| Message ID | 20240712073415.227226-1-chao@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [f2fs-dev] f2fs: don't traverse directory blocks after EOF | expand |
On 07/12, Chao Yu wrote: > All directory blocks are within the scope of i_size, so let's limit > the end_block to just check valid dirent blocks. Do we really need this? > > Meanwhile, it uses dir_blocks() instead of variable for cleanup in > __f2fs_find_entry(). > > Signed-off-by: Chao Yu <chao@kernel.org> > --- > fs/f2fs/dir.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c > index 02c9355176d3..d4591c215f07 100644 > --- a/fs/f2fs/dir.c > +++ b/fs/f2fs/dir.c > @@ -305,18 +305,21 @@ static struct f2fs_dir_entry *find_in_level(struct inode *dir, > int s = GET_DENTRY_SLOTS(fname->disk_name.len); > unsigned int nbucket, nblock; > unsigned int bidx, end_block; > + unsigned long last_block; > struct page *dentry_page; > struct f2fs_dir_entry *de = NULL; > pgoff_t next_pgofs; > bool room = false; > int max_slots; > > + last_block = dir_blocks(dir); > nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level); > nblock = bucket_blocks(level); > > bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level, > le32_to_cpu(fname->hash) % nbucket); > end_block = bidx + nblock; > + end_block = min_t(unsigned int, end_block, last_block); > > while (bidx < end_block) { > /* no need to allocate new dentry pages to all the indices */ > @@ -361,7 +364,6 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, > const struct f2fs_filename *fname, > struct page **res_page) > { > - unsigned long npages = dir_blocks(dir); > struct f2fs_dir_entry *de = NULL; > unsigned int max_depth; > unsigned int level; > @@ -373,7 +375,7 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, > goto out; > } > > - if (npages == 0) > + if (dir_blocks(dir) == 0) > goto out; > > max_depth = F2FS_I(dir)->i_current_depth; > -- > 2.40.1
On 2024/7/26 0:55, Jaegeuk Kim wrote: > On 07/12, Chao Yu wrote: >> All directory blocks are within the scope of i_size, so let's limit >> the end_block to just check valid dirent blocks. > > Do we really need this? f2fs_readdir() and f2fs_empty_dir() uses dir_blocks() for upper boundary, this patch aligns find_in_level() w/ them. Also, it can avoid grabbing never used page cache across EOF. So, we can consider taking this patch? Thanks, > >> >> Meanwhile, it uses dir_blocks() instead of variable for cleanup in >> __f2fs_find_entry(). >> >> Signed-off-by: Chao Yu <chao@kernel.org> >> --- >> fs/f2fs/dir.c | 6 ++++-- >> 1 file changed, 4 insertions(+), 2 deletions(-) >> >> diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c >> index 02c9355176d3..d4591c215f07 100644 >> --- a/fs/f2fs/dir.c >> +++ b/fs/f2fs/dir.c >> @@ -305,18 +305,21 @@ static struct f2fs_dir_entry *find_in_level(struct inode *dir, >> int s = GET_DENTRY_SLOTS(fname->disk_name.len); >> unsigned int nbucket, nblock; >> unsigned int bidx, end_block; >> + unsigned long last_block; >> struct page *dentry_page; >> struct f2fs_dir_entry *de = NULL; >> pgoff_t next_pgofs; >> bool room = false; >> int max_slots; >> >> + last_block = dir_blocks(dir); >> nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level); >> nblock = bucket_blocks(level); >> >> bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level, >> le32_to_cpu(fname->hash) % nbucket); >> end_block = bidx + nblock; >> + end_block = min_t(unsigned int, end_block, last_block); >> >> while (bidx < end_block) { >> /* no need to allocate new dentry pages to all the indices */ >> @@ -361,7 +364,6 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, >> const struct f2fs_filename *fname, >> struct page **res_page) >> { >> - unsigned long npages = dir_blocks(dir); >> struct f2fs_dir_entry *de = NULL; >> unsigned int max_depth; >> unsigned int level; >> @@ -373,7 +375,7 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, >> goto out; >> } >> >> - if (npages == 0) >> + if (dir_blocks(dir) == 0) >> goto out; >> >> max_depth = F2FS_I(dir)->i_current_depth; >> -- >> 2.40.1
On 07/26, Chao Yu wrote: > On 2024/7/26 0:55, Jaegeuk Kim wrote: > > On 07/12, Chao Yu wrote: > > > All directory blocks are within the scope of i_size, so let's limit > > > the end_block to just check valid dirent blocks. > > > > Do we really need this? > > f2fs_readdir() and f2fs_empty_dir() uses dir_blocks() for upper boundary, > this patch aligns find_in_level() w/ them. > > Also, it can avoid grabbing never used page cache across EOF. > > So, we can consider taking this patch? I'm wondering whether the current code has a bug or not. > > Thanks, > > > > > > > > > Meanwhile, it uses dir_blocks() instead of variable for cleanup in > > > __f2fs_find_entry(). > > > > > > Signed-off-by: Chao Yu <chao@kernel.org> > > > --- > > > fs/f2fs/dir.c | 6 ++++-- > > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > > > diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c > > > index 02c9355176d3..d4591c215f07 100644 > > > --- a/fs/f2fs/dir.c > > > +++ b/fs/f2fs/dir.c > > > @@ -305,18 +305,21 @@ static struct f2fs_dir_entry *find_in_level(struct inode *dir, > > > int s = GET_DENTRY_SLOTS(fname->disk_name.len); > > > unsigned int nbucket, nblock; > > > unsigned int bidx, end_block; > > > + unsigned long last_block; > > > struct page *dentry_page; > > > struct f2fs_dir_entry *de = NULL; > > > pgoff_t next_pgofs; > > > bool room = false; > > > int max_slots; > > > + last_block = dir_blocks(dir); > > > nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level); > > > nblock = bucket_blocks(level); > > > bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level, > > > le32_to_cpu(fname->hash) % nbucket); > > > end_block = bidx + nblock; > > > + end_block = min_t(unsigned int, end_block, last_block); > > > while (bidx < end_block) { > > > /* no need to allocate new dentry pages to all the indices */ > > > @@ -361,7 +364,6 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, > > > const struct f2fs_filename *fname, > > > struct page **res_page) > > > { > > > - unsigned long npages = dir_blocks(dir); > > > struct f2fs_dir_entry *de = NULL; > > > unsigned int max_depth; > > > unsigned int level; > > > @@ -373,7 +375,7 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, > > > goto out; > > > } > > > - if (npages == 0) > > > + if (dir_blocks(dir) == 0) > > > goto out; > > > max_depth = F2FS_I(dir)->i_current_depth; > > > -- > > > 2.40.1
On 2024/7/27 11:27, Jaegeuk Kim wrote: > On 07/26, Chao Yu wrote: >> On 2024/7/26 0:55, Jaegeuk Kim wrote: >>> On 07/12, Chao Yu wrote: >>>> All directory blocks are within the scope of i_size, so let's limit >>>> the end_block to just check valid dirent blocks. >>> >>> Do we really need this? >> >> f2fs_readdir() and f2fs_empty_dir() uses dir_blocks() for upper boundary, >> this patch aligns find_in_level() w/ them. >> >> Also, it can avoid grabbing never used page cache across EOF. >> >> So, we can consider taking this patch? > > I'm wondering whether the current code has a bug or not. I think it's not a bug, but, in corner case it may waste memory and cause a bit performance reduction. Thanks, > >> >> Thanks, >> >>> >>>> >>>> Meanwhile, it uses dir_blocks() instead of variable for cleanup in >>>> __f2fs_find_entry(). >>>> >>>> Signed-off-by: Chao Yu <chao@kernel.org> >>>> --- >>>> fs/f2fs/dir.c | 6 ++++-- >>>> 1 file changed, 4 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c >>>> index 02c9355176d3..d4591c215f07 100644 >>>> --- a/fs/f2fs/dir.c >>>> +++ b/fs/f2fs/dir.c >>>> @@ -305,18 +305,21 @@ static struct f2fs_dir_entry *find_in_level(struct inode *dir, >>>> int s = GET_DENTRY_SLOTS(fname->disk_name.len); >>>> unsigned int nbucket, nblock; >>>> unsigned int bidx, end_block; >>>> + unsigned long last_block; >>>> struct page *dentry_page; >>>> struct f2fs_dir_entry *de = NULL; >>>> pgoff_t next_pgofs; >>>> bool room = false; >>>> int max_slots; >>>> + last_block = dir_blocks(dir); >>>> nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level); >>>> nblock = bucket_blocks(level); >>>> bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level, >>>> le32_to_cpu(fname->hash) % nbucket); >>>> end_block = bidx + nblock; >>>> + end_block = min_t(unsigned int, end_block, last_block); >>>> while (bidx < end_block) { >>>> /* no need to allocate new dentry pages to all the indices */ >>>> @@ -361,7 +364,6 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, >>>> const struct f2fs_filename *fname, >>>> struct page **res_page) >>>> { >>>> - unsigned long npages = dir_blocks(dir); >>>> struct f2fs_dir_entry *de = NULL; >>>> unsigned int max_depth; >>>> unsigned int level; >>>> @@ -373,7 +375,7 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, >>>> goto out; >>>> } >>>> - if (npages == 0) >>>> + if (dir_blocks(dir) == 0) >>>> goto out; >>>> max_depth = F2FS_I(dir)->i_current_depth; >>>> -- >>>> 2.40.1
On 07/29, Chao Yu wrote: > On 2024/7/27 11:27, Jaegeuk Kim wrote: > > On 07/26, Chao Yu wrote: > > > On 2024/7/26 0:55, Jaegeuk Kim wrote: > > > > On 07/12, Chao Yu wrote: > > > > > All directory blocks are within the scope of i_size, so let's limit > > > > > the end_block to just check valid dirent blocks. > > > > > > > > Do we really need this? > > > > > > f2fs_readdir() and f2fs_empty_dir() uses dir_blocks() for upper boundary, > > > this patch aligns find_in_level() w/ them. > > > > > > Also, it can avoid grabbing never used page cache across EOF. > > > > > > So, we can consider taking this patch? > > > > I'm wondering whether the current code has a bug or not. > > I think it's not a bug, but, in corner case it may waste memory and > cause a bit performance reduction. Well, I don't think it's really a problem. > > Thanks, > > > > > > > > > Thanks, > > > > > > > > > > > > > > > > > Meanwhile, it uses dir_blocks() instead of variable for cleanup in > > > > > __f2fs_find_entry(). > > > > > > > > > > Signed-off-by: Chao Yu <chao@kernel.org> > > > > > --- > > > > > fs/f2fs/dir.c | 6 ++++-- > > > > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > > > > > > > diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c > > > > > index 02c9355176d3..d4591c215f07 100644 > > > > > --- a/fs/f2fs/dir.c > > > > > +++ b/fs/f2fs/dir.c > > > > > @@ -305,18 +305,21 @@ static struct f2fs_dir_entry *find_in_level(struct inode *dir, > > > > > int s = GET_DENTRY_SLOTS(fname->disk_name.len); > > > > > unsigned int nbucket, nblock; > > > > > unsigned int bidx, end_block; > > > > > + unsigned long last_block; > > > > > struct page *dentry_page; > > > > > struct f2fs_dir_entry *de = NULL; > > > > > pgoff_t next_pgofs; > > > > > bool room = false; > > > > > int max_slots; > > > > > + last_block = dir_blocks(dir); > > > > > nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level); > > > > > nblock = bucket_blocks(level); > > > > > bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level, > > > > > le32_to_cpu(fname->hash) % nbucket); > > > > > end_block = bidx + nblock; > > > > > + end_block = min_t(unsigned int, end_block, last_block); > > > > > while (bidx < end_block) { > > > > > /* no need to allocate new dentry pages to all the indices */ > > > > > @@ -361,7 +364,6 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, > > > > > const struct f2fs_filename *fname, > > > > > struct page **res_page) > > > > > { > > > > > - unsigned long npages = dir_blocks(dir); > > > > > struct f2fs_dir_entry *de = NULL; > > > > > unsigned int max_depth; > > > > > unsigned int level; > > > > > @@ -373,7 +375,7 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, > > > > > goto out; > > > > > } > > > > > - if (npages == 0) > > > > > + if (dir_blocks(dir) == 0) > > > > > goto out; > > > > > max_depth = F2FS_I(dir)->i_current_depth; > > > > > -- > > > > > 2.40.1
diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c index 02c9355176d3..d4591c215f07 100644 --- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -305,18 +305,21 @@ static struct f2fs_dir_entry *find_in_level(struct inode *dir, int s = GET_DENTRY_SLOTS(fname->disk_name.len); unsigned int nbucket, nblock; unsigned int bidx, end_block; + unsigned long last_block; struct page *dentry_page; struct f2fs_dir_entry *de = NULL; pgoff_t next_pgofs; bool room = false; int max_slots; + last_block = dir_blocks(dir); nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level); nblock = bucket_blocks(level); bidx = dir_block_index(level, F2FS_I(dir)->i_dir_level, le32_to_cpu(fname->hash) % nbucket); end_block = bidx + nblock; + end_block = min_t(unsigned int, end_block, last_block); while (bidx < end_block) { /* no need to allocate new dentry pages to all the indices */ @@ -361,7 +364,6 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, const struct f2fs_filename *fname, struct page **res_page) { - unsigned long npages = dir_blocks(dir); struct f2fs_dir_entry *de = NULL; unsigned int max_depth; unsigned int level; @@ -373,7 +375,7 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, goto out; } - if (npages == 0) + if (dir_blocks(dir) == 0) goto out; max_depth = F2FS_I(dir)->i_current_depth;
All directory blocks are within the scope of i_size, so let's limit the end_block to just check valid dirent blocks. Meanwhile, it uses dir_blocks() instead of variable for cleanup in __f2fs_find_entry(). Signed-off-by: Chao Yu <chao@kernel.org> --- fs/f2fs/dir.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)