diff options
Diffstat (limited to 'mm/shmem.c')
| -rw-r--r-- | mm/shmem.c | 743 |
1 files changed, 398 insertions, 345 deletions
diff --git a/mm/shmem.c b/mm/shmem.c index 51b3d6ccdda..f514dd392cd 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -49,6 +49,7 @@ #include <linux/ctype.h> #include <linux/migrate.h> #include <linux/highmem.h> +#include <linux/seq_file.h> #include <asm/uaccess.h> #include <asm/div64.h> @@ -78,13 +79,24 @@ /* Flag allocation requirements to shmem_getpage and shmem_swp_alloc */ enum sgp_type { - SGP_QUICK, /* don't try more than file page cache lookup */ SGP_READ, /* don't exceed i_size, don't allocate page */ SGP_CACHE, /* don't exceed i_size, may allocate page */ + SGP_DIRTY, /* like SGP_CACHE, but set new page dirty */ SGP_WRITE, /* may exceed i_size, may allocate page */ - SGP_FAULT, /* same as SGP_CACHE, return with page locked */ }; +#ifdef CONFIG_TMPFS +static unsigned long shmem_default_max_blocks(void) +{ + return totalram_pages / 2; +} + +static unsigned long shmem_default_max_inodes(void) +{ + return min(totalram_pages - totalhigh_pages, totalram_pages / 2); +} +#endif + static int shmem_getpage(struct inode *inode, unsigned long idx, struct page **pagep, enum sgp_type sgp, int *type); @@ -194,7 +206,7 @@ static struct backing_dev_info shmem_backing_dev_info __read_mostly = { }; static LIST_HEAD(shmem_swaplist); -static DEFINE_SPINLOCK(shmem_swaplist_lock); +static DEFINE_MUTEX(shmem_swaplist_mutex); static void shmem_free_blocks(struct inode *inode, long pages) { @@ -207,9 +219,33 @@ static void shmem_free_blocks(struct inode *inode, long pages) } } -/* +static int shmem_reserve_inode(struct super_block *sb) +{ + struct shmem_sb_info *sbinfo = SHMEM_SB(sb); + if (sbinfo->max_inodes) { + spin_lock(&sbinfo->stat_lock); + if (!sbinfo->free_inodes) { + spin_unlock(&sbinfo->stat_lock); + return -ENOSPC; + } + sbinfo->free_inodes--; + spin_unlock(&sbinfo->stat_lock); + } + return 0; +} + +static void shmem_free_inode(struct super_block *sb) +{ + struct shmem_sb_info *sbinfo = SHMEM_SB(sb); + if (sbinfo->max_inodes) { + spin_lock(&sbinfo->stat_lock); + sbinfo->free_inodes++; + spin_unlock(&sbinfo->stat_lock); + } +} + +/** * shmem_recalc_inode - recalculate the size of an inode - * * @inode: inode to recalc * * We have to calculate the free blocks since the mm can drop @@ -233,9 +269,8 @@ static void shmem_recalc_inode(struct inode *inode) } } -/* +/** * shmem_swp_entry - find the swap vector position in the info structure - * * @info: info structure for the inode * @index: index of the page to find * @page: optional page to add to the structure. Has to be preset to @@ -337,13 +372,13 @@ static void shmem_swp_set(struct shmem_inode_info *info, swp_entry_t *entry, uns } } -/* +/** * shmem_swp_alloc - get the position of the swap entry for the page. - * If it does not exist allocate the entry. - * * @info: info structure for the inode * @index: index of the page to find * @sgp: check and recheck i_size? skip allocation? + * + * If the entry does not exist, allocate it. */ static swp_entry_t *shmem_swp_alloc(struct shmem_inode_info *info, unsigned long index, enum sgp_type sgp) { @@ -403,9 +438,8 @@ static swp_entry_t *shmem_swp_alloc(struct shmem_inode_info *info, unsigned long return entry; } -/* +/** * shmem_free_swp - free some swap entries in a directory - * * @dir: pointer to the directory * @edir: pointer after last entry of the directory * @punch_lock: pointer to spinlock when needed for the holepunch case @@ -731,6 +765,8 @@ static int shmem_notify_change(struct dentry *dentry, struct iattr *attr) (void) shmem_getpage(inode, attr->ia_size>>PAGE_CACHE_SHIFT, &page, SGP_READ, NULL); + if (page) + unlock_page(page); } /* * Reset SHMEM_PAGEIN flag so that shmem_truncate can @@ -762,7 +798,6 @@ static int shmem_notify_change(struct dentry *dentry, struct iattr *attr) static void shmem_delete_inode(struct inode *inode) { - struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); struct shmem_inode_info *info = SHMEM_I(inode); if (inode->i_op->truncate == shmem_truncate) { @@ -771,17 +806,13 @@ static void shmem_delete_inode(struct inode *inode) inode->i_size = 0; shmem_truncate(inode); if (!list_empty(&info->swaplist)) { - spin_lock(&shmem_swaplist_lock); + mutex_lock(&shmem_swaplist_mutex); list_del_init(&info->swaplist); - spin_unlock(&shmem_swaplist_lock); + mutex_unlock(&shmem_swaplist_mutex); } } BUG_ON(inode->i_blocks); - if (sbinfo->max_inodes) { - spin_lock(&sbinfo->stat_lock); - sbinfo->free_inodes++; - spin_unlock(&sbinfo->stat_lock); - } + shmem_free_inode(inode->i_sb); clear_inode(inode); } @@ -807,19 +838,22 @@ static int shmem_unuse_inode(struct shmem_inode_info *info, swp_entry_t entry, s struct page *subdir; swp_entry_t *ptr; int offset; + int error; idx = 0; ptr = info->i_direct; spin_lock(&info->lock); + if (!info->swapped) { + list_del_init(&info->swaplist); + goto lost2; + } limit = info->next_index; size = limit; if (size > SHMEM_NR_DIRECT) size = SHMEM_NR_DIRECT; offset = shmem_find_swp(entry, ptr, ptr+size); - if (offset >= 0) { - shmem_swp_balance_unmap(); + if (offset >= 0) goto found; - } if (!info->i_indirect) goto lost2; @@ -829,6 +863,14 @@ static int shmem_unuse_inode(struct shmem_inode_info *info, swp_entry_t entry, s for (idx = SHMEM_NR_DIRECT; idx < limit; idx += ENTRIES_PER_PAGE, dir++) { if (unlikely(idx == stage)) { shmem_dir_unmap(dir-1); + if (cond_resched_lock(&info->lock)) { + /* check it has not been truncated */ + if (limit > info->next_index) { + limit = info->next_index; + if (idx >= limit) + goto lost2; + } + } dir = shmem_dir_map(info->i_indirect) + ENTRIES_PER_PAGE/2 + idx/ENTRIES_PER_PAGEPAGE; while (!*dir) { @@ -849,11 +891,11 @@ static int shmem_unuse_inode(struct shmem_inode_info *info, swp_entry_t entry, s if (size > ENTRIES_PER_PAGE) size = ENTRIES_PER_PAGE; offset = shmem_find_swp(entry, ptr, ptr+size); + shmem_swp_unmap(ptr); if (offset >= 0) { shmem_dir_unmap(dir); goto found; } - shmem_swp_unmap(ptr); } } lost1: @@ -863,19 +905,69 @@ lost2: return 0; found: idx += offset; - inode = &info->vfs_inode; - if (move_from_swap_cache(page, idx, inode->i_mapping) == 0) { - info->flags |= SHMEM_PAGEIN; - shmem_swp_set(info, ptr + offset, 0); - } - shmem_swp_unmap(ptr); + inode = igrab(&info->vfs_inode); spin_unlock(&info->lock); + /* - * Decrement swap count even when the entry is left behind: - * try_to_unuse will skip over mms, then reincrement count. + * Move _head_ to start search for next from here. + * But be careful: shmem_delete_inode checks list_empty without taking + * mutex, and there's an instant in list_move_tail when info->swaplist + * would appear empty, if it were the only one on shmem_swaplist. We + * could avoid doing it if inode NULL; or use this minor optimization. */ - swap_free(entry); - return 1; + if (shmem_swaplist.next != &info->swaplist) + list_move_tail(&shmem_swaplist, &info->swaplist); + mutex_unlock(&shmem_swaplist_mutex); + + error = 1; + if (!inode) + goto out; + /* Precharge page while we can wait, compensate afterwards */ + error = mem_cgroup_cache_charge(page, current->mm, GFP_KERNEL); + if (error) + goto out; + error = radix_tree_preload(GFP_KERNEL); + if (error) + goto uncharge; + error = 1; + + spin_lock(&info->lock); + ptr = shmem_swp_entry(info, idx, NULL); + if (ptr && ptr->val == entry.val) + error = add_to_page_cache(page, inode->i_mapping, + idx, GFP_NOWAIT); + if (error == -EEXIST) { + struct page *filepage = find_get_page(inode->i_mapping, idx); + error = 1; + if (filepage) { + /* + * There might be a more uptodate page coming down + * from a stacked writepage: forget our swappage if so. + */ + if (PageUptodate(filepage)) + error = 0; + page_cache_release(filepage); + } + } + if (!error) { + delete_from_swap_cache(page); + set_page_dirty(page); + info->flags |= SHMEM_PAGEIN; + shmem_swp_set(info, ptr, 0); + swap_free(entry); + error = 1; /* not an error, but entry was found */ + } + if (ptr) + shmem_swp_unmap(ptr); + spin_unlock(&info->lock); + radix_tree_preload_end(); +uncharge: + mem_cgroup_uncharge_page(page); +out: + unlock_page(page); + page_cache_release(page); + iput(inode); /* allows for NULL */ + return error; } /* @@ -887,20 +979,16 @@ int shmem_unuse(swp_entry_t entry, struct page *page) struct shmem_inode_info *info; int found = 0; - spin_lock(&shmem_swaplist_lock); + mutex_lock(&shmem_swaplist_mutex); list_for_each_safe(p, next, &shmem_swaplist) { info = list_entry(p, struct shmem_inode_info, swaplist); - if (!info->swapped) - list_del_init(&info->swaplist); - else if (shmem_unuse_inode(info, entry, page)) { - /* move head to start search for next from here */ - list_move_tail(&shmem_swaplist, &info->swaplist); - found = 1; - break; - } + found = shmem_unuse_inode(info, entry, page); + cond_resched(); + if (found) + goto out; } - spin_unlock(&shmem_swaplist_lock); - return found; + mutex_unlock(&shmem_swaplist_mutex); +out: return found; /* 0 or 1 or -ENOMEM */ } /* @@ -915,54 +1003,65 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc) struct inode *inode; BUG_ON(!PageLocked(page)); - /* - * shmem_backing_dev_info's capabilities prevent regular writeback or - * sync from ever calling shmem_writepage; but a stacking filesystem - * may use the ->writepage of its underlying filesystem, in which case - * we want to do nothing when that underlying filesystem is tmpfs - * (writing out to swap is useful as a response to memory pressure, but - * of no use to stabilize the data) - just redirty the page, unlock it - * and claim success in this case. AOP_WRITEPAGE_ACTIVATE, and the - * page_mapped check below, must be avoided unless we're in reclaim. - */ - if (!wbc->for_reclaim) { - set_page_dirty(page); - unlock_page(page); - return 0; - } - BUG_ON(page_mapped(page)); - mapping = page->mapping; index = page->index; inode = mapping->host; info = SHMEM_I(inode); if (info->flags & VM_LOCKED) goto redirty; - swap = get_swap_page(); - if (!swap.val) + if (!total_swap_pages) goto redirty; + /* + * shmem_backing_dev_info's capabilities prevent regular writeback or + * sync from ever calling shmem_writepage; but a stacking filesystem + * may use the ->writepage of its underlying filesystem, in which case + * tmpfs should write out to swap only in response to memory pressure, + * and not for pdflush or sync. However, in those cases, we do still + * want to check if there's a redundant swappage to be discarded. + */ + if (wbc->for_reclaim) + swap = get_swap_page(); + else + swap.val = 0; + spin_lock(&info->lock); - shmem_recalc_inode(inode); if (index >= info->next_index) { BUG_ON(!(info->flags & SHMEM_TRUNCATE)); goto unlock; } entry = shmem_swp_entry(info, index, NULL); - BUG_ON(!entry); - BUG_ON(entry->val); + if (entry->val) { + /* + * The more uptodate page coming down from a stacked + * writepage should replace our old swappage. + */ + free_swap_and_cache(*entry); + shmem_swp_set(info, entry, 0); + } + shmem_recalc_inode(inode); - if (move_to_swap_cache(page, swap) == 0) { + if (swap.val && add_to_swap_cache(page, swap, GFP_ATOMIC) == 0) { + remove_from_page_cache(page); shmem_swp_set(info, entry, swap.val); shmem_swp_unmap(entry); + if (list_empty(&info->swaplist)) + inode = igrab(inode); + else + inode = NULL; spin_unlock(&info->lock); - if (list_empty(&info->swaplist)) { - spin_lock(&shmem_swaplist_lock); + swap_duplicate(swap); + BUG_ON(page_mapped(page)); + page_cache_release(page); /* pagecache ref */ + set_page_dirty(page); + unlock_page(page); + if (inode) { + mutex_lock(&shmem_swaplist_mutex); /* move instead of add in case we're racing */ list_move_tail(&info->swaplist, &shmem_swaplist); - spin_unlock(&shmem_swaplist_lock); + mutex_unlock(&shmem_swaplist_mutex); + iput(inode); } - unlock_page(page); return 0; } @@ -972,11 +1071,15 @@ unlock: swap_free(swap); redirty: set_page_dirty(page); - return AOP_WRITEPAGE_ACTIVATE; /* Return with the page locked */ + if (wbc->for_reclaim) + return AOP_WRITEPAGE_ACTIVATE; /* Return with page locked */ + unlock_page(page); + return 0; } #ifdef CONFIG_NUMA -static inline int shmem_parse_mpol(char *value, int *policy, nodemask_t *policy_nodes) +#ifdef CONFIG_TMPFS +static int shmem_parse_mpol(char *value, int *policy, nodemask_t *policy_nodes) { char *nodelist = strchr(value, ':'); int err = 1; @@ -1025,77 +1128,99 @@ out: return err; } -static struct page *shmem_swapin_async(struct shared_policy *p, - swp_entry_t entry, unsigned long idx) +static void shmem_show_mpol(struct seq_file *seq, int policy, + const nodemask_t policy_nodes) { - struct page *page; - struct vm_area_struct pvma; + char *policy_string; - /* Create a pseudo vma that just contains the policy */ - memset(&pvma, 0, sizeof(struct vm_area_struct)); - pvma.vm_end = PAGE_SIZE; - pvma.vm_pgoff = idx; - pvma.vm_policy = mpol_shared_policy_lookup(p, idx); - page = read_swap_cache_async(entry, &pvma, 0); - mpol_free(pvma.vm_policy); - return page; + switch (policy) { + case MPOL_PREFERRED: + policy_string = "prefer"; + break; + case MPOL_BIND: + policy_string = "bind"; + break; + case MPOL_INTERLEAVE: + policy_string = "interleave"; + break; + default: + /* MPOL_DEFAULT */ + return; + } + + seq_printf(seq, ",mpol=%s", policy_string); + + if (policy != MPOL_INTERLEAVE || + !nodes_equal(policy_nodes, node_states[N_HIGH_MEMORY])) { + char buffer[64]; + int len; + + len = nodelist_scnprintf(buffer, sizeof(buffer), policy_nodes); + if (len < sizeof(buffer)) + seq_printf(seq, ":%s", buffer); + else + seq_printf(seq, ":?"); + } } +#endif /* CONFIG_TMPFS */ -static struct page *shmem_swapin(struct shmem_inode_info *info, - swp_entry_t entry, unsigned long idx) +static struct page *shmem_swapin(swp_entry_t entry, gfp_t gfp, + struct shmem_inode_info *info, unsigned long idx) { - struct shared_policy *p = &info->policy; - int i, num; + struct vm_area_struct pvma; struct page *page; - unsigned long offset; - num = valid_swaphandles(entry, &offset); - for (i = 0; i < num; offset++, i++) { - page = shmem_swapin_async(p, - swp_entry(swp_type(entry), offset), idx); - if (!page) - break; - page_cache_release(page); - } - lru_add_drain(); /* Push any new pages onto the LRU now */ - return shmem_swapin_async(p, entry, idx); + /* Create a pseudo vma that just contains the policy */ + pvma.vm_start = 0; + pvma.vm_pgoff = idx; + pvma.vm_ops = NULL; + pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, idx); + page = swapin_readahead(entry, gfp, &pvma, 0); + mpol_free(pvma.vm_policy); + return page; } -static struct page * -shmem_alloc_page(gfp_t gfp, struct shmem_inode_info *info, - unsigned long idx) +static struct page *shmem_alloc_page(gfp_t gfp, + struct shmem_inode_info *info, unsigned long idx) { struct vm_area_struct pvma; struct page *page; - memset(&pvma, 0, sizeof(struct vm_area_struct)); - pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, idx); + /* Create a pseudo vma that just contains the policy */ + pvma.vm_start = 0; pvma.vm_pgoff = idx; - pvma.vm_end = PAGE_SIZE; + pvma.vm_ops = NULL; + pvma.vm_policy = mpol_shared_policy_lookup(&info->policy, idx); page = alloc_page_vma(gfp, &pvma, 0); mpol_free(pvma.vm_policy); return page; } -#else +#else /* !CONFIG_NUMA */ +#ifdef CONFIG_TMPFS static inline int shmem_parse_mpol(char *value, int *policy, nodemask_t *policy_nodes) { return 1; } -static inline struct page * -shmem_swapin(struct shmem_inode_info *info,swp_entry_t entry,unsigned long idx) +static inline void shmem_show_mpol(struct seq_file *seq, int policy, + const nodemask_t policy_nodes) { - swapin_readahead(entry, 0, NULL); - return read_swap_cache_async(entry, NULL, 0); } +#endif /* CONFIG_TMPFS */ -static inline struct page * -shmem_alloc_page(gfp_t gfp,struct shmem_inode_info *info, unsigned long idx) +static inline struct page *shmem_swapin(swp_entry_t entry, gfp_t gfp, + struct shmem_inode_info *info, unsigned long idx) +{ + return swapin_readahead(entry, gfp, NULL, 0); +} + +static inline struct page *shmem_alloc_page(gfp_t gfp, + struct shmem_inode_info *info, unsigned long idx) { return alloc_page(gfp); } -#endif +#endif /* CONFIG_NUMA */ /* * shmem_getpage - either get the page from swap or allocate a new one @@ -1114,6 +1239,7 @@ static int shmem_getpage(struct inode *inode, unsigned long idx, struct page *swappage; swp_entry_t *entry; swp_entry_t swap; + gfp_t gfp; int error; if (idx >= SHMEM_MAX_INDEX) @@ -1126,7 +1252,7 @@ static int shmem_getpage(struct inode *inode, unsigned long idx, * Normally, filepage is NULL on entry, and either found * uptodate immediately, or allocated and zeroed, or read * in under swappage, which is then assigned to filepage. - * But shmem_readpage and shmem_write_begin pass in a locked + * But shmem_readpage (required for splice) passes in a locked * filepage, which may be found not uptodate by other callers * too, and may need to be copied from the swappage read in. */ @@ -1136,8 +1262,17 @@ repeat: if (filepage && PageUptodate(filepage)) goto done; error = 0; - if (sgp == SGP_QUICK) - goto failed; + gfp = mapping_gfp_mask(mapping); + if (!filepage) { + /* + * Try to preload while we can wait, to not make a habit of + * draining atomic reserves; but don't latch on to this cpu. + */ + error = radix_tree_preload(gfp & ~__GFP_HIGHMEM); + if (error) + goto failed; + radix_tree_preload_end(); + } spin_lock(&info->lock); shmem_recalc_inode(inode); @@ -1160,7 +1295,7 @@ repeat: *type |= VM_FAULT_MAJOR; } spin_unlock(&info->lock); - swappage = shmem_swapin(info, swap, idx); + swappage = shmem_swapin(swap, gfp, info, idx); if (!swappage) { spin_lock(&info->lock); entry = shmem_swp_alloc(info, idx, sgp); @@ -1218,23 +1353,31 @@ repeat: SetPageUptodate(filepage); set_page_dirty(filepage); swap_free(swap); - } else if (!(error = move_from_swap_cache( - swappage, idx, mapping))) { + } else if (!(error = add_to_page_cache( + swappage, mapping, idx, GFP_NOWAIT))) { info->flags |= SHMEM_PAGEIN; shmem_swp_set(info, entry, 0); shmem_swp_unmap(entry); + delete_from_swap_cache(swappage); spin_unlock(&info->lock); filepage = swappage; + set_page_dirty(filepage); swap_free(swap); } else { shmem_swp_unmap(entry); spin_unlock(&info->lock); unlock_page(swappage); - page_cache_release(swappage); if (error == -ENOMEM) { - /* let kswapd refresh zone for GFP_ATOMICs */ - congestion_wait(WRITE, HZ/50); + /* allow reclaim from this memory cgroup */ + error = mem_cgroup_cache_charge(swappage, + current->mm, gfp & ~__GFP_HIGHMEM); + if (error) { + page_cache_release(swappage); + goto failed; + } + mem_cgroup_uncharge_page(swappage); } + page_cache_release(swappage); goto repeat; } } else if (sgp == SGP_READ && !filepage) { @@ -1272,9 +1415,7 @@ repeat: if (!filepage) { spin_unlock(&info->lock); - filepage = shmem_alloc_page(mapping_gfp_mask(mapping), - info, - idx); + filepage = shmem_alloc_page(gfp, info, idx); if (!filepage) { shmem_unacct_blocks(info->flags, 1); shmem_free_blocks(inode, 1); @@ -1282,6 +1423,17 @@ repeat: goto failed; } + /* Precharge page while we can wait, compensate after */ + error = mem_cgroup_cache_charge(filepage, current->mm, + gfp & ~__GFP_HIGHMEM); + if (error) { + page_cache_release(filepage); + shmem_unacct_blocks(info->flags, 1); + shmem_free_blocks(inode, 1); + filepage = NULL; + goto failed; + } + spin_lock(&info->lock); entry = shmem_swp_alloc(info, idx, sgp); if (IS_ERR(entry)) @@ -1291,8 +1443,9 @@ repeat: shmem_swp_unmap(entry); } if (error || swap.val || 0 != add_to_page_cache_lru( - filepage, mapping, idx, GFP_ATOMIC)) { + filepage, mapping, idx, GFP_NOWAIT)) { spin_unlock(&info->lock); + mem_cgroup_uncharge_page(filepage); page_cache_release(filepage); shmem_unacct_blocks(info->flags, 1); shmem_free_blocks(inode, 1); @@ -1301,6 +1454,7 @@ repeat: goto failed; goto repeat; } + mem_cgroup_uncharge_page(filepage); info->flags |= SHMEM_PAGEIN; } @@ -1309,14 +1463,11 @@ repeat: clear_highpage(filepage); flush_dcache_page(filepage); SetPageUptodate(filepage); + if (sgp == SGP_DIRTY) + set_page_dirty(filepage); } done: - if (*pagep != filepage) { - *pagep = filepage; - if (sgp != SGP_FAULT) - unlock_page(filepage); - - } + *pagep = filepage; return 0; failed: @@ -1336,7 +1487,7 @@ static int shmem_fault(struct vm_area_struct *vma, struct vm_fault *vmf) if (((loff_t)vmf->pgoff << PAGE_CACHE_SHIFT) >= i_size_read(inode)) return VM_FAULT_SIGBUS; - error = shmem_getpage(inode, vmf->pgoff, &vmf->page, SGP_FAULT, &ret); + error = shmem_getpage(inode, vmf->pgoff, &vmf->page, SGP_CACHE, &ret); if (error) return ((error == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS); @@ -1399,15 +1550,8 @@ shmem_get_inode(struct super_block *sb, int mode, dev_t dev) struct shmem_inode_info *info; struct shmem_sb_info *sbinfo = SHMEM_SB(sb); - if (sbinfo->max_inodes) { - spin_lock(&sbinfo->stat_lock); - if (!sbinfo->free_inodes) { - spin_unlock(&sbinfo->stat_lock); - return NULL; - } - sbinfo->free_inodes--; - spin_unlock(&sbinfo->stat_lock); - } + if (shmem_reserve_inode(sb)) + return NULL; inode = new_inode(sb); if (inode) { @@ -1451,11 +1595,8 @@ shmem_get_inode(struct super_block *sb, int mode, dev_t dev) NULL); break; } - } else if (sbinfo->max_inodes) { - spin_lock(&sbinfo->stat_lock); - sbinfo->free_inodes++; - spin_unlock(&sbinfo->stat_lock); - } + } else + shmem_free_inode(sb); return inode; } @@ -1494,123 +1635,30 @@ shmem_write_end(struct file *file, struct address_space *mapping, { struct inode *inode = mapping->host; + if (pos + copied > inode->i_size) + i_size_write(inode, pos + copied); + + unlock_page(page); set_page_dirty(page); page_cache_release(page); - if (pos+copied > inode->i_size) - i_size_write(inode, pos+copied); - return copied; } -static ssize_t -shmem_file_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) -{ - struct inode *inode = file->f_path.dentry->d_inode; - loff_t pos; - unsigned long written; - ssize_t err; - - if ((ssize_t) count < 0) - return -EINVAL; - - if (!access_ok(VERIFY_READ, buf, count)) - return -EFAULT; - - mutex_lock(&inode->i_mutex); - - pos = *ppos; - written = 0; - - err = generic_write_checks(file, &pos, &count, 0); - if (err || !count) - goto out; - - err = remove_suid(file->f_path.dentry); - if (err) - goto out; - - inode->i_ctime = inode->i_mtime = CURRENT_TIME; - - do { - struct page *page = NULL; - unsigned long bytes, index, offset; - char *kaddr; - int left; - - offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */ - index = pos >> PAGE_CACHE_SHIFT; - bytes = PAGE_CACHE_SIZE - offset; - if (bytes > count) - bytes = count; - - /* - * We don't hold page lock across copy from user - - * what would it guard against? - so no deadlock here. - * But it still may be a good idea to prefault below. - */ - - err = shmem_getpage(inode, index, &page, SGP_WRITE, NULL); - if (err) - break; - - left = bytes; - if (PageHighMem(page)) { - volatile unsigned char dummy; - __get_user(dummy, buf); - __get_user(dummy, buf + bytes - 1); - - kaddr = kmap_atomic(page, KM_USER0); - left = __copy_from_user_inatomic(kaddr + offset, - buf, bytes); - kunmap_atomic(kaddr, KM_USER0); - } - if (left) { - kaddr = kmap(page); - left = __copy_from_user(kaddr + offset, buf, bytes); - kunmap(page); - } - - written += bytes; - count -= bytes; - pos += bytes; - buf += bytes; - if (pos > inode->i_size) - i_size_write(inode, pos); - - flush_dcache_page(page); - set_page_dirty(page); - mark_page_accessed(page); - page_cache_release(page); - - if (left) { - pos -= left; - written -= left; - err = -EFAULT; - break; - } - - /* - * Our dirty pages are not counted in nr_dirty, - * and we do not attempt to balance dirty pages. - */ - - cond_resched(); - } while (count); - - *ppos = pos; - if (written) - err = written; -out: - mutex_unlock(&inode->i_mutex); - return err; -} - static void do_shmem_file_read(struct file *filp, loff_t *ppos, read_descriptor_t *desc, read_actor_t actor) { struct inode *inode = filp->f_path.dentry->d_inode; struct address_space *mapping = inode->i_mapping; unsigned long index, offset; + enum sgp_type sgp = SGP_READ; + + /* + * Might this read be for a stacking filesystem? Then when reading + * holes of a sparse file, we actually need to allocate those pages, + * and even mark them dirty, so it cannot exceed the max_blocks limit. + */ + if (segment_eq(get_fs(), KERNEL_DS)) + sgp = SGP_DIRTY; index = *ppos >> PAGE_CACHE_SHIFT; offset = *ppos & ~PAGE_CACHE_MASK; @@ -1629,12 +1677,14 @@ static void do_shmem_file_read(struct file *filp, loff_t *ppos, read_descriptor_ break; } - desc->error = shmem_getpage(inode, index, &page, SGP_READ, NULL); + desc->error = shmem_getpage(inode, index, &page, sgp, NULL); if (desc->error) { if (desc->error == -EINVAL) desc->error = 0; break; } + if (page) + unlock_page(page); /* * We must evaluate after, since reads (unlike writes) @@ -1798,22 +1848,16 @@ static int shmem_create(struct inode *dir, struct dentry *dentry, int mode, static int shmem_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) { struct inode *inode = old_dentry->d_inode; - struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); + int ret; /* * No ordinary (disk based) filesystem counts links as inodes; * but each new link needs a new dentry, pinning lowmem, and * tmpfs dentries cannot be pruned until they are unlinked. */ - if (sbinfo->max_inodes) { - spin_lock(&sbinfo->stat_lock); - if (!sbinfo->free_inodes) { - spin_unlock(&sbinfo->stat_lock); - return -ENOSPC; - } - sbinfo->free_inodes--; - spin_unlock(&sbinfo->stat_lock); - } + ret = shmem_reserve_inode(inode->i_sb); + if (ret) + goto out; dir->i_size += BOGO_DIRENT_SIZE; inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; @@ -1821,21 +1865,16 @@ static int shmem_link(struct dentry *old_dentry, struct inode *dir, struct dentr atomic_inc(&inode->i_count); /* New dentry reference */ dget(dentry); /* Extra pinning count for the created dentry */ d_instantiate(dentry, inode); - return 0; +out: + return ret; } static int shmem_unlink(struct inode *dir, struct dentry *dentry) { struct inode *inode = dentry->d_inode; - if (inode->i_nlink > 1 && !S_ISDIR(inode->i_mode)) { - struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); - if (sbinfo->max_inodes) { - spin_lock(&sbinfo->stat_lock); - sbinfo->free_inodes++; - spin_unlock(&sbinfo->stat_lock); - } - } + if (inode->i_nlink > 1 && !S_ISDIR(inode->i_mode)) + shmem_free_inode(inode->i_sb); dir->i_size -= BOGO_DIRENT_SIZE; inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; @@ -1924,6 +1963,7 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s iput(inode); return error; } + unlock_page(page); inode->i_op = &shmem_symlink_inode_operations; kaddr = kmap_atomic(page, KM_USER0); memcpy(kaddr, symname, len); @@ -1951,6 +1991,8 @@ static void *shmem_follow_link(struct dentry *dentry, struct nameidata *nd) struct page *page = NULL; int res = shmem_getpage(dentry->d_inode, 0, &page, SGP_READ, NULL); nd_set_link(nd, res ? ERR_PTR(res) : kmap(page)); + if (page) + unlock_page(page); return page; } @@ -1977,7 +2019,7 @@ static const struct inode_operations shmem_symlink_inode_operations = { }; #ifdef CONFIG_TMPFS_POSIX_ACL -/** +/* * Superblocks without xattr inode operations will get security.* xattr * support from the VFS "for free". As soon as we have any other xattrs * like ACLs, we also need to implement the security.* handlers at @@ -1996,8 +2038,7 @@ static int shmem_xattr_security_get(struct inode *inode, const char *name, { if (strcmp(name, "") == 0) return -EINVAL; - return security_inode_getsecurity(inode, name, buffer, size, - -EOPNOTSUPP); + return xattr_getsecurity(inode, name, buffer, size); } static int shmem_xattr_security_set(struct inode *inode, const char *name, @@ -2093,9 +2134,8 @@ static const struct export_operations shmem_export_ops = { .fh_to_dentry = shmem_fh_to_dentry, }; -static int shmem_parse_options(char *options, int *mode, uid_t *uid, - gid_t *gid, unsigned long *blocks, unsigned long *inodes, - int *policy, nodemask_t *policy_nodes) +static int shmem_parse_options(char *options, struct shmem_sb_info *sbinfo, + bool remount) { char *this_char, *value, *rest; @@ -2138,35 +2178,37 @@ static int shmem_parse_options(char *options, int *mode, uid_t *uid, } if (*rest) goto bad_val; - *blocks = size >> PAGE_CACHE_SHIFT; + sbinfo->max_blocks = + DIV_ROUND_UP(size, PAGE_CACHE_SIZE); } else if (!strcmp(this_char,"nr_blocks")) { - *blocks = memparse(value,&rest); + sbinfo->max_blocks = memparse(value, &rest); if (*rest) goto bad_val; } else if (!strcmp(this_char,"nr_inodes")) { - *inodes = memparse(value,&rest); + sbinfo->max_inodes = memparse(value, &rest); if (*rest) goto bad_val; } else if (!strcmp(this_char,"mode")) { - if (!mode) + if (remount) continue; - *mode = simple_strtoul(value,&rest,8); + sbinfo->mode = simple_strtoul(value, &rest, 8) & 07777; if (*rest) goto bad_val; } else if (!strcmp(this_char,"uid")) { - if (!uid) + if (remount) continue; - *uid = simple_strtoul(value,&rest,0); + sbinfo->uid = simple_strtoul(value, &rest, 0); if (*rest) goto bad_val; } else if (!strcmp(this_char,"gid")) { - if (!gid) + if (remount) continue; - *gid = simple_strtoul(value,&rest,0); + sbinfo->gid = simple_strtoul(value, &rest, 0); if (*rest) goto bad_val; } else if (!strcmp(this_char,"mpol")) { - if (shmem_parse_mpol(value,policy,policy_nodes)) + if (shmem_parse_mpol(value, &sbinfo->policy, + &sbinfo->policy_nodes)) goto bad_val; } else { printk(KERN_ERR "tmpfs: Bad mount option %s\n", @@ -2186,24 +2228,20 @@ bad_val: static int shmem_remount_fs(struct super_block *sb, int *flags, char *data) { struct shmem_sb_info *sbinfo = SHMEM_SB(sb); - unsigned long max_blocks = sbinfo->max_blocks; - unsigned long max_inodes = sbinfo->max_inodes; - int policy = sbinfo->policy; - nodemask_t policy_nodes = sbinfo->policy_nodes; + struct shmem_sb_info config = *sbinfo; unsigned long blocks; unsigned long inodes; int error = -EINVAL; - if (shmem_parse_options(data, NULL, NULL, NULL, &max_blocks, - &max_inodes, &policy, &policy_nodes)) + if (shmem_parse_options(data, &config, true)) return error; spin_lock(&sbinfo->stat_lock); blocks = sbinfo->max_blocks - sbinfo->free_blocks; inodes = sbinfo->max_inodes - sbinfo->free_inodes; - if (max_blocks < blocks) + if (config.max_blocks < blocks) goto out; - if (max_inodes < inodes) + if (config.max_inodes < inodes) goto out; /* * Those tests also disallow limited->unlimited while any are in @@ -2211,23 +2249,42 @@ static int shmem_remount_fs(struct super_block *sb, int *flags, char *data) * but we must separately disallow unlimited->limited, because * in that case we have no record of how much is already in use. */ - if (max_blocks && !sbinfo->max_blocks) + if (config.max_blocks && !sbinfo->max_blocks) goto out; - if (max_inodes && !sbinfo->max_inodes) + if (config.max_inodes && !sbinfo->max_inodes) goto out; error = 0; - sbinfo->max_blocks = max_blocks; - sbinfo->free_blocks = max_blocks - blocks; - sbinfo->max_inodes = max_inodes; - sbinfo->free_inodes = max_inodes - inodes; - sbinfo->policy = policy; - sbinfo->policy_nodes = policy_nodes; + sbinfo->max_blocks = config.max_blocks; + sbinfo->free_blocks = config.max_blocks - blocks; + sbinfo->max_inodes = config.max_inodes; + sbinfo->free_inodes = config.max_inodes - inodes; + sbinfo->policy = config.policy; + sbinfo->policy_nodes = config.policy_nodes; out: spin_unlock(&sbinfo->stat_lock); return error; } -#endif + +static int shmem_show_options(struct seq_file *seq, struct vfsmount *vfs) +{ + struct shmem_sb_info *sbinfo = SHMEM_SB(vfs->mnt_sb); + + if (sbinfo->max_blocks != shmem_default_max_blocks()) + seq_printf(seq, ",size=%luk", + sbinfo->max_blocks << (PAGE_CACHE_SHIFT - 10)); + if (sbinfo->max_inodes != shmem_default_max_inodes()) + seq_printf(seq, ",nr_inodes=%lu", sbinfo->max_inodes); + if (sbinfo->mode != (S_IRWXUGO | S_ISVTX)) + seq_printf(seq, ",mode=%03o", sbinfo->mode); + if (sbinfo->uid != 0) + seq_printf(seq, ",uid=%u", sbinfo->uid); + if (sbinfo->gid != 0) + seq_printf(seq, ",gid=%u", sbinfo->gid); + shmem_show_mpol(seq, sbinfo->policy, sbinfo->policy_nodes); + return 0; +} +#endif /* CONFIG_TMPFS */ static void shmem_put_super(struct super_block *sb) { @@ -2240,15 +2297,23 @@ static int shmem_fill_super(struct super_block *sb, { struct inode *inode; struct dentry *root; - int mode = S_IRWXUGO | S_ISVTX; - uid_t uid = current->fsuid; - gid_t gid = current->fsgid; - int err = -ENOMEM; struct shmem_sb_info *sbinfo; - unsigned long blocks = 0; - unsigned long inodes = 0; - int policy = MPOL_DEFAULT; - nodemask_t policy_nodes = node_states[N_HIGH_MEMORY]; + int err = -ENOMEM; + + /* Round up to L1_CACHE_BYTES to resist false sharing */ + sbinfo = kmalloc(max((int)sizeof(struct shmem_sb_info), + L1_CACHE_BYTES), GFP_KERNEL); + if (!sbinfo) + return -ENOMEM; + + sbinfo->max_blocks = 0; + sbinfo->max_inodes = 0; + sbinfo->mode = S_IRWXUGO | S_ISVTX; + sbinfo->uid = current->fsuid; + sbinfo->gid = current->fsgid; + sbinfo->policy = MPOL_DEFAULT; + sbinfo->policy_nodes = node_states[N_HIGH_MEMORY]; + sb->s_fs_info = sbinfo; #ifdef CONFIG_TMPFS /* @@ -2257,34 +2322,22 @@ static int shmem_fill_super(struct super_block *sb, * but the internal instance is left unlimited. */ if (!(sb->s_flags & MS_NOUSER)) { - blocks = totalram_pages / 2; - inodes = totalram_pages - totalhigh_pages; - if (inodes > blocks) - inodes = blocks; - if (shmem_parse_options(data, &mode, &uid, &gid, &blocks, - &inodes, &policy, &policy_nodes)) - return -EINVAL; + sbinfo->max_blocks = shmem_default_max_blocks(); + sbinfo->max_inodes = shmem_default_max_inodes(); + if (shmem_parse_options(data, sbinfo, false)) { + err = -EINVAL; + goto failed; + } } sb->s_export_op = &shmem_export_ops; #else sb->s_flags |= MS_NOUSER; #endif - /* Round up to L1_CACHE_BYTES to resist false sharing */ - sbinfo = kmalloc(max((int)sizeof(struct shmem_sb_info), - L1_CACHE_BYTES), GFP_KERNEL); - if (!sbinfo) - return -ENOMEM; - spin_lock_init(&sbinfo->stat_lock); - sbinfo->max_blocks = blocks; - sbinfo->free_blocks = blocks; - sbinfo->max_inodes = inodes; - sbinfo->free_inodes = inodes; - sbinfo->policy = policy; - sbinfo->policy_nodes = policy_nodes; + sbinfo->free_blocks = sbinfo->max_blocks; + sbinfo->free_inodes = sbinfo->max_inodes; - sb->s_fs_info = sbinfo; sb->s_maxbytes = SHMEM_MAX_BYTES; sb->s_blocksize = PAGE_CACHE_SIZE; sb->s_blocksize_bits = PAGE_CACHE_SHIFT; @@ -2296,11 +2349,11 @@ static int shmem_fill_super(struct super_block *sb, sb->s_flags |= MS_POSIXACL; #endif - inode = shmem_get_inode(sb, S_IFDIR | mode, 0); + inode = shmem_get_inode(sb, S_IFDIR | sbinfo->mode, 0); if (!inode) goto failed; - inode->i_uid = uid; - inode->i_gid = gid; + inode->i_uid = sbinfo->uid; + inode->i_gid = sbinfo->gid; root = d_alloc_root(inode); if (!root) goto failed_iput; @@ -2375,7 +2428,8 @@ static const struct file_operations shmem_file_operations = { #ifdef CONFIG_TMPFS .llseek = generic_file_llseek, .read = shmem_file_read, - .write = shmem_file_write, + .write = do_sync_write, + .aio_write = generic_file_aio_write, .fsync = simple_sync_file, .splice_read = generic_file_splice_read, .splice_write = generic_file_splice_write, @@ -2435,6 +2489,7 @@ static const struct super_operations shmem_ops = { #ifdef CONFIG_TMPFS .statfs = shmem_statfs, .remount_fs = shmem_remount_fs, + .show_options = shmem_show_options, #endif .delete_inode = shmem_delete_inode, .drop_inode = generic_delete_inode, @@ -2503,12 +2558,11 @@ out4: } module_init(init_tmpfs) -/* +/** * shmem_file_setup - get an unlinked file living in tmpfs - * * @name: name for dentry (to be seen in /proc/<pid>/maps * @size: size to be set for the file - * + * @flags: vm_flags */ struct file *shmem_file_setup(char *name, loff_t size, unsigned long flags) { @@ -2563,9 +2617,8 @@ put_memory: return ERR_PTR(error); } -/* +/** * shmem_zero_setup - setup a shared anonymous mapping - * * @vma: the vma to be mmapped is prepared by do_mmap_pgoff */ int shmem_zero_setup(struct vm_area_struct *vma) |