| Message ID | 1393355679-11160-2-git-send-email-lczerner@redhat.com |
|---|---|
| State | Superseded, archived |
| Headers | show |
On Tue, Feb 25, 2014 at 08:14:34PM +0100, Lukas Czerner wrote: > Currently in ext4_fallocate we would update inode size, c_time and sync > the file with every partial allocation which is entirely unnecessary. It > is true that if the crash happens in the middle of truncate we might end > up with unchanged i size, or c_time which I do not think is really a > problem - it does not mean file system corruption in any way. Note that > xfs is doing things the same way e.g. update all of the mentioned after > the allocation is done. > > This commit moves all the updates after the allocation is done. In > addition we also need to change m_time as not only inode has been change > bot also data regions might have changed (unwritten extents). However > m_time will be only updated when i_size changed. > > Also we do not need to be paranoid about changing the c_time only if the > actual allocation have happened, we can change it even if we try to > allocate only to find out that there are already block allocated. It's > not really a big deal and it will save us some additional complexity. > > Also use ext4_debug, instead of ext4_warning in #ifdef EXT4FS_DEBUG > section. > > Signed-off-by: Lukas Czerner <lczerner@redhat.com> Thanks, applied. - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Feb 25, 2014 at 08:14:34PM +0100, Lukas Czerner wrote: > Currently in ext4_fallocate we would update inode size, c_time and sync > the file with every partial allocation which is entirely unnecessary. It > is true that if the crash happens in the middle of truncate we might end > up with unchanged i size, or c_time which I do not think is really a > problem - it does not mean file system corruption in any way. Note that > xfs is doing things the same way e.g. update all of the mentioned after > the allocation is done. > > This commit moves all the updates after the allocation is done. In > addition we also need to change m_time as not only inode has been change > bot also data regions might have changed (unwritten extents). However > m_time will be only updated when i_size changed. > > Also we do not need to be paranoid about changing the c_time only if the > actual allocation have happened, we can change it even if we try to > allocate only to find out that there are already block allocated. It's > not really a big deal and it will save us some additional complexity. > > Also use ext4_debug, instead of ext4_warning in #ifdef EXT4FS_DEBUG > section. > > Signed-off-by: Lukas Czerner <lczerner@redhat.com> Further testing has shown that this patch (applied on top of the ext4 dev branch) is causing a regression failure of xfstests shared/243. Could you take a look? - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sun, 16 Mar 2014, tytso@mit.edu wrote: > Date: Sun, 16 Mar 2014 23:02:01 -0400 > From: tytso@mit.edu > To: Lukas Czerner <lczerner@redhat.com> > Cc: linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, xfs@oss.sgi.com > Subject: Re: [PATCH 1/6 v2] ext4: Update inode i_size after the preallocation > > On Tue, Feb 25, 2014 at 08:14:34PM +0100, Lukas Czerner wrote: > > Currently in ext4_fallocate we would update inode size, c_time and sync > > the file with every partial allocation which is entirely unnecessary. It > > is true that if the crash happens in the middle of truncate we might end > > up with unchanged i size, or c_time which I do not think is really a > > problem - it does not mean file system corruption in any way. Note that > > xfs is doing things the same way e.g. update all of the mentioned after > > the allocation is done. > > > > This commit moves all the updates after the allocation is done. In > > addition we also need to change m_time as not only inode has been change > > bot also data regions might have changed (unwritten extents). However > > m_time will be only updated when i_size changed. > > > > Also we do not need to be paranoid about changing the c_time only if the > > actual allocation have happened, we can change it even if we try to > > allocate only to find out that there are already block allocated. It's > > not really a big deal and it will save us some additional complexity. > > > > Also use ext4_debug, instead of ext4_warning in #ifdef EXT4FS_DEBUG > > section. > > > > Signed-off-by: Lukas Czerner <lczerner@redhat.com> > > Further testing has shown that this patch (applied on top of the ext4 > dev branch) is causing a regression failure of xfstests shared/243. > > Could you take a look? > > - Ted Hi Ted, I am looking into this. Thanks! -Lukas -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 10cff47..67c7917 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4513,36 +4513,6 @@ retry: ext4_std_error(inode->i_sb, err); } -static void ext4_falloc_update_inode(struct inode *inode, - int mode, loff_t new_size, int update_ctime) -{ - struct timespec now; - - if (update_ctime) { - now = current_fs_time(inode->i_sb); - if (!timespec_equal(&inode->i_ctime, &now)) - inode->i_ctime = now; - } - /* - * Update only when preallocation was requested beyond - * the file size. - */ - if (!(mode & FALLOC_FL_KEEP_SIZE)) { - if (new_size > i_size_read(inode)) - i_size_write(inode, new_size); - if (new_size > EXT4_I(inode)->i_disksize) - ext4_update_i_disksize(inode, new_size); - } else { - /* - * Mark that we allocate beyond EOF so the subsequent truncate - * can proceed even if the new size is the same as i_size. - */ - if (new_size > i_size_read(inode)) - ext4_set_inode_flag(inode, EXT4_INODE_EOFBLOCKS); - } - -} - /* * preallocate space for a file. This implements ext4's fallocate file * operation, which gets called from sys_fallocate system call. @@ -4554,13 +4524,14 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) { struct inode *inode = file_inode(file); handle_t *handle; - loff_t new_size; + loff_t new_size = 0; unsigned int max_blocks; int ret = 0; int ret2 = 0; int retries = 0; int flags; struct ext4_map_blocks map; + struct timespec tv; unsigned int credits, blkbits = inode->i_blkbits; /* Return error if mode is not supported */ @@ -4594,12 +4565,15 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) */ credits = ext4_chunk_trans_blocks(inode, max_blocks); mutex_lock(&inode->i_mutex); - ret = inode_newsize_ok(inode, (len + offset)); - if (ret) { - mutex_unlock(&inode->i_mutex); - trace_ext4_fallocate_exit(inode, offset, max_blocks, ret); - return ret; + + if (!(mode & FALLOC_FL_KEEP_SIZE) && + offset + len > i_size_read(inode)) { + new_size = offset + len; + ret = inode_newsize_ok(inode, new_size); + if (ret) + goto out; } + flags = EXT4_GET_BLOCKS_CREATE_UNINIT_EXT; if (mode & FALLOC_FL_KEEP_SIZE) flags |= EXT4_GET_BLOCKS_KEEP_SIZE; @@ -4623,28 +4597,14 @@ retry: } ret = ext4_map_blocks(handle, inode, &map, flags); if (ret <= 0) { -#ifdef EXT4FS_DEBUG - ext4_warning(inode->i_sb, - "inode #%lu: block %u: len %u: " - "ext4_ext_map_blocks returned %d", - inode->i_ino, map.m_lblk, - map.m_len, ret); -#endif + ext4_debug("inode #%lu: block %u: len %u: " + "ext4_ext_map_blocks returned %d", + inode->i_ino, map.m_lblk, + map.m_len, ret); ext4_mark_inode_dirty(handle, inode); ret2 = ext4_journal_stop(handle); break; } - if ((map.m_lblk + ret) >= (EXT4_BLOCK_ALIGN(offset + len, - blkbits) >> blkbits)) - new_size = offset + len; - else - new_size = ((loff_t) map.m_lblk + ret) << blkbits; - - ext4_falloc_update_inode(inode, mode, new_size, - (map.m_flags & EXT4_MAP_NEW)); - ext4_mark_inode_dirty(handle, inode); - if ((file->f_flags & O_SYNC) && ret >= max_blocks) - ext4_handle_sync(handle); ret2 = ext4_journal_stop(handle); if (ret2) break; @@ -4654,6 +4614,27 @@ retry: ret = 0; goto retry; } + + handle = ext4_journal_start(inode, EXT4_HT_INODE, 2); + if (IS_ERR(handle)) + goto out; + + tv = inode->i_ctime = ext4_current_time(inode); + + if (ret > 0 && new_size) { + if (new_size > i_size_read(inode)) { + i_size_write(inode, new_size); + inode->i_mtime = tv; + } + if (new_size > EXT4_I(inode)->i_disksize) + ext4_update_i_disksize(inode, new_size); + } + ext4_mark_inode_dirty(handle, inode); + if (file->f_flags & O_SYNC) + ext4_handle_sync(handle); + + ext4_journal_stop(handle); +out: mutex_unlock(&inode->i_mutex); trace_ext4_fallocate_exit(inode, offset, max_blocks, ret > 0 ? ret2 : ret);
Currently in ext4_fallocate we would update inode size, c_time and sync the file with every partial allocation which is entirely unnecessary. It is true that if the crash happens in the middle of truncate we might end up with unchanged i size, or c_time which I do not think is really a problem - it does not mean file system corruption in any way. Note that xfs is doing things the same way e.g. update all of the mentioned after the allocation is done. This commit moves all the updates after the allocation is done. In addition we also need to change m_time as not only inode has been change bot also data regions might have changed (unwritten extents). However m_time will be only updated when i_size changed. Also we do not need to be paranoid about changing the c_time only if the actual allocation have happened, we can change it even if we try to allocate only to find out that there are already block allocated. It's not really a big deal and it will save us some additional complexity. Also use ext4_debug, instead of ext4_warning in #ifdef EXT4FS_DEBUG section. Signed-off-by: Lukas Czerner <lczerner@redhat.com> --- fs/ext4/extents.c | 89 ++++++++++++++++++++++--------------------------------- 1 file changed, 35 insertions(+), 54 deletions(-)