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From ed4e8a4bcc0370deeffeae3b5d8fc9feece54ae2 Mon Sep 17 00:00:00 2001
From: Alex Page <[email protected]>
Date: Fri, 31 Jan 2014 21:47:22 -0500
Subject: [PATCH] Implemented F2FS for use on /data
Based on commit 4776c688c705b46925f9c9e1e6daf09692519fcf of Google's
Tegra 3 kernel for the 2012 Nexus 7.
Patches thanks to Now Computing's f2fs-backports repo:
https://github.com/nowcomputing/f2fs-backports/
---
Documentation/filesystems/00-INDEX | 2 +
Documentation/filesystems/f2fs.txt | 502 ++++++++
arch/arm/configs/tegra3_android_defconfig | 3 +
fs/Kconfig | 1 +
fs/Makefile | 1 +
fs/dcache.c | 4 +-
fs/f2fs/Kconfig | 65 +
fs/f2fs/Makefile | 7 +
fs/f2fs/acl.c | 423 +++++++
fs/f2fs/acl.h | 57 +
fs/f2fs/checkpoint.c | 860 +++++++++++++
fs/f2fs/data.c | 790 ++++++++++++
fs/f2fs/debug.c | 353 ++++++
fs/f2fs/dir.c | 714 +++++++++++
fs/f2fs/f2fs.h | 1290 ++++++++++++++++++++
fs/f2fs/file.c | 725 +++++++++++
fs/f2fs/gc.c | 738 ++++++++++++
fs/f2fs/gc.h | 110 ++
fs/f2fs/hash.c | 101 ++
fs/f2fs/inode.c | 273 +++++
fs/f2fs/namei.c | 557 +++++++++
fs/f2fs/node.c | 1859 +++++++++++++++++++++++++++++
fs/f2fs/node.h | 345 ++++++
fs/f2fs/recovery.c | 502 ++++++++
fs/f2fs/segment.c | 1787 +++++++++++++++++++++++++++
fs/f2fs/segment.h | 637 ++++++++++
fs/f2fs/super.c | 1154 ++++++++++++++++++
fs/f2fs/xattr.c | 600 ++++++++++
fs/f2fs/xattr.h | 152 +++
include/linux/dcache.h | 1 +
include/linux/f2fs_fs.h | 424 +++++++
include/linux/fs.h | 13 +
include/linux/magic.h | 1 +
include/linux/security.h | 19 +-
include/linux/xattr.h | 6 +
include/trace/events/f2fs.h | 682 +++++++++++
security/security.c | 33 +
37 files changed, 15788 insertions(+), 3 deletions(-)
create mode 100644 Documentation/filesystems/f2fs.txt
create mode 100644 fs/f2fs/Kconfig
create mode 100644 fs/f2fs/Makefile
create mode 100644 fs/f2fs/acl.c
create mode 100644 fs/f2fs/acl.h
create mode 100644 fs/f2fs/checkpoint.c
create mode 100644 fs/f2fs/data.c
create mode 100644 fs/f2fs/debug.c
create mode 100644 fs/f2fs/dir.c
create mode 100644 fs/f2fs/f2fs.h
create mode 100644 fs/f2fs/file.c
create mode 100644 fs/f2fs/gc.c
create mode 100644 fs/f2fs/gc.h
create mode 100644 fs/f2fs/hash.c
create mode 100644 fs/f2fs/inode.c
create mode 100644 fs/f2fs/namei.c
create mode 100644 fs/f2fs/node.c
create mode 100644 fs/f2fs/node.h
create mode 100644 fs/f2fs/recovery.c
create mode 100644 fs/f2fs/segment.c
create mode 100644 fs/f2fs/segment.h
create mode 100644 fs/f2fs/super.c
create mode 100644 fs/f2fs/xattr.c
create mode 100644 fs/f2fs/xattr.h
create mode 100644 include/linux/f2fs_fs.h
create mode 100644 include/trace/events/f2fs.h
diff --git a/Documentation/filesystems/00-INDEX b/Documentation/filesystems/00-INDEX
index 8c624a1..ce5fd46 100644
--- a/Documentation/filesystems/00-INDEX
+++ b/Documentation/filesystems/00-INDEX
@@ -48,6 +48,8 @@ ext4.txt
- info, mount options and specifications for the Ext4 filesystem.
files.txt
- info on file management in the Linux kernel.
+f2fs.txt
+ - info and mount options for the F2FS filesystem.
fuse.txt
- info on the Filesystem in User SpacE including mount options.
gfs2.txt
diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt
new file mode 100644
index 0000000..d225139
--- /dev/null
+++ b/Documentation/filesystems/f2fs.txt
@@ -0,0 +1,502 @@
+================================================================================
+WHAT IS Flash-Friendly File System (F2FS)?
+================================================================================
+
+NAND flash memory-based storage devices, such as SSD, eMMC, and SD cards, have
+been equipped on a variety systems ranging from mobile to server systems. Since
+they are known to have different characteristics from the conventional rotating
+disks, a file system, an upper layer to the storage device, should adapt to the
+changes from the sketch in the design level.
+
+F2FS is a file system exploiting NAND flash memory-based storage devices, which
+is based on Log-structured File System (LFS). The design has been focused on
+addressing the fundamental issues in LFS, which are snowball effect of wandering
+tree and high cleaning overhead.
+
+Since a NAND flash memory-based storage device shows different characteristic
+according to its internal geometry or flash memory management scheme, namely FTL,
+F2FS and its tools support various parameters not only for configuring on-disk
+layout, but also for selecting allocation and cleaning algorithms.
+
+The following git tree provides the file system formatting tool (mkfs.f2fs),
+a consistency checking tool (fsck.f2fs), and a debugging tool (dump.f2fs).
+>> git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs-tools.git
+
+For reporting bugs and sending patches, please use the following mailing list:
+
+================================================================================
+BACKGROUND AND DESIGN ISSUES
+================================================================================
+
+Log-structured File System (LFS)
+--------------------------------
+"A log-structured file system writes all modifications to disk sequentially in
+a log-like structure, thereby speeding up both file writing and crash recovery.
+The log is the only structure on disk; it contains indexing information so that
+files can be read back from the log efficiently. In order to maintain large free
+areas on disk for fast writing, we divide the log into segments and use a
+segment cleaner to compress the live information from heavily fragmented
+segments." from Rosenblum, M. and Ousterhout, J. K., 1992, "The design and
+implementation of a log-structured file system", ACM Trans. Computer Systems
+10, 1, 26–52.
+
+Wandering Tree Problem
+----------------------
+In LFS, when a file data is updated and written to the end of log, its direct
+pointer block is updated due to the changed location. Then the indirect pointer
+block is also updated due to the direct pointer block update. In this manner,
+the upper index structures such as inode, inode map, and checkpoint block are
+also updated recursively. This problem is called as wandering tree problem [1],
+and in order to enhance the performance, it should eliminate or relax the update
+propagation as much as possible.
+
+[1] Bityutskiy, A. 2005. JFFS3 design issues. http://www.linux-mtd.infradead.org/
+
+Cleaning Overhead
+-----------------
+Since LFS is based on out-of-place writes, it produces so many obsolete blocks
+scattered across the whole storage. In order to serve new empty log space, it
+needs to reclaim these obsolete blocks seamlessly to users. This job is called
+as a cleaning process.
+
+The process consists of three operations as follows.
+1. A victim segment is selected through referencing segment usage table.
+2. It loads parent index structures of all the data in the victim identified by
+ segment summary blocks.
+3. It checks the cross-reference between the data and its parent index structure.
+4. It moves valid data selectively.
+
+This cleaning job may cause unexpected long delays, so the most important goal
+is to hide the latencies to users. And also definitely, it should reduce the
+amount of valid data to be moved, and move them quickly as well.
+
+================================================================================
+KEY FEATURES
+================================================================================
+
+Flash Awareness
+---------------
+- Enlarge the random write area for better performance, but provide the high
+ spatial locality
+- Align FS data structures to the operational units in FTL as best efforts
+
+Wandering Tree Problem
+----------------------
+- Use a term, “node”, that represents inodes as well as various pointer blocks
+- Introduce Node Address Table (NAT) containing the locations of all the “node”
+ blocks; this will cut off the update propagation.
+
+Cleaning Overhead
+-----------------
+- Support a background cleaning process
+- Support greedy and cost-benefit algorithms for victim selection policies
+- Support multi-head logs for static/dynamic hot and cold data separation
+- Introduce adaptive logging for efficient block allocation
+
+================================================================================
+MOUNT OPTIONS
+================================================================================
+
+background_gc=%s Turn on/off cleaning operations, namely garbage
+ collection, triggered in background when I/O subsystem is
+ idle. If background_gc=on, it will turn on the garbage
+ collection and if background_gc=off, garbage collection
+ will be truned off.
+ Default value for this option is on. So garbage
+ collection is on by default.
+disable_roll_forward Disable the roll-forward recovery routine
+discard Issue discard/TRIM commands when a segment is cleaned.
+no_heap Disable heap-style segment allocation which finds free
+ segments for data from the beginning of main area, while
+ for node from the end of main area.
+nouser_xattr Disable Extended User Attributes. Note: xattr is enabled
+ by default if CONFIG_F2FS_FS_XATTR is selected.
+noacl Disable POSIX Access Control List. Note: acl is enabled
+ by default if CONFIG_F2FS_FS_POSIX_ACL is selected.
+active_logs=%u Support configuring the number of active logs. In the
+ current design, f2fs supports only 2, 4, and 6 logs.
+ Default number is 6.
+disable_ext_identify Disable the extension list configured by mkfs, so f2fs
+ does not aware of cold files such as media files.
+inline_xattr Enable the inline xattrs feature.
+
+================================================================================
+DEBUGFS ENTRIES
+================================================================================
+
+/sys/kernel/debug/f2fs/ contains information about all the partitions mounted as
+f2fs. Each file shows the whole f2fs information.
+
+/sys/kernel/debug/f2fs/status includes:
+ - major file system information managed by f2fs currently
+ - average SIT information about whole segments
+ - current memory footprint consumed by f2fs.
+
+================================================================================
+SYSFS ENTRIES
+================================================================================
+
+Information about mounted f2f2 file systems can be found in
+/sys/fs/f2fs. Each mounted filesystem will have a directory in
+/sys/fs/f2fs based on its device name (i.e., /sys/fs/f2fs/sda).
+The files in each per-device directory are shown in table below.
+
+Files in /sys/fs/f2fs/<devname>
+(see also Documentation/ABI/testing/sysfs-fs-f2fs)
+..............................................................................
+ File Content
+
+ gc_max_sleep_time This tuning parameter controls the maximum sleep
+ time for the garbage collection thread. Time is
+ in milliseconds.
+
+ gc_min_sleep_time This tuning parameter controls the minimum sleep
+ time for the garbage collection thread. Time is
+ in milliseconds.
+
+ gc_no_gc_sleep_time This tuning parameter controls the default sleep
+ time for the garbage collection thread. Time is
+ in milliseconds.
+
+ gc_idle This parameter controls the selection of victim
+ policy for garbage collection. Setting gc_idle = 0
+ (default) will disable this option. Setting
+ gc_idle = 1 will select the Cost Benefit approach
+ & setting gc_idle = 2 will select the greedy aproach.
+
+ reclaim_segments This parameter controls the number of prefree
+ segments to be reclaimed. If the number of prefree
+ segments is larger than this number, f2fs tries to
+ conduct checkpoint to reclaim the prefree segments
+ to free segments. By default, 100 segments, 200MB.
+
+================================================================================
+USAGE
+================================================================================
+
+1. Download userland tools and compile them.
+
+2. Skip, if f2fs was compiled statically inside kernel.
+ Otherwise, insert the f2fs.ko module.
+ # insmod f2fs.ko
+
+3. Create a directory trying to mount
+ # mkdir /mnt/f2fs
+
+4. Format the block device, and then mount as f2fs
+ # mkfs.f2fs -l label /dev/block_device
+ # mount -t f2fs /dev/block_device /mnt/f2fs
+
+mkfs.f2fs
+---------
+The mkfs.f2fs is for the use of formatting a partition as the f2fs filesystem,
+which builds a basic on-disk layout.
+
+The options consist of:
+-l [label] : Give a volume label, up to 512 unicode name.
+-a [0 or 1] : Split start location of each area for heap-based allocation.
+ 1 is set by default, which performs this.
+-o [int] : Set overprovision ratio in percent over volume size.
+ 5 is set by default.
+-s [int] : Set the number of segments per section.
+ 1 is set by default.
+-z [int] : Set the number of sections per zone.
+ 1 is set by default.
+-e [str] : Set basic extension list. e.g. "mp3,gif,mov"
+-t [0 or 1] : Disable discard command or not.
+ 1 is set by default, which conducts discard.
+
+fsck.f2fs
+---------
+The fsck.f2fs is a tool to check the consistency of an f2fs-formatted
+partition, which examines whether the filesystem metadata and user-made data
+are cross-referenced correctly or not.
+Note that, initial version of the tool does not fix any inconsistency.
+
+The options consist of:
+ -d debug level [default:0]
+
+dump.f2fs
+---------
+The dump.f2fs shows the information of specific inode and dumps SSA and SIT to
+file. Each file is dump_ssa and dump_sit.
+
+The dump.f2fs is used to debug on-disk data structures of the f2fs filesystem.
+It shows on-disk inode information reconized by a given inode number, and is
+able to dump all the SSA and SIT entries into predefined files, ./dump_ssa and
+./dump_sit respectively.
+
+The options consist of:
+ -d debug level [default:0]
+ -i inode no (hex)
+ -s [SIT dump segno from #1~#2 (decimal), for all 0~-1]
+ -a [SSA dump segno from #1~#2 (decimal), for all 0~-1]
+
+Examples:
+# dump.f2fs -i [ino] /dev/sdx
+# dump.f2fs -s 0~-1 /dev/sdx (SIT dump)
+# dump.f2fs -a 0~-1 /dev/sdx (SSA dump)
+
+================================================================================
+DESIGN
+================================================================================
+
+On-disk Layout
+--------------
+
+F2FS divides the whole volume into a number of segments, each of which is fixed
+to 2MB in size. A section is composed of consecutive segments, and a zone
+consists of a set of sections. By default, section and zone sizes are set to one
+segment size identically, but users can easily modify the sizes by mkfs.
+
+F2FS splits the entire volume into six areas, and all the areas except superblock
+consists of multiple segments as described below.
+
+ align with the zone size <-|
+ |-> align with the segment size
+ _________________________________________________________________________
+ | | | Segment | Node | Segment | |
+ | Superblock | Checkpoint | Info. | Address | Summary | Main |
+ | (SB) | (CP) | Table (SIT) | Table (NAT) | Area (SSA) | |
+ |____________|_____2______|______N______|______N______|______N_____|__N___|
+ . .
+ . .
+ . .
+ ._________________________________________.
+ |_Segment_|_..._|_Segment_|_..._|_Segment_|
+ . .
+ ._________._________
+ |_section_|__...__|_
+ . .
+ .________.
+ |__zone__|
+
+- Superblock (SB)
+ : It is located at the beginning of the partition, and there exist two copies
+ to avoid file system crash. It contains basic partition information and some
+ default parameters of f2fs.
+
+- Checkpoint (CP)
+ : It contains file system information, bitmaps for valid NAT/SIT sets, orphan
+ inode lists, and summary entries of current active segments.
+
+- Segment Information Table (SIT)
+ : It contains segment information such as valid block count and bitmap for the
+ validity of all the blocks.
+
+- Node Address Table (NAT)
+ : It is composed of a block address table for all the node blocks stored in
+ Main area.
+
+- Segment Summary Area (SSA)
+ : It contains summary entries which contains the owner information of all the
+ data and node blocks stored in Main area.
+
+- Main Area
+ : It contains file and directory data including their indices.
+
+In order to avoid misalignment between file system and flash-based storage, F2FS
+aligns the start block address of CP with the segment size. Also, it aligns the
+start block address of Main area with the zone size by reserving some segments
+in SSA area.
+
+Reference the following survey for additional technical details.
+https://wiki.linaro.org/WorkingGroups/Kernel/Projects/FlashCardSurvey
+
+File System Metadata Structure
+------------------------------
+
+F2FS adopts the checkpointing scheme to maintain file system consistency. At
+mount time, F2FS first tries to find the last valid checkpoint data by scanning
+CP area. In order to reduce the scanning time, F2FS uses only two copies of CP.
+One of them always indicates the last valid data, which is called as shadow copy
+mechanism. In addition to CP, NAT and SIT also adopt the shadow copy mechanism.
+
+For file system consistency, each CP points to which NAT and SIT copies are
+valid, as shown as below.
+
+ +--------+----------+---------+
+ | CP | SIT | NAT |
+ +--------+----------+---------+
+ . . . .
+ . . . .
+ . . . .
+ +-------+-------+--------+--------+--------+--------+
+ | CP #0 | CP #1 | SIT #0 | SIT #1 | NAT #0 | NAT #1 |
+ +-------+-------+--------+--------+--------+--------+
+ | ^ ^
+ | | |
+ `----------------------------------------'
+
+Index Structure
+---------------
+
+The key data structure to manage the data locations is a "node". Similar to
+traditional file structures, F2FS has three types of node: inode, direct node,
+indirect node. F2FS assigns 4KB to an inode block which contains 923 data block
+indices, two direct node pointers, two indirect node pointers, and one double
+indirect node pointer as described below. One direct node block contains 1018
+data blocks, and one indirect node block contains also 1018 node blocks. Thus,
+one inode block (i.e., a file) covers:
+
+ 4KB * (923 + 2 * 1018 + 2 * 1018 * 1018 + 1018 * 1018 * 1018) := 3.94TB.
+
+ Inode block (4KB)
+ |- data (923)
+ |- direct node (2)
+ | `- data (1018)
+ |- indirect node (2)
+ | `- direct node (1018)
+ | `- data (1018)
+ `- double indirect node (1)
+ `- indirect node (1018)
+ `- direct node (1018)
+ `- data (1018)
+
+Note that, all the node blocks are mapped by NAT which means the location of
+each node is translated by the NAT table. In the consideration of the wandering
+tree problem, F2FS is able to cut off the propagation of node updates caused by
+leaf data writes.
+
+Directory Structure
+-------------------
+
+A directory entry occupies 11 bytes, which consists of the following attributes.
+
+- hash hash value of the file name
+- ino inode number
+- len the length of file name
+- type file type such as directory, symlink, etc
+
+A dentry block consists of 214 dentry slots and file names. Therein a bitmap is
+used to represent whether each dentry is valid or not. A dentry block occupies
+4KB with the following composition.
+
+ Dentry Block(4 K) = bitmap (27 bytes) + reserved (3 bytes) +
+ dentries(11 * 214 bytes) + file name (8 * 214 bytes)
+
+ [Bucket]
+ +--------------------------------+
+ |dentry block 1 | dentry block 2 |
+ +--------------------------------+
+ . .
+ . .
+ . [Dentry Block Structure: 4KB] .
+ +--------+----------+----------+------------+
+ | bitmap | reserved | dentries | file names |
+ +--------+----------+----------+------------+
+ [Dentry Block: 4KB] . .
+ . .
+ . .
+ +------+------+-----+------+
+ | hash | ino | len | type |
+ +------+------+-----+------+
+ [Dentry Structure: 11 bytes]
+
+F2FS implements multi-level hash tables for directory structure. Each level has
+a hash table with dedicated number of hash buckets as shown below. Note that
+"A(2B)" means a bucket includes 2 data blocks.
+
+----------------------
+A : bucket
+B : block
+N : MAX_DIR_HASH_DEPTH
+----------------------
+
+level #0 | A(2B)
+ |
+level #1 | A(2B) - A(2B)
+ |
+level #2 | A(2B) - A(2B) - A(2B) - A(2B)
+ . | . . . .
+level #N/2 | A(2B) - A(2B) - A(2B) - A(2B) - A(2B) - ... - A(2B)
+ . | . . . .
+level #N | A(4B) - A(4B) - A(4B) - A(4B) - A(4B) - ... - A(4B)
+
+The number of blocks and buckets are determined by,
+
+ ,- 2, if n < MAX_DIR_HASH_DEPTH / 2,
+ # of blocks in level #n = |
+ `- 4, Otherwise
+
+ ,- 2^n, if n < MAX_DIR_HASH_DEPTH / 2,
+ # of buckets in level #n = |
+ `- 2^((MAX_DIR_HASH_DEPTH / 2) - 1), Otherwise
+
+When F2FS finds a file name in a directory, at first a hash value of the file
+name is calculated. Then, F2FS scans the hash table in level #0 to find the
+dentry consisting of the file name and its inode number. If not found, F2FS
+scans the next hash table in level #1. In this way, F2FS scans hash tables in
+each levels incrementally from 1 to N. In each levels F2FS needs to scan only
+one bucket determined by the following equation, which shows O(log(# of files))
+complexity.
+
+ bucket number to scan in level #n = (hash value) % (# of buckets in level #n)
+
+In the case of file creation, F2FS finds empty consecutive slots that cover the
+file name. F2FS searches the empty slots in the hash tables of whole levels from
+1 to N in the same way as the lookup operation.
+
+The following figure shows an example of two cases holding children.
+ --------------> Dir <--------------
+ | |
+ child child
+
+ child - child [hole] - child
+
+ child - child - child [hole] - [hole] - child
+
+ Case 1: Case 2:
+ Number of children = 6, Number of children = 3,
+ File size = 7 File size = 7
+
+Default Block Allocation
+------------------------
+
+At runtime, F2FS manages six active logs inside "Main" area: Hot/Warm/Cold node
+and Hot/Warm/Cold data.
+
+- Hot node contains direct node blocks of directories.
+- Warm node contains direct node blocks except hot node blocks.
+- Cold node contains indirect node blocks
+- Hot data contains dentry blocks
+- Warm data contains data blocks except hot and cold data blocks
+- Cold data contains multimedia data or migrated data blocks
+
+LFS has two schemes for free space management: threaded log and copy-and-compac-
+tion. The copy-and-compaction scheme which is known as cleaning, is well-suited
+for devices showing very good sequential write performance, since free segments
+are served all the time for writing new data. However, it suffers from cleaning
+overhead under high utilization. Contrarily, the threaded log scheme suffers
+from random writes, but no cleaning process is needed. F2FS adopts a hybrid
+scheme where the copy-and-compaction scheme is adopted by default, but the
+policy is dynamically changed to the threaded log scheme according to the file
+system status.
+
+In order to align F2FS with underlying flash-based storage, F2FS allocates a
+segment in a unit of section. F2FS expects that the section size would be the
+same as the unit size of garbage collection in FTL. Furthermore, with respect
+to the mapping granularity in FTL, F2FS allocates each section of the active
+logs from different zones as much as possible, since FTL can write the data in
+the active logs into one allocation unit according to its mapping granularity.
+
+Cleaning process
+----------------
+
+F2FS does cleaning both on demand and in the background. On-demand cleaning is
+triggered when there are not enough free segments to serve VFS calls. Background
+cleaner is operated by a kernel thread, and triggers the cleaning job when the
+system is idle.
+
+F2FS supports two victim selection policies: greedy and cost-benefit algorithms.
+In the greedy algorithm, F2FS selects a victim segment having the smallest number
+of valid blocks. In the cost-benefit algorithm, F2FS selects a victim segment
+according to the segment age and the number of valid blocks in order to address
+log block thrashing problem in the greedy algorithm. F2FS adopts the greedy
+algorithm for on-demand cleaner, while background cleaner adopts cost-benefit
+algorithm.
+
+In order to identify whether the data in the victim segment are valid or not,
+F2FS manages a bitmap. Each bit represents the validity of a block, and the
+bitmap is composed of a bit stream covering whole blocks in main area.
\ No newline at end of file
diff --git a/arch/arm/configs/tegra3_android_defconfig b/arch/arm/configs/tegra3_android_defconfig
index ff5dde7..6d12133 100644
--- a/arch/arm/configs/tegra3_android_defconfig
+++ b/arch/arm/configs/tegra3_android_defconfig
@@ -484,6 +484,9 @@ CONFIG_FUSE_FS=y
CONFIG_VFAT_FS=y
CONFIG_NTFS_FS=y
CONFIG_TMPFS=y
+CONFIG_F2FS_FS=y
+CONFIG_F2FS_FS_XATTR=y
+CONFIG_F2FS_FS_SECURITY=y
CONFIG_NFS_FS=y
CONFIG_ROOT_NFS=y
CONFIG_PARTITION_ADVANCED=y
diff --git a/fs/Kconfig b/fs/Kconfig
index 99453ba..47fe939 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -219,6 +219,7 @@ source "fs/pstore/Kconfig"
source "fs/sysv/Kconfig"
source "fs/ufs/Kconfig"
source "fs/exofs/Kconfig"
+source "fs/f2fs/Kconfig"
endif # MISC_FILESYSTEMS
diff --git a/fs/Makefile b/fs/Makefile
index a8bbb32..974efc2 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -120,6 +120,7 @@ obj-$(CONFIG_DEBUG_FS) += debugfs/
obj-$(CONFIG_OCFS2_FS) += ocfs2/
obj-$(CONFIG_BTRFS_FS) += btrfs/
obj-$(CONFIG_GFS2_FS) += gfs2/
+obj-$(CONFIG_F2FS_FS) += f2fs/
obj-$(CONFIG_EXOFS_FS) += exofs/
obj-$(CONFIG_CEPH_FS) += ceph/
obj-$(CONFIG_PSTORE) += pstore/
diff --git a/fs/dcache.c b/fs/dcache.c
index 8b732a2..239f5e6 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1438,7 +1438,7 @@ static struct dentry * __d_find_any_alias(struct inode *inode)
return alias;
}
-static struct dentry * d_find_any_alias(struct inode *inode)
+struct dentry * d_find_any_alias(struct inode *inode)
{
struct dentry *de;
@@ -1447,7 +1447,7 @@ static struct dentry * d_find_any_alias(struct inode *inode)
spin_unlock(&inode->i_lock);
return de;
}
-
+EXPORT_SYMBOL(d_find_any_alias);
/**
* d_obtain_alias - find or allocate a dentry for a given inode
diff --git a/fs/f2fs/Kconfig b/fs/f2fs/Kconfig
new file mode 100644
index 0000000..e06e099
--- /dev/null
+++ b/fs/f2fs/Kconfig
@@ -0,0 +1,65 @@
+config F2FS_FS
+ tristate "F2FS filesystem support (EXPERIMENTAL)"
+ depends on BLOCK
+ help
+ F2FS is based on Log-structured File System (LFS), which supports
+ versatile "flash-friendly" features. The design has been focused on
+ addressing the fundamental issues in LFS, which are snowball effect
+ of wandering tree and high cleaning overhead.
+
+ Since flash-based storages show different characteristics according to
+ the internal geometry or flash memory management schemes aka FTL, F2FS
+ and tools support various parameters not only for configuring on-disk
+ layout, but also for selecting allocation and cleaning algorithms.
+
+ If unsure, say N.
+
+config F2FS_STAT_FS
+ bool "F2FS Status Information"
+ depends on F2FS_FS && DEBUG_FS
+ default y
+ help
+ /sys/kernel/debug/f2fs/ contains information about all the partitions
+ mounted as f2fs. Each file shows the whole f2fs information.
+
+ /sys/kernel/debug/f2fs/status includes:
+ - major file system information managed by f2fs currently
+ - average SIT information about whole segments
+ - current memory footprint consumed by f2fs.
+
+config F2FS_FS_XATTR
+ bool "F2FS extended attributes"
+ depends on F2FS_FS
+ default y
+ help
+ Extended attributes are name:value pairs associated with inodes by
+ the kernel or by users (see the attr(5) manual page, or visit
+ <http://acl.bestbits.at/> for details).
+
+ If unsure, say N.
+
+config F2FS_FS_POSIX_ACL
+ bool "F2FS Access Control Lists"
+ depends on F2FS_FS_XATTR
+ select FS_POSIX_ACL
+ default y
+ help
+ Posix Access Control Lists (ACLs) support permissions for users and
+ gourps beyond the owner/group/world scheme.
+
+ To learn more about Access Control Lists, visit the POSIX ACLs for
+ Linux website <http://acl.bestbits.at/>.
+
+ If you don't know what Access Control Lists are, say N
+
+config F2FS_FS_SECURITY
+ bool "F2FS Security Labels"
+ depends on F2FS_FS_XATTR
+ help
+ Security labels provide an access control facility to support Linux
+ Security Models (LSMs) accepted by AppArmor, SELinux, Smack and TOMOYO
+ Linux. This option enables an extended attribute handler for file
+ security labels in the f2fs filesystem, so that it requires enabling
+ the extended attribute support in advance.
+
+ If you are not using a security module, say N.
diff --git a/fs/f2fs/Makefile b/fs/f2fs/Makefile
new file mode 100644
index 0000000..27a0820
--- /dev/null
+++ b/fs/f2fs/Makefile
@@ -0,0 +1,7 @@
+obj-$(CONFIG_F2FS_FS) += f2fs.o
+
+f2fs-y := dir.o file.o inode.o namei.o hash.o super.o
+f2fs-y += checkpoint.o gc.o data.o node.o segment.o recovery.o
+f2fs-$(CONFIG_F2FS_STAT_FS) += debug.o
+f2fs-$(CONFIG_F2FS_FS_XATTR) += xattr.o
+f2fs-$(CONFIG_F2FS_FS_POSIX_ACL) += acl.o
diff --git a/fs/f2fs/acl.c b/fs/f2fs/acl.c
new file mode 100644
index 0000000..b20ced3
--- /dev/null
+++ b/fs/f2fs/acl.c
@@ -0,0 +1,423 @@
+/*
+ * fs/f2fs/acl.c
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ * http://www.samsung.com/
+ *
+ * Portions of this code from linux/fs/ext2/acl.c
+ *
+ * Copyright (C) 2001-2003 Andreas Gruenbacher, <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/f2fs_fs.h>
+#include "f2fs.h"
+#include "xattr.h"
+#include "acl.h"
+
+#define get_inode_mode(i) ((is_inode_flag_set(F2FS_I(i), FI_ACL_MODE)) ? \
+ (F2FS_I(i)->i_acl_mode) : ((i)->i_mode))
+
+static inline size_t f2fs_acl_size(int count)
+{
+ if (count <= 4) {
+ return sizeof(struct f2fs_acl_header) +
+ count * sizeof(struct f2fs_acl_entry_short);
+ } else {
+ return sizeof(struct f2fs_acl_header) +
+ 4 * sizeof(struct f2fs_acl_entry_short) +
+ (count - 4) * sizeof(struct f2fs_acl_entry);
+ }
+}
+
+static inline int f2fs_acl_count(size_t size)
+{
+ ssize_t s;
+ size -= sizeof(struct f2fs_acl_header);
+ s = size - 4 * sizeof(struct f2fs_acl_entry_short);
+ if (s < 0) {
+ if (size % sizeof(struct f2fs_acl_entry_short))
+ return -1;
+ return size / sizeof(struct f2fs_acl_entry_short);
+ } else {
+ if (s % sizeof(struct f2fs_acl_entry))
+ return -1;
+ return s / sizeof(struct f2fs_acl_entry) + 4;
+ }
+}
+
+static struct posix_acl *f2fs_acl_from_disk(const char *value, size_t size)
+{
+ int i, count;
+ struct posix_acl *acl;
+ struct f2fs_acl_header *hdr = (struct f2fs_acl_header *)value;
+ struct f2fs_acl_entry *entry = (struct f2fs_acl_entry *)(hdr + 1);
+ const char *end = value + size;
+
+ if (hdr->a_version != cpu_to_le32(F2FS_ACL_VERSION))
+ return ERR_PTR(-EINVAL);
+
+ count = f2fs_acl_count(size);
+ if (count < 0)
+ return ERR_PTR(-EINVAL);
+ if (count == 0)
+ return NULL;
+
+ acl = posix_acl_alloc(count, GFP_KERNEL);
+ if (!acl)
+ return ERR_PTR(-ENOMEM);
+
+ for (i = 0; i < count; i++) {
+
+ if ((char *)entry > end)
+ goto fail;
+
+ acl->a_entries[i].e_tag = le16_to_cpu(entry->e_tag);
+ acl->a_entries[i].e_perm = le16_to_cpu(entry->e_perm);
+
+ switch (acl->a_entries[i].e_tag) {
+ case ACL_USER_OBJ:
+ case ACL_GROUP_OBJ:
+ case ACL_MASK:
+ case ACL_OTHER:
+ entry = (struct f2fs_acl_entry *)((char *)entry +
+ sizeof(struct f2fs_acl_entry_short));
+ break;
+
+ case ACL_USER:
+ case ACL_GROUP:
+ acl->a_entries[i].e_id = le32_to_cpu(entry->e_id);
+ entry = (struct f2fs_acl_entry *)((char *)entry +
+ sizeof(struct f2fs_acl_entry));
+ break;
+ default:
+ goto fail;
+ }
+ }
+ if ((char *)entry != end)
+ goto fail;
+ return acl;
+fail:
+ posix_acl_release(acl);
+ return ERR_PTR(-EINVAL);
+}
+
+static void *f2fs_acl_to_disk(const struct posix_acl *acl, size_t *size)
+{
+ struct f2fs_acl_header *f2fs_acl;
+ struct f2fs_acl_entry *entry;
+ int i;
+
+ f2fs_acl = kmalloc(sizeof(struct f2fs_acl_header) + acl->a_count *
+ sizeof(struct f2fs_acl_entry), GFP_KERNEL);
+ if (!f2fs_acl)
+ return ERR_PTR(-ENOMEM);
+
+ f2fs_acl->a_version = cpu_to_le32(F2FS_ACL_VERSION);
+ entry = (struct f2fs_acl_entry *)(f2fs_acl + 1);
+
+ for (i = 0; i < acl->a_count; i++) {
+
+ entry->e_tag = cpu_to_le16(acl->a_entries[i].e_tag);
+ entry->e_perm = cpu_to_le16(acl->a_entries[i].e_perm);
+
+ switch (acl->a_entries[i].e_tag) {
+ case ACL_USER:
+ case ACL_GROUP:
+ entry->e_id = cpu_to_le32(acl->a_entries[i].e_id);
+ entry = (struct f2fs_acl_entry *)((char *)entry +
+ sizeof(struct f2fs_acl_entry));
+ break;
+ case ACL_USER_OBJ:
+ case ACL_GROUP_OBJ:
+ case ACL_MASK:
+ case ACL_OTHER:
+ entry = (struct f2fs_acl_entry *)((char *)entry +
+ sizeof(struct f2fs_acl_entry_short));
+ break;
+ default:
+ goto fail;
+ }
+ }
+ *size = f2fs_acl_size(acl->a_count);
+ return (void *)f2fs_acl;
+
+fail:
+ kfree(f2fs_acl);
+ return ERR_PTR(-EINVAL);
+}
+
+struct posix_acl *f2fs_get_acl(struct inode *inode, int type)
+{
+ struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+ int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
+ void *value = NULL;
+ struct posix_acl *acl;
+ int retval;
+
+ if (!test_opt(sbi, POSIX_ACL))
+ return NULL;
+
+ acl = get_cached_acl(inode, type);
+ if (acl != ACL_NOT_CACHED)
+ return acl;
+
+ if (type == ACL_TYPE_ACCESS)
+ name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
+
+ retval = f2fs_getxattr(inode, name_index, "", NULL, 0);
+ if (retval > 0) {
+ value = kmalloc(retval, GFP_KERNEL);
+ if (!value)
+ return ERR_PTR(-ENOMEM);
+ retval = f2fs_getxattr(inode, name_index, "", value, retval);
+ }
+
+ if (retval > 0)
+ acl = f2fs_acl_from_disk(value, retval);
+ else if (retval == -ENODATA)
+ acl = NULL;
+ else
+ acl = ERR_PTR(retval);
+ kfree(value);
+
+ if (!IS_ERR(acl))
+ set_cached_acl(inode, type, acl);
+
+ return acl;
+}
+
+static int f2fs_set_acl(struct inode *inode, int type, struct posix_acl *acl)
+{
+ struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+ struct f2fs_inode_info *fi = F2FS_I(inode);
+ int name_index;
+ void *value = NULL;
+ size_t size = 0;
+ int error;
+
+ if (!test_opt(sbi, POSIX_ACL))
+ return 0;
+ if (S_ISLNK(inode->i_mode))
+ return -EOPNOTSUPP;
+
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
+ if (acl) {
+ error = posix_acl_equiv_mode(acl, &inode->i_mode);
+ if (error < 0)
+ return error;
+ set_acl_inode(fi, inode->i_mode);
+ if (error == 0)
+ acl = NULL;
+ }
+ break;
+
+ case ACL_TYPE_DEFAULT:
+ name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
+ if (!S_ISDIR(inode->i_mode))
+ return acl ? -EACCES : 0;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ if (acl) {
+ value = f2fs_acl_to_disk(acl, &size);
+ if (IS_ERR(value)) {
+ cond_clear_inode_flag(fi, FI_ACL_MODE);
+ return (int)PTR_ERR(value);
+ }
+ }
+
+ error = f2fs_setxattr(inode, name_index, "", value, size, NULL);
+
+ kfree(value);
+ if (!error)
+ set_cached_acl(inode, type, acl);
+
+ cond_clear_inode_flag(fi, FI_ACL_MODE);
+ return error;
+}
+
+int f2fs_init_acl(struct inode *inode, struct inode *dir)
+{
+ struct posix_acl *acl = NULL;
+ struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
+ int error = 0;