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ocfs2: Read support for directories with inline data 

This splits out extent based directory read support and implements
inline-data versions of those functions. All knowledge of inline-data versus
extent based directories is internalized. For lookups the code uses
ocfs2_find_entry_id(), full dir iterations make use of
ocfs2_dir_foreach_blk_id().

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Reviewed-by: Joel Becker <joel.becker@oracle.com>
This commit is contained in:
Mark Fasheh 2007-09-12 13:01:18 -07:00
parent 1afc32b952
commit 23193e513d
1 changed files with 168 additions and 8 deletions
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176
fs/ocfs2/dir.c
View File

@ -81,6 +81,10 @@ static int ocfs2_do_extend_dir(struct super_block *sb,
struct ocfs2_alloc_context *meta_ac,
struct buffer_head **new_bh);
/*
* bh passed here can be an inode block or a dir data block, depending
* on the inode inline data flag.
*/
static int ocfs2_check_dir_entry(struct inode * dir,
struct ocfs2_dir_entry * de,
struct buffer_head * bh,
@ -125,6 +129,8 @@ static int inline ocfs2_search_dirblock(struct buffer_head *bh,
struct inode *dir,
const char *name, int namelen,
unsigned long offset,
char *first_de,
unsigned int bytes,
struct ocfs2_dir_entry **res_dir)
{
struct ocfs2_dir_entry *de;
@ -134,8 +140,8 @@ static int inline ocfs2_search_dirblock(struct buffer_head *bh,
mlog_entry_void();
de_buf = bh->b_data;
dlimit = de_buf + dir->i_sb->s_blocksize;
de_buf = first_de;
dlimit = de_buf + bytes;
while (de_buf < dlimit) {
/* this code is executed quadratically often */
@ -171,9 +177,39 @@ bail:
return ret;
}
struct buffer_head *ocfs2_find_entry(const char *name, int namelen,
struct inode *dir,
struct ocfs2_dir_entry **res_dir)
static struct buffer_head *ocfs2_find_entry_id(const char *name,
int namelen,
struct inode *dir,
struct ocfs2_dir_entry **res_dir)
{
int ret, found;
struct buffer_head *di_bh = NULL;
struct ocfs2_dinode *di;
struct ocfs2_inline_data *data;
ret = ocfs2_read_block(OCFS2_SB(dir->i_sb), OCFS2_I(dir)->ip_blkno,
&di_bh, OCFS2_BH_CACHED, dir);
if (ret) {
mlog_errno(ret);
goto out;
}
di = (struct ocfs2_dinode *)di_bh->b_data;
data = &di->id2.i_data;
found = ocfs2_search_dirblock(di_bh, dir, name, namelen, 0,
data->id_data, i_size_read(dir), res_dir);
if (found == 1)
return di_bh;
brelse(di_bh);
out:
return NULL;
}
struct buffer_head *ocfs2_find_entry_el(const char *name, int namelen,
struct inode *dir,
struct ocfs2_dir_entry **res_dir)
{
struct super_block *sb;
struct buffer_head *bh_use[NAMEI_RA_SIZE];
@ -188,7 +224,6 @@ struct buffer_head *ocfs2_find_entry(const char *name, int namelen,
mlog_entry_void();
*res_dir = NULL;
sb = dir->i_sb;
nblocks = i_size_read(dir) >> sb->s_blocksize_bits;
@ -236,6 +271,7 @@ restart:
}
i = ocfs2_search_dirblock(bh, dir, name, namelen,
block << sb->s_blocksize_bits,
bh->b_data, sb->s_blocksize,
res_dir);
if (i == 1) {
OCFS2_I(dir)->ip_dir_start_lookup = block;
@ -271,6 +307,30 @@ cleanup_and_exit:
return ret;
}
/*
* Try to find an entry of the provided name within 'dir'.
*
* If nothing was found, NULL is returned. Otherwise, a buffer_head
* and pointer to the dir entry are passed back.
*
* Caller can NOT assume anything about the contents of the
* buffer_head - it is passed back only so that it can be passed into
* any one of the manipulation functions (add entry, delete entry,
* etc). As an example, bh in the extent directory case is a data
* block, in the inline-data case it actually points to an inode.
*/
struct buffer_head *ocfs2_find_entry(const char *name, int namelen,
struct inode *dir,
struct ocfs2_dir_entry **res_dir)
{
*res_dir = NULL;
if (OCFS2_I(dir)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
return ocfs2_find_entry_id(name, namelen, dir, res_dir);
return ocfs2_find_entry_el(name, namelen, dir, res_dir);
}
int ocfs2_update_entry(struct inode *dir, handle_t *handle,
struct buffer_head *de_bh, struct ocfs2_dir_entry *de,
struct inode *new_entry_inode)
@ -459,8 +519,98 @@ bail:
return retval;
}
static int ocfs2_dir_foreach_blk(struct inode *inode, unsigned long *f_version,
loff_t *f_pos, void *priv, filldir_t filldir)
static int ocfs2_dir_foreach_blk_id(struct inode *inode,
unsigned long *f_version,
loff_t *f_pos, void *priv,
filldir_t filldir)
{
int ret, i, filldir_ret;
unsigned long offset = *f_pos;
struct buffer_head *di_bh = NULL;
struct ocfs2_dinode *di;
struct ocfs2_inline_data *data;
struct ocfs2_dir_entry *de;
ret = ocfs2_read_block(OCFS2_SB(inode->i_sb), OCFS2_I(inode)->ip_blkno,
&di_bh, OCFS2_BH_CACHED, inode);
if (ret) {
mlog(ML_ERROR, "Unable to read inode block for dir %llu\n",
(unsigned long long)OCFS2_I(inode)->ip_blkno);
goto out;
}
di = (struct ocfs2_dinode *)di_bh->b_data;
data = &di->id2.i_data;
while (*f_pos < i_size_read(inode)) {
revalidate:
/* If the dir block has changed since the last call to
* readdir(2), then we might be pointing to an invalid
* dirent right now. Scan from the start of the block
* to make sure. */
if (*f_version != inode->i_version) {
for (i = 0; i < i_size_read(inode) && i < offset; ) {
de = (struct ocfs2_dir_entry *)
(data->id_data + i);
/* It's too expensive to do a full
* dirent test each time round this
* loop, but we do have to test at
* least that it is non-zero. A
* failure will be detected in the
* dirent test below. */
if (le16_to_cpu(de->rec_len) <
OCFS2_DIR_REC_LEN(1))
break;
i += le16_to_cpu(de->rec_len);
}
*f_pos = offset = i;
*f_version = inode->i_version;
}
de = (struct ocfs2_dir_entry *) (data->id_data + *f_pos);
if (!ocfs2_check_dir_entry(inode, de, di_bh, *f_pos)) {
/* On error, skip the f_pos to the end. */
*f_pos = i_size_read(inode);
goto out;
}
offset += le16_to_cpu(de->rec_len);
if (le64_to_cpu(de->inode)) {
/* We might block in the next section
* if the data destination is
* currently swapped out. So, use a
* version stamp to detect whether or
* not the directory has been modified
* during the copy operation.
*/
unsigned long version = *f_version;
unsigned char d_type = DT_UNKNOWN;
if (de->file_type < OCFS2_FT_MAX)
d_type = ocfs2_filetype_table[de->file_type];
filldir_ret = filldir(priv, de->name,
de->name_len,
*f_pos,
le64_to_cpu(de->inode),
d_type);
if (filldir_ret)
break;
if (version != *f_version)
goto revalidate;
}
*f_pos += le16_to_cpu(de->rec_len);
}
out:
brelse(di_bh);
return 0;
}
static int ocfs2_dir_foreach_blk_el(struct inode *inode,
unsigned long *f_version,
loff_t *f_pos, void *priv,
filldir_t filldir)
{
int error = 0;
unsigned long offset, blk, last_ra_blk = 0;
@ -576,6 +726,16 @@ out:
return stored;
}
static int ocfs2_dir_foreach_blk(struct inode *inode, unsigned long *f_version,
loff_t *f_pos, void *priv, filldir_t filldir)
{
if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
return ocfs2_dir_foreach_blk_id(inode, f_version, f_pos, priv,
filldir);
return ocfs2_dir_foreach_blk_el(inode, f_version, f_pos, priv, filldir);
}
/*
* This is intended to be called from inside other kernel functions,
* so we fake some arguments.