eCryptfs: make open, truncate, and setattr use persistent file
Rather than open a new lower file for every eCryptfs file that is opened,
truncated, or setattr'd, instead use the existing lower persistent file for
the eCryptfs inode. Change truncate to use read_write.c functions. Change
ecryptfs_getxattr() to use the common ecryptfs_getxattr_lower() function.
Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index a29dc31..5701f81 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -739,8 +739,7 @@
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;
@@ -763,51 +762,43 @@
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);
- rc = ecryptfs_open_lower_file(&lower_file, lower_dentry, lower_mnt,
- O_RDWR);
- if (rc) {
- 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(inode);
- if (rc) {
- printk(KERN_ERR "Problem with "
- "ecryptfs_write_inode_size_to_metadata; "
- "rc = [%d]\n", rc);
- goto out_fput;
- }
- } else { /* new_length < i_size_read(inode) */
- pgoff_t index = 0;
- int end_pos_in_page = -1;
+ char zero[] = { 0x00 };
- 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)) {
- rc = ecryptfs_write_zeros(&fake_ecryptfs_file,
- index,
- (end_pos_in_page + 1),
- ((PAGE_CACHE_SIZE - 1)
- - end_pos_in_page));
+ /* 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
+ * PAGE_CACHE_SIZE with zeros. */
+ size_t num_zeros = (PAGE_CACHE_SIZE
+ - (new_length & ~PAGE_CACHE_MASK));
+
+ 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);
@@ -816,7 +807,7 @@
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. */
@@ -828,14 +819,6 @@
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:
- rc = ecryptfs_close_lower_file(lower_file);
- if (rc)
- 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,
@@ -895,21 +878,8 @@
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;
- rc = ecryptfs_open_lower_file(&lower_file, lower_dentry,
- lower_mnt, lower_flags);
- if (rc) {
- 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;
rc = ecryptfs_read_metadata(dentry);
@@ -923,16 +893,13 @@
"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) {
@@ -995,20 +962,8 @@
ecryptfs_getxattr(struct dentry *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;
- }
- mutex_lock(&lower_dentry->d_inode->i_mutex);
- rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
- size);
- mutex_unlock(&lower_dentry->d_inode->i_mutex);
-out:
- return rc;
+ return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
+ value, size);
}
static ssize_t