Skip to content

Commit a20af5f

Browse files
committed
befs: improve documentation in datastream.c
Convert function descriptions to kernel-doc style. Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com> Signed-off-by: Salah Triki <salah.triki@gmail.com>
1 parent d327e61 commit a20af5f

File tree

1 file changed

+98
-95
lines changed

1 file changed

+98
-95
lines changed

fs/befs/datastream.c

Lines changed: 98 additions & 95 deletions
Original file line numberDiff line numberDiff line change
@@ -75,7 +75,13 @@ befs_read_datastream(struct super_block *sb, const befs_data_stream *ds,
7575
return bh;
7676
}
7777

78-
/*
78+
/**
79+
* befs_fblock2brun - give back block run for fblock
80+
* @sb: the superblock
81+
* @data: datastream to read from
82+
* @fblock: the blocknumber with the file position to find
83+
* @run: The found run is passed back through this pointer
84+
*
7985
* Takes a file position and gives back a brun who's starting block
8086
* is block number fblock of the file.
8187
*
@@ -212,36 +218,35 @@ befs_count_blocks(struct super_block *sb, const befs_data_stream *ds)
212218
return blocks;
213219
}
214220

215-
/*
216-
Finds the block run that starts at file block number blockno
217-
in the file represented by the datastream data, if that
218-
blockno is in the direct region of the datastream.
219-
220-
sb: the superblock
221-
data: the datastream
222-
blockno: the blocknumber to find
223-
run: The found run is passed back through this pointer
224-
225-
Return value is BEFS_OK if the blockrun is found, BEFS_ERR
226-
otherwise.
227-
228-
Algorithm:
229-
Linear search. Checks each element of array[] to see if it
230-
contains the blockno-th filesystem block. This is necessary
231-
because the block runs map variable amounts of data. Simply
232-
keeps a count of the number of blocks searched so far (sum),
233-
incrementing this by the length of each block run as we come
234-
across it. Adds sum to *count before returning (this is so
235-
you can search multiple arrays that are logicaly one array,
236-
as in the indirect region code).
237-
238-
When/if blockno is found, if blockno is inside of a block
239-
run as stored on disk, we offset the start and length members
240-
of the block run, so that blockno is the start and len is
241-
still valid (the run ends in the same place).
242-
243-
2001-11-15 Will Dyson
244-
*/
221+
/**
222+
* befs_find_brun_direct - find a direct block run in the datastream
223+
* @sb: the superblock
224+
* @data: the datastream
225+
* @blockno: the blocknumber to find
226+
* @run: The found run is passed back through this pointer
227+
*
228+
* Finds the block run that starts at file block number blockno
229+
* in the file represented by the datastream data, if that
230+
* blockno is in the direct region of the datastream.
231+
*
232+
* Return value is BEFS_OK if the blockrun is found, BEFS_ERR
233+
* otherwise.
234+
*
235+
* Algorithm:
236+
* Linear search. Checks each element of array[] to see if it
237+
* contains the blockno-th filesystem block. This is necessary
238+
* because the block runs map variable amounts of data. Simply
239+
* keeps a count of the number of blocks searched so far (sum),
240+
* incrementing this by the length of each block run as we come
241+
* across it. Adds sum to *count before returning (this is so
242+
* you can search multiple arrays that are logicaly one array,
243+
* as in the indirect region code).
244+
*
245+
* When/if blockno is found, if blockno is inside of a block
246+
* run as stored on disk, we offset the start and length members
247+
* of the block run, so that blockno is the start and len is
248+
* still valid (the run ends in the same place).
249+
*/
245250
static int
246251
befs_find_brun_direct(struct super_block *sb, const befs_data_stream *data,
247252
befs_blocknr_t blockno, befs_block_run * run)
@@ -273,29 +278,28 @@ befs_find_brun_direct(struct super_block *sb, const befs_data_stream *data,
273278
return BEFS_ERR;
274279
}
275280

276-
/*
277-
Finds the block run that starts at file block number blockno
278-
in the file represented by the datastream data, if that
279-
blockno is in the indirect region of the datastream.
280-
281-
sb: the superblock
282-
data: the datastream
283-
blockno: the blocknumber to find
284-
run: The found run is passed back through this pointer
285-
286-
Return value is BEFS_OK if the blockrun is found, BEFS_ERR
287-
otherwise.
288-
289-
Algorithm:
290-
For each block in the indirect run of the datastream, read
291-
it in and search through it for search_blk.
292-
293-
XXX:
294-
Really should check to make sure blockno is inside indirect
295-
region.
296-
297-
2001-11-15 Will Dyson
298-
*/
281+
/**
282+
* befs_find_brun_indirect - find a block run in the datastream
283+
* @sb: the superblock
284+
* @data: the datastream
285+
* @blockno: the blocknumber to find
286+
* @run: The found run is passed back through this pointer
287+
*
288+
* Finds the block run that starts at file block number blockno
289+
* in the file represented by the datastream data, if that
290+
* blockno is in the indirect region of the datastream.
291+
*
292+
* Return value is BEFS_OK if the blockrun is found, BEFS_ERR
293+
* otherwise.
294+
*
295+
* Algorithm:
296+
* For each block in the indirect run of the datastream, read
297+
* it in and search through it for search_blk.
298+
*
299+
* XXX:
300+
* Really should check to make sure blockno is inside indirect
301+
* region.
302+
*/
299303
static int
300304
befs_find_brun_indirect(struct super_block *sb,
301305
const befs_data_stream *data,
@@ -365,47 +369,46 @@ befs_find_brun_indirect(struct super_block *sb,
365369
return BEFS_ERR;
366370
}
367371

368-
/*
369-
Finds the block run that starts at file block number blockno
370-
in the file represented by the datastream data, if that
371-
blockno is in the double-indirect region of the datastream.
372-
373-
sb: the superblock
374-
data: the datastream
375-
blockno: the blocknumber to find
376-
run: The found run is passed back through this pointer
377-
378-
Return value is BEFS_OK if the blockrun is found, BEFS_ERR
379-
otherwise.
380-
381-
Algorithm:
382-
The block runs in the double-indirect region are different.
383-
They are always allocated 4 fs blocks at a time, so each
384-
block run maps a constant amount of file data. This means
385-
that we can directly calculate how many block runs into the
386-
double-indirect region we need to go to get to the one that
387-
maps a particular filesystem block.
388-
389-
We do this in two stages. First we calculate which of the
390-
inode addresses in the double-indirect block will point us
391-
to the indirect block that contains the mapping for the data,
392-
then we calculate which of the inode addresses in that
393-
indirect block maps the data block we are after.
394-
395-
Oh, and once we've done that, we actually read in the blocks
396-
that contain the inode addresses we calculated above. Even
397-
though the double-indirect run may be several blocks long,
398-
we can calculate which of those blocks will contain the index
399-
we are after and only read that one. We then follow it to
400-
the indirect block and perform a similar process to find
401-
the actual block run that maps the data block we are interested
402-
in.
403-
404-
Then we offset the run as in befs_find_brun_array() and we are
405-
done.
406-
407-
2001-11-15 Will Dyson
408-
*/
372+
/**
373+
* befs_find_brun_dblindirect - find a block run in the datastream
374+
* @sb: the superblock
375+
* @data: the datastream
376+
* @blockno: the blocknumber to find
377+
* @run: The found run is passed back through this pointer
378+
*
379+
* Finds the block run that starts at file block number blockno
380+
* in the file represented by the datastream data, if that
381+
* blockno is in the double-indirect region of the datastream.
382+
*
383+
* Return value is BEFS_OK if the blockrun is found, BEFS_ERR
384+
* otherwise.
385+
*
386+
* Algorithm:
387+
* The block runs in the double-indirect region are different.
388+
* They are always allocated 4 fs blocks at a time, so each
389+
* block run maps a constant amount of file data. This means
390+
* that we can directly calculate how many block runs into the
391+
* double-indirect region we need to go to get to the one that
392+
* maps a particular filesystem block.
393+
*
394+
* We do this in two stages. First we calculate which of the
395+
* inode addresses in the double-indirect block will point us
396+
* to the indirect block that contains the mapping for the data,
397+
* then we calculate which of the inode addresses in that
398+
* indirect block maps the data block we are after.
399+
*
400+
* Oh, and once we've done that, we actually read in the blocks
401+
* that contain the inode addresses we calculated above. Even
402+
* though the double-indirect run may be several blocks long,
403+
* we can calculate which of those blocks will contain the index
404+
* we are after and only read that one. We then follow it to
405+
* the indirect block and perform a similar process to find
406+
* the actual block run that maps the data block we are interested
407+
* in.
408+
*
409+
* Then we offset the run as in befs_find_brun_array() and we are
410+
* done.
411+
*/
409412
static int
410413
befs_find_brun_dblindirect(struct super_block *sb,
411414
const befs_data_stream *data,

0 commit comments

Comments
 (0)