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path: root/Documentation/filesystems/f2fs.txt
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2019-09-06f2fs: add missing documents of reserve_root/resuid/resgidChao Yu
Add missing documents. Fixes: 7e65be49ed94f ("f2fs: add reserved blocks for root user") Fixes: 7c2e59632b846 ("f2fs: add resgid and resuid to reserve root blocks") Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2019-08-23f2fs: include charset encoding information in the superblockDaniel Rosenberg
Add charset encoding to f2fs to support casefolding. It is modeled after the same feature introduced in commit c83ad55eaa91 ("ext4: include charset encoding information in the superblock") Currently this is not compatible with encryption, similar to the current ext4 imlpementation. This will change in the future. >From the ext4 patch: """ The s_encoding field stores a magic number indicating the encoding format and version used globally by file and directory names in the filesystem. The s_encoding_flags defines policies for using the charset encoding, like how to handle invalid sequences. The magic number is mapped to the exact charset table, but the mapping is specific to ext4. Since we don't have any commitment to support old encodings, the only encoding I am supporting right now is utf8-12.1.0. The current implementation prevents the user from enabling encoding and per-directory encryption on the same filesystem at the same time. The incompatibility between these features lies in how we do efficient directory searches when we cannot be sure the encryption of the user provided fname will match the actual hash stored in the disk without decrypting every directory entry, because of normalization cases. My quickest solution is to simply block the concurrent use of these features for now, and enable it later, once we have a better solution. """ Signed-off-by: Daniel Rosenberg <drosen@google.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2019-07-02f2fs: allocate blocks for pinned fileJaegeuk Kim
This patch allows fallocate to allocate physical blocks for pinned file. Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2019-06-03f2fs: Add option to limit required GC for checkpoint=disableDaniel Rosenberg
This extends the checkpoint option to allow checkpoint=disable:%u[%] This allows you to specify what how much of the disk you are willing to lose access to while mounting with checkpoint=disable. If the amount lost would be higher, the mount will return -EAGAIN. This can be given as a percent of total space, or in blocks. Currently, we need to run garbage collection until the amount of holes is smaller than the OVP space. With the new option, f2fs can mark space as unusable up front instead of requiring garbage collection until the number of holes is small enough. Signed-off-by: Daniel Rosenberg <drosen@google.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2019-05-30f2fs: add missing sysfs entries in documentationJaegeuk Kim
This patch cleans up documentation to cover missing sysfs entries. Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2019-03-05f2fs: fix to document inline_xattr_size optionChao Yu
We missed to add document for inline_xattr_size mount option in f2fs.txt, add it. Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2018-10-16f2fs: checkpoint disablingDaniel Rosenberg
Note that, it requires "f2fs: return correct errno in f2fs_gc". This adds a lightweight non-persistent snapshotting scheme to f2fs. To use, mount with the option checkpoint=disable, and to return to normal operation, remount with checkpoint=enable. If the filesystem is shut down before remounting with checkpoint=enable, it will revert back to its apparent state when it was first mounted with checkpoint=disable. This is useful for situations where you wish to be able to roll back the state of the disk in case of some critical failure. Signed-off-by: Daniel Rosenberg <drosen@google.com> [Jaegeuk Kim: use SB_RDONLY instead of MS_RDONLY] Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2018-09-12f2fs: split IO error injection according to RWChao Yu
This patch adds to support injecting error for write IO, this can simulate IO error like fail_make_request or dm_flakey does. Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2018-08-13f2fs: support fault_type mount optionChao Yu
Previously, once fault injection is on, by default, all kind of faults will be injected to f2fs, if we want to trigger single or specified combined type during the test, we need to configure sysfs entry, it will be a little inconvenient to integrate sysfs configuring into testsuit, such as xfstest. So this patch introduces a new mount option 'fault_type' to assist old option 'fault_injection', with these two mount options, we can specify any fault rate/type at mount-time. Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2018-05-29f2fs: add fsync_mode=nobarrier for non-atomic filesJaegeuk Kim
For non-atomic files, this patch adds an option to give nobarrier which doesn't issue flush commands to the device. Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2018-03-17f2fs: introduce a new mount option test_dummy_encryptionSheng Yong
This patch introduces a new mount option `test_dummy_encryption' to allow fscrypt to create a fake fscrypt context. This is used by xfstests. Signed-off-by: Sheng Yong <shengyong1@huawei.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2018-03-17f2fs: introduce mount option for fsync modeJunling Zheng
Commit "0a007b97aad6"(f2fs: recover directory operations by fsync) fixed xfstest generic/342 case, but it also increased the written data and caused the performance degradation. In most cases, there's no need to do so heavy fsync actually. So we introduce new mount option "fsync_mode={posix,strict}" to control the policy of fsync. "fsync_mode=posix" is set by default, and means that f2fs uses a light fsync, which follows POSIX semantics. And "fsync_mode=strict" means that it's a heavy fsync, which behaves in line with xfs, ext4 and btrfs, where generic/342 will pass, but the performance will regress. Signed-off-by: Junling Zheng <zhengjunling@huawei.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2018-03-13f2fs: add mount option for segment allocation policyJaegeuk Kim
This patch adds an mount option, "alloc_mode=%s" having two options, "default" and "reuse". In "alloc_mode=reuse" case, f2fs starts to allocate segments from 0'th segment all the time to reassign segments. It'd be useful for small-sized eMMC parts. Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2018-03-13f2fs: Add the 'whint_mode' mount option to f2fs documentationHyunchul Lee
Signed-off-by: Hyunchul Lee <cheol.lee@lge.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> [Jaegeuk Kim: Add the write-hint policy in f2fs doc.] Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-08-21f2fs: support journalled quotaChao Yu
This patch supports to enable f2fs to accept quota information through mount option: - {usr,grp,prj}jquota=<quota file path> - jqfmt=<quota type> Then, in ->mount flow, we can recover quota file during log replaying, by this, journelled quota can be supported. Signed-off-by: Chao Yu <yuchao0@huawei.com> [Jaegeuk Kim: Fix wrong return values.] Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-08-15f2fs: introduce gc_urgent mode for background GCJaegeuk Kim
This patch adds a sysfs entry to control urgent mode for background GC. If this is set, background GC thread conducts GC with gc_urgent_sleep_time all the time. Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-31f2fs: support project quotaChao Yu
This patch adds to support plain project quota. Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-08f2fs: support plain user/group quotaChao Yu
This patch adds to support plain user/group quota. Change Note by Jaegeuk Kim. - Use f2fs page cache for quota files in order to consider garbage collection. so, quota files are not tolerable for sudden power-cuts, so user needs to do quotacheck. - setattr() calls dquot_transfer which will transfer inode->i_blocks. We can't reclaim that during f2fs_evict_inode(). So, we need to count node blocks as well in order to match i_blocks with dquot's space. Note that, Chao wrote a patch to count inode->i_blocks without inode block. (f2fs: don't count inode block in in-memory inode.i_blocks) - in f2fs_remount, we need to make RW in prior to dquot_resume. - handle fault_injection case during f2fs_quota_off_umount - TODO: Project quota Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-07-04f2fs: fix to document fault injection option and sysfs fileChao Yu
Commit 73faec4d9935 ("f2fs: add mount option to select fault injection ratio") and Commit 087968974fcd ("f2fs: add fault injection to sysfs") forget to document mount option and sysfs file. This patch fixes to document them. Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-02-23f2fs: introduce noinline_xattr mount optionChao Yu
This patch introduces new mount option 'noinline_xattr', so we can disable inline xattr functionality which is already set as a default mount option. Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-02-23f2fs: fix a typo in f2fs.txtTiezhu Yang
There is a typo "f2f2" in f2fs.txt, this patch fixes it. Signed-off-by: Tiezhu Yang <kernelpatch@126.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-02-22Doc: f2fs: Fix typo in Documentation/filesystems/f2fs.txtMasanari Iida
This patch fix a typo in f2fs.txt Signed-off-by: Masanari Iida <standby24x7@gmail.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2017-01-29f2fs: get io size bit from mount optionJaegeuk Kim
This patch adds to set io_size_bits from mount option. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-08-29f2fs: enable inline_dentry by default and add noinline_dentry optionChao Yu
Make inline_dentry as default mount option to improve space usage and IO performance in scenario of numerous small directory. It adds noinline_dentry mount option, instead. Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-07-08f2fs: add nodiscard mount optionChao Yu
This patch adds 'nodiscard' mount option. Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-06-13f2fs: introduce mode=lfs mount optionJaegeuk Kim
This mount option is to enable original log-structured filesystem forcefully. So, there should be no random writes for main area. Especially, this supports host-managed SMR device. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-12-16f2fs: introduce new option for controlling data flushChao Yu
Add a new option 'data_flush' to enable data flush functionality. Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-12-04Doc: f2fs: Fix typos in Documentation/filesystems/f2fs.txtMasanari Iida
This patch fix some typos in Documentation/filesystems/f2fs.txt Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-10-09f2fs: introduce background_gc=sync mount optionJaegeuk Kim
This patch introduce background_gc=sync enabling synchronous cleaning in background. Reviewed-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-08-04f2fs: add noextent_cache mount optionJaegeuk Kim
This patch adds noextent_cache mount option. Reviewed-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-04-10f2fs: enable inline data by defaultWanpeng Li
Enable inline_data feature by default since it brings us better performance and space utilization and now has already stable. Add another option noinline_data to disable it during mount. Suggested-by: Jaegeuk Kim <jaegeuk@kernel.org> Suggested-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-03-03f2fs: add a mount option for rb-tree extent cacheChao Yu
This patch adds a mount option 'extent_cache' in f2fs. It is try to use a rb-tree based extent cache to cache more mapping information with less memory if this option is set, otherwise we will use the original one extent info cache. Suggested-by: Changman Lee <cm224.lee@samsung.com> Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-02-11f2fs: introduce a batched trimJaegeuk Kim
This patch introduces a batched trimming feature, which submits split discard commands. This is to avoid long latency due to huge trim commands. If fstrim was triggered ranging from 0 to the end of device, we should lock all the checkpoint-related mutexes, resulting in very long latency. Reviewed-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2015-02-11f2fs: support norecovery mount optionJaegeuk Kim
This patch adds a mount option, norecovery, which is mostly same as disable_roll_forward. The only difference is that norecovery should be activated with read-only mount option. This can be used when user wants to check whether f2fs is mountable or not without any recovery process. (e.g., xfstests/200) Reviewed-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-11-04f2fs: introduce -o fastboot for reducing booting time onlyJaegeuk Kim
If a system wants to reduce the booting time as a top priority, now we can use a mount option, -o fastboot. With this option, f2fs conducts a little bit slow write_checkpoint, but it can avoid the node page reads during the next mount time. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-11-03f2fs: update f2fs documentation for inline dir supportChao Yu
This patch adds descriptions for the inline dir support in f2fs document. Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-09-23f2fs: change the ipu_policy option to enable combinationsJaegeuk Kim
This patch changes the ipu_policy setting to use any combination of orthogonal policies. Signed-off-by: Changman Lee <cm224.lee@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-09-16f2fs: give an option to enable in-place-updates during fsync to usersJaegeuk Kim
If user wrote F2FS_IPU_FSYNC:4 in /sys/fs/f2fs/ipu_policy, f2fs_sync_file only starts to try in-place-updates. And, if the number of dirty pages is over /sys/fs/f2fs/min_fsync_blocks, it keeps out-of-order manner. Otherwise, it triggers in-place-updates. This may be used by storage showing very high random write performance. For example, it can be used when, Seq. writes (Data) + wait + Seq. writes (Node) is pretty much slower than, Rand. writes (Data) Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-07-29f2fs: add nobarrier mount optionJaegeuk Kim
This patch adds a mount option, nobarrier, in f2fs. The assumption in here is that file system keeps the IO ordering, but doesn't care about cache flushes inside the storages. Reviewed-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-06-04f2fs: avoid overflow when large directory feathure is enabledChao Yu
When large directory feathure is enable, We have one case which could cause overflow in dir_buckets() as following: special case: level + dir_level >= 32 and level < MAX_DIR_HASH_DEPTH / 2. Here we define MAX_DIR_BUCKETS to limit the return value when the condition could trigger potential overflow. Changes from V1 o modify description of calculation in f2fs.txt suggested by Changman Lee. Suggested-by: Changman Lee <cm224.lee@samsung.com> Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-04-07f2fs: introduce f2fs_issue_flush to avoid redundant flush issueJaegeuk Kim
Some storage devices show relatively high latencies to complete cache_flush commands, even though their normal IO speed is prettry much high. In such the case, it needs to merge cache_flush commands as much as possible to avoid issuing them redundantly. So, this patch introduces a mount option, "-o flush_merge", to mitigate such the overhead. If this option is enabled by user, F2FS merges the cache_flush commands and then issues just one cache_flush on behalf of them. Once the single command is finished, F2FS sends a completion signal to all the pending threads. Note that, this option can be used under a workload consisting of very intensive concurrent fsync calls, while the storage handles cache_flush commands slowly. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2014-03-20f2fs: change reclaim rate in percentageJaegeuk Kim
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>
2014-03-20f2fs: throttle the memory footprint with a sysfs entryJaegeuk Kim
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>
2014-02-27f2fs: add an sysfs entry to control the directory levelJaegeuk Kim
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>
2014-02-27f2fs: introduce large directory supportJaegeuk Kim
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>
2014-01-09f2fs: update documents and a MAINTAINERS entryJaegeuk Kim
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>
2013-12-26f2fs: update f2fs DocumentationHuajun Li
This patch describes the inline_data support in f2fs document. Signed-off-by: Huajun Li <huajun.li@intel.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-12-23f2fs: add description about small_discards in documentJaegeuk Kim
This patch adds a description about small_disacrds in the f2fs document. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-12-23f2fs: introduce sysfs entry to control in-place-update policyJaegeuk Kim
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>
2013-11-01f2fs: update f2fs documentJaegeuk Kim
This patch describes the inline_xattr support in f2fs document. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>