On 07/02/2011 02:33 AM, Amir Goldstein wrote:
On Fri, Jul 1, 2011 at 12:22 AM, Allison Henderson <achender@xxxxxxxxxxxxxxxxxx> wrote:The first patch adds a new flag, EXT4_FREE_BLOCKS_ZERO, to ext4_free_blocks. This flag causes causes blocks to be zerod before they are freed. Files that have the EXT4_SECRM_FL attribute flag on will have their blocks zerod when they are released. The EXT4_SECRM_FL attribute flag can be enabled useing chattr +s Signed-off-by: Allison Henderson<achender@xxxxxxxxxxxxxxxxxx> --- v1->v2 Removed check for discard mount option and replaced with check for secure discard and discard_zeroes_data Added BLKDEV_DISCARD_SECURE to the sb_issue_discard call v2->v3 Removed code for discard. A seperate patch will be done to add that code in the block layer :100644 100644 1921392... 38a4d75... M fs/ext4/ext4.h :100644 100644 f815cc8... cf178f3... M fs/ext4/extents.c :100644 100644 62f86e7... 8fdae7d... M fs/ext4/inode.c :100644 100644 6ed859d... 94872b2... M fs/ext4/mballoc.c :100644 100644 c757adc... 1ff7532... M fs/ext4/xattr.c fs/ext4/ext4.h | 1 + fs/ext4/extents.c | 3 +++ fs/ext4/inode.c | 3 +++ fs/ext4/mballoc.c | 8 ++++++++ fs/ext4/xattr.c | 12 ++++++++---- 5 files changed, 23 insertions(+), 4 deletions(-) diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 1921392..38a4d75 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -526,6 +526,7 @@ struct ext4_new_group_data { #define EXT4_FREE_BLOCKS_METADATA 0x0001 #define EXT4_FREE_BLOCKS_FORGET 0x0002 #define EXT4_FREE_BLOCKS_VALIDATED 0x0004 +#define EXT4_FREE_BLOCKS_ZERO 0x0008 /* * ioctl commands diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index f815cc8..cf178f3 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -2231,6 +2231,9 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode, if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) flags |= EXT4_FREE_BLOCKS_METADATA; + + if (EXT4_I(inode)->i_flags& EXT4_SECRM_FL) + flags |= EXT4_FREE_BLOCKS_ZERO; #ifdef EXTENTS_STATS { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 62f86e7..8fdae7d 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4182,6 +4182,9 @@ static int ext4_clear_blocks(handle_t *handle, struct inode *inode, for (p = first; p< last; p++) *p = 0; + if (EXT4_I(inode)->i_flags& EXT4_SECRM_FL) + flags |= EXT4_FREE_BLOCKS_ZERO; + ext4_free_blocks(handle, inode, NULL, block_to_free, count, flags); return 0; out_err: diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 6ed859d..94872b2 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4485,6 +4485,14 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode, ext4_debug("freeing block %llu\n", block); trace_ext4_free_blocks(inode, block, count, flags); + if (flags& EXT4_FREE_BLOCKS_ZERO) { + err = sb_issue_zeroout(inode->i_sb, block, count, GFP_NOFS);But the delete of these blocks in not yet committed, so after reboot, you can end up with a non-deleted but zeroed file data. Is that acceptable? I should think not. One way around this is a 2-phase unlink/truncate. Phase 1: add to orphan list and register a callback on commit Phase 2: issue zeroout and free the blocks This won't work for punch hole, but then again, for punch hole it's probably OK to end up with zeroed data, but non-deleted blocks. Right? Amir.
Hi, I had a quick question about the orphan list. I notice that ext4_ext_truncate and also ext4_ext_punch_hole already have a call to ext4_orphan_add that happens really early before any calls to free blocks. Does this address your earlier concerns, or is there another reason I missed? Thx!
Allison Henderson
+ if (err< 0) + goto error_return; + else + err = 0; + } + if (flags& EXT4_FREE_BLOCKS_FORGET) { struct buffer_head *tbh = bh; int i; diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index c757adc..1ff7532 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -471,7 +471,7 @@ ext4_xattr_release_block(handle_t *handle, struct inode *inode, struct buffer_head *bh) { struct mb_cache_entry *ce = NULL; - int error = 0; + int free_blocks_flags, error = 0; ce = mb_cache_entry_get(ext4_xattr_cache, bh->b_bdev, bh->b_blocknr); error = ext4_journal_get_write_access(handle, bh); @@ -484,9 +484,13 @@ ext4_xattr_release_block(handle_t *handle, struct inode *inode, if (ce) mb_cache_entry_free(ce); get_bh(bh); - ext4_free_blocks(handle, inode, bh, 0, 1, - EXT4_FREE_BLOCKS_METADATA | - EXT4_FREE_BLOCKS_FORGET); + free_blocks_flags = EXT4_FREE_BLOCKS_METADATA | + EXT4_FREE_BLOCKS_FORGET; + + if (EXT4_I(inode)->i_flags& EXT4_SECRM_FL) + free_blocks_flags |= EXT4_FREE_BLOCKS_ZERO; + + ext4_free_blocks(handle, inode, bh, 0, 1, free_blocks_flags); } else { le32_add_cpu(&BHDR(bh)->h_refcount, -1); error = ext4_handle_dirty_metadata(handle, inode, bh); -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html-- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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