ext4: mark fc ineligible if inode gets evictied due to mem pressure

If inode gets evicted due to memory pressure, we have to remove it
from the fast commit list. However, that inode may have uncommitted
changes that fast commits will lose. So, just fall back to full
commits in this case. Also, rename the fast commit ineligiblity reason
from "EXT4_FC_REASON_MEM" to "EXT4_FC_REASON_MEM_NOMEM" for better
expression.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201106035911.1942128-3-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
index 8d43058386c3037f0525b85bda4c5d14d775c6b1..48b7bc12939202e6221a4f6394e7b16ad1b99323 100644 (file)
--- a/fs/ext4/fast_commit.c
+++ b/fs/ext4/fast_commit.c
@@ -384,7 +384,7 @@ static int __track_dentry_update(struct inode *inode, void *arg, bool update)
        mutex_unlock(&ei->i_fc_lock);
        node = kmem_cache_alloc(ext4_fc_dentry_cachep, GFP_NOFS);
        if (!node) {
-               ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_MEM);
+               ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_NOMEM);
                mutex_lock(&ei->i_fc_lock);
                return -ENOMEM;
        }
@@ -397,7 +397,7 @@ static int __track_dentry_update(struct inode *inode, void *arg, bool update)
                if (!node->fcd_name.name) {
                        kmem_cache_free(ext4_fc_dentry_cachep, node);
                        ext4_fc_mark_ineligible(inode->i_sb,
-                               EXT4_FC_REASON_MEM);
+                               EXT4_FC_REASON_NOMEM);
                        mutex_lock(&ei->i_fc_lock);
                        return -ENOMEM;
                }

diff --git a/fs/ext4/fast_commit.h b/fs/ext4/fast_commit.h
index 06907d485989b75f973d2d95c69c0bed3c3a554f..140fbb6af19ef5b73de34c373f51b7ced382d97d 100644 (file)
--- a/fs/ext4/fast_commit.h
+++ b/fs/ext4/fast_commit.h
@@ -100,7 +100,7 @@ enum {
        EXT4_FC_REASON_XATTR = 0,
        EXT4_FC_REASON_CROSS_RENAME,
        EXT4_FC_REASON_JOURNAL_FLAG_CHANGE,
-       EXT4_FC_REASON_MEM,
+       EXT4_FC_REASON_NOMEM,
        EXT4_FC_REASON_SWAP_BOOT,
        EXT4_FC_REASON_RESIZE,
        EXT4_FC_REASON_RENAME_DIR,

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index b96a18679a27343e92669a3775525eb9b2a1b2f1..081b6a86b5db0c8d3b13892df2387cd0645f7fc5 100644 (file)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -327,6 +327,8 @@ stop_handle:
        ext4_xattr_inode_array_free(ea_inode_array);
        return;
 no_delete:
+       if (!list_empty(&EXT4_I(inode)->i_fc_list))
+               ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_NOMEM);
        ext4_clear_inode(inode);        /* We must guarantee clearing of inode... */
 }
 

diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h
index b14314fcf732212c6d9c89ac781f4bfb3206d6b3..0f899d3b09d32e8984585373a24916d3b2153b3b 100644 (file)
--- a/include/trace/events/ext4.h
+++ b/include/trace/events/ext4.h
@@ -100,7 +100,7 @@ TRACE_DEFINE_ENUM(ES_REFERENCED_B);
                { EXT4_FC_REASON_XATTR,         "XATTR"},               \
                { EXT4_FC_REASON_CROSS_RENAME,  "CROSS_RENAME"},        \
                { EXT4_FC_REASON_JOURNAL_FLAG_CHANGE, "JOURNAL_FLAG_CHANGE"}, \
-               { EXT4_FC_REASON_MEM,   "NO_MEM"},                      \
+               { EXT4_FC_REASON_NOMEM, "NO_MEM"},                      \
                { EXT4_FC_REASON_SWAP_BOOT,     "SWAP_BOOT"},           \
                { EXT4_FC_REASON_RESIZE,        "RESIZE"},              \
                { EXT4_FC_REASON_RENAME_DIR,    "RENAME_DIR"},          \
@@ -2917,13 +2917,13 @@ TRACE_EVENT(ext4_fc_stats,
                    ),
 
            TP_printk("dev %d:%d fc ineligible reasons:\n"
-                     "%s:%d, %s:%d, %s:%d, %s:%d, %s:%d, %s:%d, %s:%d, %s,%d; "
+                     "%s:%d, %s:%d, %s:%d, %s:%d, %s:%d, %s:%d, %s:%d, %s:%d; "
                      "num_commits:%ld, ineligible: %ld, numblks: %ld",
                      MAJOR(__entry->dev), MINOR(__entry->dev),
                      FC_REASON_NAME_STAT(EXT4_FC_REASON_XATTR),
                      FC_REASON_NAME_STAT(EXT4_FC_REASON_CROSS_RENAME),
                      FC_REASON_NAME_STAT(EXT4_FC_REASON_JOURNAL_FLAG_CHANGE),
-                     FC_REASON_NAME_STAT(EXT4_FC_REASON_MEM),
+                     FC_REASON_NAME_STAT(EXT4_FC_REASON_NOMEM),
                      FC_REASON_NAME_STAT(EXT4_FC_REASON_SWAP_BOOT),
                      FC_REASON_NAME_STAT(EXT4_FC_REASON_RESIZE),
                      FC_REASON_NAME_STAT(EXT4_FC_REASON_RENAME_DIR),