X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=fs%2Fext4%2Findirect.c;h=9588240195090ce4216e87f07379121b4ffe6cfb;hb=fe0f07d08ee35fb13d2cb048970072fe4f71ad14;hp=6b9878a24182b06125cb496ef973ff0d9b739106;hpb=b5ccb078c806f4804aaf85bb59faa9b6fedf85a7;p=deliverable%2Flinux.git diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c index 6b9878a24182..958824019509 100644 --- a/fs/ext4/indirect.c +++ b/fs/ext4/indirect.c @@ -20,9 +20,9 @@ * (sct@redhat.com), 1993, 1998 */ -#include #include "ext4_jbd2.h" #include "truncate.h" +#include #include @@ -642,8 +642,8 @@ out: * crashes then stale disk data _may_ be exposed inside the file. But current * VFS code falls back into buffered path in that case so we are safe. */ -ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb, - struct iov_iter *iter, loff_t offset) +ssize_t ext4_ind_direct_IO(struct kiocb *iocb, struct iov_iter *iter, + loff_t offset) { struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; @@ -654,7 +654,7 @@ ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb, size_t count = iov_iter_count(iter); int retries = 0; - if (rw == WRITE) { + if (iov_iter_rw(iter) == WRITE) { loff_t final_size = offset + count; if (final_size > inode->i_size) { @@ -676,37 +676,38 @@ ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb, } retry: - if (rw == READ && ext4_should_dioread_nolock(inode)) { + if (iov_iter_rw(iter) == READ && ext4_should_dioread_nolock(inode)) { /* * Nolock dioread optimization may be dynamically disabled * via ext4_inode_block_unlocked_dio(). Check inode's state * while holding extra i_dio_count ref. */ - atomic_inc(&inode->i_dio_count); + inode_dio_begin(inode); smp_mb(); if (unlikely(ext4_test_inode_state(inode, EXT4_STATE_DIOREAD_LOCK))) { - inode_dio_done(inode); + inode_dio_end(inode); goto locked; } if (IS_DAX(inode)) - ret = dax_do_io(rw, iocb, inode, iter, offset, + ret = dax_do_io(iocb, inode, iter, offset, ext4_get_block, NULL, 0); else - ret = __blockdev_direct_IO(rw, iocb, inode, - inode->i_sb->s_bdev, iter, offset, - ext4_get_block, NULL, NULL, 0); - inode_dio_done(inode); + ret = __blockdev_direct_IO(iocb, inode, + inode->i_sb->s_bdev, iter, + offset, ext4_get_block, NULL, + NULL, 0); + inode_dio_end(inode); } else { locked: if (IS_DAX(inode)) - ret = dax_do_io(rw, iocb, inode, iter, offset, + ret = dax_do_io(iocb, inode, iter, offset, ext4_get_block, NULL, DIO_LOCKING); else - ret = blockdev_direct_IO(rw, iocb, inode, iter, - offset, ext4_get_block); + ret = blockdev_direct_IO(iocb, inode, iter, offset, + ext4_get_block); - if (unlikely((rw & WRITE) && ret < 0)) { + if (unlikely(iov_iter_rw(iter) == WRITE && ret < 0)) { loff_t isize = i_size_read(inode); loff_t end = offset + count; @@ -1401,10 +1402,7 @@ end_range: * to free. Everything was covered by the start * of the range. */ - return 0; - } else { - /* Shared branch grows from an indirect block */ - partial2--; + goto do_indirects; } } else { /* @@ -1435,56 +1433,96 @@ end_range: /* Punch happened within the same level (n == n2) */ partial = ext4_find_shared(inode, n, offsets, chain, &nr); partial2 = ext4_find_shared(inode, n2, offsets2, chain2, &nr2); - /* - * ext4_find_shared returns Indirect structure which - * points to the last element which should not be - * removed by truncate. But this is end of the range - * in punch_hole so we need to point to the next element - */ - partial2->p++; - while ((partial > chain) || (partial2 > chain2)) { - /* We're at the same block, so we're almost finished */ - if ((partial->bh && partial2->bh) && - (partial->bh->b_blocknr == partial2->bh->b_blocknr)) { - if ((partial > chain) && (partial2 > chain2)) { + + /* Free top, but only if partial2 isn't its subtree. */ + if (nr) { + int level = min(partial - chain, partial2 - chain2); + int i; + int subtree = 1; + + for (i = 0; i <= level; i++) { + if (offsets[i] != offsets2[i]) { + subtree = 0; + break; + } + } + + if (!subtree) { + if (partial == chain) { + /* Shared branch grows from the inode */ + ext4_free_branches(handle, inode, NULL, + &nr, &nr+1, + (chain+n-1) - partial); + *partial->p = 0; + } else { + /* Shared branch grows from an indirect block */ + BUFFER_TRACE(partial->bh, "get_write_access"); ext4_free_branches(handle, inode, partial->bh, - partial->p + 1, - partial2->p, + partial->p, + partial->p+1, (chain+n-1) - partial); - BUFFER_TRACE(partial->bh, "call brelse"); - brelse(partial->bh); - BUFFER_TRACE(partial2->bh, "call brelse"); - brelse(partial2->bh); } - return 0; } + } + + if (!nr2) { /* - * Clear the ends of indirect blocks on the shared branch - * at the start of the range + * ext4_find_shared returns Indirect structure which + * points to the last element which should not be + * removed by truncate. But this is end of the range + * in punch_hole so we need to point to the next element */ - if (partial > chain) { + partial2->p++; + } + + while (partial > chain || partial2 > chain2) { + int depth = (chain+n-1) - partial; + int depth2 = (chain2+n2-1) - partial2; + + if (partial > chain && partial2 > chain2 && + partial->bh->b_blocknr == partial2->bh->b_blocknr) { + /* + * We've converged on the same block. Clear the range, + * then we're done. + */ ext4_free_branches(handle, inode, partial->bh, - partial->p + 1, - (__le32 *)partial->bh->b_data+addr_per_block, - (chain+n-1) - partial); + partial->p + 1, + partial2->p, + (chain+n-1) - partial); BUFFER_TRACE(partial->bh, "call brelse"); brelse(partial->bh); - partial--; + BUFFER_TRACE(partial2->bh, "call brelse"); + brelse(partial2->bh); + return 0; } + /* - * Clear the ends of indirect blocks on the shared branch - * at the end of the range + * The start and end partial branches may not be at the same + * level even though the punch happened within one level. So, we + * give them a chance to arrive at the same level, then walk + * them in step with each other until we converge on the same + * block. */ - if (partial2 > chain2) { + if (partial > chain && depth <= depth2) { + ext4_free_branches(handle, inode, partial->bh, + partial->p + 1, + (__le32 *)partial->bh->b_data+addr_per_block, + (chain+n-1) - partial); + BUFFER_TRACE(partial->bh, "call brelse"); + brelse(partial->bh); + partial--; + } + if (partial2 > chain2 && depth2 <= depth) { ext4_free_branches(handle, inode, partial2->bh, (__le32 *)partial2->bh->b_data, partial2->p, - (chain2+n-1) - partial2); + (chain2+n2-1) - partial2); BUFFER_TRACE(partial2->bh, "call brelse"); brelse(partial2->bh); partial2--; } } + return 0; do_indirects: /* Kill the remaining (whole) subtrees */