The {online,offline}_one_memblock() helpers both open-coded the check
for whether a block is online. There is already a function to perform
this check - memblock_is_online(). Consolidate the checking using this
helper everywhere it is applicable.Cc: Dan Williams <[email protected]> Signed-off-by: Vishal Verma <[email protected]> --- daxctl/lib/libdaxctl.c | 90 +++++++++++++++++------------------------- 1 file changed, 37 insertions(+), 53 deletions(-) diff --git a/daxctl/lib/libdaxctl.c b/daxctl/lib/libdaxctl.c index a828644..6243857 100644 --- a/daxctl/lib/libdaxctl.c +++ b/daxctl/lib/libdaxctl.c @@ -1047,12 +1047,11 @@ DAXCTL_EXPORT unsigned long daxctl_memory_get_block_size(struct daxctl_memory *m return mem->block_size; } -static int online_one_memblock(struct daxctl_memory *mem, char *memblock) +static int memblock_is_online(struct daxctl_memory *mem, char *memblock) { struct daxctl_dev *dev = daxctl_memory_get_dev(mem); const char *devname = daxctl_dev_get_devname(dev); struct daxctl_ctx *ctx = daxctl_dev_get_ctx(dev); - const char *mode = "online_movable"; int len = mem->buf_len, rc; char buf[SYSFS_ATTR_SIZE]; char *path = mem->mem_buf; @@ -1073,41 +1072,20 @@ static int online_one_memblock(struct daxctl_memory *mem, char *memblock) return rc; } - /* - * if already online, possibly due to kernel config or a udev rule, - * there is nothing to do and we can skip over the memblock - */ if (strncmp(buf, "online", 6) == 0) return 1; - rc = sysfs_write_attr_quiet(ctx, path, mode); - if (rc) { - /* - * While we performed an already-online check above, there - * is still a TOCTOU hole where someone (such as a udev rule) - * may have raced to online the memory. In such a case, - * the sysfs store will fail, however we can check for this - * by simply reading the state again. If it changed to the - * desired state, then we don't have to error out. - */ - if (sysfs_read_attr(ctx, path, buf) == 0) { - if (strncmp(buf, "online", 6) == 0) - return 1; - } - err(ctx, "%s: Failed to online %s: %s\n", - devname, path, strerror(-rc)); - } - return rc; + /* offline */ + return 0; } -static int offline_one_memblock(struct daxctl_memory *mem, char *memblock) +static int online_one_memblock(struct daxctl_memory *mem, char *memblock) { struct daxctl_dev *dev = daxctl_memory_get_dev(mem); const char *devname = daxctl_dev_get_devname(dev); struct daxctl_ctx *ctx = daxctl_dev_get_ctx(dev); - const char *mode = "offline"; + const char *mode = "online_movable"; int len = mem->buf_len, rc; - char buf[SYSFS_ATTR_SIZE]; char *path = mem->mem_buf; const char *node_path; @@ -1119,37 +1097,39 @@ static int offline_one_memblock(struct daxctl_memory *mem, char *memblock) if (rc < 0) return -ENOMEM; - rc = sysfs_read_attr(ctx, path, buf); - if (rc) { - err(ctx, "%s: Failed to read %s: %s\n", - devname, path, strerror(-rc)); + /* + * if already online, possibly due to kernel config or a udev rule, + * there is nothing to do and we can skip over the memblock + */ + rc = memblock_is_online(mem, memblock); + if (rc) return rc; - } - - /* if already offline, there is nothing to do */ - if (strncmp(buf, "offline", 7) == 0) - return 1; rc = sysfs_write_attr_quiet(ctx, path, mode); if (rc) { - /* Close the TOCTOU hole like in online_one_memblock() above */ - if (sysfs_read_attr(ctx, path, buf) == 0) { - if (strncmp(buf, "offline", 7) == 0) - return 1; - } - err(ctx, "%s: Failed to offline %s: %s\n", + /* + * While we performed an already-online check above, there + * is still a TOCTOU hole where someone (such as a udev rule) + * may have raced to online the memory. In such a case, + * the sysfs store will fail, however we can check for this + * by simply reading the state again. If it changed to the + * desired state, then we don't have to error out. + */ + if (memblock_is_online(mem, memblock)) + return 1; + err(ctx, "%s: Failed to online %s: %s\n", devname, path, strerror(-rc)); } return rc; } -static int memblock_is_online(struct daxctl_memory *mem, char *memblock) +static int offline_one_memblock(struct daxctl_memory *mem, char *memblock) { struct daxctl_dev *dev = daxctl_memory_get_dev(mem); const char *devname = daxctl_dev_get_devname(dev); struct daxctl_ctx *ctx = daxctl_dev_get_ctx(dev); + const char *mode = "offline"; int len = mem->buf_len, rc; - char buf[SYSFS_ATTR_SIZE]; char *path = mem->mem_buf; const char *node_path; @@ -1161,18 +1141,22 @@ static int memblock_is_online(struct daxctl_memory *mem, char *memblock) if (rc < 0) return -ENOMEM; - rc = sysfs_read_attr(ctx, path, buf); - if (rc) { - err(ctx, "%s: Failed to read %s: %s\n", - devname, path, strerror(-rc)); + /* if already offline, there is nothing to do */ + rc = memblock_is_online(mem, memblock); + if (rc < 0) return rc; - } - - if (strncmp(buf, "online", 6) == 0) + if (!rc) return 1; - /* offline */ - return 0; + rc = sysfs_write_attr_quiet(ctx, path, mode); + if (rc) { + /* Close the TOCTOU hole like in online_one_memblock() above */ + if (!memblock_is_online(mem, memblock)) + return 1; + err(ctx, "%s: Failed to offline %s: %s\n", + devname, path, strerror(-rc)); + } + return rc; } static bool memblock_in_dev(struct daxctl_memory *mem, const char *memblock) -- 2.20.1 _______________________________________________ Linux-nvdimm mailing list -- [email protected] To unsubscribe send an email to [email protected]
