From e8afad656cbcd06d02a7bacd4b318fa0e2907de0 Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Wed, 14 Nov 2012 09:38:19 -0600 Subject: [PATCH] libceph: pass length to ceph_calc_file_object_mapping() ceph_calc_file_object_mapping() takes (among other things) a "file" offset and length, and based on the layout, determines the object number ("bno") backing the affected portion of the file's data and the offset into that object where the desired range begins. It also computes the size that should be used for the request--either the amount requested or something less if that would exceed the end of the object. This patch changes the input length parameter in this function so it is used only for input. That is, the argument will be passed by value rather than by address, so the value provided won't get updated by the function. The value would only get updated if the length would surpass the current object, and in that case the value it got updated to would be exactly that returned in *oxlen. Only one of the two callers is affected by this change. Update ceph_calc_raw_layout() so it records any updated value. Signed-off-by: Alex Elder Reviewed-by: Josh Durgin --- fs/ceph/ioctl.c | 2 +- include/linux/ceph/osdmap.h | 2 +- net/ceph/osd_client.c | 6 ++++-- net/ceph/osdmap.c | 9 ++++----- 4 files changed, 10 insertions(+), 9 deletions(-) diff --git a/fs/ceph/ioctl.c b/fs/ceph/ioctl.c index 36549a46e311..3b22150d3e19 100644 --- a/fs/ceph/ioctl.c +++ b/fs/ceph/ioctl.c @@ -194,7 +194,7 @@ static long ceph_ioctl_get_dataloc(struct file *file, void __user *arg) return -EFAULT; down_read(&osdc->map_sem); - r = ceph_calc_file_object_mapping(&ci->i_layout, dl.file_offset, &len, + r = ceph_calc_file_object_mapping(&ci->i_layout, dl.file_offset, len, &dl.object_no, &dl.object_offset, &olen); if (r < 0) diff --git a/include/linux/ceph/osdmap.h b/include/linux/ceph/osdmap.h index 5ea57ba69320..1f653e2ff5cc 100644 --- a/include/linux/ceph/osdmap.h +++ b/include/linux/ceph/osdmap.h @@ -110,7 +110,7 @@ extern void ceph_osdmap_destroy(struct ceph_osdmap *map); /* calculate mapping of a file extent to an object */ extern int ceph_calc_file_object_mapping(struct ceph_file_layout *layout, - u64 off, u64 *plen, + u64 off, u64 len, u64 *bno, u64 *oxoff, u64 *oxlen); /* calculate mapping of object to a placement group */ diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c index e29a3ed92958..47e5f5b1f94c 100644 --- a/net/ceph/osd_client.c +++ b/net/ceph/osd_client.c @@ -53,13 +53,15 @@ int ceph_calc_raw_layout(struct ceph_osd_client *osdc, reqhead->snapid = cpu_to_le64(snapid); /* object extent? */ - r = ceph_calc_file_object_mapping(layout, off, plen, bno, + r = ceph_calc_file_object_mapping(layout, off, orig_len, bno, &objoff, &objlen); if (r < 0) return r; - if (*plen < orig_len) + if (objlen < orig_len) { + *plen = objlen; dout(" skipping last %llu, final file extent %llu~%llu\n", orig_len - *plen, off, *plen); + } if (op_has_extent(op->op)) { u32 osize = le32_to_cpu(layout->fl_object_size); diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c index ca05871635bc..369f03ba9ee5 100644 --- a/net/ceph/osdmap.c +++ b/net/ceph/osdmap.c @@ -1016,7 +1016,7 @@ bad: * pass a stride back to the caller. */ int ceph_calc_file_object_mapping(struct ceph_file_layout *layout, - u64 off, u64 *plen, + u64 off, u64 len, u64 *ono, u64 *oxoff, u64 *oxlen) { @@ -1027,7 +1027,7 @@ int ceph_calc_file_object_mapping(struct ceph_file_layout *layout, u32 su_per_object; u64 t, su_offset; - dout("mapping %llu~%llu osize %u fl_su %u\n", off, *plen, + dout("mapping %llu~%llu osize %u fl_su %u\n", off, len, osize, su); if (su == 0 || sc == 0) goto invalid; @@ -1060,11 +1060,10 @@ int ceph_calc_file_object_mapping(struct ceph_file_layout *layout, /* * Calculate the length of the extent being written to the selected - * object. This is the minimum of the full length requested (plen) or + * object. This is the minimum of the full length requested (len) or * the remainder of the current stripe being written to. */ - *oxlen = min_t(u64, *plen, su - su_offset); - *plen = *oxlen; + *oxlen = min_t(u64, len, su - su_offset); dout(" obj extent %llu~%llu\n", *oxoff, *oxlen); return 0;