Quick question from a n00b.
What are "credits"?
I imagine I'm not the only onlooker curious about ti either.
On Sun, Feb 10, 2013 at 5:42 AM, Tao Ma <tm@xxxxxx> wrote:
> On 02/10/2013 05:53 AM, Theodore Ts'o wrote:
>> Operations which modify extended attributes may need extra journal
>> credits if inline data is used, since there is a chance that some
>> extended attributes may need to get pushed to an external attribute
>> block.
>>
>> Changes to reflect this was made in xattr.c, but they were missed in
>> fs/ext4/acl.c. To fix this, abstract the calculation of the number of
>> credits needed for xattr operations to an inline function defined in
>> ext4_jbd2.h, and use it in acl.c and xattr.c.
> Oh, yes, I forgot about the acl.
>
> Reviewed-by: Tao Ma <boyu.mt@xxxxxxxxxx>
>
> Thanks,
> Tao
>>
>> Also move the function declarations used in inline.c from xattr.h
>> (where they are non-obviously hidden, and caused problems since
>> ext4_jbd2.h needs to use the function ext4_has_inline_data), and move
>> them to ext4.h.
>>
>> Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx>
>> Cc: Tao Ma <boyu.mt@xxxxxxxxxx>
>> ---
>> fs/ext4/acl.c | 4 +--
>> fs/ext4/ext4.h | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>> fs/ext4/ext4_jbd2.h | 14 +++++++++++
>> fs/ext4/xattr.c | 9 +------
>> fs/ext4/xattr.h | 68 ---------------------------------------------------
>> 5 files changed, 87 insertions(+), 78 deletions(-)
>>
>> diff --git a/fs/ext4/acl.c b/fs/ext4/acl.c
>> index 406cf8b..39a54a0 100644
>> --- a/fs/ext4/acl.c
>> +++ b/fs/ext4/acl.c
>> @@ -325,7 +325,7 @@ ext4_acl_chmod(struct inode *inode)
>> return error;
>> retry:
>> handle = ext4_journal_start(inode, EXT4_HT_XATTR,
>> - EXT4_DATA_TRANS_BLOCKS(inode->i_sb));
>> + ext4_jbd2_credits_xattr(inode));
>> if (IS_ERR(handle)) {
>> error = PTR_ERR(handle);
>> ext4_std_error(inode->i_sb, error);
>> @@ -423,7 +423,7 @@ ext4_xattr_set_acl(struct dentry *dentry, const char *name, const void *value,
>>
>> retry:
>> handle = ext4_journal_start(inode, EXT4_HT_XATTR,
>> - EXT4_DATA_TRANS_BLOCKS(inode->i_sb));
>> + ext4_jbd2_credits_xattr(inode));
>> if (IS_ERR(handle)) {
>> error = PTR_ERR(handle);
>> goto release_and_out;
>> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
>> index c2c64da..9897cdf 100644
>> --- a/fs/ext4/ext4.h
>> +++ b/fs/ext4/ext4.h
>> @@ -2443,6 +2443,75 @@ extern const struct file_operations ext4_file_operations;
>> extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin);
>> extern void ext4_unwritten_wait(struct inode *inode);
>>
>> +/* inline.c */
>> +extern int ext4_has_inline_data(struct inode *inode);
>> +extern int ext4_get_inline_size(struct inode *inode);
>> +extern int ext4_get_max_inline_size(struct inode *inode);
>> +extern int ext4_find_inline_data_nolock(struct inode *inode);
>> +extern void ext4_write_inline_data(struct inode *inode,
>> + struct ext4_iloc *iloc,
>> + void *buffer, loff_t pos,
>> + unsigned int len);
>> +extern int ext4_prepare_inline_data(handle_t *handle, struct inode *inode,
>> + unsigned int len);
>> +extern int ext4_init_inline_data(handle_t *handle, struct inode *inode,
>> + unsigned int len);
>> +extern int ext4_destroy_inline_data(handle_t *handle, struct inode *inode);
>> +
>> +extern int ext4_readpage_inline(struct inode *inode, struct page *page);
>> +extern int ext4_try_to_write_inline_data(struct address_space *mapping,
>> + struct inode *inode,
>> + loff_t pos, unsigned len,
>> + unsigned flags,
>> + struct page **pagep);
>> +extern int ext4_write_inline_data_end(struct inode *inode,
>> + loff_t pos, unsigned len,
>> + unsigned copied,
>> + struct page *page);
>> +extern struct buffer_head *
>> +ext4_journalled_write_inline_data(struct inode *inode,
>> + unsigned len,
>> + struct page *page);
>> +extern int ext4_da_write_inline_data_begin(struct address_space *mapping,
>> + struct inode *inode,
>> + loff_t pos, unsigned len,
>> + unsigned flags,
>> + struct page **pagep,
>> + void **fsdata);
>> +extern int ext4_da_write_inline_data_end(struct inode *inode, loff_t pos,
>> + unsigned len, unsigned copied,
>> + struct page *page);
>> +extern int ext4_try_add_inline_entry(handle_t *handle, struct dentry *dentry,
>> + struct inode *inode);
>> +extern int ext4_try_create_inline_dir(handle_t *handle,
>> + struct inode *parent,
>> + struct inode *inode);
>> +extern int ext4_read_inline_dir(struct file *filp,
>> + void *dirent, filldir_t filldir,
>> + int *has_inline_data);
>> +extern struct buffer_head *ext4_find_inline_entry(struct inode *dir,
>> + const struct qstr *d_name,
>> + struct ext4_dir_entry_2 **res_dir,
>> + int *has_inline_data);
>> +extern int ext4_delete_inline_entry(handle_t *handle,
>> + struct inode *dir,
>> + struct ext4_dir_entry_2 *de_del,
>> + struct buffer_head *bh,
>> + int *has_inline_data);
>> +extern int empty_inline_dir(struct inode *dir, int *has_inline_data);
>> +extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
>> + struct ext4_dir_entry_2 **parent_de,
>> + int *retval);
>> +extern int ext4_inline_data_fiemap(struct inode *inode,
>> + struct fiemap_extent_info *fieinfo,
>> + int *has_inline);
>> +extern int ext4_try_to_evict_inline_data(handle_t *handle,
>> + struct inode *inode,
>> + int needed);
>> +extern void ext4_inline_data_truncate(struct inode *inode, int *has_inline);
>> +
>> +extern int ext4_convert_inline_data(struct inode *inode);
>> +
>> /* namei.c */
>> extern const struct inode_operations ext4_dir_inode_operations;
>> extern const struct inode_operations ext4_special_inode_operations;
>> @@ -2539,6 +2608,7 @@ extern void ext4_mmp_csum_set(struct super_block *sb, struct mmp_struct *mmp);
>> extern int ext4_mmp_csum_verify(struct super_block *sb,
>> struct mmp_struct *mmp);
>>
>> +
>> /* BH_Uninit flag: blocks are allocated but uninitialized on disk */
>> enum ext4_state_bits {
>> BH_Uninit /* blocks are allocated but uninitialized on disk */
>> diff --git a/fs/ext4/ext4_jbd2.h b/fs/ext4/ext4_jbd2.h
>> index c1fc2dc..4c216b1 100644
>> --- a/fs/ext4/ext4_jbd2.h
>> +++ b/fs/ext4/ext4_jbd2.h
>> @@ -104,6 +104,20 @@
>> #define EXT4_MAXQUOTAS_INIT_BLOCKS(sb) (MAXQUOTAS*EXT4_QUOTA_INIT_BLOCKS(sb))
>> #define EXT4_MAXQUOTAS_DEL_BLOCKS(sb) (MAXQUOTAS*EXT4_QUOTA_DEL_BLOCKS(sb))
>>
>> +static inline int ext4_jbd2_credits_xattr(struct inode *inode)
>> +{
>> + int credits = EXT4_DATA_TRANS_BLOCKS(inode->i_sb);
>> +
>> + /*
>> + * In case of inline data, we may push out the data to a block,
>> + * so we need to reserve credits for this eventuality
>> + */
>> + if (ext4_has_inline_data(inode))
>> + credits += ext4_writepage_trans_blocks(inode) + 1;
>> + return credits;
>> +}
>> +
>> +
>> /*
>> * Ext4 handle operation types -- for logging purposes
>> */
>> diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
>> index 2efc560..cc31da0 100644
>> --- a/fs/ext4/xattr.c
>> +++ b/fs/ext4/xattr.c
>> @@ -1165,16 +1165,9 @@ ext4_xattr_set(struct inode *inode, int name_index, const char *name,
>> {
>> handle_t *handle;
>> int error, retries = 0;
>> - int credits = EXT4_DATA_TRANS_BLOCKS(inode->i_sb);
>> + int credits = ext4_jbd2_credits_xattr(inode);
>>
>> retry:
>> - /*
>> - * In case of inline data, we may push out the data to a block,
>> - * So reserve the journal space first.
>> - */
>> - if (ext4_has_inline_data(inode))
>> - credits += ext4_writepage_trans_blocks(inode) + 1;
>> -
>> handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);
>> if (IS_ERR(handle)) {
>> error = PTR_ERR(handle);
>> diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h
>> index 69eda78..aa25deb 100644
>> --- a/fs/ext4/xattr.h
>> +++ b/fs/ext4/xattr.h
>> @@ -125,74 +125,6 @@ extern int ext4_xattr_ibody_inline_set(handle_t *handle, struct inode *inode,
>> struct ext4_xattr_info *i,
>> struct ext4_xattr_ibody_find *is);
>>
>> -extern int ext4_has_inline_data(struct inode *inode);
>> -extern int ext4_get_inline_size(struct inode *inode);
>> -extern int ext4_get_max_inline_size(struct inode *inode);
>> -extern int ext4_find_inline_data_nolock(struct inode *inode);
>> -extern void ext4_write_inline_data(struct inode *inode,
>> - struct ext4_iloc *iloc,
>> - void *buffer, loff_t pos,
>> - unsigned int len);
>> -extern int ext4_prepare_inline_data(handle_t *handle, struct inode *inode,
>> - unsigned int len);
>> -extern int ext4_init_inline_data(handle_t *handle, struct inode *inode,
>> - unsigned int len);
>> -extern int ext4_destroy_inline_data(handle_t *handle, struct inode *inode);
>> -
>> -extern int ext4_readpage_inline(struct inode *inode, struct page *page);
>> -extern int ext4_try_to_write_inline_data(struct address_space *mapping,
>> - struct inode *inode,
>> - loff_t pos, unsigned len,
>> - unsigned flags,
>> - struct page **pagep);
>> -extern int ext4_write_inline_data_end(struct inode *inode,
>> - loff_t pos, unsigned len,
>> - unsigned copied,
>> - struct page *page);
>> -extern struct buffer_head *
>> -ext4_journalled_write_inline_data(struct inode *inode,
>> - unsigned len,
>> - struct page *page);
>> -extern int ext4_da_write_inline_data_begin(struct address_space *mapping,
>> - struct inode *inode,
>> - loff_t pos, unsigned len,
>> - unsigned flags,
>> - struct page **pagep,
>> - void **fsdata);
>> -extern int ext4_da_write_inline_data_end(struct inode *inode, loff_t pos,
>> - unsigned len, unsigned copied,
>> - struct page *page);
>> -extern int ext4_try_add_inline_entry(handle_t *handle, struct dentry *dentry,
>> - struct inode *inode);
>> -extern int ext4_try_create_inline_dir(handle_t *handle,
>> - struct inode *parent,
>> - struct inode *inode);
>> -extern int ext4_read_inline_dir(struct file *filp,
>> - void *dirent, filldir_t filldir,
>> - int *has_inline_data);
>> -extern struct buffer_head *ext4_find_inline_entry(struct inode *dir,
>> - const struct qstr *d_name,
>> - struct ext4_dir_entry_2 **res_dir,
>> - int *has_inline_data);
>> -extern int ext4_delete_inline_entry(handle_t *handle,
>> - struct inode *dir,
>> - struct ext4_dir_entry_2 *de_del,
>> - struct buffer_head *bh,
>> - int *has_inline_data);
>> -extern int empty_inline_dir(struct inode *dir, int *has_inline_data);
>> -extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
>> - struct ext4_dir_entry_2 **parent_de,
>> - int *retval);
>> -extern int ext4_inline_data_fiemap(struct inode *inode,
>> - struct fiemap_extent_info *fieinfo,
>> - int *has_inline);
>> -extern int ext4_try_to_evict_inline_data(handle_t *handle,
>> - struct inode *inode,
>> - int needed);
>> -extern void ext4_inline_data_truncate(struct inode *inode, int *has_inline);
>> -
>> -extern int ext4_convert_inline_data(struct inode *inode);
>> -
>> #ifdef CONFIG_EXT4_FS_SECURITY
>> extern int ext4_init_security(handle_t *handle, struct inode *inode,
>> struct inode *dir, const struct qstr *qstr);
>>
>
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