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authorTyler Hicks <tyhicks@canonical.com>2012-07-03 16:50:57 -0700
committerTyler Hicks <tyhicks@canonical.com>2012-07-13 16:46:06 -0700
commit821f7494a77627fb1ab539591c57b22cdca702d6 (patch)
tree561ee1768e62c120766c40c0b8fc8aa30b4f4a95 /fs/ecryptfs
parente3ccaa9761200952cc269b1f4b7d7bb77a5e071b (diff)
downloadlinux-821f7494a77627fb1ab539591c57b22cdca702d6.tar.gz
eCryptfs: Revert to a writethrough cache model
A change was made about a year ago to get eCryptfs to better utilize its page cache during writes. The idea was to do the page encryption operations during page writeback, rather than doing them when initially writing into the page cache, to reduce the number of page encryption operations during sequential writes. This meant that the encrypted page would only be written to the lower filesystem during page writeback, which was a change from how eCryptfs had previously wrote to the lower filesystem in ecryptfs_write_end(). The change caused a few eCryptfs-internal bugs that were shook out. Unfortunately, more grave side effects have been identified that will force changes outside of eCryptfs. Because the lower filesystem isn't consulted until page writeback, eCryptfs has no way to pass lower write errors (ENOSPC, mainly) back to userspace. Additionaly, it was reported that quotas could be bypassed because of the way eCryptfs may sometimes open the lower filesystem using a privileged kthread. It would be nice to resolve the latest issues, but it is best if the eCryptfs commits be reverted to the old behavior in the meantime. This reverts: 32001d6f "eCryptfs: Flush file in vma close" 5be79de2 "eCryptfs: Flush dirty pages in setattr" 57db4e8d "ecryptfs: modify write path to encrypt page in writepage" Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Tested-by: Colin King <colin.king@canonical.com> Cc: Colin King <colin.king@canonical.com> Cc: Thieu Le <thieule@google.com>
Diffstat (limited to 'fs/ecryptfs')
-rw-r--r--fs/ecryptfs/file.c33
-rw-r--r--fs/ecryptfs/inode.c6
-rw-r--r--fs/ecryptfs/mmap.c39
3 files changed, 15 insertions, 63 deletions
diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index baf8b055039..44ce5c6a541 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -138,27 +138,6 @@ out:
return rc;
}
-static void ecryptfs_vma_close(struct vm_area_struct *vma)
-{
- filemap_write_and_wait(vma->vm_file->f_mapping);
-}
-
-static const struct vm_operations_struct ecryptfs_file_vm_ops = {
- .close = ecryptfs_vma_close,
- .fault = filemap_fault,
-};
-
-static int ecryptfs_file_mmap(struct file *file, struct vm_area_struct *vma)
-{
- int rc;
-
- rc = generic_file_mmap(file, vma);
- if (!rc)
- vma->vm_ops = &ecryptfs_file_vm_ops;
-
- return rc;
-}
-
struct kmem_cache *ecryptfs_file_info_cache;
static int read_or_initialize_metadata(struct dentry *dentry)
@@ -311,15 +290,7 @@ static int ecryptfs_release(struct inode *inode, struct file *file)
static int
ecryptfs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
{
- int rc = 0;
-
- rc = generic_file_fsync(file, start, end, datasync);
- if (rc)
- goto out;
- rc = vfs_fsync_range(ecryptfs_file_to_lower(file), start, end,
- datasync);
-out:
- return rc;
+ return vfs_fsync(ecryptfs_file_to_lower(file), datasync);
}
static int ecryptfs_fasync(int fd, struct file *file, int flag)
@@ -388,7 +359,7 @@ const struct file_operations ecryptfs_main_fops = {
#ifdef CONFIG_COMPAT
.compat_ioctl = ecryptfs_compat_ioctl,
#endif
- .mmap = ecryptfs_file_mmap,
+ .mmap = generic_file_mmap,
.open = ecryptfs_open,
.flush = ecryptfs_flush,
.release = ecryptfs_release,
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 2d4143f8f5c..769fb8524ae 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -981,12 +981,6 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
goto out;
}
- if (S_ISREG(inode->i_mode)) {
- rc = filemap_write_and_wait(inode->i_mapping);
- if (rc)
- goto out;
- fsstack_copy_attr_all(inode, lower_inode);
- }
memcpy(&lower_ia, ia, sizeof(lower_ia));
if (ia->ia_valid & ATTR_FILE)
lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index a46b3a8fee1..bd1d57f98f7 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -66,18 +66,6 @@ static int ecryptfs_writepage(struct page *page, struct writeback_control *wbc)
{
int rc;
- /*
- * Refuse to write the page out if we are called from reclaim context
- * since our writepage() path may potentially allocate memory when
- * calling into the lower fs vfs_write() which may in turn invoke
- * us again.
- */
- if (current->flags & PF_MEMALLOC) {
- redirty_page_for_writepage(wbc, page);
- rc = 0;
- goto out;
- }
-
rc = ecryptfs_encrypt_page(page);
if (rc) {
ecryptfs_printk(KERN_WARNING, "Error encrypting "
@@ -498,7 +486,6 @@ static int ecryptfs_write_end(struct file *file,
struct ecryptfs_crypt_stat *crypt_stat =
&ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
int rc;
- int need_unlock_page = 1;
ecryptfs_printk(KERN_DEBUG, "Calling fill_zeros_to_end_of_page"
"(page w/ index = [0x%.16lx], to = [%d])\n", index, to);
@@ -519,26 +506,26 @@ static int ecryptfs_write_end(struct file *file,
"zeros in page with index = [0x%.16lx]\n", index);
goto out;
}
- set_page_dirty(page);
- unlock_page(page);
- need_unlock_page = 0;
+ rc = ecryptfs_encrypt_page(page);
+ if (rc) {
+ ecryptfs_printk(KERN_WARNING, "Error encrypting page (upper "
+ "index [0x%.16lx])\n", index);
+ goto out;
+ }
if (pos + copied > i_size_read(ecryptfs_inode)) {
i_size_write(ecryptfs_inode, pos + copied);
ecryptfs_printk(KERN_DEBUG, "Expanded file size to "
"[0x%.16llx]\n",
(unsigned long long)i_size_read(ecryptfs_inode));
- balance_dirty_pages_ratelimited(mapping);
- rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode);
- if (rc) {
- printk(KERN_ERR "Error writing inode size to metadata; "
- "rc = [%d]\n", rc);
- goto out;
- }
}
- rc = copied;
+ rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode);
+ if (rc)
+ printk(KERN_ERR "Error writing inode size to metadata; "
+ "rc = [%d]\n", rc);
+ else
+ rc = copied;
out:
- if (need_unlock_page)
- unlock_page(page);
+ unlock_page(page);
page_cache_release(page);
return rc;
}