On Thu Feb 24, 2011 at 01:17:51PM -0800, Thieu Le <[email protected]> wrote:
> Hi Tyler,
> 
> Sorry for the delay, got sidetracked with some other work.  I've addressed the
> dd hang and the low memory condition as discussed in IRC.
> 
> PTAL.
> 
> Thanks,
> Thieu

Hey Thieu - Not a problem.

I'll need a proper commit message and signed-off-by line before I can
commit this.

> 
> ---
>  fs/ecryptfs/ecryptfs_kernel.h |    1 -
>  fs/ecryptfs/file.c            |    9 +++++++-
>  fs/ecryptfs/main.c            |    2 -
>  fs/ecryptfs/mmap.c            |   46 ++++++++++++++++++++++++++++------------
>  fs/ecryptfs/read_write.c      |   12 +---------
>  fs/ecryptfs/super.c           |    1 -
>  6 files changed, 42 insertions(+), 29 deletions(-)
> 
> diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
> index dbc84ed..13517ac 100644
> --- a/fs/ecryptfs/ecryptfs_kernel.h
> +++ b/fs/ecryptfs/ecryptfs_kernel.h
> @@ -297,7 +297,6 @@ struct ecryptfs_inode_info {
>       struct inode vfs_inode;
>       struct inode *wii_inode;
>       struct file *lower_file;
> -     struct mutex lower_file_mutex;
>       struct ecryptfs_crypt_stat crypt_stat;
>  };
> 
> diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
> index 81e10e6..9f7ce63 100644
> --- a/fs/ecryptfs/file.c
> +++ b/fs/ecryptfs/file.c
> @@ -273,7 +273,14 @@ static int ecryptfs_release(struct inode *inode, struct 
> file *file)
>  static int
>  ecryptfs_fsync(struct file *file, int datasync)
>  {
> -     return vfs_fsync(ecryptfs_file_to_lower(file), datasync);
> +     int rc = 0;
> +
> +     rc = generic_file_fsync(file, datasync);
> +     if (rc)
> +             goto out;
> +     rc = vfs_fsync(ecryptfs_file_to_lower(file), datasync);
> +out:
> +     return rc;
>  }
> 
>  static int ecryptfs_fasync(int fd, struct file *file, int flag)
> diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
> index 758323a..63e412c 100644
> --- a/fs/ecryptfs/main.c
> +++ b/fs/ecryptfs/main.c
> @@ -122,7 +122,6 @@ int ecryptfs_init_persistent_file(struct dentry 
> *ecryptfs_dentry)
>               ecryptfs_inode_to_private(ecryptfs_dentry->d_inode);
>       int rc = 0;
> 
> -     mutex_lock(&inode_info->lower_file_mutex);
>       if (!inode_info->lower_file) {
>               struct dentry *lower_dentry;
>               struct vfsmount *lower_mnt =
> @@ -138,7 +137,6 @@ int ecryptfs_init_persistent_file(struct dentry 
> *ecryptfs_dentry)
>                       inode_info->lower_file = NULL;
>               }
>       }
> -     mutex_unlock(&inode_info->lower_file_mutex);
>       return rc;
>  }
> 
> diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
> index cc64fca..d375210 100644
> --- a/fs/ecryptfs/mmap.c
> +++ b/fs/ecryptfs/mmap.c
> @@ -62,6 +62,23 @@ 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.
> +      *
> +      * This avoids stack overflows when called from deeply used stacks in
> +      * random callers for direct reclaim or memcg reclaim.  We explicitly
> +      * allow reclaim from kswapd as the stack usage there is relatively low.

Stack size is a problem with eCryptfs, but we also have the issue of
potential memory allocations in our writepage() path due to calling
vfs_write() on the lower file. I don't think we can allow reclaim from
kswapd.

> +      *
> +      * This should really be done by the core VM, but until that happens
> +      * filesystems like XFS, btrfs and ext4 have to take care of this
> +      * by themselves.
> +      */

Please make this entire comment block specific to eCryptfs instead of
something copied from XFS.

> +     if ((current->flags & (PF_MEMALLOC|PF_KSWAPD)) == 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 "
> @@ -70,8 +87,8 @@ static int ecryptfs_writepage(struct page *page, struct 
> writeback_control *wbc)
>               goto out;
>       }
>       SetPageUptodate(page);
> -     unlock_page(page);
>  out:
> +     unlock_page(page);
>       return rc;
>  }
> 
> @@ -486,6 +503,7 @@ 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;
> 
>       if (crypt_stat->flags & ECRYPTFS_NEW_FILE) {
>               ecryptfs_printk(KERN_DEBUG, "ECRYPTFS_NEW_FILE flag set in "
> @@ -512,26 +530,26 @@ static int ecryptfs_write_end(struct file *file,
>                       "zeros in page with index = [0x%.16lx]\n", index);
>               goto out;
>       }
> -     rc = ecryptfs_encrypt_page(page);
> -     if (rc) {
> -             ecryptfs_printk(KERN_WARNING, "Error encrypting page (upper "
> -                             "index [0x%.16lx])\n", index);
> -             goto out;
> -     }
> +     set_page_dirty(page);
> +     unlock_page(page);
> +     need_unlock_page = 0;
>       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 = 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;
> +     rc = copied;
>  out:
> -     unlock_page(page);
> +     if (need_unlock_page)
> +             unlock_page(page);
>       page_cache_release(page);
>       return rc;
>  }
> diff --git a/fs/ecryptfs/read_write.c b/fs/ecryptfs/read_write.c
> index db184ef..85d4309 100644
> --- a/fs/ecryptfs/read_write.c
> +++ b/fs/ecryptfs/read_write.c
> @@ -44,15 +44,11 @@ int ecryptfs_write_lower(struct inode *ecryptfs_inode, 
> char *data,
>       ssize_t rc;
> 
>       inode_info = ecryptfs_inode_to_private(ecryptfs_inode);
> -     mutex_lock(&inode_info->lower_file_mutex);
>       BUG_ON(!inode_info->lower_file);
> -     inode_info->lower_file->f_pos = offset;
>       fs_save = get_fs();
>       set_fs(get_ds());
> -     rc = vfs_write(inode_info->lower_file, data, size,
> -                    &inode_info->lower_file->f_pos);
> +     rc = vfs_write(inode_info->lower_file, data, size, &offset);
>       set_fs(fs_save);
> -     mutex_unlock(&inode_info->lower_file_mutex);
>       mark_inode_dirty_sync(ecryptfs_inode);
>       return rc;
>  }
> @@ -234,15 +230,11 @@ int ecryptfs_read_lower(char *data, loff_t offset, 
> size_t size,
>       mm_segment_t fs_save;
>       ssize_t rc;
> 
> -     mutex_lock(&inode_info->lower_file_mutex);
>       BUG_ON(!inode_info->lower_file);
> -     inode_info->lower_file->f_pos = offset;
>       fs_save = get_fs();
>       set_fs(get_ds());
> -     rc = vfs_read(inode_info->lower_file, data, size,
> -                   &inode_info->lower_file->f_pos);
> +     rc = vfs_read(inode_info->lower_file, data, size, &offset);
>       set_fs(fs_save);
> -     mutex_unlock(&inode_info->lower_file_mutex);
>       return rc;
>  }
> 
> diff --git a/fs/ecryptfs/super.c b/fs/ecryptfs/super.c
> index 3042fe1..15c969e 100644
> --- a/fs/ecryptfs/super.c
> +++ b/fs/ecryptfs/super.c
> @@ -55,7 +55,6 @@ static struct inode *ecryptfs_alloc_inode(struct 
> super_block *sb)
>       if (unlikely(!inode_info))
>               goto out;
>       ecryptfs_init_crypt_stat(&inode_info->crypt_stat);
> -     mutex_init(&inode_info->lower_file_mutex);
>       inode_info->lower_file = NULL;
>       inode = &inode_info->vfs_inode;
>  out:
> -- 
> 1.7.3.1
> 

_______________________________________________
Mailing list: https://launchpad.net/~ecryptfs-devel
Post to     : [email protected]
Unsubscribe : https://launchpad.net/~ecryptfs-devel
More help   : https://help.launchpad.net/ListHelp

Reply via email to