This adds a new ioctl command which limits range of segment to be
allocated. This is intended to gather data whithin a range of the
partition before shrinking the filesystem, or to control new log
location for some purpose.
If a range is specified by the ioctl, segment allocator of nilfs tries
to allocate new segments from the range unless no free segments are
available there.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxxxxxx>
---
fs/nilfs2/ioctl.c | 34 +++++++++++++++++++++
fs/nilfs2/sufile.c | 73 ++++++++++++++++++++++++++++++++++++++------
fs/nilfs2/sufile.h | 1 +
include/linux/nilfs2_fs.h | 2 +
4 files changed, 100 insertions(+), 10 deletions(-)
diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
index f2469ba..6f61777 100644
--- a/fs/nilfs2/ioctl.c
+++ b/fs/nilfs2/ioctl.c
@@ -698,6 +698,38 @@ static int nilfs_ioctl_sync(struct inode *inode, struct file *filp,
return 0;
}
+static int nilfs_ioctl_set_alloc_range(struct inode *inode, void __user *argp)
+{
+ struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
+ __u64 range[2];
+ __u64 minseg, maxseg;
+ unsigned long segbytes;
+ int ret = -EPERM;
+
+ if (!capable(CAP_SYS_ADMIN))
+ goto out;
+
+ ret = -EFAULT;
+ if (copy_from_user(range, argp, sizeof(__u64[2])))
+ goto out;
+
+ ret = -ERANGE;
+ if (range[1] > i_size_read(inode->i_sb->s_bdev->bd_inode))
+ goto out;
+
+ segbytes = nilfs->ns_blocks_per_segment * nilfs->ns_blocksize;
+
+ minseg = range[0] + segbytes - 1;
+ do_div(minseg, segbytes);
+ maxseg = NILFS_SB2_OFFSET_BYTES(range[1]);
+ do_div(maxseg, segbytes);
+ maxseg--;
+
+ ret = nilfs_sufile_set_alloc_range(nilfs->ns_sufile, minseg, maxseg);
+out:
+ return ret;
+}
+
static int nilfs_ioctl_get_info(struct inode *inode, struct file *filp,
unsigned int cmd, void __user *argp,
size_t membsz,
@@ -763,6 +795,8 @@ long nilfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
return nilfs_ioctl_clean_segments(inode, filp, cmd, argp);
case NILFS_IOCTL_SYNC:
return nilfs_ioctl_sync(inode, filp, cmd, argp);
+ case NILFS_IOCTL_SET_ALLOC_RANGE:
+ return nilfs_ioctl_set_alloc_range(inode, argp);
default:
return -ENOTTY;
}
diff --git a/fs/nilfs2/sufile.c b/fs/nilfs2/sufile.c
index 1d6f488..f4374df 100644
--- a/fs/nilfs2/sufile.c
+++ b/fs/nilfs2/sufile.c
@@ -33,7 +33,9 @@
struct nilfs_sufile_info {
struct nilfs_mdt_info mi;
- unsigned long ncleansegs;
+ unsigned long ncleansegs;/* number of clean segments */
+ __u64 allocmin; /* lower limit of allocatable segment range */
+ __u64 allocmax; /* upper limit of allocatable segment range */
};
static inline struct nilfs_sufile_info *NILFS_SUI(struct inode *sufile)
@@ -248,6 +250,35 @@ int nilfs_sufile_update(struct inode *sufile, __u64 segnum, int create,
}
/**
+ * nilfs_sufile_set_alloc_range - limit range of segment to be allocated
+ * @sufile: inode of segment usage file
+ * @start: minimum segment number of allocatable region (inclusive)
+ * @end: maximum segment number of allocatable region (inclusive)
+ *
+ * Return Value: On success, 0 is returned. On error, one of the
+ * following negative error codes is returned.
+ *
+ * %-ERANGE - invalid segment region
+ */
+int nilfs_sufile_set_alloc_range(struct inode *sufile, __u64 start, __u64 end)
+{
+ struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
+ __u64 nsegs;
+ int ret = -ERANGE;
+
+ down_write(&NILFS_MDT(sufile)->mi_sem);
+ nsegs = nilfs_sufile_get_nsegments(sufile);
+
+ if (start <= end && end < nsegs) {
+ sui->allocmin = start;
+ sui->allocmax = end;
+ ret = 0;
+ }
+ up_write(&NILFS_MDT(sufile)->mi_sem);
+ return ret;
+}
+
+/**
* nilfs_sufile_alloc - allocate a segment
* @sufile: inode of segment usage file
* @segnump: pointer to segment number
@@ -269,11 +300,12 @@ int nilfs_sufile_alloc(struct inode *sufile, __u64 *segnump)
struct buffer_head *header_bh, *su_bh;
struct nilfs_sufile_header *header;
struct nilfs_segment_usage *su;
+ struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
size_t susz = NILFS_MDT(sufile)->mi_entry_size;
__u64 segnum, maxsegnum, last_alloc;
void *kaddr;
- unsigned long nsegments, ncleansegs, nsus;
- int ret, i, j;
+ unsigned long nsegments, ncleansegs, nsus, cnt;
+ int ret, j;
down_write(&NILFS_MDT(sufile)->mi_sem);
@@ -287,13 +319,31 @@ int nilfs_sufile_alloc(struct inode *sufile, __u64 *segnump)
kunmap_atomic(kaddr, KM_USER0);
nsegments = nilfs_sufile_get_nsegments(sufile);
+ maxsegnum = sui->allocmax;
segnum = last_alloc + 1;
- maxsegnum = nsegments - 1;
- for (i = 0; i < nsegments; i += nsus) {
- if (segnum >= nsegments) {
- /* wrap around */
- segnum = 0;
- maxsegnum = last_alloc;
+ if (segnum < sui->allocmin || segnum > sui->allocmax)
+ segnum = sui->allocmin;
+
+ for (cnt = 0; cnt < nsegments; cnt += nsus) {
+ if (segnum > maxsegnum) {
+ if (cnt < sui->allocmax - sui->allocmin + 1) {
+ /*
+ * wrap around in the limited region.
+ * if allocation started from
+ * sui->allocmin, this never happens.
+ */
+ segnum = sui->allocmin;
+ maxsegnum = last_alloc;
+ } else if (segnum > sui->allocmin &&
+ sui->allocmax + 1 < nsegments) {
+ segnum = sui->allocmax + 1;
+ maxsegnum = nsegments - 1;
+ } else if (sui->allocmin > 0) {
+ segnum = 0;
+ maxsegnum = sui->allocmin - 1;
+ } else {
+ break; /* never happens */
+ }
}
ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 1,
&su_bh);
@@ -319,7 +369,7 @@ int nilfs_sufile_alloc(struct inode *sufile, __u64 *segnump)
header->sh_last_alloc = cpu_to_le64(segnum);
kunmap_atomic(kaddr, KM_USER0);
- NILFS_SUI(sufile)->ncleansegs--;
+ sui->ncleansegs--;
nilfs_mdt_mark_buffer_dirty(header_bh);
nilfs_mdt_mark_buffer_dirty(su_bh);
nilfs_mdt_mark_dirty(sufile);
@@ -679,6 +729,9 @@ int nilfs_sufile_read(struct super_block *sb, size_t susize,
kunmap_atomic(kaddr, KM_USER0);
brelse(header_bh);
+ sui->allocmax = nilfs_sufile_get_nsegments(sufile) - 1;
+ sui->allocmin = 0;
+
unlock_new_inode(sufile);
out:
*inodep = sufile;
diff --git a/fs/nilfs2/sufile.h b/fs/nilfs2/sufile.h
index a943fba..57bfee9 100644
--- a/fs/nilfs2/sufile.h
+++ b/fs/nilfs2/sufile.h
@@ -36,6 +36,7 @@ static inline unsigned long nilfs_sufile_get_nsegments(struct inode *sufile)
unsigned long nilfs_sufile_get_ncleansegs(struct inode *sufile);
+int nilfs_sufile_set_alloc_range(struct inode *sufile, __u64 start, __u64 end);
int nilfs_sufile_alloc(struct inode *, __u64 *);
int nilfs_sufile_mark_dirty(struct inode *sufile, __u64 segnum);
int nilfs_sufile_set_segment_usage(struct inode *sufile, __u64 segnum,
diff --git a/include/linux/nilfs2_fs.h b/include/linux/nilfs2_fs.h
index bd8678f..7454ad7 100644
--- a/include/linux/nilfs2_fs.h
+++ b/include/linux/nilfs2_fs.h
@@ -845,5 +845,7 @@ struct nilfs_bdesc {
_IOR(NILFS_IOCTL_IDENT, 0x8A, __u64)
#define NILFS_IOCTL_RESIZE \
_IOW(NILFS_IOCTL_IDENT, 0x8B, __u64)
+#define NILFS_IOCTL_SET_ALLOC_RANGE \
+ _IOW(NILFS_IOCTL_IDENT, 0x8C, __u64[2])
#endif /* _LINUX_NILFS_FS_H */
--
1.7.3.5
--
To unsubscribe from this list: send the line "unsubscribe linux-nilfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
