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author | Jaegeuk Kim <jaegeuk@kernel.org> | 2019-09-09 13:10:59 +0100 |
---|---|---|
committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2019-09-16 08:38:20 -0700 |
commit | 743b620cb0516f6b6cbc45b48df00fe6d14d00ba (patch) | |
tree | 3d7a0507ee9008230a9308afbf83664c06985dcf /fs/f2fs | |
parent | 957fa47823dfe449c5a15a944e4e7a299a6601db (diff) | |
download | linux-743b620cb0516f6b6cbc45b48df00fe6d14d00ba.tar.bz2 |
f2fs: avoid infinite GC loop due to stale atomic files
If committing atomic pages is failed when doing f2fs_do_sync_file(), we can
get commited pages but atomic_file being still set like:
- inmem: 0, atomic IO: 4 (Max. 10), volatile IO: 0 (Max. 0)
If GC selects this block, we can get an infinite loop like this:
f2fs_submit_page_bio: dev = (253,7), ino = 2, page_index = 0x2359a8, oldaddr = 0x2359a8, newaddr = 0x2359a8, rw = READ(), type = COLD_DATA
f2fs_submit_read_bio: dev = (253,7)/(253,7), rw = READ(), DATA, sector = 18533696, size = 4096
f2fs_get_victim: dev = (253,7), type = No TYPE, policy = (Foreground GC, LFS-mode, Greedy), victim = 4355, cost = 1, ofs_unit = 1, pre_victim_secno = 4355, prefree = 0, free = 234
f2fs_iget: dev = (253,7), ino = 6247, pino = 5845, i_mode = 0x81b0, i_size = 319488, i_nlink = 1, i_blocks = 624, i_advise = 0x2c
f2fs_submit_page_bio: dev = (253,7), ino = 2, page_index = 0x2359a8, oldaddr = 0x2359a8, newaddr = 0x2359a8, rw = READ(), type = COLD_DATA
f2fs_submit_read_bio: dev = (253,7)/(253,7), rw = READ(), DATA, sector = 18533696, size = 4096
f2fs_get_victim: dev = (253,7), type = No TYPE, policy = (Foreground GC, LFS-mode, Greedy), victim = 4355, cost = 1, ofs_unit = 1, pre_victim_secno = 4355, prefree = 0, free = 234
f2fs_iget: dev = (253,7), ino = 6247, pino = 5845, i_mode = 0x81b0, i_size = 319488, i_nlink = 1, i_blocks = 624, i_advise = 0x2c
In that moment, we can observe:
[Before]
Try to move 5084219 blocks (BG: 384508)
- data blocks : 4962373 (274483)
- node blocks : 121846 (110025)
Skipped : atomic write 4534686 (10)
[After]
Try to move 5088973 blocks (BG: 384508)
- data blocks : 4967127 (274483)
- node blocks : 121846 (110025)
Skipped : atomic write 4539440 (10)
So, refactor atomic_write flow like this:
1. start_atomic_write
- add inmem_list and set atomic_file
2. write()
- register it in inmem_pages
3. commit_atomic_write
- if no error, f2fs_drop_inmem_pages()
- f2fs_commit_inmme_pages() failed
: __revoked_inmem_pages() was done
- f2fs_do_sync_file failed
: abort_atomic_write later
4. abort_atomic_write
- f2fs_drop_inmem_pages
5. f2fs_drop_inmem_pages
- clear atomic_file
- remove inmem_list
Based on this change, when GC fails to move block in atomic_file,
f2fs_drop_inmem_pages_all() can call f2fs_drop_inmem_pages().
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs/f2fs')
-rw-r--r-- | fs/f2fs/file.c | 15 | ||||
-rw-r--r-- | fs/f2fs/segment.c | 29 |
2 files changed, 18 insertions, 26 deletions
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 10927a0b8df3..fab6e4cf8f06 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1829,6 +1829,8 @@ static int f2fs_ioc_getversion(struct file *filp, unsigned long arg) static int f2fs_ioc_start_atomic_write(struct file *filp) { struct inode *inode = file_inode(filp); + struct f2fs_inode_info *fi = F2FS_I(inode); + struct f2fs_sb_info *sbi = F2FS_I_SB(inode); int ret; if (!inode_owner_or_capable(inode)) @@ -1871,6 +1873,12 @@ static int f2fs_ioc_start_atomic_write(struct file *filp) goto out; } + spin_lock(&sbi->inode_lock[ATOMIC_FILE]); + if (list_empty(&fi->inmem_ilist)) + list_add_tail(&fi->inmem_ilist, &sbi->inode_list[ATOMIC_FILE]); + spin_unlock(&sbi->inode_lock[ATOMIC_FILE]); + + /* add inode in inmem_list first and set atomic_file */ set_inode_flag(inode, FI_ATOMIC_FILE); clear_inode_flag(inode, FI_ATOMIC_REVOKE_REQUEST); up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]); @@ -1912,11 +1920,8 @@ static int f2fs_ioc_commit_atomic_write(struct file *filp) goto err_out; ret = f2fs_do_sync_file(filp, 0, LLONG_MAX, 0, true); - if (!ret) { - clear_inode_flag(inode, FI_ATOMIC_FILE); - F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC] = 0; - stat_dec_atomic_write(inode); - } + if (!ret) + f2fs_drop_inmem_pages(inode); } else { ret = f2fs_do_sync_file(filp, 0, LLONG_MAX, 1, false); } diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index 18584d4c078a..204524943bc6 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -185,8 +185,6 @@ bool f2fs_need_SSR(struct f2fs_sb_info *sbi) void f2fs_register_inmem_page(struct inode *inode, struct page *page) { - struct f2fs_sb_info *sbi = F2FS_I_SB(inode); - struct f2fs_inode_info *fi = F2FS_I(inode); struct inmem_pages *new; f2fs_trace_pid(page); @@ -200,15 +198,11 @@ void f2fs_register_inmem_page(struct inode *inode, struct page *page) INIT_LIST_HEAD(&new->list); /* increase reference count with clean state */ - mutex_lock(&fi->inmem_lock); get_page(page); - list_add_tail(&new->list, &fi->inmem_pages); - spin_lock(&sbi->inode_lock[ATOMIC_FILE]); - if (list_empty(&fi->inmem_ilist)) - list_add_tail(&fi->inmem_ilist, &sbi->inode_list[ATOMIC_FILE]); - spin_unlock(&sbi->inode_lock[ATOMIC_FILE]); + mutex_lock(&F2FS_I(inode)->inmem_lock); + list_add_tail(&new->list, &F2FS_I(inode)->inmem_pages); inc_page_count(F2FS_I_SB(inode), F2FS_INMEM_PAGES); - mutex_unlock(&fi->inmem_lock); + mutex_unlock(&F2FS_I(inode)->inmem_lock); trace_f2fs_register_inmem_page(page, INMEM); } @@ -330,19 +324,17 @@ void f2fs_drop_inmem_pages(struct inode *inode) mutex_lock(&fi->inmem_lock); __revoke_inmem_pages(inode, &fi->inmem_pages, true, false, true); - - if (list_empty(&fi->inmem_pages)) { - spin_lock(&sbi->inode_lock[ATOMIC_FILE]); - if (!list_empty(&fi->inmem_ilist)) - list_del_init(&fi->inmem_ilist); - spin_unlock(&sbi->inode_lock[ATOMIC_FILE]); - } mutex_unlock(&fi->inmem_lock); } clear_inode_flag(inode, FI_ATOMIC_FILE); fi->i_gc_failures[GC_FAILURE_ATOMIC] = 0; stat_dec_atomic_write(inode); + + spin_lock(&sbi->inode_lock[ATOMIC_FILE]); + if (!list_empty(&fi->inmem_ilist)) + list_del_init(&fi->inmem_ilist); + spin_unlock(&sbi->inode_lock[ATOMIC_FILE]); } void f2fs_drop_inmem_page(struct inode *inode, struct page *page) @@ -471,11 +463,6 @@ int f2fs_commit_inmem_pages(struct inode *inode) mutex_lock(&fi->inmem_lock); err = __f2fs_commit_inmem_pages(inode); - - spin_lock(&sbi->inode_lock[ATOMIC_FILE]); - if (!list_empty(&fi->inmem_ilist)) - list_del_init(&fi->inmem_ilist); - spin_unlock(&sbi->inode_lock[ATOMIC_FILE]); mutex_unlock(&fi->inmem_lock); clear_inode_flag(inode, FI_ATOMIC_COMMIT); |