Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/shaggy...
[pandora-kernel.git] / fs / ecryptfs / inode.c
index abac91c..5a71918 100644 (file)
@@ -119,9 +119,9 @@ ecryptfs_do_create(struct inode *directory_inode,
        }
        rc = ecryptfs_create_underlying_file(lower_dir_dentry->d_inode,
                                             ecryptfs_dentry, mode, nd);
-       if (unlikely(rc)) {
-               ecryptfs_printk(KERN_ERR,
-                               "Failure to create underlying file\n");
+       if (rc) {
+               printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
+                      "rc = [%d]\n", __FUNCTION__, rc);
                goto out_lock;
        }
        rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
@@ -140,39 +140,30 @@ out:
 
 /**
  * grow_file
- * @ecryptfs_dentry: the ecryptfs dentry
- * @lower_file: The lower file
- * @inode: The ecryptfs inode
- * @lower_inode: The lower inode
+ * @ecryptfs_dentry: the eCryptfs dentry
  *
  * This is the code which will grow the file to its correct size.
  */
-static int grow_file(struct dentry *ecryptfs_dentry, struct file *lower_file,
-                    struct inode *inode, struct inode *lower_inode)
+static int grow_file(struct dentry *ecryptfs_dentry)
 {
-       int rc = 0;
+       struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode;
        struct file fake_file;
        struct ecryptfs_file_info tmp_file_info;
+       char zero_virt[] = { 0x00 };
+       int rc = 0;
 
        memset(&fake_file, 0, sizeof(fake_file));
        fake_file.f_path.dentry = ecryptfs_dentry;
        memset(&tmp_file_info, 0, sizeof(tmp_file_info));
        ecryptfs_set_file_private(&fake_file, &tmp_file_info);
-       ecryptfs_set_file_lower(&fake_file, lower_file);
-       rc = ecryptfs_fill_zeros(&fake_file, 1);
-       if (rc) {
-               ecryptfs_inode_to_private(inode)->crypt_stat.flags |=
-                       ECRYPTFS_SECURITY_WARNING;
-               ecryptfs_printk(KERN_WARNING, "Error attempting to fill zeros "
-                               "in file; rc = [%d]\n", rc);
-               goto out;
-       }
-       i_size_write(inode, 0);
-       rc = ecryptfs_write_inode_size_to_metadata(lower_file, lower_inode,
-                       inode, ecryptfs_dentry,
-                       ECRYPTFS_LOWER_I_MUTEX_NOT_HELD);
-       ecryptfs_inode_to_private(inode)->crypt_stat.flags |= ECRYPTFS_NEW_FILE;
-out:
+       ecryptfs_set_file_lower(
+               &fake_file,
+               ecryptfs_inode_to_private(ecryptfs_inode)->lower_file);
+       rc = ecryptfs_write(&fake_file, zero_virt, 0, 1);
+       i_size_write(ecryptfs_inode, 0);
+       rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode);
+       ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat.flags |=
+               ECRYPTFS_NEW_FILE;
        return rc;
 }
 
@@ -186,51 +177,31 @@ out:
  */
 static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry)
 {
+       struct ecryptfs_crypt_stat *crypt_stat =
+               &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat;
        int rc = 0;
-       int lower_flags;
-       struct ecryptfs_crypt_stat *crypt_stat;
-       struct dentry *lower_dentry;
-       struct file *lower_file;
-       struct inode *inode, *lower_inode;
-       struct vfsmount *lower_mnt;
 
-       lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
-       ecryptfs_printk(KERN_DEBUG, "lower_dentry->d_name.name = [%s]\n",
-                       lower_dentry->d_name.name);
-       inode = ecryptfs_dentry->d_inode;
-       crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
-       lower_flags = ((O_CREAT | O_TRUNC) & O_ACCMODE) | O_RDWR;
-       lower_mnt = ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry);
-       /* Corresponding fput() at end of this function */
-       if ((rc = ecryptfs_open_lower_file(&lower_file, lower_dentry, lower_mnt,
-                                          lower_flags))) {
-               ecryptfs_printk(KERN_ERR,
-                               "Error opening dentry; rc = [%i]\n", rc);
-               goto out;
-       }
-       lower_inode = lower_dentry->d_inode;
        if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
                ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
                crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
-               goto out_fput;
+               goto out;
        }
        crypt_stat->flags |= ECRYPTFS_NEW_FILE;
        ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
        rc = ecryptfs_new_file_context(ecryptfs_dentry);
        if (rc) {
-               ecryptfs_printk(KERN_DEBUG, "Error creating new file "
-                               "context\n");
-               goto out_fput;
+               ecryptfs_printk(KERN_ERR, "Error creating new file "
+                               "context; rc = [%d]\n", rc);
+               goto out;
        }
-       rc = ecryptfs_write_metadata(ecryptfs_dentry, lower_file);
+       rc = ecryptfs_write_metadata(ecryptfs_dentry);
        if (rc) {
-               ecryptfs_printk(KERN_DEBUG, "Error writing headers\n");
-               goto out_fput;
+               printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
+               goto out;
        }
-       rc = grow_file(ecryptfs_dentry, lower_file, inode, lower_inode);
-out_fput:
-       if ((rc = ecryptfs_close_lower_file(lower_file)))
-               printk(KERN_ERR "Error closing lower_file\n");
+       rc = grow_file(ecryptfs_dentry);
+       if (rc)
+               printk(KERN_ERR "Error growing file; rc = [%d]\n", rc);
 out:
        return rc;
 }
@@ -252,6 +223,8 @@ ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
 {
        int rc;
 
+       /* ecryptfs_do_create() calls ecryptfs_interpose(), which opens
+        * the crypt_stat->lower_file (persistent file) */
        rc = ecryptfs_do_create(directory_inode, ecryptfs_dentry, mode, nd);
        if (unlikely(rc)) {
                ecryptfs_printk(KERN_WARNING, "Failed to create file in"
@@ -374,8 +347,8 @@ static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry,
        crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
        if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
                ecryptfs_set_default_sizes(crypt_stat);
-       rc = ecryptfs_read_and_validate_header_region(page_virt, lower_dentry,
-                                                     nd->mnt);
+       rc = ecryptfs_read_and_validate_header_region(page_virt,
+                                                     dentry->d_inode);
        if (rc) {
                rc = ecryptfs_read_and_validate_xattr_region(page_virt, dentry);
                if (rc) {
@@ -465,6 +438,7 @@ static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
        dentry->d_inode->i_nlink =
                ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink;
        dentry->d_inode->i_ctime = dir->i_ctime;
+       d_drop(dentry);
 out_unlock:
        unlock_parent(lower_dentry);
        return rc;
@@ -753,8 +727,7 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
        int rc = 0;
        struct inode *inode = dentry->d_inode;
        struct dentry *lower_dentry;
-       struct vfsmount *lower_mnt;
-       struct file fake_ecryptfs_file, *lower_file = NULL;
+       struct file fake_ecryptfs_file;
        struct ecryptfs_crypt_stat *crypt_stat;
        loff_t i_size = i_size_read(inode);
        loff_t lower_size_before_truncate;
@@ -777,62 +750,52 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
                goto out;
        }
        lower_dentry = ecryptfs_dentry_to_lower(dentry);
-       /* This dget & mntget is released through fput at out_fput: */
-       lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
-       if ((rc = ecryptfs_open_lower_file(&lower_file, lower_dentry, lower_mnt,
-                                          O_RDWR))) {
-               ecryptfs_printk(KERN_ERR,
-                               "Error opening dentry; rc = [%i]\n", rc);
-               goto out_free;
-       }
-       ecryptfs_set_file_lower(&fake_ecryptfs_file, lower_file);
+       ecryptfs_set_file_lower(
+               &fake_ecryptfs_file,
+               ecryptfs_inode_to_private(dentry->d_inode)->lower_file);
        /* Switch on growing or shrinking file */
        if (new_length > i_size) {
-               rc = ecryptfs_fill_zeros(&fake_ecryptfs_file, new_length);
-               if (rc) {
-                       ecryptfs_printk(KERN_ERR,
-                                       "Problem with fill_zeros\n");
-                       goto out_fput;
-               }
-               i_size_write(inode, new_length);
-               rc = ecryptfs_write_inode_size_to_metadata(
-                       lower_file, lower_dentry->d_inode, inode, dentry,
-                       ECRYPTFS_LOWER_I_MUTEX_NOT_HELD);
-               if (rc) {
-                       printk(KERN_ERR "Problem with "
-                              "ecryptfs_write_inode_size_to_metadata; "
-                              "rc = [%d]\n", rc);
-                       goto out_fput;
-               }
+               char zero[] = { 0x00 };
+
+               /* Write a single 0 at the last position of the file;
+                * this triggers code that will fill in 0's throughout
+                * the intermediate portion of the previous end of the
+                * file and the new and of the file */
+               rc = ecryptfs_write(&fake_ecryptfs_file, zero,
+                                   (new_length - 1), 1);
        } else { /* new_length < i_size_read(inode) */
-               pgoff_t index = 0;
-               int end_pos_in_page = -1;
+               /* We're chopping off all the pages down do the page
+                * in which new_length is located. Fill in the end of
+                * that page from (new_length & ~PAGE_CACHE_MASK) to
+                * PAGE_CACHE_SIZE with zeros. */
+               size_t num_zeros = (PAGE_CACHE_SIZE
+                                   - (new_length & ~PAGE_CACHE_MASK));
 
-               if (new_length != 0) {
-                       index = ((new_length - 1) >> PAGE_CACHE_SHIFT);
-                       end_pos_in_page = ((new_length - 1) & ~PAGE_CACHE_MASK);
-               }
-               if (end_pos_in_page != (PAGE_CACHE_SIZE - 1)) {
-                       if ((rc = ecryptfs_write_zeros(&fake_ecryptfs_file,
-                                                      index,
-                                                      (end_pos_in_page + 1),
-                                                      ((PAGE_CACHE_SIZE - 1)
-                                                       - end_pos_in_page)))) {
+               if (num_zeros) {
+                       char *zeros_virt;
+
+                       zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
+                       if (!zeros_virt) {
+                               rc = -ENOMEM;
+                               goto out_free;
+                       }
+                       rc = ecryptfs_write(&fake_ecryptfs_file, zeros_virt,
+                                           new_length, num_zeros);
+                       kfree(zeros_virt);
+                       if (rc) {
                                printk(KERN_ERR "Error attempting to zero out "
                                       "the remainder of the end page on "
                                       "reducing truncate; rc = [%d]\n", rc);
-                               goto out_fput;
+                               goto out_free;
                        }
                }
                vmtruncate(inode, new_length);
-               rc = ecryptfs_write_inode_size_to_metadata(
-                       lower_file, lower_dentry->d_inode, inode, dentry,
-                       ECRYPTFS_LOWER_I_MUTEX_NOT_HELD);
+               rc = ecryptfs_write_inode_size_to_metadata(inode);
                if (rc) {
                        printk(KERN_ERR "Problem with "
                               "ecryptfs_write_inode_size_to_metadata; "
                               "rc = [%d]\n", rc);
-                       goto out_fput;
+                       goto out_free;
                }
                /* We are reducing the size of the ecryptfs file, and need to
                 * know if we need to reduce the size of the lower file. */
@@ -844,13 +807,6 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
                        vmtruncate(lower_dentry->d_inode,
                                   lower_size_after_truncate);
        }
-       /* Update the access times */
-       lower_dentry->d_inode->i_mtime = lower_dentry->d_inode->i_ctime
-               = CURRENT_TIME;
-       mark_inode_dirty_sync(inode);
-out_fput:
-       if ((rc = ecryptfs_close_lower_file(lower_file)))
-               printk(KERN_ERR "Error closing lower_file\n");
 out_free:
        if (ecryptfs_file_to_private(&fake_ecryptfs_file))
                kmem_cache_free(ecryptfs_file_info_cache,
@@ -910,23 +866,12 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
        else if (S_ISREG(dentry->d_inode->i_mode)
                 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
                     || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
-               struct vfsmount *lower_mnt;
-               struct file *lower_file = NULL;
                struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
-               int lower_flags;
-
-               lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
-               lower_flags = O_RDONLY;
-               if ((rc = ecryptfs_open_lower_file(&lower_file, lower_dentry,
-                                                  lower_mnt, lower_flags))) {
-                       printk(KERN_ERR
-                              "Error opening lower file; rc = [%d]\n", rc);
-                       mutex_unlock(&crypt_stat->cs_mutex);
-                       goto out;
-               }
+
                mount_crypt_stat = &ecryptfs_superblock_to_private(
                        dentry->d_sb)->mount_crypt_stat;
-               if ((rc = ecryptfs_read_metadata(dentry, lower_file))) {
+               rc = ecryptfs_read_metadata(dentry);
+               if (rc) {
                        if (!(mount_crypt_stat->flags
                              & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
                                rc = -EIO;
@@ -936,16 +881,13 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
                                       "enabled; returning -EIO\n");
 
                                mutex_unlock(&crypt_stat->cs_mutex);
-                               fput(lower_file);
                                goto out;
                        }
                        rc = 0;
                        crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
                        mutex_unlock(&crypt_stat->cs_mutex);
-                       fput(lower_file);
                        goto out;
                }
-               fput(lower_file);
        }
        mutex_unlock(&crypt_stat->cs_mutex);
        if (ia->ia_valid & ATTR_SIZE) {
@@ -960,6 +902,14 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
                if (rc < 0)
                        goto out;
        }
+
+       /*
+        * mode change is for clearing setuid/setgid bits. Allow lower fs
+        * to interpret this in its own way.
+        */
+       if (ia->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
+               ia->ia_valid &= ~ATTR_MODE;
+
        rc = notify_change(lower_dentry, ia);
 out:
        fsstack_copy_attr_all(inode, lower_inode, NULL);
@@ -987,13 +937,11 @@ out:
 }
 
 ssize_t
-ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
-                 size_t size)
+ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
+                       void *value, size_t size)
 {
        int rc = 0;
-       struct dentry *lower_dentry;
 
-       lower_dentry = ecryptfs_dentry_to_lower(dentry);
        if (!lower_dentry->d_inode->i_op->getxattr) {
                rc = -ENOSYS;
                goto out;
@@ -1006,6 +954,14 @@ out:
        return rc;
 }
 
+ssize_t
+ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
+                 size_t size)
+{
+       return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
+                                      value, size);
+}
+
 static ssize_t
 ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
 {