Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ecryptfs...
[pandora-kernel.git] / fs / ecryptfs / inode.c
index 7f85450..e2d4418 100644 (file)
@@ -31,6 +31,7 @@
 #include <linux/mount.h>
 #include <linux/crypto.h>
 #include <linux/fs_stack.h>
+#include <linux/slab.h>
 #include <asm/unaligned.h>
 #include "ecryptfs_kernel.h"
 
@@ -282,7 +283,8 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
                goto out;
        }
        rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
-                               ecryptfs_dir_inode->i_sb, 1);
+                               ecryptfs_dir_inode->i_sb,
+                               ECRYPTFS_INTERPOSE_FLAG_D_ADD);
        if (rc) {
                printk(KERN_ERR "%s: Error interposing; rc = [%d]\n",
                       __func__, rc);
@@ -322,6 +324,7 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
        rc = ecryptfs_read_and_validate_header_region(page_virt,
                                                      ecryptfs_dentry->d_inode);
        if (rc) {
+               memset(page_virt, 0, PAGE_CACHE_SIZE);
                rc = ecryptfs_read_and_validate_xattr_region(page_virt,
                                                             ecryptfs_dentry);
                if (rc) {
@@ -334,7 +337,7 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
                ecryptfs_dentry->d_sb)->mount_crypt_stat;
        if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
                if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
-                       file_size = (crypt_stat->num_header_bytes_at_front
+                       file_size = (crypt_stat->metadata_size
                                     + i_size_read(lower_dentry->d_inode));
                else
                        file_size = i_size_read(lower_dentry->d_inode);
@@ -386,9 +389,9 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
        mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
        if (IS_ERR(lower_dentry)) {
                rc = PTR_ERR(lower_dentry);
-               printk(KERN_ERR "%s: lookup_one_len() returned [%d] on "
-                      "lower_dentry = [%s]\n", __func__, rc,
-                      ecryptfs_dentry->d_name.name);
+               ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
+                               "[%d] on lower_dentry = [%s]\n", __func__, rc,
+                               encrypted_and_encoded_name);
                goto out_d_drop;
        }
        if (lower_dentry->d_inode)
@@ -415,9 +418,9 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
        mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
        if (IS_ERR(lower_dentry)) {
                rc = PTR_ERR(lower_dentry);
-               printk(KERN_ERR "%s: lookup_one_len() returned [%d] on "
-                      "lower_dentry = [%s]\n", __func__, rc,
-                      encrypted_and_encoded_name);
+               ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
+                               "[%d] on lower_dentry = [%s]\n", __func__, rc,
+                               encrypted_and_encoded_name);
                goto out_d_drop;
        }
 lookup_and_interpose:
@@ -454,8 +457,8 @@ static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
        rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb, 0);
        if (rc)
                goto out_lock;
-       fsstack_copy_attr_times(dir, lower_new_dentry->d_inode);
-       fsstack_copy_inode_size(dir, lower_new_dentry->d_inode);
+       fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
+       fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
        old_dentry->d_inode->i_nlink =
                ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink;
        i_size_write(new_dentry->d_inode, file_size_save);
@@ -463,9 +466,6 @@ out_lock:
        unlock_dir(lower_dir_dentry);
        dput(lower_new_dentry);
        dput(lower_old_dentry);
-       d_drop(lower_old_dentry);
-       d_drop(new_dentry);
-       d_drop(old_dentry);
        return rc;
 }
 
@@ -614,6 +614,7 @@ ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
        struct dentry *lower_new_dentry;
        struct dentry *lower_old_dir_dentry;
        struct dentry *lower_new_dir_dentry;
+       struct dentry *trap = NULL;
 
        lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
        lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
@@ -621,7 +622,17 @@ ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
        dget(lower_new_dentry);
        lower_old_dir_dentry = dget_parent(lower_old_dentry);
        lower_new_dir_dentry = dget_parent(lower_new_dentry);
-       lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
+       trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
+       /* source should not be ancestor of target */
+       if (trap == lower_old_dentry) {
+               rc = -EINVAL;
+               goto out_lock;
+       }
+       /* target should not be ancestor of source */
+       if (trap == lower_new_dentry) {
+               rc = -ENOTEMPTY;
+               goto out_lock;
+       }
        rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
                        lower_new_dir_dentry->d_inode, lower_new_dentry);
        if (rc)
@@ -638,38 +649,17 @@ out_lock:
        return rc;
 }
 
-static int
-ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
+static int ecryptfs_readlink_lower(struct dentry *dentry, char **buf,
+                                  size_t *bufsiz)
 {
+       struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
        char *lower_buf;
-       size_t lower_bufsiz;
-       struct dentry *lower_dentry;
-       struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
-       char *plaintext_name;
-       size_t plaintext_name_size;
+       size_t lower_bufsiz = PATH_MAX;
        mm_segment_t old_fs;
        int rc;
 
-       lower_dentry = ecryptfs_dentry_to_lower(dentry);
-       if (!lower_dentry->d_inode->i_op->readlink) {
-               rc = -EINVAL;
-               goto out;
-       }
-       mount_crypt_stat = &ecryptfs_superblock_to_private(
-                                               dentry->d_sb)->mount_crypt_stat;
-       /*
-        * If the lower filename is encrypted, it will result in a significantly
-        * longer name.  If needed, truncate the name after decode and decrypt.
-        */
-       if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
-               lower_bufsiz = PATH_MAX;
-       else
-               lower_bufsiz = bufsiz;
-       /* Released in this function */
        lower_buf = kmalloc(lower_bufsiz, GFP_KERNEL);
-       if (lower_buf == NULL) {
-               printk(KERN_ERR "%s: Out of memory whilst attempting to "
-                      "kmalloc [%zd] bytes\n", __func__, lower_bufsiz);
+       if (!lower_buf) {
                rc = -ENOMEM;
                goto out;
        }
@@ -679,29 +669,31 @@ ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
                                                   (char __user *)lower_buf,
                                                   lower_bufsiz);
        set_fs(old_fs);
-       if (rc >= 0) {
-               rc = ecryptfs_decode_and_decrypt_filename(&plaintext_name,
-                                                         &plaintext_name_size,
-                                                         dentry, lower_buf,
-                                                         rc);
-               if (rc) {
-                       printk(KERN_ERR "%s: Error attempting to decode and "
-                              "decrypt filename; rc = [%d]\n", __func__,
-                               rc);
-                       goto out_free_lower_buf;
-               }
-               /* Check for bufsiz <= 0 done in sys_readlinkat() */
-               rc = copy_to_user(buf, plaintext_name,
-                                 min((size_t) bufsiz, plaintext_name_size));
-               if (rc)
-                       rc = -EFAULT;
-               else
-                       rc = plaintext_name_size;
-               kfree(plaintext_name);
-               fsstack_copy_attr_atime(dentry->d_inode, lower_dentry->d_inode);
-       }
-out_free_lower_buf:
+       if (rc < 0)
+               goto out;
+       lower_bufsiz = rc;
+       rc = ecryptfs_decode_and_decrypt_filename(buf, bufsiz, dentry,
+                                                 lower_buf, lower_bufsiz);
+out:
        kfree(lower_buf);
+       return rc;
+}
+
+static int
+ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
+{
+       char *kbuf;
+       size_t kbufsiz, copied;
+       int rc;
+
+       rc = ecryptfs_readlink_lower(dentry, &kbuf, &kbufsiz);
+       if (rc)
+               goto out;
+       copied = min_t(size_t, bufsiz, kbufsiz);
+       rc = copy_to_user(buf, kbuf, copied) ? -EFAULT : copied;
+       kfree(kbuf);
+       fsstack_copy_attr_atime(dentry->d_inode,
+                               ecryptfs_dentry_to_lower(dentry)->d_inode);
 out:
        return rc;
 }
@@ -759,7 +751,7 @@ upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
 {
        loff_t lower_size;
 
-       lower_size = crypt_stat->num_header_bytes_at_front;
+       lower_size = ecryptfs_lower_header_size(crypt_stat);
        if (upper_size != 0) {
                loff_t num_extents;
 
@@ -772,18 +764,23 @@ upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
 }
 
 /**
- * ecryptfs_truncate
+ * truncate_upper
  * @dentry: The ecryptfs layer dentry
- * @new_length: The length to expand the file to
+ * @ia: Address of the ecryptfs inode's attributes
+ * @lower_ia: Address of the lower inode's attributes
  *
  * Function to handle truncations modifying the size of the file. Note
  * that the file sizes are interpolated. When expanding, we are simply
- * writing strings of 0's out. When truncating, we need to modify the
- * underlying file size according to the page index interpolations.
+ * writing strings of 0's out. When truncating, we truncate the upper
+ * inode and update the lower_ia according to the page index
+ * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
+ * the caller must use lower_ia in a call to notify_change() to perform
+ * the truncation of the lower inode.
  *
  * Returns zero on success; non-zero otherwise
  */
-int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
+static int truncate_upper(struct dentry *dentry, struct iattr *ia,
+                         struct iattr *lower_ia)
 {
        int rc = 0;
        struct inode *inode = dentry->d_inode;
@@ -794,8 +791,10 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
        loff_t lower_size_before_truncate;
        loff_t lower_size_after_truncate;
 
-       if (unlikely((new_length == i_size)))
+       if (unlikely((ia->ia_size == i_size))) {
+               lower_ia->ia_valid &= ~ATTR_SIZE;
                goto out;
+       }
        crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
        /* Set up a fake ecryptfs file, this is used to interface with
         * the file in the underlying filesystem so that the
@@ -815,28 +814,30 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
                &fake_ecryptfs_file,
                ecryptfs_inode_to_private(dentry->d_inode)->lower_file);
        /* Switch on growing or shrinking file */
-       if (new_length > i_size) {
+       if (ia->ia_size > i_size) {
                char zero[] = { 0x00 };
 
+               lower_ia->ia_valid &= ~ATTR_SIZE;
                /* 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) */
-               /* 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
+                                   (ia->ia_size - 1), 1);
+       } else { /* ia->ia_size < i_size_read(inode) */
+               /* We're chopping off all the pages down to the page
+                * in which ia->ia_size is located. Fill in the end of
+                * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
                 * PAGE_CACHE_SIZE with zeros. */
                size_t num_zeros = (PAGE_CACHE_SIZE
-                                   - (new_length & ~PAGE_CACHE_MASK));
+                                   - (ia->ia_size & ~PAGE_CACHE_MASK));
 
                if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
-                       rc = vmtruncate(inode, new_length);
+                       rc = vmtruncate(inode, ia->ia_size);
                        if (rc)
                                goto out_free;
-                       rc = vmtruncate(lower_dentry->d_inode, new_length);
+                       lower_ia->ia_size = ia->ia_size;
+                       lower_ia->ia_valid |= ATTR_SIZE;
                        goto out_free;
                }
                if (num_zeros) {
@@ -848,7 +849,7 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
                                goto out_free;
                        }
                        rc = ecryptfs_write(&fake_ecryptfs_file, zeros_virt,
-                                           new_length, num_zeros);
+                                           ia->ia_size, num_zeros);
                        kfree(zeros_virt);
                        if (rc) {
                                printk(KERN_ERR "Error attempting to zero out "
@@ -857,7 +858,7 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
                                goto out_free;
                        }
                }
-               vmtruncate(inode, new_length);
+               vmtruncate(inode, ia->ia_size);
                rc = ecryptfs_write_inode_size_to_metadata(inode);
                if (rc) {
                        printk(KERN_ERR "Problem with "
@@ -870,10 +871,12 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
                lower_size_before_truncate =
                    upper_size_to_lower_size(crypt_stat, i_size);
                lower_size_after_truncate =
-                   upper_size_to_lower_size(crypt_stat, new_length);
-               if (lower_size_after_truncate < lower_size_before_truncate)
-                       vmtruncate(lower_dentry->d_inode,
-                                  lower_size_after_truncate);
+                   upper_size_to_lower_size(crypt_stat, ia->ia_size);
+               if (lower_size_after_truncate < lower_size_before_truncate) {
+                       lower_ia->ia_size = lower_size_after_truncate;
+                       lower_ia->ia_valid |= ATTR_SIZE;
+               } else
+                       lower_ia->ia_valid &= ~ATTR_SIZE;
        }
 out_free:
        if (ecryptfs_file_to_private(&fake_ecryptfs_file))
@@ -883,6 +886,33 @@ out:
        return rc;
 }
 
+/**
+ * ecryptfs_truncate
+ * @dentry: The ecryptfs layer dentry
+ * @new_length: The length to expand the file to
+ *
+ * Simple function that handles the truncation of an eCryptfs inode and
+ * its corresponding lower inode.
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
+{
+       struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
+       struct iattr lower_ia = { .ia_valid = 0 };
+       int rc;
+
+       rc = truncate_upper(dentry, &ia, &lower_ia);
+       if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
+               struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
+
+               mutex_lock(&lower_dentry->d_inode->i_mutex);
+               rc = notify_change(lower_dentry, &lower_ia);
+               mutex_unlock(&lower_dentry->d_inode->i_mutex);
+       }
+       return rc;
+}
+
 static int
 ecryptfs_permission(struct inode *inode, int mask)
 {
@@ -905,6 +935,7 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
 {
        int rc = 0;
        struct dentry *lower_dentry;
+       struct iattr lower_ia;
        struct inode *inode;
        struct inode *lower_inode;
        struct ecryptfs_crypt_stat *crypt_stat;
@@ -943,15 +974,11 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
                }
        }
        mutex_unlock(&crypt_stat->cs_mutex);
+       memcpy(&lower_ia, ia, sizeof(lower_ia));
+       if (ia->ia_valid & ATTR_FILE)
+               lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
        if (ia->ia_valid & ATTR_SIZE) {
-               ecryptfs_printk(KERN_DEBUG,
-                               "ia->ia_valid = [0x%x] ATTR_SIZE" " = [0x%x]\n",
-                               ia->ia_valid, ATTR_SIZE);
-               rc = ecryptfs_truncate(dentry, ia->ia_size);
-               /* ecryptfs_truncate handles resizing of the lower file */
-               ia->ia_valid &= ~ATTR_SIZE;
-               ecryptfs_printk(KERN_DEBUG, "ia->ia_valid = [%x]\n",
-                               ia->ia_valid);
+               rc = truncate_upper(dentry, ia, &lower_ia);
                if (rc < 0)
                        goto out;
        }
@@ -960,17 +987,54 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
         * 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;
+       if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
+               lower_ia.ia_valid &= ~ATTR_MODE;
 
        mutex_lock(&lower_dentry->d_inode->i_mutex);
-       rc = notify_change(lower_dentry, ia);
+       rc = notify_change(lower_dentry, &lower_ia);
        mutex_unlock(&lower_dentry->d_inode->i_mutex);
 out:
        fsstack_copy_attr_all(inode, lower_inode);
        return rc;
 }
 
+int ecryptfs_getattr_link(struct vfsmount *mnt, struct dentry *dentry,
+                         struct kstat *stat)
+{
+       struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
+       int rc = 0;
+
+       mount_crypt_stat = &ecryptfs_superblock_to_private(
+                                               dentry->d_sb)->mount_crypt_stat;
+       generic_fillattr(dentry->d_inode, stat);
+       if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
+               char *target;
+               size_t targetsiz;
+
+               rc = ecryptfs_readlink_lower(dentry, &target, &targetsiz);
+               if (!rc) {
+                       kfree(target);
+                       stat->size = targetsiz;
+               }
+       }
+       return rc;
+}
+
+int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
+                    struct kstat *stat)
+{
+       struct kstat lower_stat;
+       int rc;
+
+       rc = vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry),
+                        ecryptfs_dentry_to_lower(dentry), &lower_stat);
+       if (!rc) {
+               generic_fillattr(dentry->d_inode, stat);
+               stat->blocks = lower_stat.blocks;
+       }
+       return rc;
+}
+
 int
 ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
                  size_t size, int flags)
@@ -980,7 +1044,7 @@ ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
 
        lower_dentry = ecryptfs_dentry_to_lower(dentry);
        if (!lower_dentry->d_inode->i_op->setxattr) {
-               rc = -ENOSYS;
+               rc = -EOPNOTSUPP;
                goto out;
        }
        mutex_lock(&lower_dentry->d_inode->i_mutex);
@@ -998,7 +1062,7 @@ ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
        int rc = 0;
 
        if (!lower_dentry->d_inode->i_op->getxattr) {
-               rc = -ENOSYS;
+               rc = -EOPNOTSUPP;
                goto out;
        }
        mutex_lock(&lower_dentry->d_inode->i_mutex);
@@ -1025,7 +1089,7 @@ ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
 
        lower_dentry = ecryptfs_dentry_to_lower(dentry);
        if (!lower_dentry->d_inode->i_op->listxattr) {
-               rc = -ENOSYS;
+               rc = -EOPNOTSUPP;
                goto out;
        }
        mutex_lock(&lower_dentry->d_inode->i_mutex);
@@ -1042,7 +1106,7 @@ static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
 
        lower_dentry = ecryptfs_dentry_to_lower(dentry);
        if (!lower_dentry->d_inode->i_op->removexattr) {
-               rc = -ENOSYS;
+               rc = -EOPNOTSUPP;
                goto out;
        }
        mutex_lock(&lower_dentry->d_inode->i_mutex);
@@ -1073,6 +1137,7 @@ const struct inode_operations ecryptfs_symlink_iops = {
        .put_link = ecryptfs_put_link,
        .permission = ecryptfs_permission,
        .setattr = ecryptfs_setattr,
+       .getattr = ecryptfs_getattr_link,
        .setxattr = ecryptfs_setxattr,
        .getxattr = ecryptfs_getxattr,
        .listxattr = ecryptfs_listxattr,
@@ -1100,6 +1165,7 @@ const struct inode_operations ecryptfs_dir_iops = {
 const struct inode_operations ecryptfs_main_iops = {
        .permission = ecryptfs_permission,
        .setattr = ecryptfs_setattr,
+       .getattr = ecryptfs_getattr,
        .setxattr = ecryptfs_setxattr,
        .getxattr = ecryptfs_getxattr,
        .listxattr = ecryptfs_listxattr,