Merge /spare/repo/linux-2.6/

1 files changed, 170 insertions, 124 deletions

diff --git a/fs/ntfs/aops.c b/fs/ntfs/aops.c
index 78adad7a988d..b6cc8cf24626 100644
--- a/fs/ntfs/aops.c
+++ b/fs/ntfs/aops.c
@@ -27,6 +27,7 @@
 #include <linux/swap.h>
 #include <linux/buffer_head.h>
 #include <linux/writeback.h>
+#include <linux/bit_spinlock.h>
 
 #include "aops.h"
 #include "attrib.h"
@@ -55,9 +56,8 @@
  */
 static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
 {
-        static DEFINE_SPINLOCK(page_uptodate_lock);
         unsigned long flags;
-        struct buffer_head *tmp;
+        struct buffer_head *first, *tmp;
         struct page *page;
         ntfs_inode *ni;
         int page_uptodate = 1;
@@ -89,11 +89,13 @@ static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
                 }
         } else {
                 clear_buffer_uptodate(bh);
+                SetPageError(page);
                 ntfs_error(ni->vol->sb, "Buffer I/O error, logical block %llu.",
                                 (unsigned long long)bh->b_blocknr);
-                SetPageError(page);
         }
-        spin_lock_irqsave(&page_uptodate_lock, flags);
+        first = page_buffers(page);
+        local_irq_save(flags);
+        bit_spin_lock(BH_Uptodate_Lock, &first->b_state);
         clear_buffer_async_read(bh);
         unlock_buffer(bh);
         tmp = bh;
@@ -108,7 +110,8 @@ static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
                 }
                 tmp = tmp->b_this_page;
         } while (tmp != bh);
-        spin_unlock_irqrestore(&page_uptodate_lock, flags);
+        bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
+        local_irq_restore(flags);
         /*
          * If none of the buffers had errors then we can set the page uptodate,
          * but we first have to perform the post read mst fixups, if the
@@ -141,7 +144,8 @@ static void ntfs_end_buffer_async_read(struct buffer_head *bh, int uptodate)
         unlock_page(page);
         return;
 still_busy:
-        spin_unlock_irqrestore(&page_uptodate_lock, flags);
+        bit_spin_unlock(BH_Uptodate_Lock, &first->b_state);
+        local_irq_restore(flags);
         return;
 }
 
@@ -185,13 +189,15 @@ static int ntfs_read_block(struct page *page)
         blocksize_bits = VFS_I(ni)->i_blkbits;
         blocksize = 1 << blocksize_bits;
 
-        if (!page_has_buffers(page))
+        if (!page_has_buffers(page)) {
                 create_empty_buffers(page, blocksize, 0);
-        bh = head = page_buffers(page);
-        if (unlikely(!bh)) {
-                unlock_page(page);
-                return -ENOMEM;
+                if (unlikely(!page_has_buffers(page))) {
+                        unlock_page(page);
+                        return -ENOMEM;
+                }
         }
+        bh = head = page_buffers(page);
+        BUG_ON(!bh);
 
         iblock = (s64)page->index << (PAGE_CACHE_SHIFT - blocksize_bits);
         read_lock_irqsave(&ni->size_lock, flags);
@@ -204,6 +210,7 @@ static int ntfs_read_block(struct page *page)
         nr = i = 0;
         do {
                 u8 *kaddr;
+                int err;
 
                 if (unlikely(buffer_uptodate(bh)))
                         continue;
@@ -211,6 +218,7 @@ static int ntfs_read_block(struct page *page)
                         arr[nr++] = bh;
                         continue;
                 }
+                err = 0;
                 bh->b_bdev = vol->sb->s_bdev;
                 /* Is the block within the allowed limits? */
                 if (iblock < lblock) {
@@ -252,7 +260,6 @@ lock_retry_remap:
                                 goto handle_hole;
                         /* If first try and runlist unmapped, map and retry. */
                         if (!is_retry && lcn == LCN_RL_NOT_MAPPED) {
-                                int err;
                                 is_retry = TRUE;
                                 /*
                                  * Attempt to map runlist, dropping lock for
@@ -263,20 +270,30 @@ lock_retry_remap:
                                 if (likely(!err))
                                         goto lock_retry_remap;
                                 rl = NULL;
-                                lcn = err;
                         } else if (!rl)
                                 up_read(&ni->runlist.lock);
+                        /*
+                         * If buffer is outside the runlist, treat it as a
+                         * hole.  This can happen due to concurrent truncate
+                         * for example.
+                         */
+                        if (err == -ENOENT || lcn == LCN_ENOENT) {
+                                err = 0;
+                                goto handle_hole;
+                        }
                         /* Hard error, zero out region. */
+                        if (!err)
+                                err = -EIO;
                         bh->b_blocknr = -1;
                         SetPageError(page);
                         ntfs_error(vol->sb, "Failed to read from inode 0x%lx, "
                                         "attribute type 0x%x, vcn 0x%llx, "
                                         "offset 0x%x because its location on "
                                         "disk could not be determined%s "
-                                        "(error code %lli).", ni->mft_no,
+                                        "(error code %i).", ni->mft_no,
                                         ni->type, (unsigned long long)vcn,
                                         vcn_ofs, is_retry ? " even after "
-                                        "retrying" : "", (long long)lcn);
+                                        "retrying" : "", err);
                 }
                 /*
                  * Either iblock was outside lblock limits or
@@ -289,9 +306,10 @@ handle_hole:
 handle_zblock:
                 kaddr = kmap_atomic(page, KM_USER0);
                 memset(kaddr + i * blocksize, 0, blocksize);
-                flush_dcache_page(page);
                 kunmap_atomic(kaddr, KM_USER0);
-                set_buffer_uptodate(bh);
+                flush_dcache_page(page);
+                if (likely(!err))
+                        set_buffer_uptodate(bh);
         } while (i++, iblock++, (bh = bh->b_this_page) != head);
 
         /* Release the lock if we took it. */
@@ -367,31 +385,38 @@ retry_readpage:
                 return 0;
         }
         ni = NTFS_I(page->mapping->host);
-
+        /*
+         * Only $DATA attributes can be encrypted and only unnamed $DATA
+         * attributes can be compressed.  Index root can have the flags set but
+         * this means to create compressed/encrypted files, not that the
+         * attribute is compressed/encrypted.
+         */
+        if (ni->type != AT_INDEX_ROOT) {
+                /* If attribute is encrypted, deny access, just like NT4. */
+                if (NInoEncrypted(ni)) {
+                        BUG_ON(ni->type != AT_DATA);
+                        err = -EACCES;
+                        goto err_out;
+                }
+                /* Compressed data streams are handled in compress.c. */
+                if (NInoNonResident(ni) && NInoCompressed(ni)) {
+                        BUG_ON(ni->type != AT_DATA);
+                        BUG_ON(ni->name_len);
+                        return ntfs_read_compressed_block(page);
+                }
+        }
         /* NInoNonResident() == NInoIndexAllocPresent() */
         if (NInoNonResident(ni)) {
-                /*
-                 * Only unnamed $DATA attributes can be compressed or
-                 * encrypted.
-                 */
-                if (ni->type == AT_DATA && !ni->name_len) {
-                        /* If file is encrypted, deny access, just like NT4. */
-                        if (NInoEncrypted(ni)) {
-                                err = -EACCES;
-                                goto err_out;
-                        }
-                        /* Compressed data streams are handled in compress.c. */
-                        if (NInoCompressed(ni))
-                                return ntfs_read_compressed_block(page);
-                }
-                /* Normal data stream. */
+                /* Normal, non-resident data stream. */
                 return ntfs_read_block(page);
         }
         /*
          * Attribute is resident, implying it is not compressed or encrypted.
          * This also means the attribute is smaller than an mft record and
          * hence smaller than a page, so can simply zero out any pages with
-         * index above 0.
+         * index above 0.  Note the attribute can actually be marked compressed
+         * but if it is resident the actual data is not compressed so we are
+         * ok to ignore the compressed flag here.
          */
         if (unlikely(page->index > 0)) {
                 kaddr = kmap_atomic(page, KM_USER0);
@@ -511,19 +536,21 @@ static int ntfs_write_block(struct page *page, struct writeback_control *wbc)
                 BUG_ON(!PageUptodate(page));
                 create_empty_buffers(page, blocksize,
                                 (1 << BH_Uptodate) | (1 << BH_Dirty));
+                if (unlikely(!page_has_buffers(page))) {
+                        ntfs_warning(vol->sb, "Error allocating page "
+                                        "buffers.  Redirtying page so we try "
+                                        "again later.");
+                        /*
+                         * Put the page back on mapping->dirty_pages, but leave
+                         * its buffers' dirty state as-is.
+                         */
+                        redirty_page_for_writepage(wbc, page);
+                        unlock_page(page);
+                        return 0;
+                }
         }
         bh = head = page_buffers(page);
-        if (unlikely(!bh)) {
-                ntfs_warning(vol->sb, "Error allocating page buffers. "
-                                "Redirtying page so we try again later.");
-                /*
-                 * Put the page back on mapping->dirty_pages, but leave its
-                 * buffer's dirty state as-is.
-                 */
-                redirty_page_for_writepage(wbc, page);
-                unlock_page(page);
-                return 0;
-        }
+        BUG_ON(!bh);
 
         /* NOTE: Different naming scheme to ntfs_read_block()! */
 
@@ -670,6 +697,27 @@ lock_retry_remap:
                 }
                 /* It is a hole, need to instantiate it. */
                 if (lcn == LCN_HOLE) {
+                        u8 *kaddr;
+                        unsigned long *bpos, *bend;
+
+                        /* Check if the buffer is zero. */
+                        kaddr = kmap_atomic(page, KM_USER0);
+                        bpos = (unsigned long *)(kaddr + bh_offset(bh));
+                        bend = (unsigned long *)((u8*)bpos + blocksize);
+                        do {
+                                if (unlikely(*bpos))
+                                        break;
+                        } while (likely(++bpos < bend));
+                        kunmap_atomic(kaddr, KM_USER0);
+                        if (bpos == bend) {
+                                /*
+                                 * Buffer is zero and sparse, no need to write
+                                 * it.
+                                 */
+                                bh->b_blocknr = -1;
+                                clear_buffer_dirty(bh);
+                                continue;
+                        }
                         // TODO: Instantiate the hole.
                         // clear_buffer_new(bh);
                         // unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
@@ -690,20 +738,37 @@ lock_retry_remap:
                         if (likely(!err))
                                 goto lock_retry_remap;
                         rl = NULL;
-                        lcn = err;
                 } else if (!rl)
                         up_read(&ni->runlist.lock);
+                /*
+                 * If buffer is outside the runlist, truncate has cut it out
+                 * of the runlist.  Just clean and clear the buffer and set it
+                 * uptodate so it can get discarded by the VM.
+                 */
+                if (err == -ENOENT || lcn == LCN_ENOENT) {
+                        u8 *kaddr;
+
+                        bh->b_blocknr = -1;
+                        clear_buffer_dirty(bh);
+                        kaddr = kmap_atomic(page, KM_USER0);
+                        memset(kaddr + bh_offset(bh), 0, blocksize);
+                        kunmap_atomic(kaddr, KM_USER0);
+                        flush_dcache_page(page);
+                        set_buffer_uptodate(bh);
+                        err = 0;
+                        continue;
+                }
                 /* Failed to map the buffer, even after retrying. */
+                if (!err)
+                        err = -EIO;
                 bh->b_blocknr = -1;
                 ntfs_error(vol->sb, "Failed to write to inode 0x%lx, "
                                 "attribute type 0x%x, vcn 0x%llx, offset 0x%x "
                                 "because its location on disk could not be "
-                                "determined%s (error code %lli).", ni->mft_no,
+                                "determined%s (error code %i).", ni->mft_no,
                                 ni->type, (unsigned long long)vcn,
                                 vcn_ofs, is_retry ? " even after "
-                                "retrying" : "", (long long)lcn);
-                if (!err)
-                        err = -EIO;
+                                "retrying" : "", err);
                 break;
         } while (block++, (bh = bh->b_this_page) != head);
 
@@ -714,7 +779,7 @@ lock_retry_remap:
         /* For the error case, need to reset bh to the beginning. */
         bh = head;
 
-        /* Just an optimization, so ->readpage() isn't called later. */
+        /* Just an optimization, so ->readpage() is not called later. */
         if (unlikely(!PageUptodate(page))) {
                 int uptodate = 1;
                 do {
@@ -730,7 +795,6 @@ lock_retry_remap:
 
         /* Setup all mapped, dirty buffers for async write i/o. */
         do {
-                get_bh(bh);
                 if (buffer_mapped(bh) && buffer_dirty(bh)) {
                         lock_buffer(bh);
                         if (test_clear_buffer_dirty(bh)) {
@@ -768,14 +832,8 @@ lock_retry_remap:
 
         BUG_ON(PageWriteback(page));
         set_page_writeback(page);       /* Keeps try_to_free_buffers() away. */
-        unlock_page(page);
 
-        /*
-         * Submit the prepared buffers for i/o. Note the page is unlocked,
-         * and the async write i/o completion handler can end_page_writeback()
-         * at any time after the *first* submit_bh(). So the buffers can then
-         * disappear...
-         */
+        /* Submit the prepared buffers for i/o. */
         need_end_writeback = TRUE;
         do {
                 struct buffer_head *next = bh->b_this_page;
@@ -783,9 +841,9 @@ lock_retry_remap:
                         submit_bh(WRITE, bh);
                         need_end_writeback = FALSE;
                 }
-                put_bh(bh);
                 bh = next;
         } while (bh != head);
+        unlock_page(page);
 
         /* If no i/o was started, need to end_page_writeback(). */
         if (unlikely(need_end_writeback))
@@ -860,7 +918,6 @@ static int ntfs_write_mst_block(struct page *page,
         sync = (wbc->sync_mode == WB_SYNC_ALL);
 
         /* Make sure we have mapped buffers. */
-        BUG_ON(!page_has_buffers(page));
         bh = head = page_buffers(page);
         BUG_ON(!bh);
 
@@ -1280,38 +1337,42 @@ retry_writepage:
                 ntfs_debug("Write outside i_size - truncated?");
                 return 0;
         }
+        /*
+         * Only $DATA attributes can be encrypted and only unnamed $DATA
+         * attributes can be compressed.  Index root can have the flags set but
+         * this means to create compressed/encrypted files, not that the
+         * attribute is compressed/encrypted.
+         */
+        if (ni->type != AT_INDEX_ROOT) {
+                /* If file is encrypted, deny access, just like NT4. */
+                if (NInoEncrypted(ni)) {
+                        unlock_page(page);
+                        BUG_ON(ni->type != AT_DATA);
+                        ntfs_debug("Denying write access to encrypted "
+                                        "file.");
+                        return -EACCES;
+                }
+                /* Compressed data streams are handled in compress.c. */
+                if (NInoNonResident(ni) && NInoCompressed(ni)) {
+                        BUG_ON(ni->type != AT_DATA);
+                        BUG_ON(ni->name_len);
+                        // TODO: Implement and replace this with
+                        // return ntfs_write_compressed_block(page);
+                        unlock_page(page);
+                        ntfs_error(vi->i_sb, "Writing to compressed files is "
+                                        "not supported yet.  Sorry.");
+                        return -EOPNOTSUPP;
+                }
+                // TODO: Implement and remove this check.
+                if (NInoNonResident(ni) && NInoSparse(ni)) {
+                        unlock_page(page);
+                        ntfs_error(vi->i_sb, "Writing to sparse files is not "
+                                        "supported yet.  Sorry.");
+                        return -EOPNOTSUPP;
+                }
+        }
         /* NInoNonResident() == NInoIndexAllocPresent() */
         if (NInoNonResident(ni)) {
-                /*
-                 * Only unnamed $DATA attributes can be compressed, encrypted,
-                 * and/or sparse.
-                 */
-                if (ni->type == AT_DATA && !ni->name_len) {
-                        /* If file is encrypted, deny access, just like NT4. */
-                        if (NInoEncrypted(ni)) {
-                                unlock_page(page);
-                                ntfs_debug("Denying write access to encrypted "
-                                                "file.");
-                                return -EACCES;
-                        }
-                        /* Compressed data streams are handled in compress.c. */
-                        if (NInoCompressed(ni)) {
-                                // TODO: Implement and replace this check with
-                                // return ntfs_write_compressed_block(page);
-                                unlock_page(page);
-                                ntfs_error(vi->i_sb, "Writing to compressed "
-                                                "files is not supported yet. "
-                                                "Sorry.");
-                                return -EOPNOTSUPP;
-                        }
-                        // TODO: Implement and remove this check.
-                        if (NInoSparse(ni)) {
-                                unlock_page(page);
-                                ntfs_error(vi->i_sb, "Writing to sparse files "
-                                                "is not supported yet. Sorry.");
-                                return -EOPNOTSUPP;
-                        }
-                }
                 /* We have to zero every time due to mmap-at-end-of-file. */
                 if (page->index >= (i_size >> PAGE_CACHE_SHIFT)) {
                         /* The page straddles i_size. */
@@ -1324,14 +1385,16 @@ retry_writepage:
                 /* Handle mst protected attributes. */
                 if (NInoMstProtected(ni))
                         return ntfs_write_mst_block(page, wbc);
-                /* Normal data stream. */
+                /* Normal, non-resident data stream. */
                 return ntfs_write_block(page, wbc);
         }
         /*
-         * Attribute is resident, implying it is not compressed, encrypted,
-         * sparse, or mst protected.  This also means the attribute is smaller
-         * than an mft record and hence smaller than a page, so can simply
-         * return error on any pages with index above 0.
+         * Attribute is resident, implying it is not compressed, encrypted, or
+         * mst protected.  This also means the attribute is smaller than an mft
+         * record and hence smaller than a page, so can simply return error on
+         * any pages with index above 0.  Note the attribute can actually be
+         * marked compressed but if it is resident the actual data is not
+         * compressed so we are ok to ignore the compressed flag here.
          */
         BUG_ON(page_has_buffers(page));
         BUG_ON(!PageUptodate(page));
@@ -1380,30 +1443,14 @@ retry_writepage:
         BUG_ON(PageWriteback(page));
         set_page_writeback(page);
         unlock_page(page);
-
         /*
-         * Here, we don't need to zero the out of bounds area everytime because
-         * the below memcpy() already takes care of the mmap-at-end-of-file
-         * requirements. If the file is converted to a non-resident one, then
-         * the code path use is switched to the non-resident one where the
-         * zeroing happens on each ntfs_writepage() invocation.
-         *
-         * The above also applies nicely when i_size is decreased.
-         *
-         * When i_size is increased, the memory between the old and new i_size
-         * _must_ be zeroed (or overwritten with new data). Otherwise we will
-         * expose data to userspace/disk which should never have been exposed.
-         *
-         * FIXME: Ensure that i_size increases do the zeroing/overwriting and
-         * if we cannot guarantee that, then enable the zeroing below.  If the
-         * zeroing below is enabled, we MUST move the unlock_page() from above
-         * to after the kunmap_atomic(), i.e. just before the
-         * end_page_writeback().
-         * UPDATE: ntfs_prepare/commit_write() do the zeroing on i_size
-         * increases for resident attributes so those are ok.
-         * TODO: ntfs_truncate(), others?
+         * Here, we do not need to zero the out of bounds area everytime
+         * because the below memcpy() already takes care of the
+         * mmap-at-end-of-file requirements.  If the file is converted to a
+         * non-resident one, then the code path use is switched to the
+         * non-resident one where the zeroing happens on each ntfs_writepage()
+         * invocation.
          */
-
         attr_len = le32_to_cpu(ctx->attr->data.resident.value_length);
         i_size = i_size_read(vi);
         if (unlikely(attr_len > i_size)) {
@@ -1681,27 +1728,25 @@ lock_retry_remap:
                                         if (likely(!err))
                                                 goto lock_retry_remap;
                                         rl = NULL;
-                                        lcn = err;
                                 } else if (!rl)
                                         up_read(&ni->runlist.lock);
                                 /*
                                  * Failed to map the buffer, even after
                                  * retrying.
                                  */
+                                if (!err)
+                                        err = -EIO;
                                 bh->b_blocknr = -1;
                                 ntfs_error(vol->sb, "Failed to write to inode "
                                                 "0x%lx, attribute type 0x%x, "
                                                 "vcn 0x%llx, offset 0x%x "
                                                 "because its location on disk "
                                                 "could not be determined%s "
-                                                "(error code %lli).",
+                                                "(error code %i).",
                                                 ni->mft_no, ni->type,
                                                 (unsigned long long)vcn,
                                                 vcn_ofs, is_retry ? " even "
-                                                "after retrying" : "",
-                                                (long long)lcn);
-                                if (!err)
-                                        err = -EIO;
+                                                "after retrying" : "", err);
                                 goto err_out;
                         }
                         /* We now have a successful remap, i.e. lcn >= 0. */
@@ -2357,6 +2402,7 @@ void mark_ntfs_record_dirty(struct page *page, const unsigned int ofs) {
                         buffers_to_free = bh;
         }
         bh = head = page_buffers(page);
+        BUG_ON(!bh);
         do {
                 bh_ofs = bh_offset(bh);
                 if (bh_ofs + bh_size <= ofs)