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erofs: simplify readdir operation

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- Use i_size instead of i_size_read() due to immutable fses;

 - Get rid of an unneeded goto since erofs_fill_dentries() also works;

 - Remove unnecessary lines.

Signed-off-by: Hongzhen Luo <hongzhen@linux.alibaba.com>
Link: https://lore.kernel.org/r/20240801112622.2164029-1-hongzhen@linux.alibaba.com
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
This commit is contained in:
Hongzhen Luo 2024-08-01 19:26:22 +08:00 committed by Gao Xiang
parent 47ac09b91b
commit 5b5c96c63d
2 changed files with 13 additions and 24 deletions
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35
fs/erofs/dir.c
View File

@ -8,19 +8,15 @@
static int erofs_fill_dentries(struct inode *dir, struct dir_context *ctx, static int erofs_fill_dentries(struct inode *dir, struct dir_context *ctx,
void *dentry_blk, struct erofs_dirent *de, void *dentry_blk, struct erofs_dirent *de,
unsigned int nameoff, unsigned int maxsize) unsigned int nameoff0, unsigned int maxsize)
{ {
const struct erofs_dirent *end = dentry_blk + nameoff; const struct erofs_dirent *end = dentry_blk + nameoff0;
while (de < end) { while (de < end) {
const char *de_name; unsigned char d_type = fs_ftype_to_dtype(de->file_type);
unsigned int nameoff = le16_to_cpu(de->nameoff);
const char *de_name = (char *)dentry_blk + nameoff;
unsigned int de_namelen; unsigned int de_namelen;
unsigned char d_type;
d_type = fs_ftype_to_dtype(de->file_type);
nameoff = le16_to_cpu(de->nameoff);
de_name = (char *)dentry_blk + nameoff;
/* the last dirent in the block? */ /* the last dirent in the block? */
if (de + 1 >= end) if (de + 1 >= end)
@ -52,21 +48,20 @@ static int erofs_readdir(struct file *f, struct dir_context *ctx)
struct erofs_buf buf = __EROFS_BUF_INITIALIZER; struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
struct super_block *sb = dir->i_sb; struct super_block *sb = dir->i_sb;
unsigned long bsz = sb->s_blocksize; unsigned long bsz = sb->s_blocksize;
const size_t dirsize = i_size_read(dir);
unsigned int i = erofs_blknr(sb, ctx->pos);
unsigned int ofs = erofs_blkoff(sb, ctx->pos); unsigned int ofs = erofs_blkoff(sb, ctx->pos);
int err = 0; int err = 0;
bool initial = true; bool initial = true;
buf.mapping = dir->i_mapping; buf.mapping = dir->i_mapping;
while (ctx->pos < dirsize) { while (ctx->pos < dir->i_size) {
erofs_off_t dbstart = ctx->pos - ofs;
struct erofs_dirent *de; struct erofs_dirent *de;
unsigned int nameoff, maxsize; unsigned int nameoff, maxsize;
de = erofs_bread(&buf, erofs_pos(sb, i), EROFS_KMAP); de = erofs_bread(&buf, dbstart, EROFS_KMAP);
if (IS_ERR(de)) { if (IS_ERR(de)) {
erofs_err(sb, "fail to readdir of logical block %u of nid %llu", erofs_err(sb, "fail to readdir of logical block %u of nid %llu",
i, EROFS_I(dir)->nid); erofs_blknr(sb, dbstart), EROFS_I(dir)->nid);
err = PTR_ERR(de); err = PTR_ERR(de);
break; break;
} }
@ -79,25 +74,19 @@ static int erofs_readdir(struct file *f, struct dir_context *ctx)
break; break;
} }
maxsize = min_t(unsigned int, dirsize - ctx->pos + ofs, bsz); maxsize = min_t(unsigned int, dir->i_size - dbstart, bsz);
/* search dirents at the arbitrary position */ /* search dirents at the arbitrary position */
if (initial) { if (initial) {
initial = false; initial = false;
ofs = roundup(ofs, sizeof(struct erofs_dirent)); ofs = roundup(ofs, sizeof(struct erofs_dirent));
ctx->pos = erofs_pos(sb, i) + ofs; ctx->pos = dbstart + ofs;
if (ofs >= nameoff)
goto skip_this;
} }
err = erofs_fill_dentries(dir, ctx, de, (void *)de + ofs, err = erofs_fill_dentries(dir, ctx, de, (void *)de + ofs,
nameoff, maxsize); nameoff, maxsize);
if (err) if (err)
break; break;
skip_this: ctx->pos = dbstart + maxsize;
ctx->pos = erofs_pos(sb, i) + maxsize;
++i;
ofs = 0; ofs = 0;
} }
erofs_put_metabuf(&buf); erofs_put_metabuf(&buf);

2
fs/erofs/internal.h
View File

@ -220,7 +220,7 @@ struct erofs_buf {
}; };
#define __EROFS_BUF_INITIALIZER ((struct erofs_buf){ .page = NULL }) #define __EROFS_BUF_INITIALIZER ((struct erofs_buf){ .page = NULL })
#define erofs_blknr(sb, addr) ((addr) >> (sb)->s_blocksize_bits) #define erofs_blknr(sb, addr) ((erofs_blk_t)((addr) >> (sb)->s_blocksize_bits))
#define erofs_blkoff(sb, addr) ((addr) & ((sb)->s_blocksize - 1)) #define erofs_blkoff(sb, addr) ((addr) & ((sb)->s_blocksize - 1))
#define erofs_pos(sb, blk) ((erofs_off_t)(blk) << (sb)->s_blocksize_bits) #define erofs_pos(sb, blk) ((erofs_off_t)(blk) << (sb)->s_blocksize_bits)
#define erofs_iblks(i) (round_up((i)->i_size, i_blocksize(i)) >> (i)->i_blkbits) #define erofs_iblks(i) (round_up((i)->i_size, i_blocksize(i)) >> (i)->i_blkbits)