On 2012-04-16, at 4:39 AM, Zheng Liu wrote: > Here is v2 for making e2fsprogs support inline data. Now debugfs > supports inline data in read-write mode. Meanwhile e2fsck has > been improved to support inline data feature. > > v1->v2: > * [mke2fs] automatically set EXT_ATTR feature when INLINE_DATA is set > * [debugfs] supports read-write mode As with the previous patch series, there is a need to show some benchmark data that indicates how much improvement this feature provides. Some examples would include percentage of directories stored inline (e.g. in a typical distro installation), performance improvement (e.g. cold-cache filesystem traversal). It is likely that these improvements will be more visible with bigalloc enabled for a large cluster size (e.g. space savings). Without a clear indication of performance improvement, the patch cannot be included due to added complexity and unclear benefits. > In mke2fs, EXT4_FEATURE_INCOMPAT_INLINE_DATA is set to 0x2000 to > consist with kernel. When making a new ext4 file system with > INLINE_DATA feature, mke2fs will check whether EXT_ATTR is set or > not. If it is not set, mke2fs will mark it automatically because > INLINE_DATA depends on it. > > In debugfs, it can support inline data in read-write mode. Now > there is two problems that need to be solved. No matter whether > the size of data is fit into inline data or not, 'write' command > writes the data into disk blocks rather than inode itself. 'mkdir' > command will expand dir to a new disk block when inode->i_block > has full because Tao found a performance regression when a huge > number of dirs are added and removed in EA space. It causes that > the code in kernel might be changed. So now 'mkdir' cmd doesn't > add a new dir entry in EA space. > > TODO list: > * [mke2fs] initialize ROOT dir with inline data flag > * [mke2fs] initialize LOST+FOUND dir with inline data flag Note that it does not make sense to store lost+found inline. It is purposely created with multiple leaf blocks so that blocks do not need to be allocated during e2fsck runs. Probably the same is true for root - it will almost certainly immediately be moved out of the inode due to file creations. Cheers, Andreas > * [debugfs] 'write' cmd writes the data into inode itself > * [debugfs] 'mkdir' cmd add dir entry into EA space > > Regards, > Zheng > > libext2fs: add EXT4_FEATURE_INCOMPAT_INLINE_DATA flag > mke2fs: make it support inline data feature > libext2fs: add inline_data feature > mke2fs: add inline_data feature in mke2fs's manpage > libext2fs: add ext2fs_find_entry_ext_attr function > libext2fs: add EXT4_INLINE_DATA_FL flag for inode > libext2fs: add data structures for inline data feature > libext2fs: add inline_data file > debugfs: make ncheck cmd support inline data > debugfs: make chroot and cd cmd support inline data > debugfs: make ls cmd support inline data > debugfs: make stat cmd support inline data > debufs: make blocks cmd support inline data > debugfs: make filefrag cmd support inline data > debugfs: make link cmd support inline data > debugfs: make unlink cmd support inline data > debugfs: make mkdir cmd support inline data > debugfs: make rmdir cmd support inline data > debugfs: make rm and kill_file cmd support inline data > debugfs: make pwd cmd support inline data > debugfs: make expand_dir cmd support inline data > debugfs: make lsdel cmd support inline data > debugfs: make undel cmd support inline data > debugfs: make dump and cat cmd support inline data > debugfs: make rdump cmd support inline data > debugfs: make dirsearch cmd support inline data > debugfs: make bma cmd support inline data > e2fsck: add three problem descriptions in pass1 > e2fsck: check incorrect inline data flag > e2fsck: make pass1 support inline data > libext2fs: add read/write inline data functions > e2fsck: check inline data in pass2 > > debugfs/debugfs.c | 25 ++- > debugfs/dump.c | 38 +++- > debugfs/filefrag.c | 30 ++- > debugfs/htree.c | 6 + > debugfs/ls.c | 8 +- > debugfs/lsdel.c | 19 +- > debugfs/ncheck.c | 8 +- > e2fsck/pass1.c | 70 ++++- > e2fsck/pass1b.c | 5 +- > e2fsck/pass2.c | 50 +++- > e2fsck/problem.c | 15 + > e2fsck/problem.h | 9 + > lib/e2p/feature.c | 2 + > lib/ext2fs/Makefile.in | 5 + > lib/ext2fs/Makefile.pq | 1 + > lib/ext2fs/bmap.c | 16 + > lib/ext2fs/dblist_dir.c | 8 +- > lib/ext2fs/dirblock.c | 62 ++++ > lib/ext2fs/expanddir.c | 8 +- > lib/ext2fs/ext2_ext_attr.h | 4 + > lib/ext2fs/ext2_fs.h | 9 + > lib/ext2fs/ext2fs.h | 69 ++++- > lib/ext2fs/ext_attr.c | 26 ++ > lib/ext2fs/get_pathname.c | 7 +- > lib/ext2fs/inline_data.c | 715 ++++++++++++++++++++++++++++++++++++++++++++ > lib/ext2fs/link.c | 9 +- > lib/ext2fs/lookup.c | 6 +- > lib/ext2fs/mkdir.c | 4 + > lib/ext2fs/unlink.c | 9 +- > misc/mke2fs.8.in | 3 + > misc/mke2fs.c | 10 +- > 31 files changed, 1197 insertions(+), 59 deletions(-) > -- > 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 Cheers, Andreas -- 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
