry(struct dentry *dentry,
                                       const char *stream_name)
 {
-       size_t stream_name_len = strlen(stream_name);
+       size_t stream_name_len;
        if (!stream_name)
                return NULL;
-       for (u16 i = 0; i < dentry->num_ads; i++)
-               if (ads_entry_has_name(&dentry->ads_entries[i],
-                                      stream_name, stream_name_len))
-                       return &dentry->ads_entries[i];
+       if (dentry->num_ads) {
+               u16 i = 0;
+               stream_name_len = strlen(stream_name);
+               do {
+                       if (ads_entry_has_name(&dentry->ads_entries[i],
+                                              stream_name, stream_name_len))
+                               return &dentry->ads_entries[i];
+               } while (++i != dentry->num_ads);
+       }
        return NULL;
 }
 
index 03626cf4b1a551740147f9ce983c528291a4cb6d..ac4aeb376c750d9ed94387711aca35e0a54e9aeb 100644 (file)
@@ -44,6 +44,7 @@
 #include <fuse.h>
 #include <ftw.h>
 #include <mqueue.h>
+#include <attr/xattr.h>
 
 struct wimlib_fd {
        u16 idx;
@@ -187,6 +188,20 @@ static void remove_dentry(struct dentry *dentry,
        put_dentry(dentry);
 }
 
+static void remove_ads(struct dentry *dentry,
+                      struct ads_entry *ads_entry,
+                      struct lookup_table *lookup_table)
+{
+       struct lookup_table_entry *lte;
+
+       wimlib_assert(dentry->resolved);
+
+       lte = lte_decrement_refcnt(lte, lookup_table);
+       if (lte)
+               list_del(&ads_entry->lte_group_list.list);
+       dentry_remove_ads(dentry, ads_entry);
+}
+
 /* Transfers file attributes from a struct dentry to a `stat' buffer. */
 int dentry_to_stbuf(const struct dentry *dentry, struct stat *stbuf)
 {
@@ -490,6 +505,8 @@ static int extract_resource_to_staging_dir(struct dentry *dentry,
        new_lte->resource_entry.original_size = size;
        new_lte->refcnt = link_group_size;
        random_hash(new_lte->hash);
+       if (new_lte->staging_file_name)
+               FREE(new_lte->staging_file_name);
        new_lte->staging_file_name = staging_file_name;
        new_lte->resource_location = RESOURCE_IN_STAGING_FILE;
 
@@ -977,11 +994,41 @@ static int wimfs_getattr(const char *path, struct stat *stbuf)
        return dentry_to_stbuf(dentry, stbuf);
 }
 
+/* Read an alternate data stream through the XATTR interface, or get its size */
 static int wimfs_getxattr(const char *path, const char *name, char *value,
                          size_t size)
 {
-       /* XXX */
-       return -ENOTSUP;
+       int ret;
+       struct dentry *dentry;
+       struct ads_entry *ads_entry;
+       size_t res_size;
+       struct lookup_table_entry *lte;
+
+       if (!(mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR))
+               return -ENOTSUP;
+
+       if (memcmp(name, "user.", 5) != 0)
+               return -ENOATTR;
+       name += 5;
+
+       dentry = get_dentry(w, path);
+       if (!dentry)
+               return -ENOENT;
+       ads_entry = dentry_get_ads_entry(dentry, name);
+       if (!ads_entry)
+               return -ENOATTR;
+
+       lte = ads_entry->lte;
+       res_size = wim_resource_size(lte);
+
+       if (size == 0)
+               return res_size;
+       if (res_size > size)
+               return -ERANGE;
+       ret = read_full_wim_resource(lte, value);
+       if (ret != 0)
+               return -EIO;
+       return res_size;
 }
 
 /* Create a hard link */
@@ -1038,8 +1085,35 @@ static int wimfs_link(const char *to, const char *from)
 
 static int wimfs_listxattr(const char *path, char *list, size_t size)
 {
-       /* XXX */
-       return -ENOTSUP;
+       struct dentry *dentry;
+       int ret;
+       char *p = list;
+       size_t needed_size;
+       unsigned i;
+       if (!(mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR))
+               return -ENOTSUP;
+
+       /* List alternate data streams, or get the list size */
+
+       ret = lookup_resource(w, path, get_lookup_flags(), &dentry, NULL, NULL);
+       if (ret != 0)
+               return ret;
+       if (size == 0) {
+               needed_size = 0;
+               for (i = 0; i < dentry->num_ads; i++)
+                       needed_size += dentry->ads_entries[i].stream_name_utf8_len + 6;
+               return needed_size;
+       } else {
+               for (i = 0; i < dentry->num_ads; i++) {
+                       needed_size = dentry->ads_entries[i].stream_name_utf8_len + 6;
+                       if (needed_size > size)
+                               return -ERANGE;
+                       p += sprintf(p, "user.%s",
+                                    dentry->ads_entries[i].stream_name_utf8) + 1;
+                       size -= needed_size;
+               }
+               return p - list;
+       }
 }
 
 /* 
@@ -1171,7 +1245,8 @@ static int wimfs_open(const char *path, struct fuse_file_info *fi)
         * 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 (flags_writable(fi->flags) && !lte->staging_file_name) {
+       if (flags_writable(fi->flags) &&
+             lte->resource_location != RESOURCE_IN_STAGING_FILE) {
                ret = extract_resource_to_staging_dir(dentry, stream_idx, &lte,
                                                      lte->resource_entry.original_size);
                if (ret != 0)
@@ -1328,10 +1403,28 @@ static int wimfs_releasedir(const char *path, struct fuse_file_info *fi)
        return 0;
 }
 
+/* Remove an alternate data stream through the XATTR interface */
 static int wimfs_removexattr(const char *path, const char *name)
 {
-       /* XXX */
-       return -ENOTSUP;
+       struct dentry *dentry;
+       struct ads_entry *ads_entry;
+       int ret;
+       if (!(mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR))
+               return -ENOTSUP;
+
+       if (memcmp(name, "user.", 5) != 0)
+               return -ENOATTR;
+       name += 5;
+
+       dentry = get_dentry(w, path);
+       if (!dentry)
+               return -ENOENT;
+
+       ads_entry = dentry_get_ads_entry(dentry, name);
+       if (!ads_entry)
+               return -ENOATTR;
+       remove_ads(dentry, ads_entry, w->lookup_table);
+       return 0;
 }
 
 /* Renames a file or directory.  See rename (3) */
@@ -1420,11 +1513,65 @@ static int wimfs_rmdir(const char *path)
        return 0;
 }
 
+/* Write an alternate data stream through the XATTR interface */
 static int wimfs_setxattr(const char *path, const char *name,
                          const char *value, size_t size, int flags)
 {
-       /* XXX */
-       return -ENOTSUP;
+       struct dentry *dentry;
+       struct ads_entry *existing_ads_entry;
+       struct ads_entry *new_ads_entry;
+       struct lookup_table_entry *existing_lte;
+       struct lookup_table_entry *lte;
+       u8 value_hash[SHA1_HASH_SIZE];
+       int ret;
+       int fd;
+
+       if (!(mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR))
+               return -ENOTSUP;
+
+       dentry = get_dentry(w, path);
+       if (!dentry)
+               return -ENOENT;
+       existing_ads_entry = dentry_get_ads_entry(dentry, name);
+       if (existing_ads_entry) {
+               if (flags & XATTR_CREATE)
+                       return -EEXIST;
+               remove_ads(dentry, existing_ads_entry, w->lookup_table);
+       } else {
+               if (flags & XATTR_REPLACE)
+                       return -ENOATTR;
+       }
+       new_ads_entry = dentry_add_ads(dentry, name);
+       if (!new_ads_entry)
+               return -ENOMEM;
+
+       sha1_buffer(value, size, value_hash);
+
+       existing_lte = __lookup_resource(w->lookup_table, value_hash);
+
+       if (existing_lte) {
+               lte = existing_lte;
+               lte->refcnt++;
+       } else {
+               char *value_copy;
+               lte = new_lookup_table_entry();
+               if (!lte)
+                       return -ENOMEM;
+               value_copy = MALLOC(size);
+               if (!value_copy) {
+                       FREE(lte);
+                       return -ENOMEM;
+               }
+               lte->resource_location            = RESOURCE_IN_ATTACHED_BUFFER;
+               lte->attached_buffer              = value_copy;
+               lte->resource_entry.original_size = size;
+               lte->resource_entry.size          = size;
+               lte->resource_entry.flags         = 0;
+               copy_hash(lte->hash, value_hash);
+               lookup_table_insert(w->lookup_table, lte);
+       }
+       new_ads_entry->lte = lte;
+       return 0;
 }
 
 static int wimfs_symlink(const char *to, const char *from)
@@ -1522,13 +1669,8 @@ static int wimfs_unlink(const char *path)
                remove_dentry(dentry, w->lookup_table);
        } else {
                /* We are removing an alternate data stream. */
-               struct ads_entry *ads_entry;
-               
-               ads_entry = &dentry->ads_entries[stream_idx - 1];
-               lte = lte_decrement_refcnt(lte, w->lookup_table);
-               if (lte)
-                       list_del(&ads_entry->lte_group_list.list);
-               dentry_remove_ads(dentry, ads_entry);
+               remove_ads(dentry, &dentry->ads_entries[stream_idx - 1],
+                          w->lookup_table);
        }
        /* Beware: The lookup table entry(s) may still be referenced by users
         * that have opened the corresponding streams.  They are freed later in
index b1bc947d9f61fdfbd9b17686773a25d3c4dc8028..d81421c558661cb1e2bef93a753e2a6fd9c8ee7a 100644 (file)
@@ -447,16 +447,11 @@ int read_wim_resource(const struct lookup_table_entry *lte, u8 buf[],
                                                        ctype, size, offset, buf);
                break;
        case RESOURCE_IN_STAGING_FILE:
-               /* The WIM FUSE implementation needs to handle multiple open
-                * file descriptors per lookup table entry so it does not
-                * currently work with this function. */
-               wimlib_assert(lte->staging_file_name);
-               wimlib_assert(0);
-               break;
        case RESOURCE_IN_FILE_ON_DISK:
                /* The resource is in some file on the external filesystem and
                 * needs to be read uncompressed */
                wimlib_assert(lte->file_on_disk);
+               wimlib_assert(&lte->file_on_disk == &lte->staging_file_name);
                /* Use existing file pointer if available; otherwise open one
                 * temporarily */
                if (lte->file_on_disk_fp) {