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Diffstat (limited to 'fs/befs/datastream.c')
-rw-r--r--fs/befs/datastream.c253
1 files changed, 125 insertions, 128 deletions
diff --git a/fs/befs/datastream.c b/fs/befs/datastream.c
index af1bc19b7c85..b4c7ba013c0d 100644
--- a/fs/befs/datastream.c
+++ b/fs/befs/datastream.c
@@ -22,22 +22,22 @@ const befs_inode_addr BAD_IADDR = { 0, 0, 0 };
static int befs_find_brun_direct(struct super_block *sb,
const befs_data_stream *data,
- befs_blocknr_t blockno, befs_block_run * run);
+ befs_blocknr_t blockno, befs_block_run *run);
static int befs_find_brun_indirect(struct super_block *sb,
const befs_data_stream *data,
befs_blocknr_t blockno,
- befs_block_run * run);
+ befs_block_run *run);
static int befs_find_brun_dblindirect(struct super_block *sb,
const befs_data_stream *data,
befs_blocknr_t blockno,
- befs_block_run * run);
+ befs_block_run *run);
/**
* befs_read_datastream - get buffer_head containing data, starting from pos.
* @sb: Filesystem superblock
- * @ds: datastrem to find data with
+ * @ds: datastream to find data with
* @pos: start of data
* @off: offset of data in buffer_head->b_data
*
@@ -46,7 +46,7 @@ static int befs_find_brun_dblindirect(struct super_block *sb,
*/
struct buffer_head *
befs_read_datastream(struct super_block *sb, const befs_data_stream *ds,
- befs_off_t pos, uint * off)
+ befs_off_t pos, uint *off)
{
struct buffer_head *bh;
befs_block_run run;
@@ -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.
*
@@ -88,7 +94,7 @@ befs_read_datastream(struct super_block *sb, const befs_data_stream *ds,
*/
int
befs_fblock2brun(struct super_block *sb, const befs_data_stream *data,
- befs_blocknr_t fblock, befs_block_run * run)
+ befs_blocknr_t fblock, befs_block_run *run)
{
int err;
befs_off_t pos = fblock << BEFS_SB(sb)->block_shift;
@@ -115,7 +121,7 @@ befs_fblock2brun(struct super_block *sb, const befs_data_stream *data,
/**
* befs_read_lsmylink - read long symlink from datastream.
* @sb: Filesystem superblock
- * @ds: Datastrem to read from
+ * @ds: Datastream to read from
* @buff: Buffer in which to place long symlink data
* @len: Length of the long symlink in bytes
*
@@ -128,6 +134,7 @@ befs_read_lsymlink(struct super_block *sb, const befs_data_stream *ds,
befs_off_t bytes_read = 0; /* bytes readed */
u16 plen;
struct buffer_head *bh;
+
befs_debug(sb, "---> %s length: %llu", __func__, len);
while (bytes_read < len) {
@@ -183,13 +190,13 @@ befs_count_blocks(struct super_block *sb, const befs_data_stream *ds)
metablocks += ds->indirect.len;
/*
- Double indir block, plus all the indirect blocks it mapps
- In the double-indirect range, all block runs of data are
- BEFS_DBLINDIR_BRUN_LEN blocks long. Therefore, we know
- how many data block runs are in the double-indirect region,
- and from that we know how many indirect blocks it takes to
- map them. We assume that the indirect blocks are also
- BEFS_DBLINDIR_BRUN_LEN blocks long.
+ * Double indir block, plus all the indirect blocks it maps.
+ * In the double-indirect range, all block runs of data are
+ * BEFS_DBLINDIR_BRUN_LEN blocks long. Therefore, we know
+ * how many data block runs are in the double-indirect region,
+ * and from that we know how many indirect blocks it takes to
+ * map them. We assume that the indirect blocks are also
+ * BEFS_DBLINDIR_BRUN_LEN blocks long.
*/
if (ds->size > ds->max_indirect_range && ds->max_indirect_range != 0) {
uint dbl_bytes;
@@ -212,58 +219,50 @@ 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)
+ befs_blocknr_t blockno, befs_block_run *run)
{
int i;
const befs_block_run *array = data->direct;
befs_blocknr_t sum;
- befs_blocknr_t max_block =
- data->max_direct_range >> BEFS_SB(sb)->block_shift;
befs_debug(sb, "---> %s, find %lu", __func__, (unsigned long)blockno);
- if (blockno > max_block) {
- befs_error(sb, "%s passed block outside of direct region",
- __func__);
- return BEFS_ERR;
- }
-
for (i = 0, sum = 0; i < BEFS_NUM_DIRECT_BLOCKS;
sum += array[i].len, i++) {
if (blockno >= sum && blockno < sum + (array[i].len)) {
int offset = blockno - sum;
+
run->allocation_group = array[i].allocation_group;
run->start = array[i].start + offset;
run->len = array[i].len - offset;
@@ -275,38 +274,39 @@ befs_find_brun_direct(struct super_block *sb, const befs_data_stream *data,
}
}
+ befs_error(sb, "%s failed to find file block %lu", __func__,
+ (unsigned long)blockno);
befs_debug(sb, "---> %s ERROR", __func__);
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,
befs_blocknr_t blockno,
- befs_block_run * run)
+ befs_block_run *run)
{
int i, j;
befs_blocknr_t sum = 0;
@@ -326,11 +326,12 @@ befs_find_brun_indirect(struct super_block *sb,
/* Examine blocks of the indirect run one at a time */
for (i = 0; i < indirect.len; i++) {
- indirblock = befs_bread(sb, indirblockno + i);
+ indirblock = sb_bread(sb, indirblockno + i);
if (indirblock == NULL) {
- befs_debug(sb, "---> %s failed to read "
+ befs_error(sb, "---> %s failed to read "
"disk block %lu from the indirect brun",
__func__, (unsigned long)indirblockno + i);
+ befs_debug(sb, "<--- %s ERROR", __func__);
return BEFS_ERR;
}
@@ -370,52 +371,51 @@ 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,
befs_blocknr_t blockno,
- befs_block_run * run)
+ befs_block_run *run)
{
int dblindir_indx;
int indir_indx;
@@ -430,10 +430,9 @@ befs_find_brun_dblindirect(struct super_block *sb,
struct buffer_head *indir_block;
befs_block_run indir_run;
befs_disk_inode_addr *iaddr_array;
- struct befs_sb_info *befs_sb = BEFS_SB(sb);
befs_blocknr_t indir_start_blk =
- data->max_indirect_range >> befs_sb->block_shift;
+ data->max_indirect_range >> BEFS_SB(sb)->block_shift;
off_t dbl_indir_off = blockno - indir_start_blk;
@@ -471,7 +470,7 @@ befs_find_brun_dblindirect(struct super_block *sb,
}
dbl_indir_block =
- befs_bread(sb, iaddr2blockno(sb, &data->double_indirect) +
+ sb_bread(sb, iaddr2blockno(sb, &data->double_indirect) +
dbl_which_block);
if (dbl_indir_block == NULL) {
befs_error(sb, "%s couldn't read the "
@@ -479,7 +478,6 @@ befs_find_brun_dblindirect(struct super_block *sb,
(unsigned long)
iaddr2blockno(sb, &data->double_indirect) +
dbl_which_block);
- brelse(dbl_indir_block);
return BEFS_ERR;
}
@@ -499,12 +497,11 @@ befs_find_brun_dblindirect(struct super_block *sb,
}
indir_block =
- befs_bread(sb, iaddr2blockno(sb, &indir_run) + which_block);
+ sb_bread(sb, iaddr2blockno(sb, &indir_run) + which_block);
if (indir_block == NULL) {
befs_error(sb, "%s couldn't read the indirect block "
"at blockno %lu", __func__, (unsigned long)
iaddr2blockno(sb, &indir_run) + which_block);
- brelse(indir_block);
return BEFS_ERR;
}