From: Kyungmin Park <[email protected]>
FAT supports batched discard as ext4.
Cited from Lukas words.
"The current solution is not ideal because of its bad performance impact.
So basic idea to improve things is to avoid discarding every time some
blocks are freed. and instead batching is together into bigger trims,
which tends to be more effective."
You can find an information in detail at following URLs.
http://lwn.net/Articles/397538/
http://lwn.net/Articles/383933/
Signed-off-by: Kyungmin Park <[email protected]>
---
Changelog V2:
Use the given start and len as Lukas comments
Check the queue supports discard feature
---
diff --git a/fs/fat/fat.h b/fs/fat/fat.h
index f504089..08b53e1 100644
--- a/fs/fat/fat.h
+++ b/fs/fat/fat.h
@@ -299,6 +299,7 @@ extern int fat_alloc_clusters(struct inode *inode, int *cluster,
int nr_cluster);
extern int fat_free_clusters(struct inode *inode, int cluster);
extern int fat_count_free_clusters(struct super_block *sb);
+extern int fat_trim_fs(struct super_block *sb, struct fstrim_range *range);
/* fat/file.c */
extern long fat_generic_ioctl(struct file *filp, unsigned int cmd,
diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c
index b47d2c9..ea31ee4 100644
--- a/fs/fat/fatent.c
+++ b/fs/fat/fatent.c
@@ -1,6 +1,8 @@
/*
* Copyright (C) 2004, OGAWA Hirofumi
* Released under GPL v2.
+ *
+ * Batched discard support by Kyungmin Park <[email protected]>
*/
#include <linux/module.h>
@@ -541,6 +543,16 @@ out:
return err;
}
+static int fat_issue_discard(struct super_block *sb, int cluster, int nr_clus)
+{
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+ sector_t block, nr_blocks;
+
+ block = fat_clus_to_blknr(sbi, cluster);
+ nr_blocks = nr_clus * sbi->sec_per_clus;
+ return sb_issue_discard(sb, block, nr_blocks, GFP_NOFS, 0);
+}
+
int fat_free_clusters(struct inode *inode, int cluster)
{
struct super_block *sb = inode->i_sb;
@@ -575,11 +587,7 @@ int fat_free_clusters(struct inode *inode, int cluster)
if (cluster != fatent.entry + 1) {
int nr_clus = fatent.entry - first_cl + 1;
- sb_issue_discard(sb,
- fat_clus_to_blknr(sbi, first_cl),
- nr_clus * sbi->sec_per_clus,
- GFP_NOFS, 0);
-
+ fat_issue_discard(sb, first_cl, nr_clus);
first_cl = cluster;
}
}
@@ -683,3 +691,88 @@ out:
unlock_fat(sbi);
return err;
}
+
+int fat_trim_fs(struct super_block *sb, struct fstrim_range *range)
+{
+ struct msdos_sb_info *sbi = MSDOS_SB(sb);
+ struct fatent_operations *ops = sbi->fatent_ops;
+ struct fat_entry fatent;
+ unsigned long reada_blocks, reada_mask, cur_block;
+ int err = 0, free, count, entry;
+ int start, len, minlen, trimmed;
+
+ start = range->start >> sb->s_blocksize_bits;
+ start = start / sbi->sec_per_clus;
+ len = range->len >> sb->s_blocksize_bits;
+ len = len / sbi->sec_per_clus;
+ minlen = range->minlen >> sb->s_blocksize_bits;
+ minlen = minlen / sbi->sec_per_clus;
+ trimmed = 0;
+ count = 0;
+
+ lock_fat(sbi);
+ if (sbi->free_clusters != -1 && sbi->free_clus_valid)
+ goto out;
+
+ reada_blocks = FAT_READA_SIZE >> sb->s_blocksize_bits;
+ reada_mask = reada_blocks - 1;
+ cur_block = 0;
+
+ entry = 0;
+ free = 0;
+ fatent_init(&fatent);
+
+ if (start < FAT_START_ENT)
+ start = FAT_START_ENT;
+
+ fatent_set_entry(&fatent, FAT_START_ENT);
+
+ while (count < sbi->max_cluster) {
+ if (fatent.entry >= sbi->max_cluster)
+ fatent.entry = FAT_START_ENT;
+ /* readahead of fat blocks */
+ if ((cur_block & reada_mask) == 0) {
+ unsigned long rest = sbi->fat_length - cur_block;
+ fat_ent_reada(sb, &fatent, min(reada_blocks, rest));
+ }
+ cur_block++;
+
+ err = fat_ent_read_block(sb, &fatent);
+ if (err)
+ goto out;
+
+ do {
+ if (ops->ent_get(&fatent) == FAT_ENT_FREE) {
+ free++;
+ if (!entry)
+ entry = fatent.entry;
+ if (free >= (len - trimmed) && free >= minlen) {
+ fat_issue_discard(sb, entry, free);
+ trimmed += free;
+ }
+ if (trimmed >= len)
+ goto done;
+ } else if (entry) {
+ if (free >= minlen) {
+ fat_issue_discard(sb, entry, free);
+ trimmed += free;
+ }
+ if (trimmed >= len)
+ goto done;
+ free = 0;
+ entry = 0;
+ }
+ count++;
+ } while (fat_ent_next(sbi, &fatent));
+ }
+ if (free >= minlen) {
+ fat_issue_discard(sb, entry, free);
+ trimmed += free;
+ }
+done:
+ range->len = (trimmed * sbi->sec_per_clus) << sb->s_blocksize_bits;
+ fatent_brelse(&fatent);
+out:
+ unlock_fat(sbi);
+ return err;
+}
diff --git a/fs/fat/file.c b/fs/fat/file.c
index 7257752..05e6545 100644
--- a/fs/fat/file.c
+++ b/fs/fat/file.c
@@ -125,6 +125,34 @@ long fat_generic_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
return fat_ioctl_get_attributes(inode, user_attr);
case FAT_IOCTL_SET_ATTRIBUTES:
return fat_ioctl_set_attributes(filp, user_attr);
+ case FITRIM:
+ {
+ struct super_block *sb = inode->i_sb;
+ struct request_queue *q = bdev_get_queue(sb->s_bdev);
+ struct fstrim_range range;
+ int ret = 0;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ if (!blk_queue_discard(q))
+ return -EOPNOTSUPP;
+
+ if (copy_from_user(&range, (struct fstrim_range *)arg,
+ sizeof(range)))
+ return -EFAULT;
+
+ ret = fat_trim_fs(sb, &range);
+ if (ret < 0)
+ return ret;
+
+ if (copy_to_user((struct fstrim_range *)arg, &range,
+ sizeof(range)))
+ return -EFAULT;
+
+ return 0;
+ }
+
default:
return -ENOTTY; /* Inappropriate ioctl for device */
}
On Thu, 24 Feb 2011, Kyungmin Park wrote:
> From: Kyungmin Park <[email protected]>
>
> FAT supports batched discard as ext4.
>
> Cited from Lukas words.
> "The current solution is not ideal because of its bad performance impact.
> So basic idea to improve things is to avoid discarding every time some
> blocks are freed. and instead batching is together into bigger trims,
> which tends to be more effective."
>
> You can find an information in detail at following URLs.
> http://lwn.net/Articles/397538/
> http://lwn.net/Articles/383933/
>
> Signed-off-by: Kyungmin Park <[email protected]>
Hi Kyungmin,
thanks to second version. How did you test it ? You can try xtestest
251 for simple verification.
I can not really comment on FAT specific code, however I have couple of
comments bellow.
Thanks!
-Lukas
> ---
> Changelog V2:
> Use the given start and len as Lukas comments
> Check the queue supports discard feature
> ---
> diff --git a/fs/fat/fat.h b/fs/fat/fat.h
> index f504089..08b53e1 100644
> --- a/fs/fat/fat.h
> +++ b/fs/fat/fat.h
> @@ -299,6 +299,7 @@ extern int fat_alloc_clusters(struct inode *inode, int *cluster,
> int nr_cluster);
> extern int fat_free_clusters(struct inode *inode, int cluster);
> extern int fat_count_free_clusters(struct super_block *sb);
> +extern int fat_trim_fs(struct super_block *sb, struct fstrim_range *range);
>
> /* fat/file.c */
> extern long fat_generic_ioctl(struct file *filp, unsigned int cmd,
> diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c
> index b47d2c9..ea31ee4 100644
> --- a/fs/fat/fatent.c
> +++ b/fs/fat/fatent.c
> @@ -1,6 +1,8 @@
> /*
> * Copyright (C) 2004, OGAWA Hirofumi
> * Released under GPL v2.
> + *
> + * Batched discard support by Kyungmin Park <[email protected]>
> */
>
> #include <linux/module.h>
> @@ -541,6 +543,16 @@ out:
> return err;
> }
>
> +static int fat_issue_discard(struct super_block *sb, int cluster, int nr_clus)
> +{
> + struct msdos_sb_info *sbi = MSDOS_SB(sb);
> + sector_t block, nr_blocks;
> +
> + block = fat_clus_to_blknr(sbi, cluster);
> + nr_blocks = nr_clus * sbi->sec_per_clus;
> + return sb_issue_discard(sb, block, nr_blocks, GFP_NOFS, 0);
^^^^^^^^
This patch does not pass checkpatch.pl script. Use tabs for indention.
> +}
> +
> int fat_free_clusters(struct inode *inode, int cluster)
> {
> struct super_block *sb = inode->i_sb;
> @@ -575,11 +587,7 @@ int fat_free_clusters(struct inode *inode, int cluster)
> if (cluster != fatent.entry + 1) {
> int nr_clus = fatent.entry - first_cl + 1;
>
> - sb_issue_discard(sb,
> - fat_clus_to_blknr(sbi, first_cl),
> - nr_clus * sbi->sec_per_clus,
> - GFP_NOFS, 0);
> -
> + fat_issue_discard(sb, first_cl, nr_clus);
> first_cl = cluster;
> }
> }
> @@ -683,3 +691,88 @@ out:
> unlock_fat(sbi);
> return err;
> }
> +
> +int fat_trim_fs(struct super_block *sb, struct fstrim_range *range)
> +{
> + struct msdos_sb_info *sbi = MSDOS_SB(sb);
> + struct fatent_operations *ops = sbi->fatent_ops;
> + struct fat_entry fatent;
> + unsigned long reada_blocks, reada_mask, cur_block;
> + int err = 0, free, count, entry;
> + int start, len, minlen, trimmed;
> +
> + start = range->start >> sb->s_blocksize_bits;
> + start = start / sbi->sec_per_clus;
> + len = range->len >> sb->s_blocksize_bits;
> + len = len / sbi->sec_per_clus;
> + minlen = range->minlen >> sb->s_blocksize_bits;
> + minlen = minlen / sbi->sec_per_clus;
I should have mention that earlier, but you can also adjust mineln
according to the discard_granularity, because extents smaller than that
would not be discarded anyway.
> + trimmed = 0;
> + count = 0;
> +
> + lock_fat(sbi);
> + if (sbi->free_clusters != -1 && sbi->free_clus_valid)
> + goto out;
> +
> + reada_blocks = FAT_READA_SIZE >> sb->s_blocksize_bits;
> + reada_mask = reada_blocks - 1;
> + cur_block = 0;
> +
> + entry = 0;
> + free = 0;
> + fatent_init(&fatent);
> +
> + if (start < FAT_START_ENT)
> + start = FAT_START_ENT;
You're not using start anywhere.
> +
> + fatent_set_entry(&fatent, FAT_START_ENT);
> +
> + while (count < sbi->max_cluster) {
> + if (fatent.entry >= sbi->max_cluster)
> + fatent.entry = FAT_START_ENT;
> + /* readahead of fat blocks */
> + if ((cur_block & reada_mask) == 0) {
> + unsigned long rest = sbi->fat_length - cur_block;
> + fat_ent_reada(sb, &fatent, min(reada_blocks, rest));
> + }
> + cur_block++;
> +
> + err = fat_ent_read_block(sb, &fatent);
> + if (err)
> + goto out;
> +
> + do {
> + if (ops->ent_get(&fatent) == FAT_ENT_FREE) {
> + free++;
> + if (!entry)
> + entry = fatent.entry;
> + if (free >= (len - trimmed) && free >= minlen) {
It seems to me that you are using len as number of bytes to trim. This
is not right and I am sorry for not explaining it correctly. "len" is
supposed to be a number of bytes you want to "investigate" from the start.
So it means that you will trim every single free extent bigger than minlen
between "start" byte and "start + len" byte of the underlying device, or
partition.
> + fat_issue_discard(sb, entry, free);
> + trimmed += free;
> + }
> + if (trimmed >= len)
> + goto done;
> + } else if (entry) {
> + if (free >= minlen) {
> + fat_issue_discard(sb, entry, free);
> + trimmed += free;
> + }
> + if (trimmed >= len)
> + goto done;
> + free = 0;
> + entry = 0;
> + }
> + count++;
> + } while (fat_ent_next(sbi, &fatent));
> + }
> + if (free >= minlen) {
> + fat_issue_discard(sb, entry, free);
> + trimmed += free;
> + }
> +done:
> + range->len = (trimmed * sbi->sec_per_clus) << sb->s_blocksize_bits;
> + fatent_brelse(&fatent);
> +out:
> + unlock_fat(sbi);
> + return err;
> +}
> diff --git a/fs/fat/file.c b/fs/fat/file.c
> index 7257752..05e6545 100644
> --- a/fs/fat/file.c
> +++ b/fs/fat/file.c
> @@ -125,6 +125,34 @@ long fat_generic_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
> return fat_ioctl_get_attributes(inode, user_attr);
> case FAT_IOCTL_SET_ATTRIBUTES:
> return fat_ioctl_set_attributes(filp, user_attr);
> + case FITRIM:
> + {
> + struct super_block *sb = inode->i_sb;
> + struct request_queue *q = bdev_get_queue(sb->s_bdev);
> + struct fstrim_range range;
> + int ret = 0;
> +
> + if (!capable(CAP_SYS_ADMIN))
> + return -EPERM;
> +
> + if (!blk_queue_discard(q))
> + return -EOPNOTSUPP;
> +
> + if (copy_from_user(&range, (struct fstrim_range *)arg,
> + sizeof(range)))
> + return -EFAULT;
> +
> + ret = fat_trim_fs(sb, &range);
> + if (ret < 0)
> + return ret;
> +
> + if (copy_to_user((struct fstrim_range *)arg, &range,
> + sizeof(range)))
> + return -EFAULT;
> +
> + return 0;
> + }
> +
> default:
> return -ENOTTY; /* Inappropriate ioctl for device */
> }
>
--
On Thu, Feb 24, 2011 at 5:53 PM, Lukas Czerner <[email protected]> wrote:
> On Thu, 24 Feb 2011, Kyungmin Park wrote:
>
>> From: Kyungmin Park <[email protected]>
>>
>> FAT supports batched discard as ext4.
>>
>> Cited from Lukas words.
>> "The current solution is not ideal because of its bad performance impact.
>> So basic idea to improve things is to avoid discarding every time some
>> blocks are freed. and instead batching is together into bigger trims,
>> which tends to be more effective."
>>
>> You can find an information in detail at following URLs.
>> http://lwn.net/Articles/397538/
>> http://lwn.net/Articles/383933/
>>
>> Signed-off-by: Kyungmin Park <[email protected]>
>
> Hi Kyungmin,
> thanks to second version. How did you test it ? You can try xtestest
> 251 for simple verification.
> I can not really comment on FAT specific code, however I have couple of
> comments bellow.
>
> Thanks!
> -Lukas
>
>> ---
>> Changelog V2:
>> ? ? ? Use the given start and len as Lukas comments
>> ? ? ? Check the queue supports discard feature
>> ---
>> diff --git a/fs/fat/fat.h b/fs/fat/fat.h
>> index f504089..08b53e1 100644
>> --- a/fs/fat/fat.h
>> +++ b/fs/fat/fat.h
>> @@ -299,6 +299,7 @@ extern int fat_alloc_clusters(struct inode *inode, int *cluster,
>> ? ? ? ? ? ? ? ? ? ? ? ? ? ? int nr_cluster);
>> ?extern int fat_free_clusters(struct inode *inode, int cluster);
>> ?extern int fat_count_free_clusters(struct super_block *sb);
>> +extern int fat_trim_fs(struct super_block *sb, struct fstrim_range *range);
>>
>> ?/* fat/file.c */
>> ?extern long fat_generic_ioctl(struct file *filp, unsigned int cmd,
>> diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c
>> index b47d2c9..ea31ee4 100644
>> --- a/fs/fat/fatent.c
>> +++ b/fs/fat/fatent.c
>> @@ -1,6 +1,8 @@
>> ?/*
>> ? * Copyright (C) 2004, OGAWA Hirofumi
>> ? * Released under GPL v2.
>> + *
>> + * Batched discard support by Kyungmin Park <[email protected]>
>> ? */
>>
>> ?#include <linux/module.h>
>> @@ -541,6 +543,16 @@ out:
>> ? ? ? return err;
>> ?}
>>
>> +static int fat_issue_discard(struct super_block *sb, int cluster, int nr_clus)
>> +{
>> + ? ? struct msdos_sb_info *sbi = MSDOS_SB(sb);
>> + ? ? sector_t block, nr_blocks;
>> +
>> + ? ? ? ?block = fat_clus_to_blknr(sbi, cluster);
>> + ? ? ? ?nr_blocks = nr_clus * sbi->sec_per_clus;
>> + ? ? ? ?return sb_issue_discard(sb, block, nr_blocks, GFP_NOFS, 0);
> ? ^^^^^^^^
> This patch does not pass checkpatch.pl script. Use tabs for indention.
right, I will fix it. now passed the checkpatch.pl.
>
>> +}
>> +
>> ?int fat_free_clusters(struct inode *inode, int cluster)
>> ?{
>> ? ? ? struct super_block *sb = inode->i_sb;
>> @@ -575,11 +587,7 @@ int fat_free_clusters(struct inode *inode, int cluster)
>> ? ? ? ? ? ? ? ? ? ? ? if (cluster != fatent.entry + 1) {
>> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? int nr_clus = fatent.entry - first_cl + 1;
>>
>> - ? ? ? ? ? ? ? ? ? ? ? ? ? ? sb_issue_discard(sb,
>> - ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? fat_clus_to_blknr(sbi, first_cl),
>> - ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? nr_clus * sbi->sec_per_clus,
>> - ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? GFP_NOFS, 0);
>> -
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? fat_issue_discard(sb, first_cl, nr_clus);
>> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? first_cl = cluster;
>> ? ? ? ? ? ? ? ? ? ? ? }
>> ? ? ? ? ? ? ? }
>> @@ -683,3 +691,88 @@ out:
>> ? ? ? unlock_fat(sbi);
>> ? ? ? return err;
>> ?}
>> +
>> +int fat_trim_fs(struct super_block *sb, struct fstrim_range *range)
>> +{
>> + ? ? struct msdos_sb_info *sbi = MSDOS_SB(sb);
>> + ? ? struct fatent_operations *ops = sbi->fatent_ops;
>> + ? ? struct fat_entry fatent;
>> + ? ? unsigned long reada_blocks, reada_mask, cur_block;
>> + ? ? int err = 0, free, count, entry;
>> + ? ? int start, len, minlen, trimmed;
>> +
>> + ? ? start = range->start >> sb->s_blocksize_bits;
>> + ? ? start = start / sbi->sec_per_clus;
>> + ? ? len = range->len >> sb->s_blocksize_bits;
>> + ? ? len = len / sbi->sec_per_clus;
>> + ? ? minlen = range->minlen >> sb->s_blocksize_bits;
>> + ? ? minlen = minlen / sbi->sec_per_clus;
>
> I should have mention that earlier, but you can also adjust mineln
> according to the discard_granularity, because extents smaller than that
> would not be discarded anyway.
I adjust the minlen granularity with fat cluster unit. and FAT don't
know what's the effected block size. it's role of user side.
>
>> + ? ? trimmed = 0;
>> + ? ? count = 0;
>> +
>> + ? ? lock_fat(sbi);
>> + ? ? if (sbi->free_clusters != -1 && sbi->free_clus_valid)
>> + ? ? ? ? ? ? goto out;
>> +
>> + ? ? reada_blocks = FAT_READA_SIZE >> sb->s_blocksize_bits;
>> + ? ? reada_mask = reada_blocks - 1;
>> + ? ? cur_block = 0;
>> +
>> + ? ? entry = 0;
>> + ? ? free = 0;
>> + ? ? fatent_init(&fatent);
>> +
>> + ? ? if (start < FAT_START_ENT)
>> + ? ? ? ? ? ? start = FAT_START_ENT;
>
> You're not using start anywhere.
>
>> +
>> + ? ? fatent_set_entry(&fatent, FAT_START_ENT);
It should be fatent_set_entry(&fatent, start);
>> +
>> + ? ? while (count < sbi->max_cluster) {
>> + ? ? ? ? ? ? if (fatent.entry >= sbi->max_cluster)
>> + ? ? ? ? ? ? ? ? ? ? fatent.entry = FAT_START_ENT;
>> + ? ? ? ? ? ? /* readahead of fat blocks */
>> + ? ? ? ? ? ? if ((cur_block & reada_mask) == 0) {
>> + ? ? ? ? ? ? ? ? ? ? unsigned long rest = sbi->fat_length - cur_block;
>> + ? ? ? ? ? ? ? ? ? ? fat_ent_reada(sb, &fatent, min(reada_blocks, rest));
>> + ? ? ? ? ? ? }
>> + ? ? ? ? ? ? cur_block++;
>> +
>> + ? ? ? ? ? ? err = fat_ent_read_block(sb, &fatent);
>> + ? ? ? ? ? ? if (err)
>> + ? ? ? ? ? ? ? ? ? ? goto out;
>> +
>> + ? ? ? ? ? ? do {
>> + ? ? ? ? ? ? ? ? ? ? if (ops->ent_get(&fatent) == FAT_ENT_FREE) {
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? free++;
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (!entry)
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? entry = fatent.entry;
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (free >= (len - trimmed) && free >= minlen) {
>
> It seems to me that you are using len as number of bytes to trim. This
> is not right and I am sorry for not explaining it correctly. "len" is
> supposed to be a number of bytes you want to "investigate" from the start.
> So it means that you will trim every single free extent bigger than minlen
> between "start" byte and "start + len" byte of the underlying device, or
> partition.
No. len is adjusted at fat cluster number. it's not used byte unit.
I think it's easy to compare with fat internal units.
I hope fat peoples comment this one.
Thank you,
Kyungmin Park
>
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? fat_issue_discard(sb, entry, free);
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? trimmed += free;
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? }
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (trimmed >= len)
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? goto done;
>> + ? ? ? ? ? ? ? ? ? ? } else if (entry) {
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (free >= minlen) {
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? fat_issue_discard(sb, entry, free);
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? trimmed += free;
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? }
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (trimmed >= len)
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? goto done;
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? free = 0;
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? entry = 0;
>> + ? ? ? ? ? ? ? ? ? ? }
>> + ? ? ? ? ? ? ? ? ? ? count++;
>> + ? ? ? ? ? ? } while (fat_ent_next(sbi, &fatent));
>> + ? ? }
>> + ? ? if (free >= minlen) {
>> + ? ? ? ? ? ? fat_issue_discard(sb, entry, free);
>> + ? ? ? ? ? ? trimmed += free;
>> + ? ? }
>> +done:
>> + ? ? range->len = (trimmed * sbi->sec_per_clus) << sb->s_blocksize_bits;
>> + ? ? fatent_brelse(&fatent);
>> +out:
>> + ? ? unlock_fat(sbi);
>> + ? ? return err;
>> +}
>> diff --git a/fs/fat/file.c b/fs/fat/file.c
>> index 7257752..05e6545 100644
>> --- a/fs/fat/file.c
>> +++ b/fs/fat/file.c
>> @@ -125,6 +125,34 @@ long fat_generic_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
>> ? ? ? ? ? ? ? return fat_ioctl_get_attributes(inode, user_attr);
>> ? ? ? case FAT_IOCTL_SET_ATTRIBUTES:
>> ? ? ? ? ? ? ? return fat_ioctl_set_attributes(filp, user_attr);
>> + ? ? case FITRIM:
>> + ? ? {
>> + ? ? ? ? ? ? struct super_block *sb = inode->i_sb;
>> + ? ? ? ? ? ? struct request_queue *q = bdev_get_queue(sb->s_bdev);
>> + ? ? ? ? ? ? struct fstrim_range range;
>> + ? ? ? ? ? ? int ret = 0;
>> +
>> + ? ? ? ? ? ? if (!capable(CAP_SYS_ADMIN))
>> + ? ? ? ? ? ? ? ? ? ? return -EPERM;
>> +
>> + ? ? ? ? ? ? if (!blk_queue_discard(q))
>> + ? ? ? ? ? ? ? ? ? ? return -EOPNOTSUPP;
>> +
>> + ? ? ? ? ? ? if (copy_from_user(&range, (struct fstrim_range *)arg,
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? sizeof(range)))
>> + ? ? ? ? ? ? ? ? ? ? return -EFAULT;
>> +
>> + ? ? ? ? ? ? ret = fat_trim_fs(sb, &range);
>> + ? ? ? ? ? ? if (ret < 0)
>> + ? ? ? ? ? ? ? ? ? ? return ret;
>> +
>> + ? ? ? ? ? ? if (copy_to_user((struct fstrim_range *)arg, &range,
>> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? sizeof(range)))
>> + ? ? ? ? ? ? ? ? ? ? return -EFAULT;
>> +
>> + ? ? ? ? ? ? return 0;
>> + ? ? }
>> +
>> ? ? ? default:
>> ? ? ? ? ? ? ? return -ENOTTY; /* Inappropriate ioctl for device */
>> ? ? ? }
>>
>
> --
>
On Thu, 24 Feb 2011, Kyungmin Park wrote:
> On Thu, Feb 24, 2011 at 5:53 PM, Lukas Czerner <[email protected]> wrote:
> > On Thu, 24 Feb 2011, Kyungmin Park wrote:
> >
> >> From: Kyungmin Park <[email protected]>
> >>
> >> FAT supports batched discard as ext4.
> >>
> >> Cited from Lukas words.
> >> "The current solution is not ideal because of its bad performance impact.
> >> So basic idea to improve things is to avoid discarding every time some
> >> blocks are freed. and instead batching is together into bigger trims,
> >> which tends to be more effective."
> >>
> >> You can find an information in detail at following URLs.
> >> http://lwn.net/Articles/397538/
> >> http://lwn.net/Articles/383933/
> >>
> >> Signed-off-by: Kyungmin Park <[email protected]>
> >
> > Hi Kyungmin,
> > thanks to second version. How did you test it ? You can try xtestest
> > 251 for simple verification.
> > I can not really comment on FAT specific code, however I have couple of
> > comments bellow.
> >
> > Thanks!
> > -Lukas
> >
> >> ---
> >> Changelog V2:
> >> ? ? ? Use the given start and len as Lukas comments
> >> ? ? ? Check the queue supports discard feature
> >> ---
> >> diff --git a/fs/fat/fat.h b/fs/fat/fat.h
> >> index f504089..08b53e1 100644
> >> --- a/fs/fat/fat.h
> >> +++ b/fs/fat/fat.h
> >> @@ -299,6 +299,7 @@ extern int fat_alloc_clusters(struct inode *inode, int *cluster,
> >> ? ? ? ? ? ? ? ? ? ? ? ? ? ? int nr_cluster);
> >> ?extern int fat_free_clusters(struct inode *inode, int cluster);
> >> ?extern int fat_count_free_clusters(struct super_block *sb);
> >> +extern int fat_trim_fs(struct super_block *sb, struct fstrim_range *range);
> >>
> >> ?/* fat/file.c */
> >> ?extern long fat_generic_ioctl(struct file *filp, unsigned int cmd,
> >> diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c
> >> index b47d2c9..ea31ee4 100644
> >> --- a/fs/fat/fatent.c
> >> +++ b/fs/fat/fatent.c
> >> @@ -1,6 +1,8 @@
> >> ?/*
> >> ? * Copyright (C) 2004, OGAWA Hirofumi
> >> ? * Released under GPL v2.
> >> + *
> >> + * Batched discard support by Kyungmin Park <[email protected]>
> >> ? */
> >>
> >> ?#include <linux/module.h>
> >> @@ -541,6 +543,16 @@ out:
> >> ? ? ? return err;
> >> ?}
> >>
> >> +static int fat_issue_discard(struct super_block *sb, int cluster, int nr_clus)
> >> +{
> >> + ? ? struct msdos_sb_info *sbi = MSDOS_SB(sb);
> >> + ? ? sector_t block, nr_blocks;
> >> +
> >> + ? ? ? ?block = fat_clus_to_blknr(sbi, cluster);
> >> + ? ? ? ?nr_blocks = nr_clus * sbi->sec_per_clus;
> >> + ? ? ? ?return sb_issue_discard(sb, block, nr_blocks, GFP_NOFS, 0);
> > ? ^^^^^^^^
> > This patch does not pass checkpatch.pl script. Use tabs for indention.
> right, I will fix it. now passed the checkpatch.pl.
>
> >
> >> +}
> >> +
> >> ?int fat_free_clusters(struct inode *inode, int cluster)
> >> ?{
> >> ? ? ? struct super_block *sb = inode->i_sb;
> >> @@ -575,11 +587,7 @@ int fat_free_clusters(struct inode *inode, int cluster)
> >> ? ? ? ? ? ? ? ? ? ? ? if (cluster != fatent.entry + 1) {
> >> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? int nr_clus = fatent.entry - first_cl + 1;
> >>
> >> - ? ? ? ? ? ? ? ? ? ? ? ? ? ? sb_issue_discard(sb,
> >> - ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? fat_clus_to_blknr(sbi, first_cl),
> >> - ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? nr_clus * sbi->sec_per_clus,
> >> - ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? GFP_NOFS, 0);
> >> -
> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? fat_issue_discard(sb, first_cl, nr_clus);
> >> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? first_cl = cluster;
> >> ? ? ? ? ? ? ? ? ? ? ? }
> >> ? ? ? ? ? ? ? }
> >> @@ -683,3 +691,88 @@ out:
> >> ? ? ? unlock_fat(sbi);
> >> ? ? ? return err;
> >> ?}
> >> +
> >> +int fat_trim_fs(struct super_block *sb, struct fstrim_range *range)
> >> +{
> >> + ? ? struct msdos_sb_info *sbi = MSDOS_SB(sb);
> >> + ? ? struct fatent_operations *ops = sbi->fatent_ops;
> >> + ? ? struct fat_entry fatent;
> >> + ? ? unsigned long reada_blocks, reada_mask, cur_block;
> >> + ? ? int err = 0, free, count, entry;
> >> + ? ? int start, len, minlen, trimmed;
> >> +
> >> + ? ? start = range->start >> sb->s_blocksize_bits;
> >> + ? ? start = start / sbi->sec_per_clus;
> >> + ? ? len = range->len >> sb->s_blocksize_bits;
> >> + ? ? len = len / sbi->sec_per_clus;
> >> + ? ? minlen = range->minlen >> sb->s_blocksize_bits;
> >> + ? ? minlen = minlen / sbi->sec_per_clus;
> >
> > I should have mention that earlier, but you can also adjust mineln
> > according to the discard_granularity, because extents smaller than that
> > would not be discarded anyway.
> I adjust the minlen granularity with fat cluster unit. and FAT don't
> know what's the effected block size. it's role of user side.
Actually it is not and you should check
request_queue->limits.discard_granularity
see: http://www.spinics.net/lists/linux-ext4/msg23145.html
> >
> >> + ? ? trimmed = 0;
> >> + ? ? count = 0;
> >> +
> >> + ? ? lock_fat(sbi);
> >> + ? ? if (sbi->free_clusters != -1 && sbi->free_clus_valid)
> >> + ? ? ? ? ? ? goto out;
> >> +
> >> + ? ? reada_blocks = FAT_READA_SIZE >> sb->s_blocksize_bits;
> >> + ? ? reada_mask = reada_blocks - 1;
> >> + ? ? cur_block = 0;
> >> +
> >> + ? ? entry = 0;
> >> + ? ? free = 0;
> >> + ? ? fatent_init(&fatent);
> >> +
> >> + ? ? if (start < FAT_START_ENT)
> >> + ? ? ? ? ? ? start = FAT_START_ENT;
> >
> > You're not using start anywhere.
> >
> >> +
> >> + ? ? fatent_set_entry(&fatent, FAT_START_ENT);
> It should be fatent_set_entry(&fatent, start);
> >> +
> >> + ? ? while (count < sbi->max_cluster) {
> >> + ? ? ? ? ? ? if (fatent.entry >= sbi->max_cluster)
> >> + ? ? ? ? ? ? ? ? ? ? fatent.entry = FAT_START_ENT;
> >> + ? ? ? ? ? ? /* readahead of fat blocks */
> >> + ? ? ? ? ? ? if ((cur_block & reada_mask) == 0) {
> >> + ? ? ? ? ? ? ? ? ? ? unsigned long rest = sbi->fat_length - cur_block;
> >> + ? ? ? ? ? ? ? ? ? ? fat_ent_reada(sb, &fatent, min(reada_blocks, rest));
> >> + ? ? ? ? ? ? }
> >> + ? ? ? ? ? ? cur_block++;
> >> +
> >> + ? ? ? ? ? ? err = fat_ent_read_block(sb, &fatent);
> >> + ? ? ? ? ? ? if (err)
> >> + ? ? ? ? ? ? ? ? ? ? goto out;
> >> +
> >> + ? ? ? ? ? ? do {
> >> + ? ? ? ? ? ? ? ? ? ? if (ops->ent_get(&fatent) == FAT_ENT_FREE) {
> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? free++;
> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (!entry)
> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? entry = fatent.entry;
> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (free >= (len - trimmed) && free >= minlen) {
> >
> > It seems to me that you are using len as number of bytes to trim. This
> > is not right and I am sorry for not explaining it correctly. "len" is
> > supposed to be a number of bytes you want to "investigate" from the start.
> > So it means that you will trim every single free extent bigger than minlen
> > between "start" byte and "start + len" byte of the underlying device, or
> > partition.
> No. len is adjusted at fat cluster number. it's not used byte unit.
> I think it's easy to compare with fat internal units.
Does not matter what units are you using for len. I it just that you are
checking for (free >= (len - trimmed)) which is wrong because len is not
meant to be "overall length of trimmed data" but rather "overall length
of data to walk through and check for free extents" see ext4
implementation for reference.
Thanks!
-Lukas
>
> I hope fat peoples comment this one.
>
> Thank you,
> Kyungmin Park
> >
> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? fat_issue_discard(sb, entry, free);
> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? trimmed += free;
> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? }
> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (trimmed >= len)
> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? goto done;
> >> + ? ? ? ? ? ? ? ? ? ? } else if (entry) {
> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (free >= minlen) {
> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? fat_issue_discard(sb, entry, free);
> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? trimmed += free;
> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? }
> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (trimmed >= len)
> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? goto done;
> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? free = 0;
> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? entry = 0;
> >> + ? ? ? ? ? ? ? ? ? ? }
> >> + ? ? ? ? ? ? ? ? ? ? count++;
> >> + ? ? ? ? ? ? } while (fat_ent_next(sbi, &fatent));
> >> + ? ? }
> >> + ? ? if (free >= minlen) {
> >> + ? ? ? ? ? ? fat_issue_discard(sb, entry, free);
> >> + ? ? ? ? ? ? trimmed += free;
> >> + ? ? }
> >> +done:
> >> + ? ? range->len = (trimmed * sbi->sec_per_clus) << sb->s_blocksize_bits;
> >> + ? ? fatent_brelse(&fatent);
> >> +out:
> >> + ? ? unlock_fat(sbi);
> >> + ? ? return err;
> >> +}
> >> diff --git a/fs/fat/file.c b/fs/fat/file.c
> >> index 7257752..05e6545 100644
> >> --- a/fs/fat/file.c
> >> +++ b/fs/fat/file.c
> >> @@ -125,6 +125,34 @@ long fat_generic_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
> >> ? ? ? ? ? ? ? return fat_ioctl_get_attributes(inode, user_attr);
> >> ? ? ? case FAT_IOCTL_SET_ATTRIBUTES:
> >> ? ? ? ? ? ? ? return fat_ioctl_set_attributes(filp, user_attr);
> >> + ? ? case FITRIM:
> >> + ? ? {
> >> + ? ? ? ? ? ? struct super_block *sb = inode->i_sb;
> >> + ? ? ? ? ? ? struct request_queue *q = bdev_get_queue(sb->s_bdev);
> >> + ? ? ? ? ? ? struct fstrim_range range;
> >> + ? ? ? ? ? ? int ret = 0;
> >> +
> >> + ? ? ? ? ? ? if (!capable(CAP_SYS_ADMIN))
> >> + ? ? ? ? ? ? ? ? ? ? return -EPERM;
> >> +
> >> + ? ? ? ? ? ? if (!blk_queue_discard(q))
> >> + ? ? ? ? ? ? ? ? ? ? return -EOPNOTSUPP;
> >> +
> >> + ? ? ? ? ? ? if (copy_from_user(&range, (struct fstrim_range *)arg,
> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? sizeof(range)))
> >> + ? ? ? ? ? ? ? ? ? ? return -EFAULT;
> >> +
> >> + ? ? ? ? ? ? ret = fat_trim_fs(sb, &range);
> >> + ? ? ? ? ? ? if (ret < 0)
> >> + ? ? ? ? ? ? ? ? ? ? return ret;
> >> +
> >> + ? ? ? ? ? ? if (copy_to_user((struct fstrim_range *)arg, &range,
> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? sizeof(range)))
> >> + ? ? ? ? ? ? ? ? ? ? return -EFAULT;
> >> +
> >> + ? ? ? ? ? ? return 0;
> >> + ? ? }
> >> +
> >> ? ? ? default:
> >> ? ? ? ? ? ? ? return -ENOTTY; /* Inappropriate ioctl for device */
> >> ? ? ? }
> >>
> >
> > --
> >
>
--
On Thu, Feb 24, 2011 at 8:03 PM, Lukas Czerner <[email protected]> wrote:
> On Thu, 24 Feb 2011, Kyungmin Park wrote:
>
>> On Thu, Feb 24, 2011 at 5:53 PM, Lukas Czerner <[email protected]> wrote:
>> > On Thu, 24 Feb 2011, Kyungmin Park wrote:
>> >
>> >> From: Kyungmin Park <[email protected]>
>> >>
>> >> FAT supports batched discard as ext4.
>> >>
>> >> Cited from Lukas words.
>> >> "The current solution is not ideal because of its bad performance impact.
>> >> So basic idea to improve things is to avoid discarding every time some
>> >> blocks are freed. and instead batching is together into bigger trims,
>> >> which tends to be more effective."
>> >>
>> >> You can find an information in detail at following URLs.
>> >> http://lwn.net/Articles/397538/
>> >> http://lwn.net/Articles/383933/
>> >>
>> >> Signed-off-by: Kyungmin Park <[email protected]>
>> >
>> > Hi Kyungmin,
>> > thanks to second version. How did you test it ? You can try xtestest
>> > 251 for simple verification.
>> > I can not really comment on FAT specific code, however I have couple of
>> > comments bellow.
>> >
>> > Thanks!
>> > -Lukas
>> >
>> >> ---
>> >> Changelog V2:
>> >> ? ? ? Use the given start and len as Lukas comments
>> >> ? ? ? Check the queue supports discard feature
>> >> ---
>> >> diff --git a/fs/fat/fat.h b/fs/fat/fat.h
>> >> index f504089..08b53e1 100644
>> >> --- a/fs/fat/fat.h
>> >> +++ b/fs/fat/fat.h
>> >> @@ -299,6 +299,7 @@ extern int fat_alloc_clusters(struct inode *inode, int *cluster,
>> >> ? ? ? ? ? ? ? ? ? ? ? ? ? ? int nr_cluster);
>> >> ?extern int fat_free_clusters(struct inode *inode, int cluster);
>> >> ?extern int fat_count_free_clusters(struct super_block *sb);
>> >> +extern int fat_trim_fs(struct super_block *sb, struct fstrim_range *range);
>> >>
>> >> ?/* fat/file.c */
>> >> ?extern long fat_generic_ioctl(struct file *filp, unsigned int cmd,
>> >> diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c
>> >> index b47d2c9..ea31ee4 100644
>> >> --- a/fs/fat/fatent.c
>> >> +++ b/fs/fat/fatent.c
>> >> @@ -1,6 +1,8 @@
>> >> ?/*
>> >> ? * Copyright (C) 2004, OGAWA Hirofumi
>> >> ? * Released under GPL v2.
>> >> + *
>> >> + * Batched discard support by Kyungmin Park <[email protected]>
>> >> ? */
>> >>
>> >> ?#include <linux/module.h>
>> >> @@ -541,6 +543,16 @@ out:
>> >> ? ? ? return err;
>> >> ?}
>> >>
>> >> +static int fat_issue_discard(struct super_block *sb, int cluster, int nr_clus)
>> >> +{
>> >> + ? ? struct msdos_sb_info *sbi = MSDOS_SB(sb);
>> >> + ? ? sector_t block, nr_blocks;
>> >> +
>> >> + ? ? ? ?block = fat_clus_to_blknr(sbi, cluster);
>> >> + ? ? ? ?nr_blocks = nr_clus * sbi->sec_per_clus;
>> >> + ? ? ? ?return sb_issue_discard(sb, block, nr_blocks, GFP_NOFS, 0);
>> > ? ^^^^^^^^
>> > This patch does not pass checkpatch.pl script. Use tabs for indention.
>> right, I will fix it. now passed the checkpatch.pl.
>>
>> >
>> >> +}
>> >> +
>> >> ?int fat_free_clusters(struct inode *inode, int cluster)
>> >> ?{
>> >> ? ? ? struct super_block *sb = inode->i_sb;
>> >> @@ -575,11 +587,7 @@ int fat_free_clusters(struct inode *inode, int cluster)
>> >> ? ? ? ? ? ? ? ? ? ? ? if (cluster != fatent.entry + 1) {
>> >> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? int nr_clus = fatent.entry - first_cl + 1;
>> >>
>> >> - ? ? ? ? ? ? ? ? ? ? ? ? ? ? sb_issue_discard(sb,
>> >> - ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? fat_clus_to_blknr(sbi, first_cl),
>> >> - ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? nr_clus * sbi->sec_per_clus,
>> >> - ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? GFP_NOFS, 0);
>> >> -
>> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? fat_issue_discard(sb, first_cl, nr_clus);
>> >> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? first_cl = cluster;
>> >> ? ? ? ? ? ? ? ? ? ? ? }
>> >> ? ? ? ? ? ? ? }
>> >> @@ -683,3 +691,88 @@ out:
>> >> ? ? ? unlock_fat(sbi);
>> >> ? ? ? return err;
>> >> ?}
>> >> +
>> >> +int fat_trim_fs(struct super_block *sb, struct fstrim_range *range)
>> >> +{
>> >> + ? ? struct msdos_sb_info *sbi = MSDOS_SB(sb);
>> >> + ? ? struct fatent_operations *ops = sbi->fatent_ops;
>> >> + ? ? struct fat_entry fatent;
>> >> + ? ? unsigned long reada_blocks, reada_mask, cur_block;
>> >> + ? ? int err = 0, free, count, entry;
>> >> + ? ? int start, len, minlen, trimmed;
>> >> +
>> >> + ? ? start = range->start >> sb->s_blocksize_bits;
>> >> + ? ? start = start / sbi->sec_per_clus;
>> >> + ? ? len = range->len >> sb->s_blocksize_bits;
>> >> + ? ? len = len / sbi->sec_per_clus;
>> >> + ? ? minlen = range->minlen >> sb->s_blocksize_bits;
>> >> + ? ? minlen = minlen / sbi->sec_per_clus;
>> >
>> > I should have mention that earlier, but you can also adjust mineln
>> > according to the discard_granularity, because extents smaller than that
>> > would not be discarded anyway.
>> I adjust the minlen granularity with fat cluster unit. and FAT don't
>> know what's the effected ?block size. it's role of user side.
>
> Actually it is not and you should check
> request_queue->limits.discard_granularity
Okay, it's simple one, I will add it.
>
> see: http://www.spinics.net/lists/linux-ext4/msg23145.html
>
>> >
>> >> + ? ? trimmed = 0;
>> >> + ? ? count = 0;
>> >> +
>> >> + ? ? lock_fat(sbi);
>> >> + ? ? if (sbi->free_clusters != -1 && sbi->free_clus_valid)
>> >> + ? ? ? ? ? ? goto out;
>> >> +
>> >> + ? ? reada_blocks = FAT_READA_SIZE >> sb->s_blocksize_bits;
>> >> + ? ? reada_mask = reada_blocks - 1;
>> >> + ? ? cur_block = 0;
>> >> +
>> >> + ? ? entry = 0;
>> >> + ? ? free = 0;
>> >> + ? ? fatent_init(&fatent);
>> >> +
>> >> + ? ? if (start < FAT_START_ENT)
>> >> + ? ? ? ? ? ? start = FAT_START_ENT;
>> >
>> > You're not using start anywhere.
>> >
>> >> +
>> >> + ? ? fatent_set_entry(&fatent, FAT_START_ENT);
>> It should be fatent_set_entry(&fatent, start);
>> >> +
>> >> + ? ? while (count < sbi->max_cluster) {
>> >> + ? ? ? ? ? ? if (fatent.entry >= sbi->max_cluster)
>> >> + ? ? ? ? ? ? ? ? ? ? fatent.entry = FAT_START_ENT;
>> >> + ? ? ? ? ? ? /* readahead of fat blocks */
>> >> + ? ? ? ? ? ? if ((cur_block & reada_mask) == 0) {
>> >> + ? ? ? ? ? ? ? ? ? ? unsigned long rest = sbi->fat_length - cur_block;
>> >> + ? ? ? ? ? ? ? ? ? ? fat_ent_reada(sb, &fatent, min(reada_blocks, rest));
>> >> + ? ? ? ? ? ? }
>> >> + ? ? ? ? ? ? cur_block++;
>> >> +
>> >> + ? ? ? ? ? ? err = fat_ent_read_block(sb, &fatent);
>> >> + ? ? ? ? ? ? if (err)
>> >> + ? ? ? ? ? ? ? ? ? ? goto out;
>> >> +
>> >> + ? ? ? ? ? ? do {
>> >> + ? ? ? ? ? ? ? ? ? ? if (ops->ent_get(&fatent) == FAT_ENT_FREE) {
>> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? free++;
>> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (!entry)
>> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? entry = fatent.entry;
>> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (free >= (len - trimmed) && free >= minlen) {
>> >
>> > It seems to me that you are using len as number of bytes to trim. This
>> > is not right and I am sorry for not explaining it correctly. "len" is
>> > supposed to be a number of bytes you want to "investigate" from the start.
>> > So it means that you will trim every single free extent bigger than minlen
>> > between "start" byte and "start + len" byte of the underlying device, or
>> > partition.
>> No. len is adjusted at fat cluster number. it's not used byte unit.
>> I think it's easy to compare with fat internal units.
>
> Does not matter what units are you using for len. I it just that you are
> checking for (free >= (len - trimmed)) which is wrong because len is not
> meant to be "overall length of trimmed data" but rather "overall length
> of data to walk through and check for free extents" see ext4
> implementation for reference.
I think I used it as you said. e.g., I want to trim 256 (* minimum
discard granularity),
First time, I can find 10 entries. and trimmed has 10 and len has still 256.
next time, I found the 246 free entries then trim remaining 246 one.
do you want to trim it more than given len?
Thank you,
Kyungmin Park
>
> Thanks!
> -Lukas
>
>>
>> I hope fat peoples comment this one.
>>
>> Thank you,
>> Kyungmin Park
>> >
>> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? fat_issue_discard(sb, entry, free);
>> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? trimmed += free;
>> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? }
>> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (trimmed >= len)
>> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? goto done;
>> >> + ? ? ? ? ? ? ? ? ? ? } else if (entry) {
>> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (free >= minlen) {
>> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? fat_issue_discard(sb, entry, free);
>> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? trimmed += free;
>> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? }
>> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (trimmed >= len)
>> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? goto done;
>> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? free = 0;
>> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? entry = 0;
>> >> + ? ? ? ? ? ? ? ? ? ? }
>> >> + ? ? ? ? ? ? ? ? ? ? count++;
>> >> + ? ? ? ? ? ? } while (fat_ent_next(sbi, &fatent));
>> >> + ? ? }
>> >> + ? ? if (free >= minlen) {
>> >> + ? ? ? ? ? ? fat_issue_discard(sb, entry, free);
>> >> + ? ? ? ? ? ? trimmed += free;
>> >> + ? ? }
>> >> +done:
>> >> + ? ? range->len = (trimmed * sbi->sec_per_clus) << sb->s_blocksize_bits;
>> >> + ? ? fatent_brelse(&fatent);
>> >> +out:
>> >> + ? ? unlock_fat(sbi);
>> >> + ? ? return err;
>> >> +}
>> >> diff --git a/fs/fat/file.c b/fs/fat/file.c
>> >> index 7257752..05e6545 100644
>> >> --- a/fs/fat/file.c
>> >> +++ b/fs/fat/file.c
>> >> @@ -125,6 +125,34 @@ long fat_generic_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
>> >> ? ? ? ? ? ? ? return fat_ioctl_get_attributes(inode, user_attr);
>> >> ? ? ? case FAT_IOCTL_SET_ATTRIBUTES:
>> >> ? ? ? ? ? ? ? return fat_ioctl_set_attributes(filp, user_attr);
>> >> + ? ? case FITRIM:
>> >> + ? ? {
>> >> + ? ? ? ? ? ? struct super_block *sb = inode->i_sb;
>> >> + ? ? ? ? ? ? struct request_queue *q = bdev_get_queue(sb->s_bdev);
>> >> + ? ? ? ? ? ? struct fstrim_range range;
>> >> + ? ? ? ? ? ? int ret = 0;
>> >> +
>> >> + ? ? ? ? ? ? if (!capable(CAP_SYS_ADMIN))
>> >> + ? ? ? ? ? ? ? ? ? ? return -EPERM;
>> >> +
>> >> + ? ? ? ? ? ? if (!blk_queue_discard(q))
>> >> + ? ? ? ? ? ? ? ? ? ? return -EOPNOTSUPP;
>> >> +
>> >> + ? ? ? ? ? ? if (copy_from_user(&range, (struct fstrim_range *)arg,
>> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? sizeof(range)))
>> >> + ? ? ? ? ? ? ? ? ? ? return -EFAULT;
>> >> +
>> >> + ? ? ? ? ? ? ret = fat_trim_fs(sb, &range);
>> >> + ? ? ? ? ? ? if (ret < 0)
>> >> + ? ? ? ? ? ? ? ? ? ? return ret;
>> >> +
>> >> + ? ? ? ? ? ? if (copy_to_user((struct fstrim_range *)arg, &range,
>> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? sizeof(range)))
>> >> + ? ? ? ? ? ? ? ? ? ? return -EFAULT;
>> >> +
>> >> + ? ? ? ? ? ? return 0;
>> >> + ? ? }
>> >> +
>> >> ? ? ? default:
>> >> ? ? ? ? ? ? ? return -ENOTTY; /* Inappropriate ioctl for device */
>> >> ? ? ? }
>> >>
>> >
>> > --
>> >
>>
>
> --
On Thu, 24 Feb 2011, Kyungmin Park wrote:
...snip...
> >> >> + ? ? while (count < sbi->max_cluster) {
> >> >> + ? ? ? ? ? ? if (fatent.entry >= sbi->max_cluster)
> >> >> + ? ? ? ? ? ? ? ? ? ? fatent.entry = FAT_START_ENT;
> >> >> + ? ? ? ? ? ? /* readahead of fat blocks */
> >> >> + ? ? ? ? ? ? if ((cur_block & reada_mask) == 0) {
> >> >> + ? ? ? ? ? ? ? ? ? ? unsigned long rest = sbi->fat_length - cur_block;
> >> >> + ? ? ? ? ? ? ? ? ? ? fat_ent_reada(sb, &fatent, min(reada_blocks, rest));
> >> >> + ? ? ? ? ? ? }
> >> >> + ? ? ? ? ? ? cur_block++;
> >> >> +
> >> >> + ? ? ? ? ? ? err = fat_ent_read_block(sb, &fatent);
> >> >> + ? ? ? ? ? ? if (err)
> >> >> + ? ? ? ? ? ? ? ? ? ? goto out;
> >> >> +
> >> >> + ? ? ? ? ? ? do {
> >> >> + ? ? ? ? ? ? ? ? ? ? if (ops->ent_get(&fatent) == FAT_ENT_FREE) {
> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? free++;
> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (!entry)
> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? entry = fatent.entry;
> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (free >= (len - trimmed) && free >= minlen) {
> >> >
> >> > It seems to me that you are using len as number of bytes to trim. This
> >> > is not right and I am sorry for not explaining it correctly. "len" is
> >> > supposed to be a number of bytes you want to "investigate" from the start.
> >> > So it means that you will trim every single free extent bigger than minlen
> >> > between "start" byte and "start + len" byte of the underlying device, or
> >> > partition.
> >> No. len is adjusted at fat cluster number. it's not used byte unit.
> >> I think it's easy to compare with fat internal units.
> >
> > Does not matter what units are you using for len. I it just that you are
> > checking for (free >= (len - trimmed)) which is wrong because len is not
> > meant to be "overall length of trimmed data" but rather "overall length
> > of data to walk through and check for free extents" see ext4
> > implementation for reference.
> I think I used it as you said. e.g., I want to trim 256 (* minimum
> discard granularity),
> First time, I can find 10 entries. and trimmed has 10 and len has still 256.
> next time, I found the 246 free entries then trim remaining 246 one.
>
> do you want to trim it more than given len?
Let the "O" be free (bytes, blocks, whatever), and "=" be used.
Now, we have a filesystem like this.
OOOO==O===OO===OOOOO==O===O===OOOOOOO===
^ ^
0 40
This is how it supposed to wotk if you have called FITIRM with parameters:
start = 0
minlen = 2
len = 20
So you will go through (blocks, bytes...) 0 -> 20
OOOO==O===OO===OOOOO==O===O===OOOOOOO===
^ ^
0 20
So, you will call discard on extents:
0-3
You'll skip 6 because is smaller than minlen
10-11
15-19
But in your implementation you will trim extents:
0-3
10-11
15-19
30-36
Hope it is clear now.
>
> Thank you,
> Kyungmin Park
> >
> > Thanks!
> > -Lukas
> >
> >>
> >> I hope fat peoples comment this one.
> >>
> >> Thank you,
> >> Kyungmin Park
> >> >
> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? fat_issue_discard(sb, entry, free);
> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? trimmed += free;
> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? }
> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (trimmed >= len)
> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? goto done;
> >> >> + ? ? ? ? ? ? ? ? ? ? } else if (entry) {
> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (free >= minlen) {
> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? fat_issue_discard(sb, entry, free);
> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? trimmed += free;
> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? }
> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (trimmed >= len)
> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? goto done;
> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? free = 0;
> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? entry = 0;
> >> >> + ? ? ? ? ? ? ? ? ? ? }
> >> >> + ? ? ? ? ? ? ? ? ? ? count++;
> >> >> + ? ? ? ? ? ? } while (fat_ent_next(sbi, &fatent));
> >> >> + ? ? }
> >> >> + ? ? if (free >= minlen) {
> >> >> + ? ? ? ? ? ? fat_issue_discard(sb, entry, free);
> >> >> + ? ? ? ? ? ? trimmed += free;
> >> >> + ? ? }
> >> >> +done:
> >> >> + ? ? range->len = (trimmed * sbi->sec_per_clus) << sb->s_blocksize_bits;
> >> >> + ? ? fatent_brelse(&fatent);
> >> >> +out:
> >> >> + ? ? unlock_fat(sbi);
> >> >> + ? ? return err;
> >> >> +}
...snip...
On Thu, Feb 24, 2011 at 8:40 PM, Lukas Czerner <[email protected]> wrote:
> On Thu, 24 Feb 2011, Kyungmin Park wrote:
>
> ...snip...
>> >> >> + ? ? while (count < sbi->max_cluster) {
>> >> >> + ? ? ? ? ? ? if (fatent.entry >= sbi->max_cluster)
>> >> >> + ? ? ? ? ? ? ? ? ? ? fatent.entry = FAT_START_ENT;
>> >> >> + ? ? ? ? ? ? /* readahead of fat blocks */
>> >> >> + ? ? ? ? ? ? if ((cur_block & reada_mask) == 0) {
>> >> >> + ? ? ? ? ? ? ? ? ? ? unsigned long rest = sbi->fat_length - cur_block;
>> >> >> + ? ? ? ? ? ? ? ? ? ? fat_ent_reada(sb, &fatent, min(reada_blocks, rest));
>> >> >> + ? ? ? ? ? ? }
>> >> >> + ? ? ? ? ? ? cur_block++;
>> >> >> +
>> >> >> + ? ? ? ? ? ? err = fat_ent_read_block(sb, &fatent);
>> >> >> + ? ? ? ? ? ? if (err)
>> >> >> + ? ? ? ? ? ? ? ? ? ? goto out;
>> >> >> +
>> >> >> + ? ? ? ? ? ? do {
>> >> >> + ? ? ? ? ? ? ? ? ? ? if (ops->ent_get(&fatent) == FAT_ENT_FREE) {
>> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? free++;
>> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (!entry)
>> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? entry = fatent.entry;
>> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (free >= (len - trimmed) && free >= minlen) {
>> >> >
>> >> > It seems to me that you are using len as number of bytes to trim. This
>> >> > is not right and I am sorry for not explaining it correctly. "len" is
>> >> > supposed to be a number of bytes you want to "investigate" from the start.
>> >> > So it means that you will trim every single free extent bigger than minlen
>> >> > between "start" byte and "start + len" byte of the underlying device, or
>> >> > partition.
>> >> No. len is adjusted at fat cluster number. it's not used byte unit.
>> >> I think it's easy to compare with fat internal units.
>> >
>> > Does not matter what units are you using for len. I it just that you are
>> > checking for (free >= (len - trimmed)) which is wrong because len is not
>> > meant to be "overall length of trimmed data" but rather "overall length
>> > of data to walk through and check for free extents" see ext4
>> > implementation for reference.
>> I think I used it as you said. e.g., I want to trim 256 (* minimum
>> discard granularity),
>> First time, I can find 10 entries. and trimmed has 10 and len has still 256.
>> next time, I found the 246 free entries then trim remaining 246 one.
>>
>> do you want to trim it more than given len?
>
> Let the "O" be free (bytes, blocks, whatever), and "=" be used.
> Now, we have a filesystem like this.
>
> ? OOOO==O===OO===OOOOO==O===O===OOOOOOO===
> ? ^ ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?^
> ? 0 ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?40
>
> This is how it supposed to wotk if you have called FITIRM with parameters:
>
> start = 0
> minlen = 2
> len = 20
>
> So you will go through (blocks, bytes...) 0 -> 20
>
> ? OOOO==O===OO===OOOOO==O===O===OOOOOOO===
> ? ^ ? ? ? ? ? ? ? ? ? ^
> ? 0 ? ? ? ? ? ? ? ? ? 20
>
> So, you will call discard on extents:
>
> 0-3
> You'll skip 6 because is smaller than minlen
> 10-11
> 15-19
>
>
> But in your implementation you will trim extents:
> 0-3
> 10-11
> 15-19
> 30-36
>
> Hope it is clear now.
Okay you mean it's end address instead of total amount of trim size.
It will be helpful if you add these diagram or comments on
linux/include/fs.h
Thank you,
Kyungmin Park
>
>>
>> Thank you,
>> Kyungmin Park
>> >
>> > Thanks!
>> > -Lukas
>> >
>> >>
>> >> I hope fat peoples comment this one.
>> >>
>> >> Thank you,
>> >> Kyungmin Park
>> >> >
>> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? fat_issue_discard(sb, entry, free);
>> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? trimmed += free;
>> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? }
>> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (trimmed >= len)
>> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? goto done;
>> >> >> + ? ? ? ? ? ? ? ? ? ? } else if (entry) {
>> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (free >= minlen) {
>> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? fat_issue_discard(sb, entry, free);
>> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? trimmed += free;
>> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? }
>> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? if (trimmed >= len)
>> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? goto done;
>> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? free = 0;
>> >> >> + ? ? ? ? ? ? ? ? ? ? ? ? ? ? entry = 0;
>> >> >> + ? ? ? ? ? ? ? ? ? ? }
>> >> >> + ? ? ? ? ? ? ? ? ? ? count++;
>> >> >> + ? ? ? ? ? ? } while (fat_ent_next(sbi, &fatent));
>> >> >> + ? ? }
>> >> >> + ? ? if (free >= minlen) {
>> >> >> + ? ? ? ? ? ? fat_issue_discard(sb, entry, free);
>> >> >> + ? ? ? ? ? ? trimmed += free;
>> >> >> + ? ? }
>> >> >> +done:
>> >> >> + ? ? range->len = (trimmed * sbi->sec_per_clus) << sb->s_blocksize_bits;
>> >> >> + ? ? fatent_brelse(&fatent);
>> >> >> +out:
>> >> >> + ? ? unlock_fat(sbi);
>> >> >> + ? ? return err;
>> >> >> +}
>
> ...snip...