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Message-ID: <20141220211949.25563.76451.stgit@birch.djwong.org>
Date: Sat, 20 Dec 2014 13:19:49 -0800
From: "Darrick J. Wong" <darrick.wong@...cle.com>
To: tytso@....edu, darrick.wong@...cle.com
Cc: linux-ext4@...r.kernel.org
Subject: [PATCH 27/31] libext2fs: implement fallocate
Create a library function to perform fallocation on arbitrary files,
and wire up a few users for this function. This is a bit more intense
than Ted's original mk_hugefiles implementation since we have to honor
any blocks that may already be allocated to the file.
Signed-off-by: Darrick J. Wong <darrick.wong@...cle.com>
---
lib/ext2fs/Makefile.in | 8
lib/ext2fs/ext2fs.h | 10 +
lib/ext2fs/fallocate.c | 853 ++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 871 insertions(+)
create mode 100644 lib/ext2fs/fallocate.c
diff --git a/lib/ext2fs/Makefile.in b/lib/ext2fs/Makefile.in
index 2706bfa..d1350b5 100644
--- a/lib/ext2fs/Makefile.in
+++ b/lib/ext2fs/Makefile.in
@@ -79,6 +79,7 @@ OBJS= $(DEBUGFS_LIB_OBJS) $(RESIZE_LIB_OBJS) $(E2IMAGE_LIB_OBJS) \
expanddir.o \
ext_attr.o \
extent.o \
+ fallocate.o \
fileio.o \
finddev.o \
flushb.o \
@@ -763,6 +764,13 @@ extent.o: $(srcdir)/extent.c $(top_builddir)/lib/config.h \
$(top_srcdir)/lib/et/com_err.h $(srcdir)/ext2_io.h \
$(top_builddir)/lib/ext2fs/ext2_err.h $(srcdir)/ext2_ext_attr.h \
$(srcdir)/bitops.h $(srcdir)/e2image.h
+fallocate.o: $(srcdir)/fallocate.c $(top_builddir)/lib/config.h \
+ $(top_builddir)/lib/dirpaths.h $(srcdir)/ext2_fs.h \
+ $(top_builddir)/lib/ext2fs/ext2_types.h $(srcdir)/ext2fsP.h \
+ $(srcdir)/ext2fs.h $(srcdir)/ext2_fs.h $(srcdir)/ext3_extents.h \
+ $(top_srcdir)/lib/et/com_err.h $(srcdir)/ext2_io.h \
+ $(top_builddir)/lib/ext2fs/ext2_err.h $(srcdir)/ext2_ext_attr.h \
+ $(srcdir)/bitops.h $(srcdir)/e2image.h
fileio.o: $(srcdir)/fileio.c $(top_builddir)/lib/config.h \
$(top_builddir)/lib/dirpaths.h $(srcdir)/ext2_fs.h \
$(top_builddir)/lib/ext2fs/ext2_types.h $(srcdir)/ext2fs.h \
diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index ea7e624..23f6fa5 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -1255,6 +1255,16 @@ extern errcode_t ext2fs_extent_goto2(ext2_extent_handle_t handle,
extern errcode_t ext2fs_extent_fix_parents(ext2_extent_handle_t handle);
size_t ext2fs_max_extent_depth(ext2_extent_handle_t handle);
+/* fallocate.c */
+#define EXT2_FALLOCATE_ZERO_BLOCKS (0x1)
+#define EXT2_FALLOCATE_FORCE_INIT (0x2)
+#define EXT2_FALLOCATE_FORCE_UNINIT (0x4)
+#define EXT2_FALLOCATE_INIT_BEYOND_EOF (0x8)
+#define EXT2_FALLOCATE_ALL_FLAGS (0xF)
+errcode_t ext2fs_fallocate(ext2_filsys fs, int flags, ext2_ino_t ino,
+ struct ext2_inode *inode, blk64_t goal,
+ blk64_t start, blk64_t len);
+
/* fileio.c */
extern errcode_t ext2fs_file_open2(ext2_filsys fs, ext2_ino_t ino,
struct ext2_inode *inode,
diff --git a/lib/ext2fs/fallocate.c b/lib/ext2fs/fallocate.c
new file mode 100644
index 0000000..8b502d5
--- /dev/null
+++ b/lib/ext2fs/fallocate.c
@@ -0,0 +1,853 @@
+/*
+ * fallocate.c -- Allocate large chunks of file.
+ *
+ * Copyright (C) 2014 Oracle.
+ *
+ * %Begin-Header%
+ * This file may be redistributed under the terms of the GNU Library
+ * General Public License, version 2.
+ * %End-Header%
+ */
+
+#include "config.h"
+
+#include "ext2_fs.h"
+#include "ext2fs.h"
+#define min(a, b) ((a) < (b) ? (a) : (b))
+
+#undef DEBUG
+
+#ifdef DEBUG
+# define dbg_printf(f, a...) do {printf(f, ## a); fflush(stdout); } while (0)
+#else
+# define dbg_printf(f, a...)
+#endif
+
+/*
+ * Extent-based fallocate code.
+ *
+ * Find runs of unmapped logical blocks by starting at start and walking the
+ * extents until we reach the end of the range we want.
+ *
+ * For each run of unmapped blocks, try to find the extents on either side of
+ * the range. If there's a left extent that can grow by at least a cluster and
+ * there are lblocks between start and the next lcluster after start, see if
+ * there's an implied cluster allocation; if so, zero the blocks (if the left
+ * extent is initialized) and adjust the extent. Ditto for the blocks between
+ * the end of the last full lcluster and end, if there's a right extent.
+ *
+ * Try to attach as much as we can to the left extent, then try to attach as
+ * much as we can to the right extent. For the remainder, try to allocate the
+ * whole range; map in whatever we get; and repeat until we're done.
+ *
+ * To attach to a left extent, figure out the maximum amount we can add to the
+ * extent and try to allocate that much, and append if successful. To attach
+ * to a right extent, figure out the max we can add to the extent, try to
+ * allocate that much, and prepend if successful.
+ *
+ * We need an alloc_range function that tells us how much we can allocate given
+ * a maximum length and one of a suggested start, a fixed start, or a fixed end
+ * point.
+ *
+ * Every time we modify the extent tree we also need to update the block stats.
+ *
+ * At the end, update i_blocks and i_size appropriately.
+ */
+
+static void dbg_print_extent(char *desc, struct ext2fs_extent *extent)
+{
+#ifdef DEBUG
+ if (desc)
+ printf("%s: ", desc);
+ printf("extent: lblk %llu--%llu, len %u, pblk %llu, flags: ",
+ extent->e_lblk, extent->e_lblk + extent->e_len - 1,
+ extent->e_len, extent->e_pblk);
+ if (extent->e_flags & EXT2_EXTENT_FLAGS_LEAF)
+ fputs("LEAF ", stdout);
+ if (extent->e_flags & EXT2_EXTENT_FLAGS_UNINIT)
+ fputs("UNINIT ", stdout);
+ if (extent->e_flags & EXT2_EXTENT_FLAGS_SECOND_VISIT)
+ fputs("2ND_VISIT ", stdout);
+ if (!extent->e_flags)
+ fputs("(none)", stdout);
+ fputc('\n', stdout);
+ fflush(stdout);
+#endif
+}
+
+static errcode_t claim_range(ext2_filsys fs, struct ext2_inode *inode,
+ blk64_t blk, blk64_t len)
+{
+ blk64_t clusters;
+
+ clusters = (len + EXT2FS_CLUSTER_RATIO(fs) - 1) /
+ EXT2FS_CLUSTER_RATIO(fs);
+ ext2fs_block_alloc_stats_range(fs, blk,
+ clusters * EXT2FS_CLUSTER_RATIO(fs), +1);
+ return ext2fs_iblk_add_blocks(fs, inode, clusters);
+}
+
+static errcode_t ext_falloc_helper(ext2_filsys fs,
+ int flags,
+ ext2_ino_t ino,
+ struct ext2_inode *inode,
+ ext2_extent_handle_t handle,
+ struct ext2fs_extent *left_ext,
+ struct ext2fs_extent *right_ext,
+ blk64_t range_start, blk64_t range_len,
+ blk64_t alloc_goal)
+{
+ struct ext2fs_extent newex, ex;
+ int op;
+ blk64_t fillable, pblk, plen, x, y;
+ blk64_t eof_blk = 0, cluster_fill = 0;
+ errcode_t err;
+ blk_t max_extent_len, max_uninit_len, max_init_len;
+
+#ifdef DEBUG
+ printf("%s: ", __func__);
+ if (left_ext)
+ printf("left_ext=%llu--%llu, ", left_ext->e_lblk,
+ left_ext->e_lblk + left_ext->e_len - 1);
+ if (right_ext)
+ printf("right_ext=%llu--%llu, ", right_ext->e_lblk,
+ right_ext->e_lblk + right_ext->e_len - 1);
+ printf("start=%llu len=%llu, goal=%llu\n", range_start, range_len,
+ alloc_goal);
+ fflush(stdout);
+#endif
+ /* Can't create initialized extents past EOF? */
+ if (!(flags & EXT2_FALLOCATE_INIT_BEYOND_EOF))
+ eof_blk = EXT2_I_SIZE(inode) / fs->blocksize;
+
+ /* The allocation goal must be as far into a cluster as range_start. */
+ alloc_goal = (alloc_goal & ~EXT2FS_CLUSTER_MASK(fs)) |
+ (range_start & EXT2FS_CLUSTER_MASK(fs));
+
+ max_uninit_len = EXT_UNINIT_MAX_LEN & ~EXT2FS_CLUSTER_MASK(fs);
+ max_init_len = EXT_INIT_MAX_LEN & ~EXT2FS_CLUSTER_MASK(fs);
+
+ /* We must lengthen the left extent to the end of the cluster */
+ if (left_ext && EXT2FS_CLUSTER_RATIO(fs) > 1) {
+ /* How many more blocks can be attached to left_ext? */
+ if (left_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT)
+ fillable = max_uninit_len - left_ext->e_len;
+ else
+ fillable = max_init_len - left_ext->e_len;
+
+ if (fillable > range_len)
+ fillable = range_len;
+ if (fillable == 0)
+ goto expand_right;
+
+ /*
+ * If range_start isn't on a cluster boundary, try an
+ * implied cluster allocation for left_ext.
+ */
+ cluster_fill = EXT2FS_CLUSTER_RATIO(fs) -
+ (range_start & EXT2FS_CLUSTER_MASK(fs));
+ cluster_fill &= EXT2FS_CLUSTER_MASK(fs);
+ if (cluster_fill == 0)
+ goto expand_right;
+
+ if (cluster_fill > fillable)
+ cluster_fill = fillable;
+
+ /* Don't expand an initialized left_ext beyond EOF */
+ if (!(flags & EXT2_FALLOCATE_INIT_BEYOND_EOF)) {
+ x = left_ext->e_lblk + left_ext->e_len - 1;
+ dbg_printf("%s: lend=%llu newlend=%llu eofblk=%llu\n",
+ __func__, x, x + cluster_fill, eof_blk);
+ if (eof_blk >= x && eof_blk <= x + cluster_fill)
+ cluster_fill = eof_blk - x;
+ if (cluster_fill == 0)
+ goto expand_right;
+ }
+
+ err = ext2fs_extent_goto(handle, left_ext->e_lblk);
+ if (err)
+ goto expand_right;
+ left_ext->e_len += cluster_fill;
+ range_start += cluster_fill;
+ range_len -= cluster_fill;
+ alloc_goal += cluster_fill;
+
+ dbg_print_extent("ext_falloc clus left+", left_ext);
+ err = ext2fs_extent_replace(handle, 0, left_ext);
+ if (err)
+ goto out;
+ err = ext2fs_extent_fix_parents(handle);
+ if (err)
+ goto out;
+
+ /* Zero blocks */
+ if (!(left_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT)) {
+ err = ext2fs_zero_blocks2(fs, left_ext->e_pblk +
+ left_ext->e_len -
+ cluster_fill, cluster_fill,
+ NULL, NULL);
+ if (err)
+ goto out;
+ }
+ }
+
+expand_right:
+ /* We must lengthen the right extent to the beginning of the cluster */
+ if (right_ext && EXT2FS_CLUSTER_RATIO(fs) > 1) {
+ /* How much can we attach to right_ext? */
+ if (right_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT)
+ fillable = max_uninit_len - right_ext->e_len;
+ else
+ fillable = max_init_len - right_ext->e_len;
+
+ if (fillable > range_len)
+ fillable = range_len;
+ if (fillable == 0)
+ goto try_merge;
+
+ /*
+ * If range_end isn't on a cluster boundary, try an implied
+ * cluster allocation for right_ext.
+ */
+ cluster_fill = right_ext->e_lblk & EXT2FS_CLUSTER_MASK(fs);
+ if (cluster_fill == 0)
+ goto try_merge;
+
+ err = ext2fs_extent_goto(handle, right_ext->e_lblk);
+ if (err)
+ goto out;
+
+ if (cluster_fill > fillable)
+ cluster_fill = fillable;
+ right_ext->e_lblk -= cluster_fill;
+ right_ext->e_pblk -= cluster_fill;
+ right_ext->e_len += cluster_fill;
+ range_len -= cluster_fill;
+
+ dbg_print_extent("ext_falloc clus right+", right_ext);
+ err = ext2fs_extent_replace(handle, 0, right_ext);
+ if (err)
+ goto out;
+ err = ext2fs_extent_fix_parents(handle);
+ if (err)
+ goto out;
+
+ /* Zero blocks if necessary */
+ if (!(right_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT)) {
+ err = ext2fs_zero_blocks2(fs, right_ext->e_pblk,
+ cluster_fill, NULL, NULL);
+ if (err)
+ goto out;
+ }
+ }
+
+try_merge:
+ /* Merge both extents together, perhaps? */
+ if (left_ext && right_ext) {
+ /* Are the two extents mergeable? */
+ if ((left_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT) !=
+ (right_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT))
+ goto try_left;
+
+ /* User requires init/uninit but extent is uninit/init. */
+ if (((flags & EXT2_FALLOCATE_FORCE_INIT) &&
+ (left_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT)) ||
+ ((flags & EXT2_FALLOCATE_FORCE_UNINIT) &&
+ !(left_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT)))
+ goto try_left;
+
+ /*
+ * Skip initialized extent unless user wants to zero blocks
+ * or requires init extent.
+ */
+ if (!(left_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT) &&
+ (!(flags & EXT2_FALLOCATE_ZERO_BLOCKS) ||
+ !(flags & EXT2_FALLOCATE_FORCE_INIT)))
+ goto try_left;
+
+ /* Will it even fit? */
+ x = left_ext->e_len + range_len + right_ext->e_len;
+ if (x > (left_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT ?
+ max_uninit_len : max_init_len))
+ goto try_left;
+
+ err = ext2fs_extent_goto(handle, left_ext->e_lblk);
+ if (err)
+ goto try_left;
+
+ /* Allocate blocks */
+ y = left_ext->e_pblk + left_ext->e_len;
+ err = ext2fs_new_range(fs, EXT2_NEWRANGE_FIXED_GOAL |
+ EXT2_NEWRANGE_MIN_LENGTH, y,
+ right_ext->e_pblk - y + 1, NULL,
+ &pblk, &plen);
+ if (err)
+ goto try_left;
+ if (pblk + plen != right_ext->e_pblk)
+ goto try_left;
+ err = claim_range(fs, inode, pblk, plen);
+ if (err)
+ goto out;
+
+ /* Modify extents */
+ left_ext->e_len = x;
+ dbg_print_extent("ext_falloc merge", left_ext);
+ err = ext2fs_extent_replace(handle, 0, left_ext);
+ if (err)
+ goto out;
+ err = ext2fs_extent_fix_parents(handle);
+ if (err)
+ goto out;
+ err = ext2fs_extent_get(handle, EXT2_EXTENT_NEXT_LEAF, &newex);
+ if (err)
+ goto out;
+ err = ext2fs_extent_delete(handle, 0);
+ if (err)
+ goto out;
+ err = ext2fs_extent_fix_parents(handle);
+ if (err)
+ goto out;
+ *right_ext = *left_ext;
+
+ /* Zero blocks */
+ if (!(left_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT) &&
+ (flags & EXT2_FALLOCATE_ZERO_BLOCKS)) {
+ err = ext2fs_zero_blocks2(fs, range_start, range_len,
+ NULL, NULL);
+ if (err)
+ goto out;
+ }
+
+ return 0;
+ }
+
+try_left:
+ /* Extend the left extent */
+ if (left_ext) {
+ /* How many more blocks can be attached to left_ext? */
+ if (left_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT)
+ fillable = max_uninit_len - left_ext->e_len;
+ else if (flags & EXT2_FALLOCATE_ZERO_BLOCKS)
+ fillable = max_init_len - left_ext->e_len;
+ else
+ fillable = 0;
+
+ /* User requires init/uninit but extent is uninit/init. */
+ if (((flags & EXT2_FALLOCATE_FORCE_INIT) &&
+ (left_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT)) ||
+ ((flags & EXT2_FALLOCATE_FORCE_UNINIT) &&
+ !(left_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT)))
+ goto try_right;
+
+ if (fillable > range_len)
+ fillable = range_len;
+
+ /* Don't expand an initialized left_ext beyond EOF */
+ x = left_ext->e_lblk + left_ext->e_len - 1;
+ if (!(flags & EXT2_FALLOCATE_INIT_BEYOND_EOF)) {
+ dbg_printf("%s: lend=%llu newlend=%llu eofblk=%llu\n",
+ __func__, x, x + fillable, eof_blk);
+ if (eof_blk >= x && eof_blk <= x + fillable)
+ fillable = eof_blk - x;
+ }
+
+ if (fillable == 0)
+ goto try_right;
+
+ /* Test if the right edge of the range is already mapped? */
+ if (EXT2FS_CLUSTER_RATIO(fs) > 1) {
+ err = ext2fs_map_cluster_block(fs, ino, inode,
+ x + fillable, &pblk);
+ if (err)
+ goto out;
+ if (pblk)
+ fillable -= 1 + ((x + fillable)
+ & EXT2FS_CLUSTER_MASK(fs));
+ if (fillable == 0)
+ goto try_right;
+ }
+
+ /* Allocate range of blocks */
+ x = left_ext->e_pblk + left_ext->e_len;
+ err = ext2fs_new_range(fs, EXT2_NEWRANGE_FIXED_GOAL |
+ EXT2_NEWRANGE_MIN_LENGTH,
+ x, fillable, NULL, &pblk, &plen);
+ if (err)
+ goto try_right;
+ err = claim_range(fs, inode, pblk, plen);
+ if (err)
+ goto out;
+
+ /* Modify left_ext */
+ err = ext2fs_extent_goto(handle, left_ext->e_lblk);
+ if (err)
+ goto out;
+ range_start += plen;
+ range_len -= plen;
+ left_ext->e_len += plen;
+ dbg_print_extent("ext_falloc left+", left_ext);
+ err = ext2fs_extent_replace(handle, 0, left_ext);
+ if (err)
+ goto out;
+ err = ext2fs_extent_fix_parents(handle);
+ if (err)
+ goto out;
+
+ /* Zero blocks if necessary */
+ if (!(left_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT) &&
+ (flags & EXT2_FALLOCATE_ZERO_BLOCKS)) {
+ err = ext2fs_zero_blocks2(fs, pblk, plen, NULL, NULL);
+ if (err)
+ goto out;
+ }
+ }
+
+try_right:
+ /* Extend the right extent */
+ if (right_ext) {
+ /* How much can we attach to right_ext? */
+ if (right_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT)
+ fillable = max_uninit_len - right_ext->e_len;
+ else if (flags & EXT2_FALLOCATE_ZERO_BLOCKS)
+ fillable = max_init_len - right_ext->e_len;
+ else
+ fillable = 0;
+
+ /* User requires init/uninit but extent is uninit/init. */
+ if (((flags & EXT2_FALLOCATE_FORCE_INIT) &&
+ (right_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT)) ||
+ ((flags & EXT2_FALLOCATE_FORCE_UNINIT) &&
+ !(right_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT)))
+ goto try_anywhere;
+
+ if (fillable > range_len)
+ fillable = range_len;
+ if (fillable == 0)
+ goto try_anywhere;
+
+ /* Test if the left edge of the range is already mapped? */
+ if (EXT2FS_CLUSTER_RATIO(fs) > 1) {
+ err = ext2fs_map_cluster_block(fs, ino, inode,
+ right_ext->e_lblk - fillable, &pblk);
+ if (err)
+ goto out;
+ if (pblk)
+ fillable -= EXT2FS_CLUSTER_RATIO(fs) -
+ ((right_ext->e_lblk - fillable)
+ & EXT2FS_CLUSTER_MASK(fs));
+ if (fillable == 0)
+ goto try_anywhere;
+ }
+
+ /*
+ * FIXME: It would be nice if we could handle allocating a
+ * variable range from a fixed end point instead of just
+ * skipping to the general allocator if the whole range is
+ * unavailable.
+ */
+ err = ext2fs_new_range(fs, EXT2_NEWRANGE_FIXED_GOAL |
+ EXT2_NEWRANGE_MIN_LENGTH,
+ right_ext->e_pblk - fillable,
+ fillable, NULL, &pblk, &plen);
+ if (err)
+ goto try_anywhere;
+ err = claim_range(fs, inode,
+ pblk & ~EXT2FS_CLUSTER_MASK(fs),
+ plen + (pblk & EXT2FS_CLUSTER_MASK(fs)));
+ if (err)
+ goto out;
+
+ /* Modify right_ext */
+ err = ext2fs_extent_goto(handle, right_ext->e_lblk);
+ if (err)
+ goto out;
+ range_len -= plen;
+ right_ext->e_lblk -= plen;
+ right_ext->e_pblk -= plen;
+ right_ext->e_len += plen;
+ dbg_print_extent("ext_falloc right+", right_ext);
+ err = ext2fs_extent_replace(handle, 0, right_ext);
+ if (err)
+ goto out;
+ err = ext2fs_extent_fix_parents(handle);
+ if (err)
+ goto out;
+
+ /* Zero blocks if necessary */
+ if (!(right_ext->e_flags & EXT2_EXTENT_FLAGS_UNINIT) &&
+ (flags & EXT2_FALLOCATE_ZERO_BLOCKS)) {
+ err = ext2fs_zero_blocks2(fs, pblk,
+ plen + cluster_fill, NULL, NULL);
+ if (err)
+ goto out;
+ }
+ }
+
+try_anywhere:
+ /* Try implied cluster alloc on the left and right ends */
+ if (range_len > 0 && (range_start & EXT2FS_CLUSTER_MASK(fs))) {
+ cluster_fill = EXT2FS_CLUSTER_RATIO(fs) -
+ (range_start & EXT2FS_CLUSTER_MASK(fs));
+ cluster_fill &= EXT2FS_CLUSTER_MASK(fs);
+ if (cluster_fill > range_len)
+ cluster_fill = range_len;
+ newex.e_lblk = range_start;
+ err = ext2fs_map_cluster_block(fs, ino, inode, newex.e_lblk,
+ &pblk);
+ if (err)
+ goto out;
+ if (pblk == 0)
+ goto try_right_implied;
+ newex.e_pblk = pblk;
+ newex.e_len = cluster_fill;
+ newex.e_flags = (flags & EXT2_FALLOCATE_FORCE_INIT ? 0 :
+ EXT2_EXTENT_FLAGS_UNINIT);
+ dbg_print_extent("ext_falloc iclus left+", &newex);
+ ext2fs_extent_goto(handle, newex.e_lblk);
+ err = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT,
+ &ex);
+ if (err == EXT2_ET_NO_CURRENT_NODE)
+ ex.e_lblk = 0;
+ else if (err)
+ goto out;
+
+ if (ex.e_lblk > newex.e_lblk)
+ op = 0; /* insert before */
+ else
+ op = EXT2_EXTENT_INSERT_AFTER;
+ dbg_printf("%s: inserting %s lblk %llu newex=%llu\n",
+ __func__, op ? "after" : "before", ex.e_lblk,
+ newex.e_lblk);
+ err = ext2fs_extent_insert(handle, op, &newex);
+ if (err)
+ goto out;
+ err = ext2fs_extent_fix_parents(handle);
+ if (err)
+ goto out;
+
+ if (!(newex.e_flags & EXT2_EXTENT_FLAGS_UNINIT) &&
+ (flags & EXT2_FALLOCATE_ZERO_BLOCKS)) {
+ err = ext2fs_zero_blocks2(fs, newex.e_pblk,
+ newex.e_len, NULL, NULL);
+ if (err)
+ goto out;
+ }
+
+ range_start += cluster_fill;
+ range_len -= cluster_fill;
+ }
+
+try_right_implied:
+ y = range_start + range_len;
+ if (range_len > 0 && (y & EXT2FS_CLUSTER_MASK(fs))) {
+ cluster_fill = y & EXT2FS_CLUSTER_MASK(fs);
+ if (cluster_fill > range_len)
+ cluster_fill = range_len;
+ newex.e_lblk = y & ~EXT2FS_CLUSTER_MASK(fs);
+ err = ext2fs_map_cluster_block(fs, ino, inode, newex.e_lblk,
+ &pblk);
+ if (err)
+ goto out;
+ if (pblk == 0)
+ goto no_implied;
+ newex.e_pblk = pblk;
+ newex.e_len = cluster_fill;
+ newex.e_flags = (flags & EXT2_FALLOCATE_FORCE_INIT ? 0 :
+ EXT2_EXTENT_FLAGS_UNINIT);
+ dbg_print_extent("ext_falloc iclus right+", &newex);
+ ext2fs_extent_goto(handle, newex.e_lblk);
+ err = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT,
+ &ex);
+ if (err == EXT2_ET_NO_CURRENT_NODE)
+ ex.e_lblk = 0;
+ else if (err)
+ goto out;
+
+ if (ex.e_lblk > newex.e_lblk)
+ op = 0; /* insert before */
+ else
+ op = EXT2_EXTENT_INSERT_AFTER;
+ dbg_printf("%s: inserting %s lblk %llu newex=%llu\n",
+ __func__, op ? "after" : "before", ex.e_lblk,
+ newex.e_lblk);
+ err = ext2fs_extent_insert(handle, op, &newex);
+ if (err)
+ goto out;
+ err = ext2fs_extent_fix_parents(handle);
+ if (err)
+ goto out;
+
+ if (!(newex.e_flags & EXT2_EXTENT_FLAGS_UNINIT) &&
+ (flags & EXT2_FALLOCATE_ZERO_BLOCKS)) {
+ err = ext2fs_zero_blocks2(fs, newex.e_pblk,
+ newex.e_len, NULL, NULL);
+ if (err)
+ goto out;
+ }
+
+ range_len -= cluster_fill;
+ }
+
+no_implied:
+ if (range_len == 0)
+ return 0;
+
+ newex.e_lblk = range_start;
+ if (flags & EXT2_FALLOCATE_FORCE_INIT) {
+ max_extent_len = max_init_len;
+ newex.e_flags = 0;
+ } else {
+ max_extent_len = max_uninit_len;
+ newex.e_flags = EXT2_EXTENT_FLAGS_UNINIT;
+ }
+ pblk = alloc_goal;
+ y = range_len;
+ for (x = 0; x < y;) {
+ cluster_fill = newex.e_lblk & EXT2FS_CLUSTER_MASK(fs);
+ fillable = min(range_len + cluster_fill, max_extent_len);
+ err = ext2fs_new_range(fs, 0, pblk & ~EXT2FS_CLUSTER_MASK(fs),
+ fillable,
+ NULL, &pblk, &plen);
+ if (err)
+ goto out;
+ err = claim_range(fs, inode, pblk, plen);
+ if (err)
+ goto out;
+
+ /* Create extent */
+ newex.e_pblk = pblk + cluster_fill;
+ newex.e_len = plen - cluster_fill;
+ dbg_print_extent("ext_falloc create", &newex);
+ ext2fs_extent_goto(handle, newex.e_lblk);
+ err = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT,
+ &ex);
+ if (err == EXT2_ET_NO_CURRENT_NODE)
+ ex.e_lblk = 0;
+ else if (err)
+ goto out;
+
+ if (ex.e_lblk > newex.e_lblk)
+ op = 0; /* insert before */
+ else
+ op = EXT2_EXTENT_INSERT_AFTER;
+ dbg_printf("%s: inserting %s lblk %llu newex=%llu\n",
+ __func__, op ? "after" : "before", ex.e_lblk,
+ newex.e_lblk);
+ err = ext2fs_extent_insert(handle, op, &newex);
+ if (err)
+ goto out;
+ err = ext2fs_extent_fix_parents(handle);
+ if (err)
+ goto out;
+
+ if (!(newex.e_flags & EXT2_EXTENT_FLAGS_UNINIT) &&
+ (flags & EXT2_FALLOCATE_ZERO_BLOCKS)) {
+ err = ext2fs_zero_blocks2(fs, pblk, plen, NULL, NULL);
+ if (err)
+ goto out;
+ }
+
+ /* Update variables at end of loop */
+ x += plen - cluster_fill;
+ range_len -= plen - cluster_fill;
+ newex.e_lblk += plen - cluster_fill;
+ pblk += plen - cluster_fill;
+ if (pblk >= ext2fs_blocks_count(fs->super))
+ pblk = fs->super->s_first_data_block;
+ }
+
+out:
+ return err;
+}
+
+static errcode_t extent_fallocate(ext2_filsys fs, int flags, ext2_ino_t ino,
+ struct ext2_inode *inode, blk64_t goal,
+ blk64_t start, blk64_t len)
+{
+ ext2_extent_handle_t handle;
+ struct ext2fs_extent left_extent, right_extent;
+ struct ext2fs_extent *left_adjacent, *right_adjacent;
+ errcode_t err;
+ blk64_t range_start, range_end = 0, end, next;
+ blk64_t count, goal_distance;
+
+ end = start + len - 1;
+ err = ext2fs_extent_open2(fs, ino, inode, &handle);
+ if (err)
+ return err;
+
+ /*
+ * Find the extent closest to the start of the alloc range. We don't
+ * check the return value because _goto() sets the current node to the
+ * next-lowest extent if 'start' is in a hole; or the next-highest
+ * extent if there aren't any lower ones; or doesn't set a current node
+ * if there was a real error reading the extent tree. In that case,
+ * _get() will error out.
+ */
+start_again:
+ ext2fs_extent_goto(handle, start);
+ err = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &left_extent);
+ if (err == EXT2_ET_NO_CURRENT_NODE) {
+ blk64_t max_blocks = ext2fs_blocks_count(fs->super);
+
+ if (goal == ~0ULL)
+ goal = ext2fs_find_inode_goal(fs, ino, inode, start);
+ err = ext2fs_find_first_zero_block_bitmap2(fs->block_map,
+ goal, max_blocks - 1, &goal);
+ goal += start;
+ err = ext_falloc_helper(fs, flags, ino, inode, handle, NULL,
+ NULL, start, len, goal);
+ goto errout;
+ } else if (err)
+ goto errout;
+
+ dbg_print_extent("ext_falloc initial", &left_extent);
+ next = left_extent.e_lblk + left_extent.e_len;
+ if (left_extent.e_lblk > start) {
+ /* The nearest extent we found was beyond start??? */
+ goal = left_extent.e_pblk - (left_extent.e_lblk - start);
+ err = ext_falloc_helper(fs, flags, ino, inode, handle, NULL,
+ &left_extent, start,
+ left_extent.e_lblk - start, goal);
+ if (err)
+ goto errout;
+
+ goto start_again;
+ } else if (next >= start) {
+ range_start = next;
+ left_adjacent = &left_extent;
+ } else {
+ range_start = start;
+ left_adjacent = NULL;
+ }
+ goal = left_extent.e_pblk + (range_start - left_extent.e_lblk);
+ goal_distance = range_start - next;
+
+ do {
+ err = ext2fs_extent_get(handle, EXT2_EXTENT_NEXT_LEAF,
+ &right_extent);
+ dbg_printf("%s: ino=%d get next =%d\n", __func__, ino,
+ (int)err);
+ dbg_print_extent("ext_falloc next", &right_extent);
+ /* Stop if we've seen this extent before */
+ if (!err && right_extent.e_lblk <= left_extent.e_lblk)
+ err = EXT2_ET_EXTENT_NO_NEXT;
+
+ if (err && err != EXT2_ET_EXTENT_NO_NEXT)
+ goto errout;
+ if (err == EXT2_ET_EXTENT_NO_NEXT ||
+ right_extent.e_lblk > end + 1) {
+ range_end = end;
+ right_adjacent = NULL;
+ } else {
+ /* Handle right_extent.e_lblk <= end */
+ range_end = right_extent.e_lblk - 1;
+ right_adjacent = &right_extent;
+ }
+ if (err != EXT2_ET_EXTENT_NO_NEXT &&
+ goal_distance > (range_end - right_extent.e_lblk)) {
+ goal = right_extent.e_pblk -
+ (right_extent.e_lblk - range_start);
+ goal_distance = range_end - right_extent.e_lblk;
+ }
+
+ dbg_printf("%s: ino=%d rstart=%llu rend=%llu\n", __func__, ino,
+ range_start, range_end);
+ err = 0;
+ if (range_start <= range_end) {
+ count = range_end - range_start + 1;
+ err = ext_falloc_helper(fs, flags, ino, inode, handle,
+ left_adjacent, right_adjacent,
+ range_start, count, goal);
+ if (err)
+ goto errout;
+ }
+
+ if (range_end == end)
+ break;
+
+ err = ext2fs_extent_goto(handle, right_extent.e_lblk);
+ if (err)
+ goto errout;
+ next = right_extent.e_lblk + right_extent.e_len;
+ left_extent = right_extent;
+ left_adjacent = &left_extent;
+ range_start = next;
+ goal = left_extent.e_pblk + (range_start - left_extent.e_lblk);
+ goal_distance = range_start - next;
+ } while (range_end < end);
+
+errout:
+ ext2fs_extent_free(handle);
+ return err;
+}
+
+/*
+ * Map physical blocks to a range of logical blocks within a file. The range
+ * of logical blocks are (start, start + len). If there are already extents,
+ * the mappings will try to extend the mappings; otherwise, it will try to map
+ * start as if logical block 0 points to goal. If goal is ~0ULL, then the goal
+ * is calculated based on the inode group.
+ *
+ * Flags:
+ * - EXT2_FALLOCATE_ZERO_BLOCKS: Zero the blocks that are allocated.
+ * - EXT2_FALLOCATE_FORCE_INIT: Create only initialized extents.
+ * - EXT2_FALLOCATE_FORCE_UNINIT: Create only uninitialized extents.
+ * - EXT2_FALLOCATE_INIT_BEYOND_EOF: Create extents beyond EOF.
+ *
+ * If neither FORCE_INIT nor FORCE_UNINIT are specified, this function will
+ * try to expand any extents it finds, zeroing blocks as necessary.
+ */
+errcode_t ext2fs_fallocate(ext2_filsys fs, int flags, ext2_ino_t ino,
+ struct ext2_inode *inode, blk64_t goal,
+ blk64_t start, blk64_t len)
+{
+ struct ext2_inode inode_buf;
+ blk64_t blk, x;
+ errcode_t err;
+
+ if (((flags & EXT2_FALLOCATE_FORCE_INIT) &&
+ (flags & EXT2_FALLOCATE_FORCE_UNINIT)) ||
+ (flags & ~EXT2_FALLOCATE_ALL_FLAGS))
+ return EXT2_ET_INVALID_ARGUMENT;
+
+ if (len > ext2fs_blocks_count(fs->super))
+ return EXT2_ET_BLOCK_ALLOC_FAIL;
+ else if (len == 0)
+ return 0;
+
+ /* Read inode structure if necessary */
+ if (!inode) {
+ err = ext2fs_read_inode(fs, ino, &inode_buf);
+ if (err)
+ return err;
+ inode = &inode_buf;
+ }
+ dbg_printf("%s: ino=%d start=%llu len=%llu goal=%llu\n", __func__, ino,
+ start, len, goal);
+
+ if (inode->i_flags & EXT4_EXTENTS_FL) {
+ err = extent_fallocate(fs, flags, ino, inode, goal, start, len);
+ goto out;
+ }
+
+ /* XXX: Allocate a bunch of blocks the slow way */
+ for (blk = start; blk < start + len; blk++) {
+ err = ext2fs_bmap2(fs, ino, inode, NULL, 0, blk, 0, &x);
+ if (err)
+ return err;
+ if (x)
+ continue;
+
+ err = ext2fs_bmap2(fs, ino, inode, NULL,
+ BMAP_ALLOC | BMAP_UNINIT | BMAP_ZERO, blk,
+ 0, &x);
+ if (err)
+ return err;
+ }
+
+out:
+ if (inode == &inode_buf)
+ ext2fs_write_inode(fs, ino, inode);
+ return err;
+}
--
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