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authorLuis de Bethencourt <luisbg@osg.samsung.com>2016-08-13 18:11:20 +0100
committerLuis de Bethencourt <luisbg@osg.samsung.com>2016-10-08 10:01:36 +0100
commita20af5f9eaac083e2865e94f37e47af74d70f187 (patch)
tree13484afbbc5a70c82d13b1c7eff673a59d24c1af
parentd327e612bd1f854f08bc4c419122a41440455cbe (diff)
downloadlinux-sh-a20af5f9eaac083e2865e94f37e47af74d70f187.tar.gz
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>
-rw-r--r--fs/befs/datastream.c193
1 files changed, 98 insertions, 95 deletions
diff --git a/fs/befs/datastream.c b/fs/befs/datastream.c
index b2eb5b5cdff2..5ce85cfd8ae1 100644
--- a/fs/befs/datastream.c
+++ b/fs/befs/datastream.c
@@ -75,7 +75,13 @@ befs_read_datastream(struct super_block *sb, const befs_data_stream *ds,
return bh;
}
-/*
+/**
+ * befs_fblock2brun - give back block run for fblock
+ * @sb: the superblock
+ * @data: datastream to read from
+ * @fblock: the blocknumber with the file position to find
+ * @run: The found run is passed back through this pointer
+ *
* Takes a file position and gives back a brun who's starting block
* is block number fblock of the file.
*
@@ -212,36 +218,35 @@ befs_count_blocks(struct super_block *sb, const befs_data_stream *ds)
return blocks;
}
-/*
- Finds the block run that starts at file block number blockno
- in the file represented by the datastream data, if that
- blockno is in the direct region of the datastream.
-
- sb: the superblock
- data: the datastream
- blockno: the blocknumber to find
- run: The found run is passed back through this pointer
-
- Return value is BEFS_OK if the blockrun is found, BEFS_ERR
- otherwise.
-
- Algorithm:
- Linear search. Checks each element of array[] to see if it
- contains the blockno-th filesystem block. This is necessary
- because the block runs map variable amounts of data. Simply
- keeps a count of the number of blocks searched so far (sum),
- incrementing this by the length of each block run as we come
- across it. Adds sum to *count before returning (this is so
- you can search multiple arrays that are logicaly one array,
- as in the indirect region code).
-
- When/if blockno is found, if blockno is inside of a block
- run as stored on disk, we offset the start and length members
- of the block run, so that blockno is the start and len is
- still valid (the run ends in the same place).
-
- 2001-11-15 Will Dyson
-*/
+/**
+ * befs_find_brun_direct - find a direct block run in the datastream
+ * @sb: the superblock
+ * @data: the datastream
+ * @blockno: the blocknumber to find
+ * @run: The found run is passed back through this pointer
+ *
+ * Finds the block run that starts at file block number blockno
+ * in the file represented by the datastream data, if that
+ * blockno is in the direct region of the datastream.
+ *
+ * Return value is BEFS_OK if the blockrun is found, BEFS_ERR
+ * otherwise.
+ *
+ * Algorithm:
+ * Linear search. Checks each element of array[] to see if it
+ * contains the blockno-th filesystem block. This is necessary
+ * because the block runs map variable amounts of data. Simply
+ * keeps a count of the number of blocks searched so far (sum),
+ * incrementing this by the length of each block run as we come
+ * across it. Adds sum to *count before returning (this is so
+ * you can search multiple arrays that are logicaly one array,
+ * as in the indirect region code).
+ *
+ * When/if blockno is found, if blockno is inside of a block
+ * run as stored on disk, we offset the start and length members
+ * of the block run, so that blockno is the start and len is
+ * still valid (the run ends in the same place).
+ */
static int
befs_find_brun_direct(struct super_block *sb, const befs_data_stream *data,
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,
return BEFS_ERR;
}
-/*
- Finds the block run that starts at file block number blockno
- in the file represented by the datastream data, if that
- blockno is in the indirect region of the datastream.
-
- sb: the superblock
- data: the datastream
- blockno: the blocknumber to find
- run: The found run is passed back through this pointer
-
- Return value is BEFS_OK if the blockrun is found, BEFS_ERR
- otherwise.
-
- Algorithm:
- For each block in the indirect run of the datastream, read
- it in and search through it for search_blk.
-
- XXX:
- Really should check to make sure blockno is inside indirect
- region.
-
- 2001-11-15 Will Dyson
-*/
+/**
+ * befs_find_brun_indirect - find a block run in the datastream
+ * @sb: the superblock
+ * @data: the datastream
+ * @blockno: the blocknumber to find
+ * @run: The found run is passed back through this pointer
+ *
+ * Finds the block run that starts at file block number blockno
+ * in the file represented by the datastream data, if that
+ * blockno is in the indirect region of the datastream.
+ *
+ * Return value is BEFS_OK if the blockrun is found, BEFS_ERR
+ * otherwise.
+ *
+ * Algorithm:
+ * For each block in the indirect run of the datastream, read
+ * it in and search through it for search_blk.
+ *
+ * XXX:
+ * Really should check to make sure blockno is inside indirect
+ * region.
+ */
static int
befs_find_brun_indirect(struct super_block *sb,
const befs_data_stream *data,
@@ -365,47 +369,46 @@ befs_find_brun_indirect(struct super_block *sb,
return BEFS_ERR;
}
-/*
- Finds the block run that starts at file block number blockno
- in the file represented by the datastream data, if that
- blockno is in the double-indirect region of the datastream.
-
- sb: the superblock
- data: the datastream
- blockno: the blocknumber to find
- run: The found run is passed back through this pointer
-
- Return value is BEFS_OK if the blockrun is found, BEFS_ERR
- otherwise.
-
- Algorithm:
- The block runs in the double-indirect region are different.
- They are always allocated 4 fs blocks at a time, so each
- block run maps a constant amount of file data. This means
- that we can directly calculate how many block runs into the
- double-indirect region we need to go to get to the one that
- maps a particular filesystem block.
-
- We do this in two stages. First we calculate which of the
- inode addresses in the double-indirect block will point us
- to the indirect block that contains the mapping for the data,
- then we calculate which of the inode addresses in that
- indirect block maps the data block we are after.
-
- Oh, and once we've done that, we actually read in the blocks
- that contain the inode addresses we calculated above. Even
- though the double-indirect run may be several blocks long,
- we can calculate which of those blocks will contain the index
- we are after and only read that one. We then follow it to
- the indirect block and perform a similar process to find
- the actual block run that maps the data block we are interested
- in.
-
- Then we offset the run as in befs_find_brun_array() and we are
- done.
-
- 2001-11-15 Will Dyson
-*/
+/**
+ * befs_find_brun_dblindirect - find a block run in the datastream
+ * @sb: the superblock
+ * @data: the datastream
+ * @blockno: the blocknumber to find
+ * @run: The found run is passed back through this pointer
+ *
+ * Finds the block run that starts at file block number blockno
+ * in the file represented by the datastream data, if that
+ * blockno is in the double-indirect region of the datastream.
+ *
+ * Return value is BEFS_OK if the blockrun is found, BEFS_ERR
+ * otherwise.
+ *
+ * Algorithm:
+ * The block runs in the double-indirect region are different.
+ * They are always allocated 4 fs blocks at a time, so each
+ * block run maps a constant amount of file data. This means
+ * that we can directly calculate how many block runs into the
+ * double-indirect region we need to go to get to the one that
+ * maps a particular filesystem block.
+ *
+ * We do this in two stages. First we calculate which of the
+ * inode addresses in the double-indirect block will point us
+ * to the indirect block that contains the mapping for the data,
+ * then we calculate which of the inode addresses in that
+ * indirect block maps the data block we are after.
+ *
+ * Oh, and once we've done that, we actually read in the blocks
+ * that contain the inode addresses we calculated above. Even
+ * though the double-indirect run may be several blocks long,
+ * we can calculate which of those blocks will contain the index
+ * we are after and only read that one. We then follow it to
+ * the indirect block and perform a similar process to find
+ * the actual block run that maps the data block we are interested
+ * in.
+ *
+ * Then we offset the run as in befs_find_brun_array() and we are
+ * done.
+ */
static int
befs_find_brun_dblindirect(struct super_block *sb,
const befs_data_stream *data,