Merge branch 'hwpoison-cleanups' into hwpoison
This commit is contained in:
commit
e9d08567ef
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@ -7,21 +7,26 @@
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* Free Software Foundation.
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*
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* High level machine check handler. Handles pages reported by the
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* hardware as being corrupted usually due to a 2bit ECC memory or cache
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* hardware as being corrupted usually due to a multi-bit ECC memory or cache
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* failure.
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*
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* In addition there is a "soft offline" entry point that allows stop using
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* not-yet-corrupted-by-suspicious pages without killing anything.
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*
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* Handles page cache pages in various states. The tricky part
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* here is that we can access any page asynchronous to other VM
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* users, because memory failures could happen anytime and anywhere,
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* possibly violating some of their assumptions. This is why this code
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* has to be extremely careful. Generally it tries to use normal locking
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* rules, as in get the standard locks, even if that means the
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* error handling takes potentially a long time.
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*
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* The operation to map back from RMAP chains to processes has to walk
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* the complete process list and has non linear complexity with the number
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* mappings. In short it can be quite slow. But since memory corruptions
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* are rare we hope to get away with this.
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* here is that we can access any page asynchronously in respect to
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* other VM users, because memory failures could happen anytime and
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* anywhere. This could violate some of their assumptions. This is why
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* this code has to be extremely careful. Generally it tries to use
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* normal locking rules, as in get the standard locks, even if that means
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* the error handling takes potentially a long time.
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*
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* There are several operations here with exponential complexity because
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* of unsuitable VM data structures. For example the operation to map back
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* from RMAP chains to processes has to walk the complete process list and
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* has non linear complexity with the number. But since memory corruptions
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* are rare we hope to get away with this. This avoids impacting the core
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* VM.
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*/
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/*
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@ -30,7 +35,6 @@
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* - kcore/oldmem/vmcore/mem/kmem check for hwpoison pages
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* - pass bad pages to kdump next kernel
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*/
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#define DEBUG 1 /* remove me in 2.6.34 */
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/page-flags.h>
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@ -78,7 +82,7 @@ static int hwpoison_filter_dev(struct page *p)
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return 0;
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/*
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* page_mapping() does not accept slab page
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* page_mapping() does not accept slab pages.
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*/
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if (PageSlab(p))
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return -EINVAL;
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@ -268,7 +272,7 @@ struct to_kill {
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struct list_head nd;
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struct task_struct *tsk;
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unsigned long addr;
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unsigned addr_valid:1;
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char addr_valid;
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};
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/*
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@ -309,7 +313,7 @@ static void add_to_kill(struct task_struct *tsk, struct page *p,
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* a SIGKILL because the error is not contained anymore.
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*/
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if (tk->addr == -EFAULT) {
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pr_debug("MCE: Unable to find user space address %lx in %s\n",
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pr_info("MCE: Unable to find user space address %lx in %s\n",
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page_to_pfn(p), tsk->comm);
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tk->addr_valid = 0;
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}
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@ -577,7 +581,7 @@ static int me_pagecache_clean(struct page *p, unsigned long pfn)
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pfn, err);
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} else if (page_has_private(p) &&
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!try_to_release_page(p, GFP_NOIO)) {
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pr_debug("MCE %#lx: failed to release buffers\n", pfn);
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pr_info("MCE %#lx: failed to release buffers\n", pfn);
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} else {
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ret = RECOVERED;
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}
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@ -836,8 +840,6 @@ static int page_action(struct page_state *ps, struct page *p,
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return (result == RECOVERED || result == DELAYED) ? 0 : -EBUSY;
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}
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#define N_UNMAP_TRIES 5
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/*
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* Do all that is necessary to remove user space mappings. Unmap
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* the pages and send SIGBUS to the processes if the data was dirty.
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@ -849,7 +851,6 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
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struct address_space *mapping;
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LIST_HEAD(tokill);
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int ret;
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int i;
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int kill = 1;
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struct page *hpage = compound_head(p);
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@ -903,17 +904,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
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if (kill)
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collect_procs(hpage, &tokill);
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/*
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* try_to_unmap can fail temporarily due to races.
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* Try a few times (RED-PEN better strategy?)
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*/
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for (i = 0; i < N_UNMAP_TRIES; i++) {
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ret = try_to_unmap(hpage, ttu);
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if (ret == SWAP_SUCCESS)
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break;
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pr_debug("MCE %#lx: try_to_unmap retry needed %d\n", pfn, ret);
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}
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ret = try_to_unmap(hpage, ttu);
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if (ret != SWAP_SUCCESS)
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printk(KERN_ERR "MCE %#lx: failed to unmap page (mapcount=%d)\n",
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pfn, page_mapcount(hpage));
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@ -1147,7 +1138,7 @@ int unpoison_memory(unsigned long pfn)
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page = compound_head(p);
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if (!PageHWPoison(p)) {
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pr_debug("MCE: Page was already unpoisoned %#lx\n", pfn);
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pr_info("MCE: Page was already unpoisoned %#lx\n", pfn);
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return 0;
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}
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@ -1156,7 +1147,7 @@ int unpoison_memory(unsigned long pfn)
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if (!get_page_unless_zero(page)) {
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if (TestClearPageHWPoison(p))
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atomic_long_sub(nr_pages, &mce_bad_pages);
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pr_debug("MCE: Software-unpoisoned free page %#lx\n", pfn);
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pr_info("MCE: Software-unpoisoned free page %#lx\n", pfn);
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return 0;
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}
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@ -1168,7 +1159,7 @@ int unpoison_memory(unsigned long pfn)
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* the free buddy page pool.
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*/
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if (TestClearPageHWPoison(page)) {
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pr_debug("MCE: Software-unpoisoned page %#lx\n", pfn);
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pr_info("MCE: Software-unpoisoned page %#lx\n", pfn);
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atomic_long_sub(nr_pages, &mce_bad_pages);
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freeit = 1;
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}
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@ -1217,12 +1208,12 @@ static int get_any_page(struct page *p, unsigned long pfn, int flags)
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set_migratetype_isolate(p);
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if (!get_page_unless_zero(compound_head(p))) {
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if (is_free_buddy_page(p)) {
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pr_debug("get_any_page: %#lx free buddy page\n", pfn);
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pr_info("get_any_page: %#lx free buddy page\n", pfn);
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/* Set hwpoison bit while page is still isolated */
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SetPageHWPoison(p);
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ret = 0;
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} else {
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pr_debug("get_any_page: %#lx: unknown zero refcount page type %lx\n",
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pr_info("get_any_page: %#lx: unknown zero refcount page type %lx\n",
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pfn, p->flags);
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ret = -EIO;
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}
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@ -1288,7 +1279,7 @@ int soft_offline_page(struct page *page, int flags)
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goto done;
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}
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if (!PageLRU(page)) {
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pr_debug("soft_offline: %#lx: unknown non LRU page type %lx\n",
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pr_info("soft_offline: %#lx: unknown non LRU page type %lx\n",
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pfn, page->flags);
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return -EIO;
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}
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@ -1302,7 +1293,7 @@ int soft_offline_page(struct page *page, int flags)
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if (PageHWPoison(page)) {
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unlock_page(page);
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put_page(page);
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pr_debug("soft offline: %#lx page already poisoned\n", pfn);
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pr_info("soft offline: %#lx page already poisoned\n", pfn);
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return -EBUSY;
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}
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@ -1323,7 +1314,7 @@ int soft_offline_page(struct page *page, int flags)
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put_page(page);
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if (ret == 1) {
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ret = 0;
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pr_debug("soft_offline: %#lx: invalidated\n", pfn);
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pr_info("soft_offline: %#lx: invalidated\n", pfn);
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goto done;
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}
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@ -1339,13 +1330,13 @@ int soft_offline_page(struct page *page, int flags)
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list_add(&page->lru, &pagelist);
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ret = migrate_pages(&pagelist, new_page, MPOL_MF_MOVE_ALL, 0);
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if (ret) {
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pr_debug("soft offline: %#lx: migration failed %d, type %lx\n",
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pr_info("soft offline: %#lx: migration failed %d, type %lx\n",
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pfn, ret, page->flags);
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if (ret > 0)
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ret = -EIO;
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}
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} else {
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pr_debug("soft offline: %#lx: isolation failed: %d, page count %d, type %lx\n",
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pr_info("soft offline: %#lx: isolation failed: %d, page count %d, type %lx\n",
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pfn, ret, page_count(page), page->flags);
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}
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if (ret)
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