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* f2fs: change reclaim rate in percentageJaegeuk Kim2016-06-051-3/+5
| | | | | | | | | It is more reasonable to determine the reclaiming rate of prefree segments according to the volume size, which is set to 5% by default. For example, if the volume is 128GB, the prefree segments are reclaimed when the number reaches to 6.4GB. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
* f2fs: throttle the memory footprint with a sysfs entryJaegeuk Kim2016-06-051-0/+4
| | | | | | | | | | | | | | | | | This patch introduces ram_thresh, a sysfs entry, which controls the memory footprint used by the free nid list and the nat cache. Previously, the free nid list was controlled by MAX_FREE_NIDS, while the nat cache was managed by NM_WOUT_THRESHOLD. However, this approach cannot be applied dynamically according to the system. So, this patch adds ram_thresh that users can specify the threshold, which is in order of 1 / 1024. For example, if the total ram size is 4GB and the value is set to 10 by default, f2fs tries to control the number of free nids and nat caches not to consume over 10 * (4GB / 1024) = 10MB. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
* f2fs: add an sysfs entry to control the directory levelJaegeuk Kim2016-06-051-0/+7
| | | | | | | | | | | | | | | This patch adds an sysfs entry to control dir_level used by the large directory. The description of this entry is: dir_level This parameter controls the directory level to support large directory. If a directory has a number of files, it can reduce the file lookup latency by increasing this dir_level value. Otherwise, it needs to decrease this value to reduce the space overhead. The default value is 0. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
* f2fs: update documents and a MAINTAINERS entryJaegeuk Kim2016-06-051-0/+5
| | | | | | | | | | This patch adds missing some description of sysfs entries in - Documentation/ABI/testing/sysfs-fs-f2fs - Documentation/filesystems/f2fs.txt. And it adds a maintained document entry of F2FS in MAINTAINERS. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
* f2fs: introduce large directory supportJaegeuk Kim2016-06-051-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces an i_dir_level field to support large directory. Previously, f2fs maintains multi-level hash tables to find a dentry quickly from a bunch of chiild dentries in a directory, and the hash tables consist of the following tree structure as below. In Documentation/filesystems/f2fs.txt, ---------------------- 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) But, if we can guess that a directory will handle a number of child files, we don't need to traverse the tree from level #0 to #N all the time. Since the lower level tables contain relatively small number of dentries, the miss ratio of the target dentry is likely to be high. In order to avoid that, we can configure the hash tables sparsely from level #0 like this. level #0 | A(2B) - A(2B) - A(2B) - A(2B) level #1 | A(2B) - A(2B) - 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) With this structure, we can skip the ineffective tree searches in lower level hash tables. This patch adds just a facility for this by introducing i_dir_level in f2fs_inode. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
* f2fs: introduce sysfs entry to control in-place-update policyJaegeuk Kim2016-06-051-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces new sysfs entries for users to control the policy of in-place-updates, namely IPU, in f2fs. Sometimes f2fs suffers from performance degradation due to its out-of-place update policy that produces many additional node block writes. If the storage performance is very dependant on the amount of data writes instead of IO patterns, we'd better drop this out-of-place update policy. This patch suggests 5 polcies and their triggering conditions as follows. [sysfs entry name = ipu_policy] 0: F2FS_IPU_FORCE all the time, 1: F2FS_IPU_SSR if SSR mode is activated, 2: F2FS_IPU_UTIL if FS utilization is over threashold, 3: F2FS_IPU_SSR_UTIL if SSR mode is activated and FS utilization is over threashold, 4: F2FS_IPU_DISABLE disable IPU. (=default option) [sysfs entry name = min_ipu_util] This parameter controls the threshold to trigger in-place-updates. The number indicates percentage of the filesystem utilization, and used by F2FS_IPU_UTIL and F2FS_IPU_SSR_UTIL policies. For more details, see need_inplace_update() in segment.h. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
* f2fs: update f2fs documentJaegeuk Kim2016-06-051-0/+1
| | | | | | This patch describes the inline_xattr support in f2fs document. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
* f2fs: add reclaiming control by sysfsJaegeuk Kim2016-06-051-0/+6
| | | | | | | This patch adds a control method in sysfs to reclaim prefree segments. Signed-off-by: Changman Lee <cm224.lee@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
* f2fs: add sysfs entries to select the gc policyNamjae Jeon2016-06-051-0/+6
| | | | | | | | | | | | | | | | Add sysfs entry gc_idle to control the gc policy. Where gc_idle = 1 corresponds to selecting a cost benefit approach, while gc_idle = 2 corresponds to selecting a greedy approach to garbage collection. The selection is mutually exclusive one approach will work at any point. If gc_idle = 0, then this option is disabled. Cc: Gu Zheng <guz.fnst@cn.fujitsu.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Pankaj Kumar <pankaj.km@samsung.com> Reviewed-by: Gu Zheng <guz.fnst@cn.fujitsu.com> [Jaegeuk Kim: change the select_gc_type() flow slightly] Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
* f2fs: add sysfs support for controlling the gc_threadNamjae Jeon2016-06-051-0/+26
| | | | | | | | | | | | | | | | | | | | | | Add sysfs entries to control the timing parameters for f2fs gc thread. Various Sysfs options introduced are: gc_min_sleep_time: Min Sleep time for GC in ms gc_max_sleep_time: Max Sleep time for GC in ms gc_no_gc_sleep_time: Default Sleep time for GC in ms Cc: Gu Zheng <guz.fnst@cn.fujitsu.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Pankaj Kumar <pankaj.km@samsung.com> Reviewed-by: Gu Zheng <guz.fnst@cn.fujitsu.com> [Jaegeuk Kim: fix an umount bug and some minor changes] Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com> Conflicts: fs/f2fs/gc.c Change-Id: I16db84c4590d1010fd1079de8f811bca8a19ddd4
* f2fs: add description for fsck.f2fs and dump.f2fsChangman Lee2016-06-051-4/+39
| | | | | | | | This patch adds some description on fsck.f2fs and dump.f2fs which is recently merged into f2fs-tools. Signed-off-by: Changman Lee <cm224.lee@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
* f2fs: add remount_fs callback supportNamjae Jeon2016-06-051-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add the f2fs_remount function call which will be used during the filesystem remounting. This function will help us to change the mount options specific to f2fs. Also modify the f2fs background_gc mount option, which will allow the user to dynamically trun on/off the garbage collection in f2fs based on the background_gc value. If background_gc=on, Garbage collection will be turned off & if background_gc=off, Garbage collection will be truned on. By default the garbage collection is on in f2fs. Change Log: v2: Incorporated the review comments by Gu Zheng. Removing the restore part for VFS flags Updating comments with proper flag conditions Display GC background option as ON/OFF Revised conditions to stop GC in case of remount v1: Initial changes for adding remount_fs callback support. Cc: Gu Zheng <guz.fnst@cn.fujitsu.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Pankaj Kumar <pankaj.km@samsung.com> Reviewed-by: Gu Zheng <guz.fnst@cn.fujitsu.com> [Jaegeuk Kim: change /** with /* for the coding style] Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com> Change-Id: I5a66412430ab809636396cbb5eabaef26ec2414e
* f2fs: update f2fs.txt related with discard at mkfsChangman Lee2016-06-051-1/+3
| | | | | | | | o mkfs.f2fs supports no discard option. o fixed volume label size in 512 bytes. Signed-off-by: Changman Lee <cm224.lee@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
* f2fs: update f2fs document to reflect SIT/NAT layout correctlyHuajun Li2016-06-051-9/+9
| | | | | | | document to reflect the layout generated by mkfs.f2fs . Signed-off-by: Huajun Li <huajun.li.lee@gmail.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
* f2fs: fix a typo in f2fs documentationHuajun Li2016-06-051-1/+1
| | | | | | | In f2fs_fs.h, one f2fs inode contains 923 data block pointers, while f2fs documentation says it is 929. Fix this inconsistence. Signed-off-by: Huajun Li <huajun.li.lee@gmail.com>
* f2fs: update the f2fs documentJaegeuk Kim2016-06-051-1/+5
| | | | | | | I moved the f2fs-tools.git into kernel.org. And I added a new mailing list, linux-f2fs-devel@lists.sourceforge.net. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
* f2fs: add documentJaegeuk Kim2016-06-051-0/+417
This adds a document describing the mount options, proc entries, usage, and design of Flash-Friendly File System, namely F2FS. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
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