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path: root/fs/f2fs/segment.c
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2013-04-30f2fs: modify the number of issued pages to merge IOsJaegeuk Kim
When testing f2fs on an SSD, I found some 128 page IOs followed by 1 page IO were issued by f2fs_write_node_pages. This means that there were some mishandling flows which degrades performance. Previous f2fs_write_node_pages determines the number of pages to be written, nr_to_write, as follows. 1. The bio_get_nr_vecs returns 129 pages. 2. The bio_alloc makes a room for 128 pages. 3. The initial 128 pages go into one bio. 4. The existing bio is submitted, and a new bio is prepared for the last 1 page. 5. Finally, sync_node_pages submits the last 1 page bio. The problem is from the use of bio_get_nr_vecs, so this patch replace it with max_hw_blocks using queue_max_sectors. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-04-26f2fs: add REQ_META about metadata requests for submitNamjae Jeon
Adding REQ_META for all the metadata requests can help in improving the FS performance, if the underlying device supports TAGGING. So, when considering the submit_bio path for all the f2fs requests. We can add REQ_META for all the META requests. As a precursor to this change we considered the commit 4265900e0be653f5b78baf2816857ef57cf1332f 'mmc: MMC-4.5 Data Tag Support' Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-04-23f2fs: add tracepoints for write page operationsNamjae Jeon
Add tracepoints to debug the various page write operation like data pages, meta pages. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Pankaj Kumar <pankaj.km@samsung.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> [Jaegeuk: remove unnecessary tracepoints] Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-04-03f2fs: fix the bitmap consistency of dirty segmentsJaegeuk Kim
Like below, there are 8 segment bitmaps for SSR victim candidates. enum dirty_type { DIRTY_HOT_DATA, /* dirty segments assigned as hot data logs */ DIRTY_WARM_DATA, /* dirty segments assigned as warm data logs */ DIRTY_COLD_DATA, /* dirty segments assigned as cold data logs */ DIRTY_HOT_NODE, /* dirty segments assigned as hot node logs */ DIRTY_WARM_NODE, /* dirty segments assigned as warm node logs */ DIRTY_COLD_NODE, /* dirty segments assigned as cold node logs */ DIRTY, /* to count # of dirty segments */ PRE, /* to count # of entirely obsolete segments */ NR_DIRTY_TYPE }; The upper 6 bitmaps indicates segments dirtied by active log areas respectively. And, the DIRTY bitmap integrates all the 6 bitmaps. For example, o DIRTY_HOT_DATA : 1010000 o DIRTY_WARM_DATA: 0100000 o DIRTY_COLD_DATA: 0001000 o DIRTY_HOT_NODE : 0000010 o DIRTY_WARM_NODE: 0000001 o DIRTY_COLD_NODE: 0000000 In this case, o DIRTY : 1111011, which means that we should guarantee the consistency between DIRTY and other bitmaps concreately. However, the SSR mode selects victims freely from any log types, which can set multiple bits across the various bitmap types. So, this patch eliminates this inconsistency. Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-04-03f2fs: allocate remained free segments in the LFS modeJaegeuk Kim
This patch adds a new condition that allocates free segments in the current active section even if SSR is needed. Otherwise, f2fs cannot allocate remained free segments in the section since SSR finds dirty segments only. Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-04-03f2fs: change GC bitmaps to apply the section granularityJaegeuk Kim
This patch removes a bitmap for victim segments selected by foreground GC, and modifies the other bitmap for victim segments selected by background GC. 1) foreground GC bitmap : We don't need to manage this, since we just only one previous victim section number instead of the whole victim history. The f2fs uses the victim section number in order not to allocate currently GC'ed section to current active logs. 2) background GC bitmap : This bitmap is used to avoid selecting victims repeatedly by background GCs. In addition, the victims are able to be selected by foreground GCs, since there is no need to read victim blocks during foreground GCs. By the fact that the foreground GC reclaims segments in a section unit, it'd be better to manage this bitmap based on the section granularity. Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-04-03f2fs: allocate new segment aligned with sectionsJaegeuk Kim
When allocating a new segment under the LFS mode, we should keep the section boundary. Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-04-03f2fs: introduce TOTAL_SECS macroJaegeuk Kim
Let's use a macro to get the total number of sections. Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-03-31f2fs: use kmemdupAlexandru Gheorghiu
Use kmemdup instead of kzalloc and memcpy. Signed-off-by: Alexandru Gheorghiu <gheorghiuandru@gmail.com> Acked-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12f2fs: clarify and enhance the f2fs_gc flowJaegeuk Kim
This patch makes clearer the ambiguous f2fs_gc flow as follows. 1. Remove intermediate checkpoint condition during f2fs_gc (i.e., should_do_checkpoint() and GC_BLOCKED) 2. Remove unnecessary return values of f2fs_gc because of #1. (i.e., GC_NODE, GC_OK, etc) 3. Simplify write_checkpoint() because of #2. 4. Clarify the main f2fs_gc flow. o monitor how many freed sections during one iteration of do_garbage_collect(). o do GC more without checkpoints if we can't get enough free sections. o do checkpoint once we've got enough free sections through forground GCs. 5. Adopt thread-logging (Slack-Space-Recycle) scheme more aggressively on data log types. See. get_ssr_segement() Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2013-02-12f2fs: prevent checkpoint once any IO failure is detectedJaegeuk Kim
This patch enhances the checkpoint routine to cope with IO errors. Basically f2fs detects IO errors from end_io_write, and the errors are able to be occurred during one of data, node, and meta page writes. In the previous code, when an IO error is occurred during writes, f2fs sets a flag, CP_ERROR_FLAG, in the raw ckeckpoint buffer which will be written to disk. Afterwards, write_checkpoint() will check the flag and remount f2fs as a read-only (ro) mode. However, even once f2fs is remounted as a ro mode, dirty checkpoint pages are freely able to be written to disk by flusher or kswapd in background. In such a case, after cold reboot, f2fs would restore the checkpoint data having CP_ERROR_FLAG, resulting in disabling write_checkpoint and remounting f2fs as a ro mode again. Therefore, let's prevent any checkpoint page (meta) writes once an IO error is occurred, and remount f2fs as a ro mode right away at that moment. Reported-by: Oliver Winker <oliver@oli1170.net> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com> Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
2013-01-10f2fs: revisit the f2fs_gc flowJaegeuk Kim
I'd like to revisit the f2fs_gc flow and rewrite as follows. 1. In practical, the nGC parameter of f2fs_gc is meaningless. So, let's remove it. 2. Background GC marks victim blocks as dirty one at a time. 3. Foreground GC should do cleaning job until acquiring enough free sections. Afterwards, it needs to do checkpoint. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-12-28f2fs: remove unneeded initialization of nr_dirty in dirty_seglist_infoNamjae Jeon
Since, the memory for the object of dirty_seglist_info is allocated using kzalloc - which returns zeroed out memory. So, there is no need to initialize the nr_dirty values with zeroes. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-12-28f2fs: fix equation of has_not_enough_free_secs()Jaegeuk Kim
Practically, has_not_enough_free_secs() should calculate with the numbers of current node and directory data blocks together. Actually the equation was implemented in need_to_flush(). So, this patch removes need_flush() and moves the equation into has_not_enough_free_secs(). Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-12-28f2fs: return a default value for non-void functionJaegeuk Kim
This patch resolves a build warning reported by kbuild test robot. " fs/f2fs/segment.c: In function '__get_segment_type': fs/f2fs/segment.c:806:1: warning: control reaches end of non-void function [-Wreturn-type] " Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-12-28f2fs: add missing #include <linux/prefetch.h>Geert Uytterhoeven
m68k allmodconfig: fs/f2fs/data.c: In function ‘read_end_io’: fs/f2fs/data.c:311: error: implicit declaration of function ‘prefetchw’ fs/f2fs/segment.c: In function ‘f2fs_end_io_write’: fs/f2fs/segment.c:628: error: implicit declaration of function ‘prefetchw’ Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-12-26f2fs: remove set_page_dirty for atomic f2fs_end_io_writeJaegeuk Kim
We should guarantee not to do *scheduling while atomic*. I found, in atomic f2fs_end_io_write(), there is a set_page_dirty() call to deal with IO errors. But, set_page_dirty() calls: -> f2fs_set_data_page_dirty() -> set_dirty_dir_page() -> cond_resched() which results in scheduling. In order to avoid this, I'd like to remove simply set_page_dirty(), since the page is already marked as ERROR and f2fs will be operated as the read-only mode as well. So, there is no recovery issue with this. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-12-11f2fs: cleanup the f2fs_bio_alloc routineJaegeuk Kim
Do cleanup more for better code readability. - Change the parameter set of f2fs_bio_alloc() This function should allocate a bio only since it is not something like f2fs_bio_init(). Instead, the caller should initialize the allocated bio. - Introduce SECTOR_FROM_BLOCK This macro translates a block address to its sector address. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com> Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
2012-12-11f2fs: rewrite f2fs_bio_alloc to make it simplerNamjae Jeon
Since, GFP_NOFS(__GFP_WAIT) is used for allocation requests of bio in f2fs. So, there is no chance of returning NULL from the BIO allocation. Making the bio allocation routine for f2fs simpler. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
2012-12-11f2fs: remove unneeded initializationNamjae Jeon
No need to initialize "struct f2fs_gc_kthread *gc_th = NULL", as gc_th = NULL, will be taken care by the return values of kmalloc(). And fix codes in other places. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
2012-12-11f2fs: adjust kernel coding styleJaegeuk Kim
As pointed out by Randy Dunlap, this patch removes all usage of "/**" for comment blocks. Instead, just use "/*". Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-12-11f2fs: fix endian conversion bugs reported by sparseJaegeuk Kim
This patch should resolve the bugs reported by the sparse tool. Initial reports were written by "kbuild test robot" managed by fengguang.wu. In my local machines, I've tested also by running: > make C=2 CF="-D__CHECK_ENDIAN__" Accordingly, I've found lots of warnings and bugs related to the endian conversion. And I've fixed all at this moment. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-12-11f2fs: add segment operationsJaegeuk Kim
This adds specific functions not only to manage dirty/free segments, SIT pages, a cache for SIT entries, and summary entries, but also to allocate free blocks and write three types of pages: data, node, and meta. - F2FS maintains three types of bitmaps in memory, which indicate free, prefree, and dirty segments respectively. - The key information of an SIT entry consists of a segment number, the number of valid blocks in the segment, a bitmap to identify there-in valid or invalid blocks. - An SIT page is composed of a certain range of SIT entries, which is maintained by the address space of meta_inode. - To cache SIT entries, a simple array is used. The index for the array is the segment number. - A summary entry for data contains the parent node information. A summary entry for node contains its node offset from the inode. - F2FS manages information about six active logs and those summary entries in memory. Whenever one of them is changed, its summary entries are flushed to its SIT page maintained by the address space of meta_inode. - This patch adds a default block allocation function which supports heap-based allocation policy. - This patch adds core functions to write data, node, and meta pages. Since LFS basically produces a series of sequential writes, F2FS merges sequential bios with a single one as much as possible to reduce the IO scheduling overhead. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>